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From yogurt to yield: Potential applications of lactic acid bacteria in plant production
Abstract
Ferments containing lactic acid bacteria (LAB) have been used for decades in agricultural systems to improve soils, control disease and promote plant growth, however, the functional roles of LAB in the phytomicrobiome have yet to be discovered. An understanding of the symbiotic relationship between plants and LAB could be exploited to improve agricultural plant production.
Scientific investigations to validate plant growth promoting properties of LAB are increasing in number and scope. LAB isolated from diverse sources have been shown to be effective biofertilizers, biocontrol agents, biostimulants. As biofertilizers, LAB can improve nutrient availability from compost and other organic material. In fermented food, LAB has served as an effective biocontrol agent; recently LAB have been shown to be effective in the control of a wide variety of fungal and bacterial phytopathogens. As biostimulants, LAB can directly promote plant growth or seed germination, as well as alleviating various abiotic stresses.
In this review, we discuss the history and ecology of plants and LAB, appraise the available information on the use of LAB in improving plant production, and consider the limitations and potential new directions for the use of LAB in plant agriculture.
... Although this sole role played by LAB in the food industry and as probiotics is well documented, advances in knowledge of soil-plantbacteria interactions have kept pointing to the additional vital importance of these bacteria in enhancing plant and soil health and resilience as a promising strategy for stabilizing plant production in these climatechanging and population growing times (Lamont et al., 2017;Smith et al., 2015). The mutual and symbiotic relationship between these three without causing any harm to either has helped the evolution and survival of LAB, as well as studies on them. ...
... Apart from decomposing macromolecular substances in organic material, degrading indigestible polysaccharides, and transforming undesirable flavor substances especially during composting (Wang et al., 2021), it was demonstrated that LAB with other useful (effective) microorganisms enhance the release of nutrients necessary for soil fertility, plant growth, and also produce antimicrobial secondary metabolites. Different studies have proven an increase in root and shoot length, plant biomass, IAA, and other organic acids following the addition of organic matter treated with LAB compared to the untreated control, and this has resulted in increased yields (Caplice, 1999;Higa and Kinjo, 1989;Lamont et al., 2017;Primavesi and Molina, 1984). LAB are used together with other microorganisms to accelerate decomposition during compost and compost teas making for soil amendment and nutrient mineralization before or after planting (Higa and Kinjo, 1989). ...
... Bacteriocins, acids, and other compounds produced by lactic acid bacteria. Y.T. Murindangabo et al. seed, and plants have shown many of these latter-highlighted properties (Dhaliwal and Koul, 2011;Kumariya et al., 2019;Lamont et al., 2017;Raman et al., 2022) and can positively impact soil nutrient balance, plant growth, plant defense, and crop productivity without adverse risks. The use of lactic acid bacteria (LAB) in soil-plant systems has been the subject of increasing interest in recent years, but there is still a need for more comprehensive and contextualized reviews of their use. ...
Lactic acid bacteria (LAB) are ubiquitous, Gram-positive, probiotic, and facultative aerophilic microorganisms. They are commonly found in wide range of environments including food-rich environments, decaying plants, milk products, the human gut, vaginal flora, and on the skin of various living organisms. These multifaceted bacteria have multiple roles including promoting food safety; promoting plant growth; improving soil, animal, and human health. They are also an integral part of sustainable farming strategies with a low risk of resistance to chemical pesticides, making them an environmentally friendly and effective way of managing pests and diseases and improving plant production. While the traditional role of LAB in food processing and human health sectors has been widely studied and documented, there is increasing attention to their additional roles that empirical evidences and research have validated such as serving as biofertilizers, biocontrol, and biostimulant agents in plant production through the production of bacteriocins, organic acids, and other compounds. However, there is still a gap in unlocking the relationship between LAB, soil, and plant hosts. Through a review of the literature and metadata, this study aims to discuss the less-explored relevance of LAB in soil-plant systems and spotlight the prospects for increased acceptance as sustainable and safe soil and plant health enhancers. The first part concentrates on analysing the existing metadata, while the discussion part essentially focus on literature review.
... As illustrated in Figure 1, LAB can help directly with plant disease control and plant growth by modulating the uptake of important nutrients like phosphorus and potassium, fixing nitrogen, and the production of plant hormones and siderophores. Indirectly, LAB could aid in the biocontrol of phytopathogens through the production of a wide range of antimicrobial compounds including diketopiperazines, hydroxy derivatives of fatty acids, 3-phenyllactate; antibacterial bacteriocins and bacteriocin-like inhibitory substances (BLIS) organic acids, hydrogen peroxide, pyrrolidone-5-carboxylic acid, diacetyl, and reuterin (Lamont et al., 2017), modulating defense mechanism by creating systemic resistance, and decreasing pathogen iron availability. It has also been proposed that multiple mechanisms of action might be involved in the attack of LAB against phytopathogens (Sangmanee and Hongpattarakere, 2014). ...
... 3.1.1 Modulating the intake of nutrients and the fixation of nitrogen Some strains of LAB can boost the availability of nutrients derived from compost and other forms of organic or inorganic matter to plants (Lamont et al., 2017). Phosphorus (P), the major macronutrient for plant growth, is mostly stored in the soil either as an organic compound or as an inorganic precipitate. ...
... The increased metabolic activity caused by phytohormones production aids in defence, normal cell function, and abiotic stress management . Several LAB species are capable of secreting phytohormones such as gibberellin (GA) and auxins such as indole-3-acetic acid (IAA) which play various functions in plant growth promotion (Lamont et al., 2017). According to Turaeva et al. (2021), GA 4 and GA 7 were detected from the culture fluid of L. plantarum which enhances the plant growth and development of wheat coleoptiles through the usage of HPLC-MS. ...
The microbial diseases cause significant damage in agriculture, resulting in major yield and quality losses. To control microbiological damage and promote plant growth, a number of chemical control agents such as pesticides, herbicides, and insecticides are available. However, the rising prevalence of chemical control agents has led to unintended consequences for agricultural quality, environmental devastation, and human health. Chemical agents are not naturally broken down by microbes and can be found in the soil and environment long after natural decomposition has occurred. As an alternative to chemical agents, biocontrol agents are employed to manage phytopathogens. Interest in lactic acid bacteria (LAB) research as another class of potentially useful bacteria against phytopathogens has increased in recent years. Due to the high level of biosafety, they possess and the processes they employ to stimulate plant growth, LAB is increasingly being recognized as a viable option. This paper will review the available information on the antagonistic and plant-promoting capabilities of LAB and its mechanisms of action as well as its limitation as BCA. This review aimed at underlining the benefits and inputs from LAB as potential alternatives to chemical usage in sustaining crop productivity.
... Use of L. helveticus in plant agriculture, especially as biostimulants is not widely documented although the use of members of the genera Lactobacillus in crop production, as biostimulants and biocontrol agents, among other uses, has been practiced (Hamed et al., 2011). Members of the genus Lactobacillus are endophytic to a variety of plants species (Baffoni et al., 2015;Minervini et al., 2015;Lamont et al., 2017) while others have been isolated from the rhizosphere of plants. Examples of LAB species that have been used in plant agriculture include Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus and L. helveticus (Hamed et al., 2011;Caballero et al., 2020;Msimbira et al., 2022). ...
... Examples of LAB species that have been used in plant agriculture include Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus rhamnosus and L. helveticus (Hamed et al., 2011;Caballero et al., 2020;Msimbira et al., 2022). LAB play an important role in fermentation of organic matter to form organic fertilisers used in crop production (Lamont et al., 2017;Caballero et al., 2020). Lactic acid, a by-product of LAB has been reported to enhance plant growth (Rodríguez-Morgado et al., 2017). ...
... Consequently, the possible modes of action through CFS could enhance plant growth include presence of phytohormones such as jasmonic acid; presence of enzymes such as ACC deaminase; presence of osmoprotectants such as proline and presence of volatile organic compounds and exopolysaccharides, all of which may function to mitigate osmotic, oxidative and ionic stress associated with salinity (Forni et al., 2017;Khan et al., 2019;Cappellari and Banchio, 2020;Kumar et al., 2020;Fincheira et al., 2021;Lopes et al., 2021). There is limited publication on the role of members of the genus Lactobacillus and/or their CFS as plant growth biostimulants (Hamed et al., 2011;Lamont et al., 2017;Msimbira et al., 2022). The modes of action through which members of the genus Lactobacillus and their CFSs enhance plant growth are not fully understood (Lamont et al., 2017). ...
Plant growth promoting microorganisms and their derived compounds, such as cell-free supernatant (CFS), enhance plant growth under stressed and non stressed conditions. Such technology is sustainable and environmentally friendly, which is desirable amidst the climate change threat. The current study evaluated the effect of CFS obtained from Lactobacillus helveticus EL2006H on its ability to enhance mean percentage germination and mean radicle length of corn and soybean, as well as growth parameters of potato, using treatment formulations that consisted of 0.2 and 1.0% [v/v] L. helveticus EL2006H CFS concentrations and 100 mM NaCl and 150 mM NaCl levels. Results show that treatment with 100 mM NaCl lowered percentage germination of corn by 52.63%, at 72 h, and soybean by 50%, at 48 h. Treatment with 100 NaCl +0.2% EL2006H enhanced percentage germination of soybean by 44.37%, at 48 h, in comparison to that of the 100 mM NaCl control. One hundred mM NaCl lowered radicle length of corn and soybean by 38.58 and 36.43%, respectively. Treatment with 100 Mm NaCl +1.0% EL2006H significantly increased radicle length of corn by 23.04%. Treatment with 100 mM NaCl +0.2% EL2006H significantly increased photosynthetic rate, leaf greenness and fresh weight of potato. Increasing NaCl concentration to 150 NaCl lowered the effectiveness of the 0.2% EL2006H CFS on the same growth variables of potato. In general, the lower CFS concentration of 0.2% was more efficient at enhancing germination in soybean while the higher concentration of 1.0% was more efficient at enhancing radicle length of corn. There was an observed variation in the effectiveness of L. helveticus EL2006H CFS across the different CFS concentrations, NaCl levels and crop species studied. In conclusion, based on findings of this study, CFS obtained from L. helveticus can be used as a bio stimulant to enhance growth of corn, soybean and potato. However, further studies need to be conducted, for validation, especially under field conditions, for commercial application.
... Recent advances in plant-microbe relationship and plant growth-promoting microorganisms have drawn higher attention. These microbes enhance the growth by increasing nutrient acquisition while improving the ability of the plant to survive under abiotic and biotic stress and stimulating plant growth (Lamont et al, 2017). Limited recommendations are available for organic fertilizers usage as they are varying in their nutrient composition and mineralization rate (Masunga et al., 2016). ...
... Compost produced from Mimosa invisa contains 2.35 % nitrogen, 0.13% P2O5 and 0.41 % K2O (Barman et al., 2007). For weed fermentation, yoghurt was added as a source of microorganisms for effective decomposition, and Lamont et al. (2017) proved that yogurt waste can optimize microbial growth during composting. Ferments containing lactic acid bacteria can improve soil, control diseases, and promote plant growth. ...
... As organic fertilizers, yoghurt can improve nutrient availability in weed fermentation. Recently found that yoghurt effectively promotes seed germination, and diminishes various abiotic stresses in different plant species (Lamont et al., 2017). Tong et al. (2011) tested weed fermentation prepared from (Artemisia princeps, Ranunculus japonicus, and Stellaria media (Linn.) ...
Use of liquid organic fertilizers is popular among container gardeners in urban areas. The impact of five organic liquid fertilizers (banana waste, weeds, Gliricidia leaves, fish waste, and cow dung) Albert's solution (control) on growth and yield of three test crops of Abelmoschus esculentus, Raphanus sativus and Amaranthusspp were studied in the present study. Three separate experiments were laid out as randomized complete block designs with six replicates. The effect of treatments on plant growth and yield of Abelmoschus esculentus was significant. Treatment 1, 2 and 3 recorded the greatest fresh weight of pods in okra (p < 0.0001). Treatments used in the study significantly influenced the average plant height, fresh weight of leaves, diameter, length and weight of the tuberous root of Raphanus sativus. Albert's solution and cow dung liquid fertilizer treated plants produced the tuberous roots with the greatest diameter (p < 0.0001) and length (P=0.015) while the plants that received Gliricidia leaves liquid fertilizers recorded the least values. Furthermore, the highest and lowest tuberous root fresh was reported by cow dung liquid fertilizer and Gliricidia leaves liquid fertilizer, respectively. There was a significant difference between treatments for the average plant height (p < 0.0001), number of leaves (p =0.0006), leaf length (p =0.03), leaf width (p < 0.0001), stem girth (p < 0.0001) and root length (p =0.0001) of Amaranthus spp. Nevertheless, the volume of the roots per plant was not significantly different among treatments. As per the results of the present study, it could be concluded that the banana and weeds liquid fertilizer could be used as same as Albert's solution for Abelmoschus esculentus while cow dung liquid fertilizer influenced the growth and yield of Raphanus sativus in container gardening. Vegetative growth and economic yield of Amaranthus spp. can be achieved by applying Albert's solution, banana, weed and fish liquid fertilizers. Selected types of organic liquid fertilizers could be used to replace Albert's solution for short-term vegetable crops. However, the performance of the liquid fertilizer might be affected by the size, shape and colour of the containers used for gardening as well as the quality of the potting mixture.
... PSBs play a crucial role in solubilizing fixed P into plant-available P forms. It has been reported that one of the most important traits of plant growth-promoting microbial consortia is mineral solubilization and consequent nutrient availability for plant uptake [65][66][67][68]. Regardless of treatments, in both summers, soil TKP and OP content decreased significantly (p < 0.05) at the 4th week from Baseline (Figure 4a,b). ...
... PSBs play a crucial role in solubilizing fixed P into plant-available P forms. It has been reported that one of the most important traits of plant growth-promoting microbial consortia is mineral solubilization and consequent nutrient availability for plant uptake [65][66][67][68]. Regardless of treatments, in both summers, soil TKP and OP content decreased ...
Soil macro- and micronutrient nutrient availability and their uptake by plants are critically reliant upon an active presence of the soil microbiome. This study investigated the effect of two locally sourced bio-inocula, local effective microorganisms (LEMs) and false-local effective microorganisms (F-LEMs), on plant available nitrogen (N) and phosphorus (P), and the uptake of calcium (Ca), magnesium (Mg), potassium (K), and zinc (Zn) content in edamame (Glycine max. L.) and pumpkin (Cucurbita maxima) grown in a randomized complete block design with four reps, summer 2017 and 2018, respectively. LEM plots showed greater plant-available N during the first week (edamame season) and fourth week (pumpkin season) after treatment applications. During the pumpkin season, post-treatment plant-available P was greater in both summers in LEM plots. Edamame bean had 19%, 3%, 5%, and 16% greater Ca, Mg, K, and Zn content in LEM plots compared to the Control, respectively. The concentration of K in pumpkin pulp at harvest was 31% higher in LEMs than in F-LEMs, while Mg concentration was 42% higher. Pumpkin pulp and seeds also had 27% and 34% greater Ca and Zn concentrations compared to the Control. Our study suggests that LEMs were effective in solubilizing macro- and micronutrients, which led to increased plant uptake.
... LAB có thể cải thiện tình trạng dinh dưỡng trong đất thông qua nguồn phân bón compost và các vật liệu hữu cơ khác. Ngoài ra, LAB còn ức chế nhiều loại vi khuẩn và nấm bệnh (Lamont et al., 2017). ...
... Kết quả này tương tự với công bố của Bakonyi et al. (2013) và De et al. (2018) cho thấy hạt được xử lý với vi khuẩn tổng hợp acid lactic giúp gia tăng tỷ lệ nảy mầm và sinh trưởng của cây trồng so với nghiệm thức đối chứng. Đồng thời, vi khuẩn LAB kích thích sinh trưởng giúp gia tăng tỷ lệ nảy mầm của hạt rau muống và lúa mạch (Nhu & Riddech, 2016;Lamont, 2017;Raman et al., 2022). ...
Nghiên cứu nhằm khảo sát một số chức năng sinh học của 6 dòng vi sinh vật ở điều kiện phòng thí nghiệm gồm khả năng tổng hợp acid lactic, đối kháng bệnh, kích thích nảy mầm hạt và khả năng tương thích. Kết quả cho thấy 6 dòng vi sinh vật có khả năng tổng hợp acid lactic trong khoảng 777-18.343 mg/L, đối kháng tốt với nấm bệnh Fusarium oxysporum và Rhizoctonia solani, hiệu suất đối kháng cao nhất lần lượt dao động 26,7-37,0% và 36,3-46,6%. Mặt khác, 5 dòng vi sinh vật Enterococcus sp. G1, Bacillus sp. LB7, Pichia sp. LB1, Pichia sp. B9, Bacillus sp. M3 và Bacillus sp. G5 giúp gia tăng tỷ lệ nảy mầm của hạt rau muống và cải xà lách (5,2-10,8%) so với nghiệm thức đối chứng. Sáu dòng vi sinh vật thử nghiệm còn kích thích gia tăng chiều cao cây, chiều dài rễ, đường kính thân và sinh khối khô cây rau muống và cải xà lách, đặc biệt sinh khối khô cây rau muống và cải xà lách gia tăng lần lượt 33,9-48,3% và 19,4-58,9% so với nghiệm thức đối chứng. Ngoài ra, 6 dòng vi sinh vật này không ức chế lẫn nhau.
... Pseudomonas fluorescens and Pseudomonas aeruginosa produce various siderophores such as pseudobactin, pyochelin, and pyoverdine. Rhizospheric bacteria usually release these compounds to increase their competitive potential (Hillel 2008;Gontia-Mishra et al. 2016;Lamont et al. 2017;Meena et al. 2017). In addition, these compounds also improve plant iron nutrition. ...
... In addition, these compounds also improve plant iron nutrition. In general, siderophore-producing microorganisms through (a) improving the iron nutrition, (b) restricting the growth of other microorganisms through antibiotic molecules released by these bacteria, and (c) preventing the growth of pathogenic microorganisms, especially fungi, by limiting their access to iron increase the health of plants (Lamont et al. 2017;Meena et al. 2017). ...
Excessive consumption of chemical fertilizer for improving the yield and health of agricultural crops eliminates the ecosystem balance in the water and soil environment. For the environmental concerns and high cost of chemical fertilizer, the production of biological fertilizers has been considered. In sustainable agricultural systems, microbial inoculants have special importance in increasing productivity and sustainable soil fertility management. The use of microbial inoculants leads to stability of soil resources, maintains long-term production capacity, and prevents environmental pollution. Decades of research in greenhouse and field conditions have shown that these inoculants are more effective on plants’ growth when used as a consortium. In addition to the individual effects of microorganisms, productivity and quality of agricultural crops can be improved by inoculation with other microorganisms due to their synergistic effects. The association of different organisms in microbial consortium enhances fertility and health status of soil for the growth of legume and non-legume plants. This chapter presents an overview of recent researches on the soil microbial consortia, mechanisms, and their impact on improving the productivity and quality of agricultural crops.KeywordsMicrobial consortiaNitrogen fixerPhosphate solubilizerPhytostimulationBiocontrol
... In addition to their importance in the food industry and public health, some LAB have been widely studied because of their potential to control undesired microorganisms . Several studies published over the last years have demonstrated the ability of some LAB species to inhibit the growth of a wide variety of deteriorating and toxigenic fungi (Lamont et al. 2017, Shehata et al. 2019. Some species that stand out include Lactiplantibacillus plantarum (Lactobacillus plantarum) (Crowley et al. 2013), Lacticaseibacillus rhamnosus (Lactobacillus rhamnosus) (Leyva Salas et al. 2018), Limosilactobacillus fermentum (Lactobacillus fermentum) (Muhialdin and Hassan 2011), and Limosilactobacillus reuteri (Lactobacillus reuteri) (Gerez et al. 2009). ...
... The development of research that evaluates the antimicrobial properties of LAB aims mainly to select potential bacteria and/or their metabolites for use in food biopreservation (Oliveira et al. 2014). However, the characteristics of LAB also make them promising for agricultural application, as a biocontrol agent for biopesticide formulation, but it is still an underexplored field (Lamont et al. 2017). ...
Fungal pathogens are one of the most important agents affecting crop production and food safety, and agrochemical application is one of the main approaches to reduce phytopathogenic fungi contamination in agricultural products. However, excessive and inadequate use can cause environmental damage, human and animal hazard, and increased phytopathogen resistance to fungicides. Biological control using lactic acid bacteria (LAB) and Bacillus spp. is an environmentally friendly strategy for phytopathogenic fungi management. Several molecules produced by these bacteria indeed affect fungal growth and viability in different plant crops. In this article, the activity spectra are reviewed along with the antifungal effect and antifungal compounds produced by LAB (e.g. organic acids, peptides, cyclic dipeptides, fatty acids, and volatile compounds) and Bacillus spp. (e.g. peptides, enzymes, and volatile compounds).
... Other microorganisms, such as plant growth promoting bacteria (PGPB), also have the capacity to increase yield and reduce biotic and abiotic plant stress without conferring pathogenicity [26,27]. Additionally, products with lactic acid bacteria (LAB) are a common alternative in agricultural systems for improving soils and enhancing plant growth [28]. ...
... On account of the additional nutrient release from the disintegrating organic components, the resistance to abiotic stresses could be amplified with the use of organic ingredients in growing media [95]. Moreover, it has been noted that LAB, as biostimulants, are in a position to directly promote the alleviation of various abiotic stresses [28]. Several strains of plant-growth-promoting bacteria, such as Burkholderia [106], Arthrobacter, and Bacillus [107] amplify proline synthesis in stressed plants, which conduces to preserving the cell water status, contributing in this way to the plant coping with the saline conditions [108]. ...
The issue of high concentration of salt in soil is not restricted to coastal areas, but also expands to cultivated lands, complicating, or even intercepting, the growth of plants. The objective of this paper is to study the effect of zeolite, compost and effective microorganisms (EM), seaweed extract, and ceramic powder on MM106 apple (Malus domestica Borkh.) plants in normal and saline conditions. More specifically, the weight of the dry matter of the plants, physiological parameters, proline, carbohydrate, carotenoid, phenolic, and flavonoid concentrations in leaf tissues and antioxidant capacity were determined. At the end of the experiment, it was ascertained that the plants of the treatments which included zeolite or EM exhibited the highest dry matter weight of the leaves in normal (5.07 g and 4.68 g, respectively) and saline conditions (4.14 g and 3.02 g, respectively), while the leaf dry weight in the control treatment was 4.37 g in the absence and 2.34 g in the presence of NaCl. Furthermore, these treatments resulted in significantly higher proline concentration in plant leaves under salinity with values of 5.63 in the EM treatment, 2.44 in the zeolite treatment, and 0.75 μmol/g of leaf fresh weight in the control. At the same time, the application of ceramic powder in combination with effective microorganisms led to the highest rate of photosynthesis in salinity conditions (12.8 μmol CO2/m2s), while the seaweed extract spraying was associated with low stomatal conductance in all treatments (0.09–0.13 mol H2O/m2s). Overall, the application of effective microorganisms appeared to associate more with plant vigor in both normal and salinity conditions. In this context, the implementation of EM could improve the growth of potted plants, but it could also be used in orchards before and after their establishment.
... The role of LAB as fermentative and probiotic microorganisms is well known, as is their use in food (dairy, bakery, and wine) and feed industries and human and veterinary medicines. Current knowledge on plant and soil microbiomes allows the use of LAB or their products as protective agents, having antimicrobial, antifungal, and biostimulant activities [8][9][10]. LAB colonise all plant parts at varying concentrations depending on the geographic and environmental conditions, host species, phenology, and many other factors. ...
Legumes are indispensable crops in sustainable agricultural systems because of their capability for biological nitrogen fixation owing to symbiosis with rhizobia and soil fertility restoration. Fungal pathogens from the genera Fusarium cause rotting and wilting and produce mycotoxins in plant tissues. The use of fungicides in sustainable agricultural systems is limited; therefore, the application of biological agents with antifungal activity against Fusarium spp. is desirable. Lactic acid bacteria (LAB) are promising control agents that produce a wide spectrum of functional metabolites. Lactiplantibacillus plantarum and other lactobacilli are the most intensively studied genera of LAB in relation to antifungal activity against Fusarium spp. However, LAB strains belonging to the lactobacilli and lactococci genera have not yet been isolated and characterised from legumes. Therefore, we aimed to obtain wild strains of LAB from legumes, screen them for functional characteristics with respect to their antifungal activity, and compare their antifungal activity against isolates of Fusarium spp. from legumes. Consequently, 31 LAB isolates belonging to 10 species were obtained and identified from legumes. Their functional properties, including genetics and proteomics, short-chain organic acid production, and antifungal activity against five Fusarium spp., of Lactiplantibacillus plantarum, Lacticaseibacillus paracasei, and Lactiplantibacillus pentosus isolates, were studied. Cell-free supernatants of L. plantarum and L. pentosus showed significant suppression of mycelial growth and conidial germination.
... In a parallel study by Kusvuran et al. 18 , they have observed increased oxidative stress by salt stress in sweet sorghum. Inoculation with Lp (ATCC 9019) decreased the antioxidant activity of S. chirayita plants, except of guaiacol peroxidase, when salt concentrations were elevated 56,84 . ...
The impact of bio-organic amendments on crop production is poorly understood in saline calcareous soils. The aim in the present study was to determine the effects of the application of organic manure along with lactic acid bacteria (LAB) on soil quality, and morpho-physio-biochemical responses, seed yield (SY) and essential oil yield (EOY) of fennel plants (Foeniculum vulgare Mill.) grown in saline calcareous soils. Eight treatments of farmyard manure (FM) or poultry manure (PM) individually or combined with Lactobacillus plantarum (Lp) and/or Lactococcus lactis (Ll) were applied to saline calcareous soil in two growing seasons. Either FM or PM combined with LAB had beneficial effects on lowering ECe, pH and bulk density and increasing total porosity, organic matter, and water and nutrient retention capacities in addition to total bacterial population in the soil. Growth, nutrient uptake, SY and EOY of plants were also enhanced when fennel seeds were inoculated with Lp and/ or Ll and the soil was amended with any of the organic manures under unfavorable conditions. Compared to control (no bio-organic amendments), FM + Lp + Lt or PM + Lp + Lt treatment signficantlly (P ≤ 0.05) increased plant height by 86.2 or 65.0%, total chlorophyll by 73 or 50%, proline by 35 or 45%, glutathione by 100 or 138%, SY by 625 or 463% and EOY by 300 or 335%, respectively, in fennel plants. Co-application of the naturally occurring microorganisms (i.e., LAB) and organically-derived, nutrient-rich fertilizer (i.e., FM or PM) is recommended to improve yield of fennel plants in saline calcareous soils.
... On the other hand, the use of bacteria of the genus Paenibacillus has been shown to have important advantages in other crops such as wheat (Hussain et al., 2020), maize (Puri et al., 2016), Poa annua or pigeon pea (Devi et al., 2021), although part of the work has focused on their biocontrol capabilities (Ran et al., 2023). On the other hand, in recent years, the study of the bioinoculant properties of lactic acid bacteria in agriculture has received significant attention, showing that they exhibit mechanisms for promoting plant growth and as biocontrol agents (Lamont et al., 2017). Moreover, the use of lactic acid bacteria is a counterpoint to the current trend where the use of bacteria belonging to pathogenic genera such as Pantoea, Serratia or Klebsiella, whose use and application in the form of bacterial inoculants poses a clear risk to the end user, is proposed (Tariq et al., 2022). ...
... Plant growth-promoting bacteria (PGPB) includes a diverse group of microorganisms that represent a broad range of genera. Few genera viz., Pseudomonas, Bacillus, Lactobacillus, and actinobacteria are involved in plant growth promotion [156][157][158][159]. They perform growth promotion, advancement, and development of plants by increasing beneficial microbiota in the vicinity of the rhizosphere, root colonization, competition with native harmful microbes, and build-up resistance in host plants against RKNs [160]. ...
Root-knot nematodes (Meloidogyne spp.) are obligate sedentary endoparasites, considered severe crop-damaging taxa among all plant-parasitic nematodes globally. Their attacks through parasitic proteins alter the physiology and machinery of the host cells to favour parasitism and reduction in crop yield. Currently, the use of excessive pesticides as a fast remedy to manage this pest is hazardous for both the environment and humans. Keeping this view in mind, there is an urgent need for developing efficient eco-friendly strategies. Bio-control as an eco-friendly is considered the best approach to manage nematodes without disturbing non-target microbes. In bio-control, living agents such as fungi and bacteria are the natural enemies of nematodes and the best substitute for pesticides. Fungi, including nematode-trapping fungi, can sense host signals and produce special trapping devices viz., constricting rings and adhesive knobs/loops, to capture nematodes and kill them. Whereas, endo-parasitic fungi kill nematodes by enzymatic secretions and spore adhesion through their hyphae. Bacteria can also control nematodes by producing antibiotic compounds, competing for nutrients and rhizosphere, production of hydrolytic enzymes viz., chitinases, proteases, lipases, and induction of systemic resistance (ISR) in host plants. Scientists throughout the world are trying to evolve environmentally benign methods that sustain agricultural production and keep nematodes below a threshold level. Whatever methods evolve, in the future the focus should be on important aspects like green approaches for managing nematodes without disturbing human health and the environment.
... The bacteria are Gram-positive rods or cocci that are facultative anaerobes due to their lack of catalase and oxidase. Milk, fruits, flowers, vegetables, dirt, feces, sewage water, etc. are all said to contain them (Lamont et al., 2017). Infants' guts are populated by lactic acid bacteria, some of which are supplied by human breast milk, the gold standard in infant nutrition (Kim et al., 2020). ...
Twelve infants aged below six months were sampled from Women and Children Hospital of Ramadi, Iraq during the period April the 1 st 2021 till October the 1 st 2022. Infants were divided into two main groups; breast and bottle milk fed. Each group comprise three males and three females. Samples of feces were collected and lactobacillus specie were extracted. The extract was used once alone and another as a mixture with each of Amoxicillin, Amikacin and Cefixime antibiotics on petri dishes cultured with Staphylococcus, Klabsella and Psedudomonas bacteria. Diameter of inhibition was measure and resulted data were subjected to statistical analysis. The results of the statistical analysis showed that lactobacillus specie extract with the Cefixime has significantly highest mean diameter of inhibition compared to all other types of treatments. Infants who were on breast milk fed showed significantly better respond to the treatment than their counter part in the bottle milk fed group. Klabsella was found to respond weakly under almost all of the applied treatments.
... Probiotics directly intervene in the biocontrol of phytopathogens by modulating nutrient absorption (phosphorus and potassium), hormone production, nitrogen fixation and siderophores. Through the diversity of compounds with an antimicrobial role, probiotics also intervene indirectly in the biological control of phytopathogens by causing reactions to induce systemic resistance, mechanisms involved in the attack, as well as by decreasing the availability of iron for the phytopathogen (Sathe et al., 2007;Fhoula et al., 2013;Guo et al., 2013;Sangmanee and Hongpattarakere, 2014;Cortes-Zavaleta et al., 2014;Mislin et al., 2014;Lamont et al., 2017, Kharazian et al., 2017Juodeikiene et al., 2018;Arena et al., 2019;Sadiq et al., 2019;Muhialdin et al., 2020;Chen at al., 2021;Patel et al., 2021;Dopazo et al., 2022;Jaini et al., 2022 ). The siderophores produced by the selected probiotic bacteria help plants to obtain iron requirements from the environment. ...
The paper aims to select probiotic microorganisms capable of producing siderophores for iron chelation and to make conjugates with the water-soluble fulvic fraction of Mollic Gleysol (WRB), (0-20 cm). The biosynthetic performances of 5 strains of probiotic bacteria from the collection, belonging to genera Lactobacillus (LAB 41, LAB 62, LAB 57, LAB 83, LAB 69), isolated from different soil types, were evaluated in terms of siderophores production (CAS method), type (Arnow and Csaky tests) and complexation capacity. The probiotic strains produced amounts of siderophores between 97-158 µmol L −1 in 48-96 hours, of catecholate and hydroxymate type and of both types in the case of LAB 62, LAB 69 and LAB 83 strains. LAB 83 strain had the highest iron chelating capacity. The inhibition capacity of the conjugates was tested and evaluated on 3 phytopathogenic fungal isolates (P. expansum, A. flavus and A. ochraceus). Probiotic strains are promising for the purpose of producing siderophores but also for antifungal effect when these act as conjugants with a fulvic acid subfraction.
... LAB induces metabolic changes in plants involved in plant response pathways to alleviate plant stress. As a biostimulant, LAB can also produce beneficial plant growth hormones (Lamont et al. 2017). Moreover, LAB is known to degrade some antinutrients that reduce the availability of nutrients required by plants (Faizal et al. 2023). ...
A growing world population means greater pressure on earth’s resources. Currently, 30% of food is wasted, which poses a significant risk to both humans and the environment. One way to offset the growth in food waste (FW) is through the process of microbial bioconversion, whereby FW is transformed into a range of nutrient-dense biofertilisers. This approach not only promotes a highly desirable circular economy, but it can also reduce the use of inorganic fertilisers, which adversely impact the environment through increased greenhouse gases, changes in soil and water characteristics, and loss of biodiversity. The bioconversion of FW to biofertiliser relies on the processes of aerobic (composting) and anaerobic digestion. Recently, alternative decomposition techniques included growing specific beneficial microbes, such as effective microorganisms, to speed up the breakdown process. Microorganisms can act as biostimulants and biodecomposers, possessing nutrient-fixing abilities and providing protection from biotic and abiotic stresses, thus enhancing plant growth and overall health. The potential uses of FW are complex and diverse, but research is actively done to effectively utilise this resource for biofertiliser applications.
... The negative environmental effects of synthetic chemicals, combined with concerns over the emergence of fungicide-resistant human pathogen biotypes and a strong consumer desire for food free of pesticide residues, harmful microorganisms, and toxins, as well as strict legal restrictions on the use of synthetic fungicides, have led to a global search for safer, more efficient, low-residue, nontoxic, environmentally and economically friendly alternative biocontrol methods (Romanazzi et al., 2017;Spadaro & Droby, 2016). The use of main yeasts, but also molds, lactic acid bacteria, and Gram-positive and Gram-negative bacteria as microbial biocontrol agents (BCAs) has emerged as a promising approach among various methods to prevent postharvest diseases of fruits and vegetables (Lamont et al., 2017). ...
Fresh fruits and vegetables are susceptible to a large variety of spoilage agents before and after harvest. Among these, fungi are mostly responsible for the microbiological deteriorations that lead to economically significant losses of fresh produce. Today, synthetic fungicides represent the first approach for controlling postharvest spoilage in fruits and vegetables worldwide. However, the emergence of fungicide‐resistant pathogen biotypes and the increasing awareness of consumers toward the health implications of hazardous chemicals imposed an urgent need to reduce the use of synthetic fungicides in the food supply; this phenomenon strengthened the search for alternative biocontrol strategies that are more effective, safer, nontoxic, low‐residue, environment friendly, and cost‐effective. In the last decade, biocontrol with antagonistic yeasts became a promising strategy to reduce chemical compounds during fruit and vegetable postharvest, and several yeast‐based biocontrol products have been commercialized. Biocontrol is a multipartite system that includes different microbial groups (spoilage mold, yeast, bacteria, and nonspoilage resident microorganisms), host fruit, vegetables, or plants, and the environment. The majority of biocontrol studies focused on yeast‐mold mechanisms, with little consideration for yeast–bacteria and yeast–yeast interactions. The current review focused mainly on the unexplored yeast‐based interactions and the mechanisms of actions in biocontrol systems as well as on the importance and advantages of using yeasts as biocontrol agents, improving antagonist efficiency, the commercialization process and associated challenges, and future perspectives.
... Apart from that, bacteria can also be utilized as a biofertilizer, such as rhizobacteria that was isolated from some plant rhizosphere soil of Bangkinang, Kampar, Sumatra Island Indonesia and rhizobacteria have the ability to increase the germination and growth of bok choy seedling in red-yellow podzolic soil environments (Agustiyani et al. 2021). Lamont et al. (2017) reported Lactic Acid Bacteria (LAB) able to improve soil's condition control the disease and boost plant's growth. Lysinibacillus macroides can be used as a biofertilizer with the dry matter from organic wastes, such as elephant grass, cassava peels and poultry droppings, because it can produce nitrogen, phosphorus, potassium and total organic carbon from degradation of that wastes (Amadi et al. 2021). ...
Prihartin I, Ismail AS, Sukorini H, Nursandi F, Zakia A, Farahdina FAR. 2023. Identification of bacterial isolates of Tumpang and Bumiasri (East Java, Indonesia) using 16S rRNA gene sequencing and screening of their active compounds as a biofertilizer. Biodiversitas 24: 3338-3343. The objective of the study was to identify Tumpang (TPG) and Bumiasri (BAS) isolates using 16S rRNA gene sequencing and screen-on biofertilizer active-compounds. Research materials used in the study were bacterial isolates of TPG isolated from Tumpang area and BAS isolated from Bumiasri area, East Java, Indonesia. The variables observed was isolate identification using 16S-rRNA gene and screen for active compounds for biofertilizer using liquid chromatography tandem-mass spectrometry (LC-MS/MS-QTOF). The biofertilizer composed of mineral mix (P, K, Fe, Mg and S), rice-straw extract, water and TPG isolate as C1 Biofertilizer and BAS as C2 Biofertilizer. The sequencing results of TPG isolates obtained DNA sequences that resembled the bacterium Lysinibacillus fusiformis with a similarity of 99%, while BAS isolate resembled the bacterium Lysinibacillus macroides with a similarity of 99%. These genes sequences have been submitted to GenBank under the bacterial names L. fusiformis BIP-211 and L. macroides BIP-212 respectively. The LC-MS/MS-QTOF screening result shows that the C1 biofertilizer contain benzoic-acid compound, 4-(butylamino), methoxycinnamyl P-coumarate. Futhermore, betaine (glycine betaine) and benzoic-acid 4-(butylamino) was identified in C2. So, the TPG and BAS isolates was confirmed as L. fusiformis BIP-211 and L. macroides BIP-212 respectively. The both C1 and C2 biofertilizer consists two active-compounds.
... Feng et al. 2020;Megali et al. 2015;Shin et al. 2017), water management in the context of climate change adaptation (AbdEl- Mageed et al. 2020;Grum et al. 2017) or the valorization of organic biowaste (Che Jusoh et al. 2013; Daur 2016; Qu et al. 2019). Research on EM effects in agricultural application with a focus on soil processes had been published in an interdisciplinary collection of journals, including (in chronological order of publication): sustainable agriculture (Daly and Stewart 1999; Townsend et al. 2016; Twardowski, Gruss, and Kordas 2017), biology (Cóndor-Golec et al. 2007; Daur 2016), plant nutrition, soil science (Schenck Zu Schweinsberg-Mickan and Müller 2009), soil ecology (Mayer et al. 2010), social sciences (Pangsoi 2011), biotechnology (Olle and Williams 2013), environmental engineering (Che Jusoh et al. 2013; Qu et al. 2019), sustainable development(Megali et al. 2015), microbiology(Vílchez et al. 2016), biochemistry(Lamont et al. 2017), land degradation(Grum et al. 2017), agronomy, and elementology(Franczuk et al. 2019). ...
Effective microorganisms® (EM) is a microbial inoculant promoted in organic agriculture to stimulate organic-matter (OM) decomposition, the formation of soil organic matter (SOM) and soil fertility. Despite being one of the most well-known and most commonly applied microbial mixed cultures worldwide, few scientific investigations have evaluated EM’s effectiveness. In the context of the increasingly popular regenerative land management practice Flächenrotte, the shallow incorporation of OM, this thesis consisted of: 1) a comprehensive review of qualitative and valid research around EM effects on soil processes in an agricultural context, and 2) a soil incubation experiment with an agriculturally used soil in temperate climate (Thurgau, Switzerland) to explore the effects of EM addition on SOM transformation, nutrient- and potentially toxic trace element (PTTE) dynamics. The systematic literature review detected 19 relevant articles and uncovered that it remains unclear how exactly EM affect soil properties and processes due to three main factors which are causing methodological challenges and are limiting the comparability of published studies: a) EM can be applied in various forms; b) EM have different effects on different plant species; c) EM can be applied in combination with different substrates. No previous study had considered EM effects on PTTE dynamics in soil. In the incubation experiment, 8 soil treatments with varying levels of EM and OM addition were incubated (28d, 12°C, 80% air humidity) to monitor trends in soil microbial activity (soil respiration), labile organic carbon (permanganate oxidizable carbon, POX-C), nutrient concentration (IC) and PTTE dynamics (ICP-MS). We observed a) no conclusive significant effects of EM on additional SOM formation, but OM addition strongly enhanced soil microbial activity; b) slightly increased nutrient availability for Mg2+ and Ca2+, which were likely substrate effects due to the activation of the local microflora rather than the activity of the newly added microorganisms; and c) no effects on PTTE availability, an important result to endorse the safety of EM application in Flächenrotte. POX-C was found methodologically not suited for the short time span of the experiment. Overall, the results strongly suggest that OM addition had significantly bigger effects than EM on respiration, nutrient- and PTTE dynamics. It will be important to better understand the concentration of PTTE present in commercially available EM products. We conclude that more research is needed to understand the effects of EM on soil processes and recommend to establish a common research agenda including the definition of main indicators of interest along with suitable methods, which will be crucial in order to make findings comparable.
... Lactic acid bacteria are used as biocontrol agents in agricultural research and applications, as they show anti-fungal effects on vegetables and fruits (Wang et al. 2011;Kang et al. 2014;Li et al. 2020). Besides, inoculating compost with specific formulations of PPM comprising LAB has been shown to be beneficial for crop plants (Lamont et al. 2017). Our previous study found that applying LAB in saline-alkali field could improve the agronomic traits and crop yields, improving the yield of cucumber (Cucumis sativus L) and tomato (Solanum lycopersicum) by 28.8% and 18.2%, respectively (Hou et al. 2020). ...
Management and improving saline-alkali land is necessary for sustainable agricultural development. We conducted a field experiment to investigate the effects of spraying lactic acid bacteria (LAB) on the cucumber and tomato plant soils. Three treatments were designed, including spraying of water, viable or sterilized LAB preparations to the soils of cucumber and tomato plants every 20 days. Spraying sterilized or viable LAB could reduce the soil pH, with a more obvious effect by using viable LAB, particularly after multiple applications. Metagenomic sequencing revealed that the soil microbiota in LAB-treated groups had higher alpha-diversity and more nitrogen-fixing bacteria compared with the water-treated groups. Both viable and sterilized LAB, but not water application, increased the complexity of the soil microbiota interactive network. The LAB-treated subgroups were enriched in some KEGG pathways compared with water or sterilized LAB subgroups, such as environmental information processing–related pathways in cucumber plant; and metabolism-related pathways in tomato plant, respectively. Redundancy analysis revealed association between some soil physico-chemical parameters (namely soil pH and total nitrogen) and bacterial biomarkers (namely Rhodocyclaceae, Pseudomonadaceae, Gemmatimonadaceae, and Nitrosomonadales). Our study demonstrated that LAB is a suitable strategy for decreasing soil pH and improving the microbial communities in saline-alkali land.
... The results of this study demonstrated that cultivated crops (lupin and pea) and management practices (involving microorganisms) had a profound influence on the soil organic matter pool, especially the labile fraction (Figures 2 and 3). This interaction between cultivated crops and inoculated microorganisms was proven to improve soil fertility, nutrient cycling, and overall soil health [41,43,61]. Previous studies by Virk et al. and Van der Pol et al. [43,62] have shown that addressing the soil carbon dilemma through the inclusion of legumes in intensified rotations can enhance soil carbon while maintaining yields through a simultaneous increase in nitrogen (N) and soil organic carbon (SOC) by way of rhizodeposition, root senescence, and decomposition. ...
The growing global population and increasing demand for agricultural products have exerted significant pressure on agricultural systems. As a result, soil organic matter depletion and degradation have become prevalent issues, including in regions such as South Bohemia, Czech Republic, where conventional farming practices are predominant. Soil organic matter (SOM) plays a critical role in soil health, crop productivity, and the sustainability of agricultural systems, with changes occurring in both the total and labile fractions of the organic matter pools. However, changes in the total soil organic matter carbon pool (TOC) resulting from agricultural practices occur gradually and may become evident only after several years, posing challenges for timely management adjustments. Therefore, the identification of early indicators of SOM dynamics is crucial for implementing prompt corrective actions. The aim of this study was to evaluate the effects of sustainable management practices, such as cultivated crops (Pisum sativum and Lupinus albus), selected entomopathogenic and mycoparasitic fungi (Trichoderma virens and Metarhizium brunneum), and lactic acid bacteria (LAB) on the labile fraction of the SOM pool (CLSOM) and identify potential early indicators. Our findings demonstrated that the type of crop and applied microorganisms (treatments) significantly affected the CLSOM in peas, and the crop growth stages affected the TOC in both pea and lupin. Growth stages also showed an impact on the CLSOM in lupin. Moreover , in both crops, the change in CLSOM correlated with changes in the SOM oxidation rate constant (k), carbon lability index (LI), carbon management index (CMI), and carbon enrichment ratio (ER). Conversely, changes in the TOC did not exhibit significant correlations, except for LI and CMI, which showed a positive correlation with the TOC in peas (p < 0.05). Furthermore, the separate application of MEHA and LAB on seeds or leaves resulted in increased SOM carbon pools compared with the combined application. The application of these beneficial microorganisms in pea and lupin crops showed potential in maintaining or increasing CLSOM, which can be assessed early through indicators such as k, LI, CMI, and ER. Contributing to the development of sustainable soil management strategies, future research should further investigate different crops and microorganisms-and the mechanisms underlying their observed relationships-and explore additional early indicators to refine and optimize sustainable agricultural practices.
... were shown to be hostile to the pathogen. Additionally, lactic acid bacteria, such as Lactobacillus plantarum and Lactobacillus paracasei, were applied to plants to stimulate development and control of diseases (Lamont et al., 2017). A very interesting isolate from the maize rhizosphere was typified as Micrococcus luteus according to molecular and electronic microscope analysis. ...
Pesticide and fertilizer usage is at the center of agricultural production to meet the demands of an ever-increasing global population. However, rising levels of chemicals impose a serious threat to the health of humans, animals, plants, and even the entire biosphere because of their toxic effects. Biostimulants offer the opportunity to reduce the agricultural chemical footprint owing their multilevel, beneficial properties helping to make agriculture more sustainable and resilient. When applied to plants or to the soil an increased absorption and distribution of nutrients, tolerance to environmental stress, and improved quality of plant products explain the mechanisms by which these probiotics are useful. In recent years, the use of plant biostimulants has received widespread attention across the globe as an ecologically acceptable alternative to sustainable agricultural production. As a result, their worldwide market continues to grow, and further research will be conducted to broaden the range of the products now available. Through this review, we present a current understanding of biostimulants, their mode of action and their involvement in modulating abiotic stress responses, including omics research, which may provide a comprehensive assessment of the crop's response by correlating molecular changes to physiological pathways activated under stress conditions aggravated by climate change.
... Bacteria in the genus Lactobacillus, or LAB, have been employed in agricultural systems for decades to improve soil quality, control disease, and promote plant growth. LAB isolated from a variety of sources have been demonstrated to be efficient biofertilizers, biocontrol agents, and biostimulants (Lamont et al. 2017). ...
... Finally, based on the amount of production, the top three most popular fruits in the world include apples, which underlines their importance from an economic point of view (Shahbandeh, 2021). Lactic acid bacteria (LAB), especially Lactobacilli, are considered to be plantassociated bacteria (Lamont et al., 2017), and LAB are often isolated from fruits and vegetables (Yu et al., 2019). One of the species of lactic acid bacteria, Lactiplantibacillus (Lpb.) ...
In this study, twenty isolates of lactic acid bacteria (LAB) from different apple varieties were obtained. Their probiotic properties together with those of 12 strains, isolated by us earlier from fermented milk, Levilactobacillus brevis (10, 15, 18, 49, 51), Lactiplantibacillus pentosus (40, 57, 63, 85, 88, 92) and Lactobacillus fermentum (44) were studied. Apple Lactiplantibacillus plantarum 52, 53, 74, and 76 were found to be pH 2-resistant during incubation for 30, 60 and 90 min. Overall, exposure to bile salts (0.3%; 0.5%; 1%; and 1.5%) had no effect on the growth of Lactobacillus sp. Antimicrobial activity and antibiotic resistance/susceptibility studies were performed on ten pathogenic microorganisms and nine antibiotics, respectively. Lactiplantibacillus (Lpb.) plantarum 52, 53, and 74 from apple samples had susceptibility to oxytetracycline, tetracycline, and rifampicin, Lpb. plantarum 52, 74 and 76 were susceptible to erythromycin. Almost all strains of lactobacillus showed antimicrobial activity to Enterococcus faecalis ATCC 29212, except Lpb. plantarum 76 and L. brevis 51. Lpb. plantarum 76 had inhibitory activity against Bacillus cereus ATCC 10876 (16.3±0.52), Klebsiella pneumoniae ATCC 13833 (16.4±0.4), Streptococcus pyogenes ATCC 21059 (16.3±0.3), Pseudomonas aeruginosa ATCC 27853 (16.3±0.4), Escherichia coli ATCCB322 (16.3±0.5), Proteus mirabilis ATCC 12453 (12.4±0.4), and Shigella flexneri ATCC 12022 (12.3±0.3). Based on the studied probiotic properties, apple Lpb. plantarum 52, Lpb. plantarum 53, Lpb. plantarum 74, Lpb. plantarum 76, identified by MALDI-TOF mass spectrometry and 16S rDNA sequencing, were selected as potential candidates for the fermentation of apple juices. Fermented apple juices could be a new source of probiotics for lactose intolerant and vegetarian consumers.
... PGPR not only plays a crucial role in nutrient acquisition and assimilation, improving soil properties, but also regulates extracellular molecules and secreted compounds as valuable biological stimulants to cope with stress responses of plant (Backer et al., 2018;Vejan et al., 2016). In recent years, Bacillus, Pseudomonas, Actinobacteria and other strains have been commercialized (Lamont et al., 2017;Shivlata and Satyanarayana, 2017;Sivasakthi et al., 2014). These PGPR products are employed in agricultural production to improve plant growth and alleviate biotic and abiotic stresses, pushing forward the development of sustainable and environment-friendly ecosystems (Hashem et al., 2019). ...
Plant growth-promoting rhizobacteria (PGPR) can promote plant growth and protect plants from pathogens, which contributes to sustainable agricultural development. Several studies have reported their beneficial characteristics in facilitating plant growth and development and enhancing plant stress resistance through different mechanisms. However, there is still a challenge to study the molecular mechanism of plant response to PGPR. We integrated the transcriptome and metabolome of Arabidopsis thaliana (Arabidopsis) to understand its responses to the inoculation with an isolated PGPR strain (BT22) of Bacillus megaterium. Fresh shoot weight, dry shoot weight and leaf number of Arabidopsis were increased by BT22 treatment, showing a positive growth-promoting effect. According multi-omics analysis, 878 differentially expressed genes (296 up-regulated, 582 down-regulated) and 139 differentially expressed metabolites (66 up-regulated, 73 down-regulated) response to BT22 inoculation. GO enrichment results indicate that the up-regulated genes mainly enriched in the regulation of growth and auxin response pathways. In contrast, the down-regulated genes mainly enriched in wounding response, jasmonic acid and ethylene pathways. BT22 inoculation regulated plant hormone signal transduction of Arabidopsis, including auxin and cytokinin response genes AUX/IAA, SAUR, and A-ARR related to cell enlargement and cell division. The contents of nine flavonoids and seven phenylpropanoid metabolites were increased, which help to induce systemic resistance in plants. These results suggest that BT22 promoted Arabidopsis growth by regulating plant hormone homeostasis and inducing metabolome reprogramming.
... (Prusky, 2011). Bio-preservation is an alternative technology for controlling the growth of harmful microorganisms that is safe for consumers and the environment (Lamont et al., 2017;Muhialdin, et al., 2020a). Lactic Acid Bacteria (LAB) has long been used as a bio preservative agent in food, and the use of LAB metabolites as bio preservatives showed significant results against a wide range of fungi. ...
Optimization of antifungal activity and determination of antifungal mechanism in Lacto-fermented palm kernel cake against colletotrichum gloeosporioides. Tropical Agriculturist, 170 (3), 10-25. Abstract Anthracnose disease caused by Colletotrichum gloeosporioides reduces the postharvest quality of fruits and vegetables which creates large economic losses. natural preservation methods of fruits have been popular due to the preference of modern consumers to consume chemical-free fruits. therefore, there is a requirement for industrial-level natural preservation techniques for fruits and vegetables. the current study aimed to optimize the antifungal activity of previously produced fungal growth inhibitor (PKCL1) by Lactobacillus plantarum cultivated in palm kernel cake (PKC) against Colletotrichum gloeosporioides and to determine the antifungal mechanism. Box Behnken design under response surface methodology was applied to optimize the fermentation conditions. the antifungal mechanism of optimized PKCL1 was determined by the leakage of intercellular components, ergosterol synthesis, and the morphological changes of treated fungi. the substrate ratio, fermentation time, and temperature influenced the production of antifungal compounds while altering the antifungal activity. the combinations of optimum fermentation conditions comprised of substrate ratio of 24.75%, fermentation time of 96 hours, and fermentation temperature of 37 ºC to obtain 88.08% C. gloeosporioides inhibition. Significant differences were observed in the protein concentration, DnA, sugars, and ergosterol synthesis between the treated and non-treated fungi. thus, PKCL1 was affected in the cell membrane structure and biosynthesis pathways of C. gloeosporioides. Besides, PKCL1 changed the cell morphology and destroyed the cell wall structure. Box Behnken design is an appropriate model to optimize the fermentation conditions to maximize the antifungal activity of PKCL1. it was concluded that optimized PKCL1 has a strong capability to destroy C. gloeosporioides.
... Lactic acid bacteria as biocontrol have been used in agricultural research and applications, showing anti-fungal effects on vegetables and fruits (Kang et al., 2014;Li et al., 2020;Wang et al., 2011). Besides, compost inoculated with Effective Microorganisms (a consortium of yeast, mold fungi, lactic acid bacteria etc.), has been shown to be bene cial for crop plants (Lamont et al., 2017).The effects of lactic acid bacterial in improving yield of saline-alkali elds investigated by our previous work, and that showed that lactic acid bacterial application effectively improved the agronomic traits of cucumber (Cucumis sativus L) and tomato (Solanum lycopersicum), bringing an increase in the vegetable yield by 28.8% and 18.2%, respectively (Hou et al., 2020), but it's potential microbial mechanism have not been revealed. ...
The management and improvement of saline-alkali land is necessary for sustainable agricultural development. We conducted a field experiment to investigate the effects of spraying lactic acid bacteria (LAB) on the of cucumber and tomato plantation soil. Three treatments were designed, include spraying of non-sterilized/sterilized LAB preparation or water (control) to the soil of planting every 20 days. Treatment with either sterilized or viable LAB reduced the soil pH. Metagenomic sequencing revealed that the LAB-treated groups had higher alpha-diversity and more nitrogen fixing bacteria compared with the water-treated groups. Treatment with viable or sterilized LAB increased the complexity of soil microbial interactive network in different pattern. Differential enrichment of KEGG pathways and genes were observed between LAB-treated groups: changes in environmental information processing-related pathways in cucumber soil and metabolism-related pathways in tomato soil, respectively. RDA analysis revealed biomarker bacterial communities in different treatments were associated with soil pH and total nitrogen. Our study demonstrated that LAB might be a suitable strategy for decreasing soil pH and improving community structure of certain plants in saline-alkali land.
... Selain itu, sifat maltodekstrin dapat berfungsi sebagai bahan tambahan pangan yang dapat melindungi bahan dari kerusakan. Hal ini sesuai dengan penelitian Teixeira (2014) melaporkan bahwa starter bakteri Lactobacillus bulgaricus memiliki suhu optimum untuk mendukung pertumbuhan berkisar 40-50 0 C dan maksimum sampai 62 0 C. Lamont et al., (2017);Sauer et al., (2017) melaporkan bahwa bakteri asam laktat merupakan bakteri gram positif anaerob fakultatif yang dilaporkan terdapat pada makanan kaya nutrisi dan bergantung pada asam amino dan karbohidrat yang difermentasi menjadi asam organik, sehingga mempengaruhi tingkat penggandaan. Sugindro et al., (2008) menunjukkan bahwa semakin tinggi konsentrasi penyalut, efisiensi enkapsulasi semakin meningkat, lapisan kulit (shell) semakin baik dan kuat,sehingga dapat melindungi bahan inti dengan baik serta melindungi zat yang mudah menguap ketika proses pengeringan berlangsung, yang berakibat retensi bahan inti akan semakin meningkat. ...
Penelitian ini bertujuan untuk mengetahui pengaruh konsentrasi maltodekstrin terhadap kadar protein, total mikroba, total asam dan kadar air pada yogurt bubuk dari biji nangka. Metode yang digunakan adalah Rancangan Acak Lengkap non-faktorial dengan konsentrasi maltodekstrin (M) terdiri dari 4 taraf (M1= 10%, M2= 15% M3= 20%, M4= 25%) dan 3 ulangan. Penelitian ini menggunakan analisis secara kuantitatif yaitu kadar protein, total mikroba, total asam dan kadar air. Parameter penelitian ini diolah secara ANOVA dan dilanjutkan uji DMRT 5% menggunakan software IBM SPSS Statistik. Hasil penelitian menunjukan bahwa penambahan konsentrasi maltodekstrin dari 10-25% menunjukkan peningkatan kadar protein, total mikroba, dan kadar air, namun menurunkan total asam pada yoghurt bubuk biji nangka dengan konsentrasi terbaik terdapat pada 25%.
... stimulates the growth of the tomato roots (Gaiero et al., 2013;Zhao et al., 2018b;Dias et al., 2017). Zhao et al. (2018a) reported that about 276 endophytic bacteria isolated from root nodules of soybean that highly protect soybean roots against various fungal infections (Lamont et al., 2017). ...
... Fermentation is a centuries-old process that is widely used in the production of various foods by human societies all over the world (Mishra et al., 2017). LABs create a high acidic environment during fermentation and outcompete spoilage-causing microorganisms (Lamont et al., 2017). Moreover, fermented foods have an important place in human diet because the fermentation process plays a significant role in preserving the food taste, quality, and enrichment of the food content (Sharma et al., 2020). ...
Glutamate decarboxylase (GAD) pathway (GDP) is a major acid resistance mechanism enabling microorganisms’ survival in low pH environments. We aimed to study the molecular evolution and population genetics of GDP in Lactic Acid Bacteria (LAB) to understand evolutionary processes shaping adaptation to acidic environments comparing species where the GDP genes are organized in an operon structure (Levilactobacillus brevis) versus lack of an operon structure (Lactiplantibacillus plantarum). Within species molecular population genetic analyses of GDP genes in L. brevis and L. plantarum sampled from diverse fermented food and other environments showed abundant synonymous and non-synonymous nucleotide diversity, mostly driven by low frequency changes, distributed throughout the coding regions for all genes in both species. GAD genes showed higher level of replacement polymorphism compared to transporter genes (gadC and YjeM) for both species, and GAD genes that are outside of an operon structure showed even higher level of replacement polymorphism. Population genetic tests suggest negative selection against replacement changes in all genes. Molecular structure and amino acid characteristics analyses showed that in none of the GDP genes replacement changes alter 3D structure or charge distribution supporting negative selection against non-conservative amino acid changes. Phylogenetic and between species divergence analyses suggested adaptive protein evolution on GDP genes comparing phylogenetically distant species, but conservative evolution comparing closely related species. GDP genes within an operon structure showed slower molecular evolution and higher conservation. All GAD and transporter genes showed high codon usage bias in examined LAB species suggesting high expression and utilization of acid resistance genes. Substantial discordances between species, GAD, and transporter gene tree topologies were observed suggesting molecular evolution of GDP genes do not follow speciation events. Distribution of operon structure on the species tree suggested multiple independent gain or loss of operon structure in LABs. In conclusion, GDP genes in LABs exhibit a dynamic molecular evolutionary history shaped by gene loss, gene transfer, negative and positive selection to maintain its active role in acid resistance mechanism, and enable organisms to thrive in acidic environments.
... The mean moisture content of the yoghurt powders was significant. Water was removed during drying from the yoghurt foam which forms the three-dimensional structure of yoghurt and resulted in an amorphous structure of the yoghurt powder [26]. This is similar to the report by [27] and [28]. ...
This experimental study examines the effect of different production parameters such as moringa seed flour, ginger extract, forming agent, mixing time and drying temperature on the selected proximate and microbiological qualities of foam-mat dried yoghurt. The design and analysis of the experiment were conducted with the central composite design technique of the Design Expert statistical software. The study aimed at fortifying and optimizing the production of foam-mat dried yoghurt, which involves powdered milk, water, starter culture and flavour which are kept constant and followed by the addition of moringa seed flour, ginger extract and forming agent (egg white). Twenty-five experimental runs with the control experiment inclusive were carried out based on the mixture-process design matrix and the nutritional properties evaluated include moisture content, crude protein, fat content, ash content, carbohydrate content, total lactic acid, bacteria and fungi. Numerical optimization, via the desirability approach, was utilized to determine the optimum production parameters for the fortified foam-mat dried yoghurt. Graphical optimization was also used to display the prediction of all responses in the mixture-process factors space. Results got revealed that foam-mat dried yoghurt with 10.79 % moisture content, 12.115% crude protein, 0.552% ash content, 2.196% fat and 16.409% carbohydrate could be produced from 80% of fresh yoghurt, 5.466% of moringa seed flour, 7.534% of ginger extract, 7% of foaming agent, mixing duration 2.53mins, drying temperature at 50oC and 0.721 desirability index gave the optimum quality. The results of this work are of great use to the food and beverage industries as they provide a basis for selecting process parameters for optimal foam-mat dried yoghurt production. Prospects for more studies were suggested.
... Lactic acid bacteria (LAB) act as effective bio-fertilizers and bio-stimulants, improving nutrient availability, minimal biotic and abiotic stresses, and directly stimulate plant growth (Hamed et al. 2011;Lamont et al. 2017;Shrestha et al. 2014). Shrestha et al. (2009) showed that LABs can suppress soil borne bacterial pathogens and improve plant growth such as bacterial spot in pepper and tomato as well as bacterial wilt (R. solanacearum) in pepper. ...
Biological control has received increasing interest in recent decades as one of the alternatives to chemical pesticides in the field of plant disease control, especially after the increased awareness of the dangers of pesticides to the environment in general and human health in particular, and the emergence of resistance to pesticides in some causes. Biological control is defined as any conditions or procedures in which a particular organism or substances produced from a living organism are used to reduce infection with a particular pathogen. Plant growth promoting rhizobacteria (PGPR) are able to stimulate growth and resistance against plant diseases when they are able to have a positive effect on the plant health, and then demonstrate good competitive qualities and capabilities over existing rhizosphere communities. PGPR affects plant growth improvement by fixing atmospheric nitrogen, siderophore production dissolving insoluble phosphates, and releasing hormones. In this review, we tried to focus on the potential effects of PGPR as an effective and safe technique for plant disease resistance. PGPR play a major role in plant disease resistance through induced systemic resistance (ISR), antibiotics, hydrogen cyanide, Lytic enzyme, degradation of toxins, competition for nutrients, and parasitism.
... Engineering the phytomicrobiome to meliorate plant growth is a promising approach for maintaining crop productivity in a dynamic climate and increasing population. Broadly, plant growth-promoting microorganisms (PGPM) enhance plant growth by improving nutrient uptake, serving as biocontrol agents (BCAs), abating the potential of the plant to withstand abiotic stress, or by producing compounds that directly stimulate plant growth (Lamont et al., 2017). Many PGPMs enhance plant growth via different mechanisms simultaneously (Avis et al., 2008). ...
The degrading effects of synthetic agrochemicals on soil health and fertility have
provoked a revolution for sustainable pathways to improve soil quality and
productivity. Recent advances have proven and postulated soil fertility
enhancement using plant growth promoting beneficial microorganisms without
deleterious effects on soil health. Such beneficial microbes are lactic acid
bacteria. LAB is a group of microorganisms that are non-motile, gram-positive
cocci or bacilli, non-spore-forming, and finally produce lactic acid for the
fermentation of carbohydrates through heterofermentative or homofermentative. LAB have shown to enhance soil fertility and plant nutrition
through phosphorus solubilization, nitrogen fixation, siderophore secretion,
and decomposition of organic matter. Due to LAB’s role in soil quality
augmentation, their isolation from different sources has increased in modern
times. They are found to be dominant in fermented products such as compost,
yoghurt, palm wine, and sha’a also known as corn beer. Palm wine and sha’a are
drinks that is been produced and consumed traditionally in most developing
nations. They harbour an array of LAB with the potential to increase crop
productivity and enhance soil quality. Nonetheless little is known about the
isolation of LAB from palm wine and sha’a and their role in soil fertility and plant
nutrition. This review is therefore set out to explore the potential roles of LAB
from palm wine and sha’a on soil quality and plant nutrition.
Keywords: Beneficial microbes, soil health, plant and LAB sources
... Regardless of the high N and P content of Blac, its elaboration process is focused on lactic bacteria content and their effect on plant growth. These microorganisms serve as biofertilizers, biocontrollers, biostimulants, and bioelicitors (19,33), probably explaining the increase in lettuce biomass. On the other hand, Biog process is the only one not trying to increase plant nutrition and beneficial microorganisms, but producing energetic compounds. ...
Bioslurries, obtained by anaerobic digestion of fresh organic matter, are emerging as a cheaper and low-impact alternative for synthetic products in agriculture. The aim of this study was to evaluate bioslurry obtained from biogas digestion (Biog), bioslurry for plant nutrition by FAO (Bfao), and lactic fermentation (Blac) as biostimulant in tomato and lettuce plants. Based on a toxicity test, a 10% dilution was finally applied to the plants. In lettuce, Bfao and Blac significantly increased aerial biomass (2.17 ±0.54 and
2.33 ±1.13 g respectively), regarding water control (1.16 ±0.60 g), while root biomass was only increased by Bfao (1.60 ±0.44 g) compared to control (0.66 ±0.34 g). All digestates increased chlorophyll content index (CCI), while yield (Fv/Fm) and performance index (Plabs) did not show differences with water control. In tomato, only aerial biomass was significantly increased by Bfao. All digestates significantly increased CCI, while Fv/Fm was only significantly higher in Bfao and Blac, related to water control. PIabs showed no differences. In both plant species, commercial fertilizer showed significantly higher values for all parameters. In conclusion, all digestates stimulated plant growth, Bfao showed the highest effect on tomatoes and lettuce biomass followed by Blac and Biog, being a cheaper, safer and lower-impact alternative for traditional products for crop growing.
... After that, the sample was placed in a plastic container (layer thickness 20 mm) and sonicated (850 kHz, 1.5 W/cm 2 ) at 40 • C for 20 min in a ultrasonic bath (Meinhardt Ultraschalltechnik, Leipzig, Germany). The fermentation conditions were selected based on previous experiments [15,16]. For the fermentation experiment, the untreated RB sample (100 g) was mixed with sterile distilled water at a 1:4 ratio. ...
In this study, water extracts from fermented (F), ultrasonicated (US), and enzyme-hydrolyzed (E) rice bran (RB) were evaluated against sixteen fungal plant stem and root-rot-associated pathogens. The effects of pre-treated RB additives on plant growth substrate (PGS) on bean and tomato seed germination, stem height and root length of seedlings, and chlorophyll concentration in plants were analyzed. The results showed that US-assisted pre-treatments did not affect protein content in RB, while 36 h semi-solid fermentation (SSF) reduced protein content by 10.3–14.8%. US initiated a 2.9- and 2-fold increase in total sugar and total phenolics (TPC) contents compared to the untreated RB (3.89 g/100 g dw and 0.61 mg GAE/g dw, respectively). Lactic acid (19.66–23.42 g/100 g dw), acetic acid (10.54–14.24 g/100g dw), propionic acid (0.40–1.72 g/100 g dw), phenolic compounds (0.82–1.04 mg GAE/g dw), among which phenolic acids, such as p-coumaric, cinnamic, sinapic, vanillic, and ferulic, were detected in the fermented RB. The RBF extracts showed the greatest growth-inhibition effect against soil-born plant pathogens, such as Fusarium, Pythium, Sclerotinia, Aspergillus, Pseudomonas, and Verticillium. Beans and tomatoes grown in RBUS+E- and RBF-supplemented PGS increased the germination rate (14–75%), root length (21–44%), and stem height (25–47%) compared to seedlings grown in PGS. The RB additives increased up to 44.6–48.8% of the chlorophyll content in both plants grown under greenhouse conditions. The results indicate that the biological potential of rice-milling waste as a plant-growth-promoting substrate component can be enhanced using solid-state fermentation with antimicrobial LABs and US processing.
... On the contrary, B. subtilis has many secretory pathways, which, in most cases, leave the cell intact, but large quantities of proteins are secreted into the medium [55]. The sec-dependent secretory pathway is responsible for the majority of proteins exported from the cytoplasm to the growth medium, which typically contain cleavable N-terminal signal peptides [56,57]. Other proteins are secreted through twin-arginine translocation (TAT) systems [58]. ...
It is well-known that there is a high frequency of plant-growth-promoting strains in Bacillus subtilis and that these can be effective under both stressful and stress-free conditions. There are very few studies of this activity in the case of Lactobacillus helveticus. In this study, the effects of pH on the secretome (proteins) in the cell-free supernatants of two bacterial strains were evaluated. The bacteria were cultured at pH 5, 7 and 8, and their secretome profiles were analyzed, with pH 7 (optimal growth pH) considered as the “control”. The results showed that acidity (lower pH 5) diminishes the detectable production of most of the secretome proteins, whereas alkalinity (higher pH 8) increases the detectable protein production. At pH 5, five (5) new proteins were produced by L. helveticus, including class A sortase, fucose-binding lectin II, MucBP-domain-containing protein, SLAP-domain-containing protein and hypothetical protein LHEJCM1006_11110, whereas for B. subtilis, four (4) types of proteins were uniquely produced (p ≤ 0.05), including helicase-exonuclease AddAB subunit AddB, 5-methyltetrahydropteroyltriglutamate-homocysteine S-methyltransferase, a cluster of ABC-F family ATP-binding-cassette-domain-containing proteins and a cluster of excinuclease ABC (subunit B). At pH 8, Bacillus subtilis produced 56 unique proteins. Many of the detected proteins were involved in metabolic processes, whereas the others had unknown functions. The unique and new proteins with known and unknown functions suggest potential the acclimatization of the microbes to pH stress.
... and Lactobacillus spp. [1]. ...
Lactic acid bacteria (LAB) are ubiquitous, Gram-positive, fermentative bacteria, which are regarded as safe for both humans and the environment. The present study aimed to evaluate the biocontrol efficiency of LAB isolated from different natural ecosystems against fungal pathogens. A total of 30 LAB was isolated from rhizosphere soil and phyllosphere sample of Solanaceous crop viz., Brinjal, Capsicum, Chilli, Tomato, whey, and sauerkraut out of them 14, 9, 4 and 3 lactic acid bacteria (LAB) were isolated from rhizosphere soil & phyllosphere sample of Solanaceous crops, whey and Sauerkraut respectively. The biocontrol ability of LAB isolates were tested against fungal plant pathogens such as Fusarium oxysporum, Pythium aphanidermatum, Sclerotium rolfsi, Rhizoctonia solani, Alternaria sp. agar well diffusion assay and mycelial growth inhibition in liquid culture. The results indicated that the isolates LAB 4, LAB 10, LAB 22, LAB 24 and LAB 29 were prominent in inhibiting the growth of most of the pathogens. Molecular characterization of selected LAB isolates revealed that LAB 4, LAB 10, LAB 22, LAB 24 belongs to Lactobacillus plantarum and LAB 29 belong to Leuconostoc mesentroides.
Objective. Investigate the possibility of enriching mineral fertilizers (Azofoska: NPK 16:16:16) with agronomically useful microorganisms by applying their suspensions to solid fertilizer granules. Methods. Microbiological (cultivation of microorganisms on different media, obtaining suspensions, determination of titre in suspensions, microscopy), field small-plot experiment in six repetitions (growing potatoes on sod-podzolic soil), full accounting of the harvest from each plot, statistical. Results. Enrichment of Azofoska with microorganisms by applying aqueous suspensions of Trichoderma harzianum PD3 and representatives of the genus Bacillus to fertilizer granules before their application to sod-podzolic soil at the rate of N80P80K80 had different effects on the yield of Bellaroza potatoes. T. harzianum PD3- and Bacillus sp. 102-enriched fertilizers contributed to a reliable increase in crop yield in a three-year experiment. The combination of these microorganisms to enrich Azofoska did not provide a stable effect over the years of research. The use of B. vallismortis 44- and B. cereus SB1-enriched fertilizers was not effective. The greatest increase in potato yield was ensured by the use of Bacillus sp. 102-enriched fertilizers. At the same time, minor deviations from the average parameter were reported for all six repetitions in the experiments (in contrast to other variants). Conclusion. The fundamental possibility of increasing the efficiency of mineral fertilizers by enriching them with agronomically useful microorganisms when growing potatoes on sod-podzolic soil has been shown. The efficiency of biologically modified Azofoska depended on the microorganism used for enrichment. Additional research both on the screening of microorganism strains promising for this purpose, as well as technological aspects (the number of cells of microorganisms on fertilizer granules, the use of adhesives, carbon sources and adjuvants during fertilizer enrichment, the terms of preservation of microorganisms on granules depending on the conditions of enrichment, extension of the spectrum of fertilizer types and types of agricultural crops, etc.) is necessary.
Surface composting is an interesting method to end a cover crop without the use of glyphosate and ploughing. The purpose of the project was to investigate whether adding the herbal ferment Terra Biosa improves the effect of surface composting on soil fertility by stimulating faster and more controlled conversion of the organic material. We have investigated the effect on soil biology, the amount of mineral nitrogen in the soil and the plants' nutrient uptake and plant growth.
The field trial will be carried out on the farm Ormo in Skjeberg in Sarpsborg municipality, hosted by Dag Molteberg. Conventional grain production with synthetic fertilizers has been carried out on the farm since the 1970s. Since 2020, the farm operation is run according to regenerative principles, i.e. all chemical-synthetic spraying is omitted, the use of synthetic fertilizers reduced, cover crops are used to avoid bare land and tillage is more gentle (surface composting with application of fermented herbs and microorganisms Terra Biosa).
In the spring of 2021, spring wheat was sown with a cover crop mixture that grew throughout the autumn of 2021. The cover crop was relatively dense when it was surface composted on 1st of May 2022. The cover crop was shallowly mixed into the soil with a rotary tiller and the plant roots were cut off at a depth of about 3 cm. At the same time as rotary tilling, Terra Biosa (10 litres/day mixed with 30 litres/day of water) was sprayed on plots with Terra Biosa treatment. On 6th of May, the field was harrowed and seedbeds prepared. Six-row barley and a new cover crops were sown on 8th of May. The experimental field was not weeded. The experimental field was laid out as a block experiment with four replicates. Each route was 8.5 m wide and 25 m long.
We expected that the addition of Terra Biosa would stimulate the content and activity of the soil microbiology and their metabolic processes. In our investigations, we cannot confirm that we have had a more controlled transformation of the plant material, but we found a significant effect of Terra Biosa on an increased content of fungi in the soil registered with microBIOMETER. At the first soil sampling on 5th of May, four days after surface composting with the addition of Terra Biosa, there was no significant effect on microbial carbon (fungi and bacteria), but the content of fungi increased throughout the season and after harvesting in September, significantly more fungi were measured with microBIOMETER. We found no significant effect of Terra Biosa on the concentration of nitrate and ammonium in the soil, soil respiration (Solvita CO2-C), microbial active carbon (POX- C), soil odor, microscopy according to the SoilFoodWeb methodology soil attachment ("root fur") on the barley roots. All these surveys were only done early in the season. Nutrient uptake was examined using leaf sap analyzes of the barley plants on 1st of June (2-3-leaf stage) and 15th of June (beginning stretch), but here too there was no difference between the treatments. We also found no effect of Terra Biosa on barley yield.
Significant effect of Terra Biosa found late in the season suggests that beneficial processes may continue for a long time after application. Simultaneously, the 2022 season started dry and cool and may have reduced and delayed the effect of Terra Biosa. These facts may indicate that there are a greater effects of Terra Biosa than we could demonstrate in this survey. Therefore, more research is desirable to understand how Norwegian arable soil responds to the treatment of Terra Biosa during surface composting of cover crops and other organic material. More research is also needed on surface composting itself to find the best methods for different soil types and climates. Future investigations should therefore take place on several soil types, over a longer period of the growing season and perhaps over several seasons.
Plant growth-promoting microorganisms (PGPM) and endophytes are naturally plant-inhabiting microbial species that contribute as a resource for innumerable metabolites, agriculturally important promoters, and stress-adaptive molecules in their host plants and confer benefits to their hosts with respect to growth enhancement, a surge of metabolic competences, and conferring stress resistance. However, the interaction between the symbionts is a complex phenomenon. It is imperative to explore the host–microbial crosstalk at the root–surface and internal plant tissues to identify the cellular and molecular aspects of the alliance. This chapter focuses on the critical evaluation of the colonization and multifaceted interactions of PGPM and endophytes in the host, their impacts on the health management of plants, crop productivity, multistress tolerance, and production of agriculturally and biotechnologically important metabolites. Given that the literature is replete with various information regarding the beneficial roles of PGPMs and endophytes in plant health, the possibilities of commercialization of PGPMs in sustainable agriculture are critically apprised in this synthesis.KeywordsEndophytesPlant growth-promoting microorganismsPlant–microbe interactionPlant protectionSoil health management
Background:
Orange peels can serve as a cost-effective raw material for the production of lactic acid. Indeed, given their high concentration of carbohydrates and low content of lignin, they represent an important source of fermentable sugars, recoverable after a hydrolytic step.
Results:
In the present paper, the fermented solid, obtained after 5 days of Aspergillus awamori growth, was used as the only source of enzymes, mainly composed of xylanase (40.6 IU g-1 of dried washed orange peels) and exo-polygalacturonase (16.3 IU g-1 of dried washed orange peels) activities. After the hydrolysis, the highest concentration of reducing sugars (24.4 g L-1 ) was achieved with 20 % fermented and 80 % non-fermented orange peels. The hydrolysate was fermented with three lactic acid bacteria strains (L. casei 2246, 2240 and L. rhamnosus 1019) which demonstrated good growth ability. The yeast extract supplementation increased the lactic acid production rate and yield. Overall, L. casei 2246 produced the highest concentration of lactic acid in mono-culture.
Conclusion:
To the best of our knowledge this is the first study exploiting orange peels as low-cost raw material for the production of lactic acid avoiding the employment of commercial enzymes. The enzymes necessary for the hydrolyses were directly produced during Aspergillus awamori fermentation and the reducing sugars obtained were fermented for lactic acid production. Despite this preliminary work carried out to study the feasibility of this approach, the concentrations of reducing sugars and lactic acid produced were encouraging, leaving open the possibility of other studies for the optimization of the strategy proposed here. This article is protected by copyright. All rights reserved.
Assessment of lactic acid bacteria (LAB) activity plays a key role in the fermented food industry. Fluorescence imaging method based on dye is facile to detect LAB viability. However, it is difficult to obtain stable fluorescence, non-toxic and low-cost dyes. In this study, we prepare P- and N-doped carbon dots (PN-CDs) via microwave-assisted hydrothermal synthesis. The properties of high quantum yield (60.36%) and excitation dependence allowed for multicolor imaging of LAB (Lactobacillus plantarum [L.p] and Streptococcus thermophilus [S.t]). The abundant functional groups and positive charges (+2.34 mV) on the surface of PN-CDs facilitated their quickly integrated into cell wall of live LAB with obvious fluorescence or into dead cells. As a result, PN-CDs can not only be used to rapidly and efficiently monitor bacterial viability (one minute), but can also be used to visualize LAB division using fluorescence imaging. Importantly, the PN-CDs have potential to rapidly detect LAB activity in LAB-fermented juices.
This study describes the effects of lactic acid bacteria (LAB) on photosynthetic performance and antioxidant metabolism in Solanum lycopersicum L. (tomato) plants. Two strains of previously isolated and characterized LAB, Enterococcus sp. BB3 and Lactobacillus sp. BB6, were used alone or in combination as inoculants of tomato plants under controlled conditions in a 30-day assay. At the end of the assay, the physiological parameters of the plants were studied, including chlorophyll fluorescence, net photosynthesis, lipid peroxidation, antioxidant activity, and the content of photosynthetic pigments, total phenols, and flavonoids. The results show that, both individually and combined, these strains improve all physiological parameters in S. lycopersicum plants, where BB3 and BB6 alone increase photochemical features such as Fv′/Fm′, ФPSII, and ETR. Pn, gs, and E were higher in all three treatments with LAB. Meanwhile, oxidative damage, measured as lipid peroxidation, significantly decreased (P<0.05) in all bacterial treatments, especially in the combined assay (BB3+BB6) in comparison with the control assays. Finally, a significant increase (P<0.05) in antioxidant activity was observed but not in total phenol and flavonoid content in tomato plants treated with bacteria. Conclusion. Our data suggest positive effects on physiological features in S. lycopersicum L. mainly related to the BB3 and BB6 strains of LAB and a reduction of oxidative damage and antioxidant metabolism, generally associated with combined treatments.
Introduction
The use of novel soil amendments and the exploitation of plant growth-promoting microorganisms are considered promising tools for developing a more sustainable agriculture in times when ensuring high-yield productions with limited resources is essential.
Methods
In this study, the potential of brewers' spent grain (BSG), the major by-product of the brewing industry, as organic soil amendment, was investigated. Bioprocessed BSG, obtained by an enzymatic treatment coupled with fermentation, together with native BSG, were used as amendments in a pot-trial. An integrated analytical approach aimed at assessing the modification of the physicochemical properties of a typical Mediterranean alkaline agricultural soil, and the plant growth-promoting effect on escarole ( Cichorium endivia var. Cuartana ), was carried out.
Results
The use of biomasses led to soil organic content and total nitrogen content up to 72 and 42% higher, compared to the unamended soils. Moreover, the lower pH and the higher organic acids content doubled phosphorus availability. Although the number of leaves per plant in escaroles from pots amended with native and bioprocessed BSG did not show any difference compared to plants cultivated on unamended pots, the average fresh weight per escarole head, was higher in pots amended with bioprocessed BSG.
Discussion
Hence, the results collected so far encourage BSG application for agricultural purpose, while solving the problem of disposing of such abundant side stream.
Lactic acid bacteria (LAB), isolated from milk and yoghurt, were tested for their efficacy against some phytopathogenic fungi under in vitro and in vivo tests. Fusarium oxysporum, one of most important pathogenic fungi invade tomato plants, was chosen to evaluate the effectiveness of LAB as a biocontrol agent under in vivo tests. Culture broth of LAB was applied as seed treatment or soil drench. The protective effect of LAB significantly increased after challenging inoculation by F. oxysporem, especially when LAB were applied as seed treatment; the number of roots increased by 216, 311, and 358% over control with LB-1, LB-4, and LB-5, respectively, whereas the increment was 169, 163, and 181% for soil drench. Interestingly, when LAB were applied as seed treatment, in soil infested with F.oxysporum, the total fresh weight of tomato plants increased by 348, 260, and 390% with LB-1, LB-3, LB-5, respectively, whereas the increment was 268, 427, and 393% with LB-1, LB-4, and LB-5, respectively, for soil drench. Overall, while previous reports of antifungal activity by LAB under in vitro tests are scarce, we have demonstrated for the first time the capability of LAB to act as plant growth promoting bacteria and biocontrol agent against some phytopathogenic fungi under in vivo tests.
The aim of the research was to investigate the effect of mixture of Lacto-
bacillus plantarum ONU87 and autolysate of Erwinia carotovora ZM1 cells
containing macromolecular bacteriocins and bacteriophages on the patho-
genesis of the crown gall. Materials and Methods. As an infectious agent,
a strain of Rhizobium radiobacter C58 characterized by its high virulence
was chosen. As test-models, carrot roots (Daucuscarota subsp. sativus L.)
and plants Kalanchoe daigremontiana Mill were used. Results. The effect
of mixture of L. plantarum ONU87 and autolysate of E. carotovora ZM1
on survival of R. radiobacter C58 in vitro has been studied. Amount of vi-
able cells of plant pathogenic bacteria decreased after 4 hours of culturing.
Treatment with a mixture of lactobacilli and autolysate of erwinias results
in complete inhibition of crown gall pathogenesis on Kalanchoe plants.
Treatment of carrot roots with an experimental mixture results in decrease of
the amount of infected explants in 14.3%.The mentioned results enabled us
to conclude that depending on the sensitivity of the test-objects, treatment
with the mixture of L. plantarum ONU87 and autolysate of E. carotovora
ZM1 results in complete inhibition of crown gall pathogenesis or decrease
of its symptoms.
The aim of investigation was to detect the presence of genes responsible for bacteriocin synthesis in strains of Lactobacillus plantarum with the clear antagonistic effect against the gram-negative phytopathogens. Methods. To reveal eleven genes involved in plantaricin synthesis the polymerase chain reaction was used. To test the ability to synthesize bacteriocins as antagonistic compounds the experiments with the lawns of test-strains Listeria ivanovii INRA, Rhizobium radiobacter C58, Ralstonia solanacearum B-1109-UCM, Erwinia carotovora ZM1, Rhizobium vitis OНУ 389, R. vitis OНУ 388, R. vitis 379 and R. rhizogenes 15834 were used. Results. In genomes of the tested L. plantarum strains the genes plnD, plnEF, plnG, plnI, plnN were present, but the genes plnA, plnB, plnC, plnW were not revealed. Applying the cultural liquids of lactobacilli on the lawns of the test-strains has shown that the cell-free cultural liquid with the initially low pH (4.1–4.3) caused the zones of growth inhibition on the lawns of all test-strains. The neutralized cell-free cultural liquid did not affect the growth of the test-strains. Conclusion. Although the tested strains L. plantarum ОNU 87, L. plantarum ОNU 206 and L. plantarum ОNU 991 possessed some genes of plantaricin regulon, in the investigations in vitro they caused the inhibition of the phytopathogens and listerias due to the low pH of the cell-free cultural liquids but not due to the synthesis of bacteriocins. The combination of the genes of plantaricin regulon of L. plantarum ONU 206 and L. plantarum ONU 991 resembled that in L. plantarum J23 described in literature.
Organic-biological agriculture still draws on the theories on soil fertility published by the German scientist Hans Peter Rusch in the 1950s and 1960s, namely the Rusch-Test determining the biological quality of organic matter and soils, the decomposition of organic material in soils to humus and the surface-composting. Rusch's teachings address the advancing of soil tilth by efficient application of organic matter and humus formation and an improved nutrient use. Rusch strictly rejected the upcoming mineral fertilization and emphasized the role of humus for soil quality, which is even today beyond debate. Rusch's methods to characterize degradability of organic materials in soil and his microbial parameters are of little importance in practical agriculture and they have not been scientifically proven. However, his systematic approach to the decomposition of organic materials in soil, to humus formation and his consequences for the management of farmyard manure and other sources of organic matter can not be refuted with today's knowledge, but still need to be validated.
Introduction. In the context of sustainable agricultural production, agroecology aims at optimizing the economic and environmental performances of beneficial ecosystem services in order to (i) increase the productivity and resilience of cultivated ecosystems and (ii) preserve their natural resources. The maintenance of such performances is supported by research via the development of new tools that enhance plant tolerance to numerous biotic and abiotic stresses. Literature. Biostimulants can be used as a tool to complement the use of chemical inputs, by involving non-living-based products, or living-based products containing beneficial rhizosphere microbiome, such as plant growth-promoting rhizobacteria (PGPR). Pest management research has also made major advances in the development of efficient biocontrol methods. Elicitors and semiochemicals are considered to be some of the most promising tools for inducing plant resistance to various diseases and enhancing natural predation, respectively. Several products are already on the market. This review discusses current methods for exploiting and applying biostimulant and biocontrol products in contemporary agricultural systems. Future applications of these tools for sustainable management of cultivated ecosystems are also discussed. Conclusions. These tools are still difficult to use because of their lack of reliability in the field and their uneasy integration in the cropping systems. Further studies are needed to better understand the parameters influencing the efficiency of PGPR, elicitors and semiochemicals. Special attention needs to be given to the formulation and the interactions of these products with plant physiology and the environment. © 2016, FAC UNIV SCIENCES AGRONOMIQUES GEMBLOUX. All rights reserved.
Plants possess a broad array of defenses that could be actively expressed in response of pathogenic organisms or parasites but also following beneficial saprophytic microorganisms recognition. Specifically, there are compounds derived from these organisms and called elicitors that are perceived by the plant to induce a locally or systemically expressed resistance. The understanding of the physiological and biological basis of these induced immunity mechanisms have greatly advanced over the past years but a deeper investigation of the mechanisms underlying the perception of elicitors is essential to develop novel strategies for pest control. The application of chemical and biological stimulators of plant immune defenses in conventional agriculture is expected to increase within the next years. Because of their organic origin and as they provide means for conferring plant protection in a non-transgenic manner, elicitors of plant immunity have a huge potential as biocontrol products. Through this review, we want to illustrate the diversity of compounds identified as stimulators of the plant immune system and describe the mechanisms by which they could be recognized at the plasma membrane level.
Background:
Fusarium head blight (FHB) is a severe disease caused by different Fusarium species, which affects a wide range of cereal crops, including wheat. It determines from 10 to 30 % of yield loss in Europe. Chemical fungicides are mainly used to reduce the incidence of FHB, but low environmental impact solutions are looked forward. Applications of soil/rhizobacteria as biocontrol agents against FHB in wheat are described in literature, whereas the potential use of lactobacilli in agriculture has scarcely been explored.
Results:
The aim of this work was to study the inhibitory effect of two bacterial strains, Lactobacillus plantarum SLG17 and Bacillus amyloliquefaciens FLN13, against Fusarium spp. in vitro and to assess their efficacy in field, coupled to the study of the microbial community profile of wheat seeds. Antimicrobial assays were performed on agar plates and showed that the two antagonistic strains possessed antimicrobial activity against Fusarium spp. In the field study, a mixture of the two strains was applied to durum wheat i) weekly from heading until anthesis and ii) at flowering, compared to untreated and fungicide treated plots. The FHB index, combining both disease incidence and disease severity, was used to evaluate the extent of the disease on wheat. A mixture of the two microorganisms, when applied in field from heading until anthesis, was capable of reducing the FHB index. Microbial community profile of seeds was studied via PCR-DGGE, showing the presence of L. plantarum SLG17 in wheat seeds and thus underlining an endophytic behavior of the strain.
Conclusions:
L. plantarum SLG17 and B. amyloliquefaciens FLN13, applied as biocontrol agents starting from the heading period until anthesis of wheat plants, are promising agents for the reduction of FHB index.
The organisms of the phytomicrobiome use signal compounds to regulate aspects of each other's behavior. Legumes use signals (flavonoids) to regulate rhizobial nod gene expression during establishment of the legume-rhizobia N2-fixation symbiosis. Lipochitooligosaccharides (LCOs) produced by rhizobia act as return signals to the host plant and are recognized by specific lysine motif receptor like kinases, which triggers a signal cascade leading to nodulation of legume roots. LCOs also enhance plant growth, particularly when plants are stressed. Chitooligosaccharides activate plant immune responses, providing enhanced resistance against diseases. Co-inoculation of rhizobia with other plant growth promoting rhizobacteria (PGPR) can improve nodulation and crop growth. PGPR also alleviate plant stress by secreting signal compounds including phytohormones and antibiotics. Thuricin 17, a small bacteriocin produced by a phytomicrobiome member promotes plant growth. Lumichrome synthesized by soil rhizobacteria function as stress-sensing cues. Inter-organismal signaling can be used to manage/engineer the phytomicrobiome to enhance crop productivity, particularly in the face of stress. Stressful conditions are likely to become more frequent and more severe because of climate change.
Inhibition of crown gall on test plants in case of co-inoculation with lactic acid bacteria (LAB) has been investigated. From nine LAB strains tested, eight reduced amount of galled carrot explants by 36.4-87.7% and decreased the intensity of disease manifestation. The antagonistic activity against Agrobacterium tumefaciens, in vitro, was due to the low pH of organic acids produced by LAB. However, in the same pH, different LAB cultures displayed various levels of inhibition in vivo. Lactobacillus plantarum ONU 12 with the best results in tumor inhibition on carrots, showed high antagonistic activity on surfaces of kalanchoe and grapevines. Depending on the method of inoculation, the culture of L. plantarum ONU 12 could protect from 72.7% to 100% of wounded kalanchoe tissues. Evaluation of number of surviving cuttings and amount of buds that grew indicated that co-inoculation with agrobacteria and LAB removed completely the negative influence of phytopathogen on grapevines and reduced the number of infected cuttings by approximately 80%. One-hour treatment with L. plantarum ONU 12 helped to decrease the number of infected plants by approximately 68%. The studied strain L. plantarum ONU 12 can be proposed for further evaluation of possibility of practical use in plant protection.
Higher plants have evolved intimate, complex, subtle, and relatively constant relationships with a suite of microbes, the phytomicrobiome. Over the last few decades we have learned that plants and microbes can use molecular signals to communicate. This is well-established for the legume-rhizobia nitrogen-fixing symbiosis, and reasonably elucidated for mycorrhizal associations. Bacteria within the phytomircobiome communicate among themselves through quorum sensing and other mechanisms. Plants also detect materials produced by potential pathogens and activate pathogen-response systems. This intercommunication dictates aspects of plant development, architecture, and productivity. Understanding this signaling via biochemical, genomics, proteomics, and metabolomic studies has added valuable knowledge regarding development of effective, low-cost, eco-friendly crop inputs that reduce fossil fuel intense inputs. This knowledge underpins phytomicrobiome engineering: manipulating the beneficial consortia that manufacture signals/products that improve the ability of the plant-phytomicrobiome community to deal with various soil and climatic conditions, leading to enhanced overall crop plant productivity.
This study aimed at assessing the dynamics of lactic acid bacteria and other Firmicutes associated with durum wheat organs and processed products. 16S rRNA gene-based high-throughput sequencing approaches and culture-independent analyses showed that Lactobacillus, Streptococcus, Enterococcus and Lactococcus were the main epiphytic and endophytic genera among lactic acid bacteria. Bacillus, Exiguobacterium, Paenibacillus and Staphylococcus completed the picture of the core genera microbiome. The relative abundance of each lactic acid bacteria genus was affected by cultivars, phenological stages, other Firmicutes genera, environmental temperature and water activity (aw) of plant organs. Lactobacilli, showing the highest sensitivity to aw, markedly decreased during milk development (Odisseo) and physiological maturity (Saragolla). At these stages, Lactobacillus was mainly replaced by Streptococcus, Lactococcus and Enterococcus. However, a key sourdough species such as Lactobacillus plantarum was associated to plant organs during the life cycle of Odisseo and Saragolla wheat. The composition of the sourdough microbiota and the overall quality of leavened baked goods is also determined throughout the phenological stages of wheat cultivation, with variations depending on environmental and agronomic factors. Based on the adaptability of lactic acid bacteria on wheat plant, future research has to assess the potential of these bacteria for biocontrol and plant growth promotion.
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Climate change is forecasted to induce more drought stress events. Water scarcity is already the most limiting abiotic stress for crop production. With higher food demand, there is a need for sustainable solutions to cope with the loss of productivity due to water stress. It is known that plant growth-promoting rhizobacteria (PGPR) can colonize plant roots and increase plant growth. However, there is actually no sustainable method to decrease the impact of water stress. Therefore, we hypothesized that an application of thuricin-17, a molecule produced by the PGPR Bacillus thuringiensis, could enhance soybean tolerance to water stress. We grew soybean plants for 1 month in growth chambers in order to evaluate their response to thuricin-17 root application under drought, in association with the inoculation of N2-fixing Bradyrhizobium japonicum. We measured traits reflecting root architecture: number of tips, root diameter, root length, number of nodules; water fluxes: water potential, stomatal conductance; carbon nutrition: leaf area, photosynthetic rate, biomass and carbon partitioning; nitrogen nutrition: nitrogen partitioning and hormone signalling: abscisic acid concentration during the vegetative growth period. Our results show that thuricin-17 application under water stress increased plant biomass by 17 %, thus masking drought impact. This effect is due to modifications of below-ground structures, with 37 % increase of root and 55 % increase of nodule biomass, and to slight increases of leaf area and photosynthetic rate. We also observed that application of thuricin-17 induced a 30 % increase of root abscisic acid, an increase of root length and of leaf water potential. Finally, thuricin-17 induced an activation of nodule formation by 40 %, a partial restoration of nodule-specific activity, nodule growth and consequently, an increase by 17 % of the total nitrogen amount in the plant. Overall, our findings reveal a new method to decrease the negative impact of water stress. Results also demonstrate that the plant restored an adequate water and N balance by changing its root structure.
Numerous studies have demonstrated that water-based compost preparations, referred to as
compost tea and compost-water extract, can suppress phytopathogens and plant diseases. Despite
its potential, compost tea has generally been considered as inadequate for use as a biocontrol
agent in conventional cropping systems but important to organic producers who have limited
disease control options. The major impediments to the use of compost tea have been the less-
than-desirable and inconsistent levels of plant disease suppression as influenced by compost tea
production and application factors including compost source and maturity, brewing time and
aeration, dilution and application rate and application frequency. Although the mechanisms
involved in disease suppression are not fully understood, sterilization of compost tea has generally
resulted in a loss in disease suppressiveness. This indicates that the mechanisms of suppression are
often, or predominantly, biological, although physico-chemical factors have also been implicated.
Increasing the use of molecular approaches, such as metagenomics, metaproteomics, metatran-
scriptomics and metaproteogenomics should prove useful in better understanding the relation-
ships between microbial abundance, diversity, functions and disease suppressive efficacy of
compost tea. Such investigations are crucial in developing protocols for optimizing the compost
tea production process so as to maximize disease suppressive effect without exposing the man-
ufacturer or user to the risk of human pathogens. To this end, it is recommended that compost tea
be used as part of an integrated disease management system.
We investigated the effects of inoculation of Rhodobacter sphaeroides, Lactobacillus plantarum, and Saccharomyces cerevisiae on cucumber plant growth promotion and on the contents of plant hormones, amino acids, and mineral nutrients. We showed that treatment with all three bio-inoculants significantly increased the shoot length, root length, shoot fresh weight, shoot dry weight, and chlorophyll content, via secretion of indole acetic acid and/or organic acids. Inoculation with R. sphaeroides had more favorable effect on plant growth than did inoculation with L. plantarum or S. cerevisiae, by significantly enhancing the gibberellin and reducing the abscisic acid contents. The results of amino acid analysis revealed that inoculation with R. sphaeroides, L. plantarum, and S. cerevisiae generally increased the contents of 17 amino acids, namely, aspartic acid, threonine, serine, glutamic acid, glycine, alanine, cysteine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, lysine, histidine, arginine, and proline. With the exception of cysteine, all these amino acids were present in higher concentrations in plants inoculated with R. sphaeroides than in control plants or in plants inoculated with L. plantarum and S. cerevisiae. Furthermore, inoculation with R. sphaeroides significantly increased the calcium, potassium, magnesium, and phosphate contents. Our results suggest that the use of R. sphaeroides, L. plantarum, and S. cerevisiae in agricultural fields can improve plant growth. Moreover, inoculation of cucumber plants with R. sphaeroides regulates plant functional metabolites, thereby promoting plant growth.
After the inoculation of wheat roots with a suspension of the bacterium Lactobacillus plantarum, reduction or decrease of oxidative stress detected by the accumulation of H2O2 and MDA was found in leaves. Activation of catalase and increased integral antioxidant capacity in seedlings treated with NO-producing lactobacilli were detected during the determination of the contribution of bacterial NO to the plant stress reaction. Thus, for the first time, we have demonstrated that lactobacilli affect plant adaptive responses to stress by the involvement of nitric oxide.
In our previous studies, we observed the biological control effect of lactic acid bacteria strains (LABs) KLF01, KLC02 and KPD03 against different plant pathogenic bacteria in vitro against Ralstonia solanacearum, and strains KLF01 and KLC02 against Pectobacterium carotovorum under greenhouse and field experiments, respectively. In this study, we observed the efficacy of these bacteria against bacterial spot pathogen (Xanthomonas campestris pv. vesicatoria) and their plant growth-promoting activities in pepper (Capsicum annuum L. var. annuum), under greenhouse and field conditions. LABs significantly (P P Keywords: Xanthomonas campestris pv. vesicatoria; bacterial spot; lactic acid bacteria; plant growth promotion Document Type: Research Article DOI: http://dx.doi.org/10.1080/09583157.2014.894495 Affiliations: Department of Applied Biology, College of Agriculture and Life Science, Kangwon National University, Chuncheon, Republic of Korea Publication date: July 3, 2014 More about this publication? Editorial Board Information for Authors Subscribe to this Title ingentaconnect is not responsible for the content or availability of external websites $(document).ready(function() { var shortdescription = $(".originaldescription").text().replace(/\\&/g, '&').replace(/\\, '<').replace(/\\>/g, '>').replace(/\\t/g, ' ').replace(/\\n/g, ''); if (shortdescription.length > 350){ shortdescription = "" + shortdescription.substring(0,250) + "... more"; } $(".descriptionitem").prepend(shortdescription); $(".shortdescription a").click(function() { $(".shortdescription").hide(); $(".originaldescription").slideDown(); return false; }); }); Related content In this: publication By this: publisher In this Subject: Plant Culture , Zoology , Entomology By this author: Shrestha ; Kim ; Park GA_googleFillSlot("Horizontal_banner_bottom");
An increasing body of experimental evidence indicates that plant disease can be suppressed by treating plant surfaces with a variety of water-based compost preparations, referred to in the literature as watery fermented compost extracts or compost teas. The terms nonaerated compost teas (NCT) and aerated compost teas (ACT) are used in this review to refer to the common production methods that diverge in the intent to actively aerate. Very little data directly compares the efficacy of NCT and ACT for plant disease suppression. A variety of foliar plant pathogens and/or diseases have been suppressed by applications of NCT while few controlled studies have examined ACT. For some diseases the level of control would be considered inadequate for conventional agriculture; organic producers with limited control options consider partial disease control to be an important improvement. For both compost tea production methods, decisions that influence pathogen suppression include choice of compost feedstocks, compost age, water ratio, fermentation time, added nutrients, temperature and pH. Application technology choices include the dilution ratio, application equipment, timing, rates, spray adjuncts and adding specific microbial antagonists. Increased understanding of compost tea microbiology and the survival and interactions of microbes on plants surfaces should make it possible to modify compost tea production practices and application technology to optimize delivery of a microflora with multiple modes of pathogen suppression. Innovative growers and practitioners are leading the development of new compost tea production methods and uses, generating many potential research opportunities. The use of compost tea as part of an integrated plant health management strategy will require much additional whole systems research by a cohesive team of farmers and experts in composting, plant pathology, phyllosphere biology, molecular microbial ecology, fermentation science, plant physiology, plant breeding, soil science, and horticulture.
Bacteriocins from lactic acid bacteria (LAB) are a diverse group of antimicrobial proteins/peptides, offering potential as biopreservatives, and exhibit a broad spectrum of antimicrobial activity at low concentrations along with thermal as well as pH stability in foods. High bacteriocin production usually occurs in complex media. However, such media are expensive for an economical production process. For effective use of bacteriocins as food biopreservatives, there is a need to have heat-stable wide spectrum bacteriocins produced with high-specific activity in food-grade medium. The main hurdles concerning the application of bacteriocins as food biopreservatives is their low yield in food-grade medium and time-consuming, expensive purification processes, which are suitable at laboratory scale but not at industrial scale. So, the present review focuses on the bacteriocins production using complex and food-grade media, which mainly emphasizes on the bacteriocin producer strains, media used, different production systems used and effect of different fermentation conditions on the bacteriocin production. In addition, this review emphasizes the purification processes designed for efficient recovery of bacteriocins at small and large scale.
Indole acetic acid (IAA) production is a major property of rhizosphere bacteria that
stimulate and facilitate plant growth. The present work deals with isolation, characterization
and identification of indole acetic acid producing bacteria from the rhizospheric soil. Out of
ten Indole acetic acid producing isolates, five were selected as efficient producers.
Optimization of indole acetic acid production was carried out at different cultural conditions
of pH and temperature with varying media components such as carbon and nitrogen ...
Sweet potatoes (Ipomoea batatas) were investigated as a basic component to develop a medium for the cultivation of lactobacilli. Extract from baked sweet potatoes was used to form a sweet potato medium (SPM) which was supplemented with 0, 4, or 8 g/L of each nitrogen source (beef extract, yeast extract, and proteose peptone #3) to develop SPM1, SPM2, and SPM3, respectively. The growth of Lactobacillus in SPM was compared to lactobacilli MRS. Low inoculums’ levels (2–2.5 log CFU/mL) were used to investigate the suitability of SPM to support the growth of Lactobacillus. Lactobacillus strains were individually inoculated into batches of MRS, SPM1, SPM2, and SPM3 then incubated at 37 °C. The growth of Lactobacillus was monitored using turbidity (OD at 610 nm), bacterial population (log CFU/mL), and pH values. Our results showed no significant differences (p < 0.05) in the maximum specific growth rates (μ
max) of Lactobacillus strains growing in MRS, SPM2, and SPM3. After 24 h on incubation, Lactobacillus strains grown in SPM2, SPM3, and MRS reached averages of 10.59 ± 0.27, 10.72 ± 0.19, and 10.41 ± 0.35 log CFU/mL, respectively. Slower growth rates were observed in SPM1 with 1.57 ± 0.55 log CFU/mL less of bacterial populations than MRS. SPM2 and SPM3 maintained higher pH values throughout the incubation period compared to MRS. Therefore, these findings indicated that SPM2, containing 12 g/L of nitrogen sources, is suitable for the growth of Lactobacillus, and SPM2 could be used as an alternative low-cost medium.
Lactic acid bacteria (LAB) can be a source of biological control agents (BCA) of fire blight disease. Several species of LAB are inhabitants of plants and are currently used as biopreservatives of food because of their antagonistic properties against bacteria, and are considered as generally safe. Candidates to BCA were selected from a large collection of LAB strains obtained from plant environments. Strains were first chosen based on the consistency of the suppressive effect against E. amylovora infections in detached plant organs (flowers, fruits and leaves). Lactobacillus plantarum strains PC40, PM411, TC54 and TC92 were effective against E. amylovora in most of the experiments performed. Besides, strains PM411, TC54 and TC92 had strong antagonistic activity against E. amylovora and also other target bacteria, and presented genes involved in plantaricin biosynthesis (plnJ, plnK, plnL, plnR and plnEF). The strains efficiently colonized pear and apple flowers; they maintained stable populations for at least 1 week under high RH conditions, and survived at low RH conditions. They were effective in preventing fire blight on pear flowers, fruits and leaves, as well as in whole plants and in a semi-field blossom assay. The present study confirms the potential of certain strains of L. plantarum to be used as active ingredient of microbial biopesticides for fire blight control that could be eventually extended to other plant bacterial diseases.
A total of 119 lactic acid bacteria (LAB) were isolated, by culture-dependant method, from rhizosphere samples of olive trees and desert truffles and evaluated for different biotechnological properties. Using the variability of the intergenic spacer 16S-23S and 16S rRNA gene sequences, the isolates were identified as the genera Lactococcus, Pediococcus, Lactobacillus, Weissella, and Enterococcus. All the strains showed proteolytic activity with variable rates 42% were EPS producers, while only 10% showed the ability to grow in 9% NaCl. In addition, a low rate of antibiotic resistance was detected among rhizospheric enterococci. Furthermore, a strong antibacterial activity against plant and/or pathogenic bacteria of Stenotrophomonas maltophilia, Pantoea agglomerans, Pseudomonas savastanoi, the food-borne Staphylococcus aureus, and Listeria monocytogenes was recorded. Antifungal activity evaluation showed that Botrytis cinerea was the most inhibited fungus followed by Penicillium expansum, Verticillium dahliae, and Aspergillus niger. Most of the active strains belonged to the genera Enterococcus and Weissella. This study led to suggest that environmental-derived LAB strains could be selected for technological application to control pathogenic bacteria and to protect food safety from postharvest deleterious microbiota.
Significant stimulation of germination of tomatoes (Lycopersicon
esculentum Mill. cv Odessa plum) with poor initial germination capacity was achieved by soaking their seeds during 6 h in suspensions of nine out of ten Lactobacillus
plantarum strains tested. The increase in percentage of germination ranged from 15.1 to 7.6 %. Lengths of shoots, main and lateral roots and development of root hairs increased after inoculation of seeds with studied L.
plantarum strains. The treatments of seeds with L.
plantarum expanded shoot lengths by 16.4–18.2 %. Stimulation of main root lengths in the tested tomato seedlings varied from 10.5 to 31.4 %, and the stimulation of lateral roots from 28.6 to 32.2 %. Lactobacilli from different strains exert different effects on the seedlings: for instance, inoculation with certain strains resulted in the stimulation of the main root growth and the inoculation with another strain stimulated shoot growth or growth of the lateral roots. It is the first report about plant-stimulating activities of L.
plantarum from different ecological niches (plant surfaces, surfaces of edible mushrooms, dairy products) in the absence of nutritional compounds.
The effectiveness of whey against powdery mildew (Podosphaera xanthii) of cucumber and zucchini squash was tested in greenhouse experiments. Plants were sprayed once or twice a week with whey at concentrations of 0, 5, 10, 15, 20, 25, and 30% in water. Severity of powdery mildew was estimated weekly by visual assessment of individual leaves and scored as percentage of leaf area affected. Effectiveness of treatments did not differ significantly when applied weekly compared to twice a week. In each instance, powdery mildew severity correlated negatively with whey concentration. For cucumber, the rate of the disease progress in the control ranged from 0.45 to 0.75. Disease progressed more slowly in plants treated with 25–30% whey than when lower concentrations were used. The rate of disease progress varied from 0.12 to 0.33 in plants treated once a week and from 0.13 to 0.17 when applied twice a week. Similar tendencies were observed for zucchini,