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Neutralized electrolyzed water efficiently reduces Fusarium spp. in vitro and on wheat kernels but can trigger deoxynivalenol (DON) biosynthesis
Abstract
Fusarium Head Blight (FHB), caused by a blend of Fusarium species, is a destructive fungal disease of wheat and other small grain cereals. FHB has become an important issue in food and feed industry. Moreover, the majority of FHB pathogens have the ability to synthesize a range of mycotoxins. Although several physical and chemical control measures can be taken to control these fungi in the field, research is needed to provide new techniques for control during storage and transport of cereals. Mounting evidence shows that electrolyzed oxidizing water (EOW) has antimicrobial activity and might be a useful alternative for conventional control measures. The objective of the present work, was to investigate the influence of EOW on outgrowth and germination of Fusarium spp. and deoxynivalenol (DON) production. Both an in vitro and in vivo approach were pursued. In a first approach, a screening of the main FHB causing species was conducted. Secondly, the effect of EOW on Fusarium graminearum and the effect on DON biosynthesis was investigated using a trichothecene knockout mutant. These experiments showed an increase in DON levels upon sub lethal amendments of EOW to F. graminearum spores. In addition, the reactive oxygen species H2O2 was shown to govern this induction.Finally, the work was validated on a laboratory scale via an in vivo assay using wheat grains in which the Fusarium outgrowth was measured. The present work demonstrates that EOW has potential to control Fusarium spp. in wheat grains during transport and storage although sub lethal concentrations can result in increased DON biosynthesis.
... when exposed to EW (11e16 ppm free chlorine) for 20 min. Audenaert et al. (2012) also observed significant reductions in Fusarium spp. when conidial suspensions were exposed to EW with free chlorine concentrations of 100 and 200 ppm. ...
... when conidial suspensions were exposed to EW with free chlorine concentrations of 100 and 200 ppm. Audenaert et al. (2012) validated the in vitro result by applying EW (400 ppm free chlorine) to wheat grain, which revealed a reduction of 93.6% in Fusarium spp. A significant reduction in fungal load in comparison to the control was still evident 14 days after the treatment was applied (Audenaert et al., 2012). ...
... Audenaert et al. (2012) validated the in vitro result by applying EW (400 ppm free chlorine) to wheat grain, which revealed a reduction of 93.6% in Fusarium spp. A significant reduction in fungal load in comparison to the control was still evident 14 days after the treatment was applied (Audenaert et al., 2012). ...
The extent and type of microbial growth on barley grain is a key determinant of malt quality for beer production, as problematic microbial products can persist into the brewing process and impact beer quality. Microbial composition on malting barley grain are influenced by field growth, storage and malting conditions. The present study investigated the efficacy of electrolysed water (EW) with free chlorine concentrations of 5, 50, 100 and 500 ppm, as well as peroxyacetic acid (PAA) at 100 and 500 ppm, as pre-steep treatments to control microbes on grains during the malting process. The research determined the reduction in the load of Pseudomonas spp., heterotrophic bacteria, yeasts and filamentous fungi on weathered and on non-weathered grains. Pseudomonas spp., heterotrophic bacteria and yeasts were significantly reduced up to 4 logs when treated with 500 ppm PAA. PAA reduced filamentous fungi but 500 ppm free chlorine EW showed greater reductions. None of the treatments had detrimental effect on grain germination. The variation in antimicrobial efficacy among treatments can be attributed to variations in microbial susceptibility as well as differences in anti-microbial mechanisms specific to each antimicrobial agent.
... Although Fusarium spp. are typical field pathogens and unlikely to develop during storage, previously produced and accumulated mycotoxins remain a serious issue during cereal storage and processing [8]. Hence, in addition to the living organisms, a broad variety of mycotoxins must be countered during post-harvest treatments, as the prevention of their production is not always possible. ...
... A study conducted by Vidal et al. [10] showed that wheat bran obtained from a Spanish market contained substantial amounts of various mycotoxins, mainly deoxynivalenol (DON) and zearalenone (ZEA). The authors concluded that the production of whole grain products from these Aflatoxin B 2 Ochratoxin A Nivalenol typical field pathogens and unlikely to develop during storage, previously produced and accumulated mycotoxins remain a serious issue during cereal storage and processing [8]. Hence, in addition to the living organisms, a broad variety of mycotoxins must be countered during postharvest treatments, as the prevention of their production is not always possible. ...
... A study conducted by Vidal et al. [10] showed that wheat bran obtained from a Spanish market contained substantial amounts of various mycotoxins, mainly deoxynivalenol (DON) and zearalenone (ZEA). The authors concluded that the production of whole grain products from these Foods 2018, 7, x FOR PEER REVIEW 3 of 22 typical field pathogens and unlikely to develop during storage, previously produced and accumulated mycotoxins remain a serious issue during cereal storage and processing [8]. Hence, in addition to the living organisms, a broad variety of mycotoxins must be countered during postharvest treatments, as the prevention of their production is not always possible. ...
As a result of the rapidly growing global population and limited agricultural area, sufficient supply of cereals for food and animal feed has become increasingly challenging. Consequently, it is essential to reduce pre- and post-harvest crop losses. Extensive research, featuring several physical treatments, has been conducted to improve cereal post-harvest preservation, leading to increased food safety and sustainability. Various pests can lead to post-harvest losses and grain quality deterioration. Microbial spoilage due to filamentous fungi and bacteria is one of the main reasons for post-harvest crop losses and mycotoxins can induce additional consumer health hazards. In particular, physical treatments have gained popularity making chemical additives unnecessary. Therefore, this review focuses on recent advances in physical treatments with potential applications for microbial post-harvest decontamination of cereals. The treatments discussed in this article were evaluated for their ability to inhibit spoilage microorganisms and degrade mycotoxins without compromising the grain quality. All treatments evaluated in this review have the potential to inhibit grain spoilage microorganisms. However, each method has some drawbacks, making industrial application difficult. Even under optimal processing conditions, it is unlikely that cereals can be decontaminated of all naturally occurring spoilage organisms with a single treatment. Therefore, future research should aim for the development of a combination of treatments to harness their synergistic properties and avoid grain quality deterioration. For the degradation of mycotoxins the same conclusion can be drawn. In addition, future research must investigate the fate of degraded toxins, to assess the toxicity of their respective degradation products.
... ▪ AEW contains free chlorine which is phytotoxic to plants and damage plant tissues which make its application in farms impossible (Schubert et al., 1995) [26] . ▪ Sub-lethal doses of AEW and NEW can trigger toxin production in mold such as deoxynivalenol (DON) in Fusarium (Audenaert et al., 2012) [27] . ...
... ▪ AEW contains free chlorine which is phytotoxic to plants and damage plant tissues which make its application in farms impossible (Schubert et al., 1995) [26] . ▪ Sub-lethal doses of AEW and NEW can trigger toxin production in mold such as deoxynivalenol (DON) in Fusarium (Audenaert et al., 2012) [27] . ...
... However, studies evaluating this efficacy against fungi are limited to in vitro studies with mycotoxigenic Aspergillus sp., such as one reporting low efficacy of EW (Lemos et al., 2020) and its application in wheat to inhibit Fusarium sp. growth (Audenaert et al., 2012;Lyu et al., 2018). As previously mentioned, it is important to know the sensitivity of the main species involved in the spoilage of different classes of food products to the different sanitizers available in order to adequately choose the best method and agent for fungal control (Bernardi et al., 2019c). ...
... When compared to other species of the genus Paecilomyces, P. fulvus presented the highest heat resistance when submitted to typical heat treatments used in the food industry, presenting D values of 89.6 and 16.7 min at 80 and 85 °C (Hosoya et al., 2012). Audenaert et al. (2012) evaluated whether neutral EW was capable of reducing the fungal growth of species of the genus Fusarium spp. in wheat grains. The authors described that neutral EW effectively reduced Fusarium spp. ...
This study aimed to evaluate the sensitivity of heat-resistant molds isolated from spoiled thermally processed foods to antimicrobial compounds used for food industry sanitation. An ortho-phenylphenol-based smoke generator sanitizer, liquid chemical sanitizers (benzalkonium chloride, biguanide, iodine, peracetic acid, and sodium hypochlorite), and acidic and alkaline electrolyzed water were used against Aspergillus australensis (MB 2579; NFF 02), Aspergillus aureoluteus (NFC1), Paecilomyces fulvus (PFF 01), Paecilomyces niveus (PNT 01; PNDC 01; PNB1 01), and Paecilomyces variotii (PV 01; PV 01; PVCH 03). The fungal strains were exposed separately to liquid sanitizers and electrolyzed water in stainless steel discs for 15 minutes following the European Committee for Standardization (CEN) recommendations. Moreover, the fungal strains were exposed to the smoke generator sanitizer for 7 hours following French protocol NF-T-72281. The best results of fungal inactivation were achieved when the highest concentration specified in the label of these sanitizers was tested. On the opposite, the lowest concentration specified in the label should be avoided since it was ineffective in most cases (94%). The ortho-phenyphenol-based smoke generator sanitizer and peracetic acid (1%) showed the best results of spore inactivation, while iodine and benzalkonium chloride achieved satisfactory results against the strains evaluated. Sodium hypochlorite and biguanide were ineffective against most of the fungi studied at all concentrations tested. Acidic and basic electrolyzed water was also ineffective to achieve the 3-log CFU reduction required in the concentrations tested. In general, Paecilomyces spp. was more sensitive than Aspergillus spp. against all sanitizers evaluated, whereas A. aureoluteus NFC1 was resistant to all agents and concentrations tested. The heat-resistant fungal strains showed varied sensitivity against the different agents. Notably, the two most effective commercial sanitizers against the heat-resistant strains were ineffective against the filamentous fungi recommended for sanitizer testing (A. brasiliensis ATCC 16404), which demonstrates the relevance of testing fungal isolates that cause spoilage to choose the most effective compound and obtain the best results of fungal control.
... 25,26 Despite the fact that F. poae is a predominant species in Belgian wheat, 13,27 the concentrations of BEA were low, which suggests that this molecule is not necessary for F. poae to infect or colonize the wheat ear or that perhaps another species is responsible for BEA production in wheat. 13,28 With regard to ENNs, the highest correlation was observed with F. avenaceum. Fusarium avenaceum is a known potent producer of ENNs and is present in the Belgian FHB population. ...
... Similar results have been described previously and F. poae is known to have a higher resistance level towards azole-type fungicides. 28,35 In this paper, we describe for the first time that fungicide application does not only cause a shift in the population towards an F. poae-dominated population, but also an accumulation of BEA is pointed out. To the best of our knowledge, this is the first study that delves into the impact of fungicides on cyclodepsipeptide concentrations. ...
BACKGROUND
Fusarium head blight (FHB) is a well‐known disease of wheat caused by a complex of Fusarium species. In this research, an extensive study on the occurrence of the emerging Fusarium cyclodepsipeptide mycotoxins beauvericin and enniatins was conducted in Belgian wheat grains harvested in 2015 and 2016. To assess the link between Fusarium species and their mycotoxin production, ultra‐performance liquid chromatography–tandem mass spectrometry was used to quantify the cyclodepsipeptide mycotoxins, while quantitative polymerase chain reaction was applied to quantify the presence of Fusarium species.
RESULTS
It was shown that enniatins were mainly associated with the presence of F. avenaceum, while beauvericin, despite its low incidence, correlated significantly with F. poae. The application of fungicides resulted in a species shift and in the occurring mycotoxins. Concerning the effect of weather conditions, it was seen that levels of enniatins were positively correlated with the rainfall in May and June, while a negative correlation was observed with rainfall in the first half of July.
CONCLUSION
Our study provides new insights into the occurrence of the emerging cyclodepsipeptide mycotoxins in an agro‐ecosystem in which fungicides are the main control measure against FHB. It seems that beauvericin and enniatin levels are affected by different parameters and behave differently upon application of fungicides. © 2018 Society of Chemical Industry
... EW affect Aspergillus flavus (Xiong et al., 2010), Candida albicans (Zeng et al., 2011), Botrytis cinerea and Moniliniafructicola (Guentzel et al., 2010), Fusarium spp. (Audenaert et al., 2012). AEW still decrease aflatoxin B1 concentration in peanuts , SAEW can trigger deoxynivalenol biosynthesis (Audenaert et al., 2012). ...
... (Audenaert et al., 2012). AEW still decrease aflatoxin B1 concentration in peanuts , SAEW can trigger deoxynivalenol biosynthesis (Audenaert et al., 2012). ...
Electrolyzed water (EW) is a new technology that emerged in the last years with potential
application in foods, mainly in microbiological aspects, with variation in application modes,
dipping the food in solution, where variation of time can be changed and be apply in the form
of spray. Because EW characteristics, its action in microorganisms are still been studied for
mechanism elucidation and possible damages, as well its influence in the intrinsic characteristics
of food, like color and oxidation. This unconventional or ‘green’ technology has the purpose
to prove microbiological quality of food and decrease the use of natural resources like water
with minimal generation of chemical/toxic residues. More studies are necessary in relation
to this technology and its possible applications in food industry, as well characteristics and
mechanisms.
... Most studies have defined EW with a pH of 5.0-6.5 as SAEW [1][2][3]15,28,33, . However, it has also been called electrolyzed neutral water [58] , near-neutral electrolyzed oxidizing water [25,59] and NEW [24,48,60,61] . It is important to distinguish SAEW and NEW using an agreed standard. ...
... NEW has also been employed to inactivate a variety of microorganisms, including Alicyclobacillus acidoterrestris spores [78] , B. subtilis [75] , E. coli [26,29,46,[72][73][74][75] , Erwinia carotovora [27] , L. monocytogenes [26,27,29,74] , Monilinia fructicola and Botrytis cinerea [83] , Salmonella spp [27,46,73,74] , S. aureus [26,29] , Pseudomonas aeruginosa [26,29] , V. vulnificus and V. parahemolyticus [72] , Fusarium spp [60] . and avian influenza viruses [84] . ...
Electrolyzed water (EW) can be produced by electrolysis of a dilute salt solution. Slightly acidic electrolyzed water (SAEW, pH 5.0-6.5) and neutral electrolyzed water (NEW, pH 6.5-8.5) are considered healthy and environmentally friendly because no hazardous chemicals are added in its production, there is reduced corrosion of surfaces and it minimizes the potential for damage to animal and human health. Over the last decade, EW has become increasingly popular as an alternative disinfectant for decontamination in animal houses. However, there have been some issues related to EW that are not well known, including different mechanisms for generation of SAEW and NEW, and the antimicrobial mechanism of EW. This review covers the definitions of SAEW and NEW, different generation systems for SAEW and NEW, the antimicrobial mechanism of EW, and recent developments related to the application of SAEW and NEW in animal houses.
... Indirect proof comes from in vitro fungicide assays with a tri5 knockout mutant of F. graminearum. The overall fitness and fecundity of the mutant was comparable to that of the parent strain; but, when homeopathic levels of azole fungicides were applied, only the mutant fungus promptly stopped growing [94]. Apparently, when a strain cannot produce its toxic secondary metabolite DON, it becomes hypersensitive to azole fungicides. ...
... However, at sublethal levels, this decrease in biomass coincided with an increase in DON level. The ROS liberated from the electrolyzed water oxidatively stimulated the Tri gene machinery to produce DON [94]. ...
The mycotoxin deoxynivalenol (DON), produced by several Fusarium spp., acts as a virulence factor and is essential for symptom development after initial wheat infection. Accumulating evidence shows that the production of this secondary metabolite can be triggered by diverse environmental and cellular signals, implying that it might have additional roles during the life cycle of the fungus. Here, we review data that position DON in the saprophytic fitness of Fusarium, in defense and in the primary C and N metabolism of the plant and the fungus. We combine the available information in speculative models on the role of DON throughout the interaction with the host, providing working hypotheses that await experimental validation. We also highlight the possible impact of control measures in the field on DON production and summarize the influence of abiotic factors during processing and storage of food and feed matrices. Altogether, we can conclude that DON is a very important compound for Fusarium to cope with a changing environment and to assure its growth, survival, and production of toxic metabolites in diverse situations.
... Other studies published on electrolyzed water as a postharvest treatment [28][29][30][31][32][33][34] reported its ability to maintain the quality and nutritional values of harvested fruit, which in turn helps to enhance its storability [24]. ...
Alternative means of control are becoming increasingly relevant to the improvement of safety and the reduction of postharvest losses and waste of fruit and vegetables, especially in view of the application of the EU Greed Deal. A previous study from our research group that focused on the electrolysis process of water and was conducted using NaCl and NaHCO3 as electrolytes proved to efficiently reduce pathogen inoculum in packinghouse washing water. In the present study, we examined the effect of the electrolyzed salt solutions (eNaCl and eNaHCO3) produced in the same experimental conditions previously reported to be used as postharvest treatments during handling and commercialization, and/or at the consumer’s site. We tested the electrolyzed solutions, obtained in the presence or absence of the salts, against five relevant fungal pathogens in terms of conidia viability, and on various hosts in terms of rot incidence/severity. Chemical parameters of electrolyzed and non-electrolyzed solutions were also assessed. Although a different susceptibility to treatments was observed among pathogens, electrolyzed sodium chloride (eNaCl) was the most efficient treatment for preventing spore germination, as well as for minimizing fruit rot. However, a consistent control of fungal viability and consequent rot was also achieved using electrolyzed tap water (eW). The eNaHCO3, although less efficient on fungal viability, provided a significant effect against fruit rot. The investigated electrolyzed solutions seem promising for reducing the waste of fresh fruit and vegetables.
... Although there are many studies focused on the antibacterial properties of NEW, studies focusing on its antifungal activity are not many. Some studies reported that NEW shown promising effects on Aspergillus spores isolated from peanut seeds (Xiong et al., 2010), on Botrytis cinerea and Monilia fructicola (Guentzel et al., 2010), and, on Fusarium isolated from cereals (Audenaert et al., 2012). In the same available chlorine concentration level, NEW contains more . ...
In this study, the antimicrobial activity of neutral electrolyzed water (NEW) on Bacillus cereus forming endospore, Escherichia coli and, toxin producer Aspergillus flavus and Penicillium expansum was determined both on the surface of steel plates in the presence of organic matter artificially inoculated and in cell suspensions. Also, the antimicrobial efficiency of NEW was compared to that of Sodium hypochlorite (NaClO). Experiments were carried out at room temperature (22 °C). 1% sodium hypochlorite solution (with 531 ppm free chlorine), and different concentrations of NEW, 5% (with 63 ppm free chlorine), 10% (with 120 ppm free chlorine), and 15% (with 187 ppm free chlorine) were used for the comparison. Cell suspensions and stainless-steel plates inoculated with a final 10% liquid fig solution were treated with NEW and NaClO for 0 (untreated, control), 15, 30, and 60 seconds. Then, viable cell counts both in cell suspensions and on the inoculated stainless-steel plates were determined. It was determined that there were significant differences (P
... Hence, these findings demonstrate that these agents can be used as an important and environmentally sustainable alternative to reduce both fungi and mycotoxin contamination. Similar results were described by Audenaert et al. (2012), where the efficacy of neutral EW was observed on DON producers Fusarium in vitro and in vivo. Concerning in vitro experiments, all EW tested (ACC between 12.5 and 200 mg/L) reduced conidia germination after 48 h of exposure. ...
Controlling food spoilage fungi remains a challenge for food industries, and regulations on the usage of chemical disinfectants are becoming restrictive. Then, this study aimed to evaluate electrolyzed water (EW) as a sustainable alternative for food spoilage fungi inactivation. The experiment was carried out according to the protocol for testing the antifungal effects of chemical sanitizers by the European Committee for Standardization (CEN), using acidic electrolyzed water (AEW-AAC: 85 ppm; pH: 2.65; ORP: 1120 mV) and a basic electrolyzed water (BEW- pH: 11.12; ORP: -209 mV) to inactivate spoilage fungi strains from bread (Hyphopichia burtonii and Penicillium roqueforti) and cheese (P. roqueforti and Penicillium commune), besides the standard fungi for this type of essay (Candida albicans and Aspergillus brasiliensis). AEW presented a higher antifungal effect, inactivating an average of 89% of the exposed population when compared to its respective BEW, which inactivates about 81.5%. In general, the standard strains A. brasiliensis (ATCC 16404) and Candida albicans (ATCC 24433) were more sensitive to both AEW and BEW than the food-spoilage strains. Among those, P. roqueforti strains were the most sensitive, followed by P. commune strains, while H. burtonii strains were the most tolerant. EW can be a sustainable alternative for product surface and facility cleaning with further antifungal action when a sanitization step is not mandatory or needed. Future studies searching for conditions to improve the antifungal action of EW could make their industrial usage more viable.
... A study conducted by Audenaert et al. (2012) demonstrated that EW has potential to control Fusarium spp. in wheat grains during transport and storage although sublethal concentrations can result in increased deoxynivalenol (DON) biosynthesis. According to Zhang et al. (2012), soaking contaminated peanuts in an EW solution, the content of aflatoxin B1 (AFB 1 ) decreased of about 85%. ...
The control of plant diseases is still widely carried out through the use of synthetic chemicals. However, many fungal and bacterial pathogens have developed resistance to the active ingredients of a wide range of pesticides. In addition, the problems associated with their use (i.e., waste disposal) as well as the increasing public awareness regarding residues and environmental risks have promoted the search for new and safer alternatives. Thus, the replacement of chemical pesticides with non-toxic compounds for consumers and for the environment is gaining considerable attention worldwide. Lowering the loss of products can be achieved through the use of an integrated disease management program, which employs a variety of control means and methods with a focus on preventing, reducing, and eradicating predisposing/instigating factors.
In this Special Issue, we invite scientists and researchers to contribute research articles on the utilization of a range of alternative control strategies, such as biological control using antagonistic/beneficial agents; physical strategies using low temperatures, modified and controlled atmospheres, heat, and irradiation; and substances generally regarded as safe, such as sanitizers, plant extracts, and essential oils. Papers that concentrate on the integrated disease management of agricultural products are also accepted.
In this Special Issue, original research articles and reviews are welcome. Research areas may include (but are not limited to) the following:
Integrated strategies to control plant diseases;
Alternatives to reducing/substituting chemical pesticides;
Natural compounds to control plant diseases;
Physical means of managing plant pathogens/diseases;
The role of biocontrol agents in managing plant diseases;
Nanotechnology as a way to control plant diseases.
We look forward to receiving your contributions.
Prof. Dr. Youssef Khamis
Prof. Dr. Antonio Ippolito
Prof. Dr. Khaled A. El-Tarabily
Guest Editors
... Being the main fluid in the body, it serves as a solvent for nutrients, acts as a medium for the safe elimination of toxins and waste products, determines the quality of blood, and affects redox processes [2,8,9]. Water, which has a negative redox potential, is an excellent stimulant, restores the immune system of the body, provides its antioxidant protection, and also improves metabolism [10][11][12][13][14][15]. ...
One of the most significant factors in regulating the parameters of redox reactions occurring in any liquid medium is the electron activity or redox potential (RP) of this medium. Water that has a negative RP is easily absorbed by the body and replenishes the cells with lost negative charges and energy. As a result of the conducted studies, it was found that the hydrochemical parameters in the experimental and control variants were within the standard values for growing tilapia juveniles. It was found that the redox potential of the blood of juvenile tilapia has a negative value of - 96 mV. It is recorded that at a sufficiently low water temperature for thermophilic tilapia (21 °C) and at a negative RP (-212 mV), a high growth rate of fish is observed. It was found that the use of water with a redox potential of -100 mV is the most effective, since the linear weight gain of juveniles increases by 41 % in comparison with the control. Tilapia juveniles grown in structured water have the highest levels of hemoglobin (62-64 g/l) and total serum protein (13.3-14.3 g/l).
... Los resultados obtenidos en el presente trabajo experimental con el producto Neuthox son consistentes con los hallazgos concluyentes de ensayos previos. En ese contexto, ciertos estudios demuestran que el HClO es capaz de reducir en ≥ 99,99 % el número de macroconidios viables de Fusarium solani, en condiciones de laboratorio, a una concentración de 0,01 % a partir del minuto de exposición y a concentraciones de 0,004 a 0,006 % a partir de los 10 minutos de exposición (Robson et al. 2007;Audenaert et al. 2012;Odorcic et al. 2015;Guerra et al. 2019). Las concentraciones de ácido hipocloroso que inhibieron el desarrollo de Fusarium spp. ...
El cultivo de banano es uno de los más importantes a nivel mundial y el Ecuador es uno de los países con mayor capacidad de exportación. Esto representa elevados ingresos económicos para el país. Sin embargo, estos cultivos pueden ser afectados nuevamente por el Mal de Panamá, causado por Fusarium oxysporum f. sp. cubense (Foc). Este trabajo está dirigido a determinar la efectividad de desinfectantes frente a cinco cepas distintas de Fusarium spp., con el fin de contribuir a la implementación de procesos de bioseguridad en puntos de ingreso al país y en bananeras. Un total de 5 desinfectantes comerciales fueron seleccionados y su actividad fue evaluada luego de 30 segundos, 1 minuto y 5 minutos de exposición a una suspensión de macroconidios y otra de clamidosporas (106 /mL). De los desinfectantes probados, aquel compuesto por glutaraldehído y dos amonios cuaternarios fue el más eficiente al inhibir el desarrollo de Fusarium spp, en la mayoría de las concentraciones evaluadas y en todos los tiempos de exposición. El producto a base de cloruro de alquil dimetil bencil amonio 20 % (amonio cuaternario) y aquel compuesto por ácido hipocloroso 0,05 % (neuthox) fueron efectivos generalmente en concentraciones mayores o iguales a la recomendada. Ninguno de los desinfectantes de dióxido de cloro fue eficaz inhibiendo el desarrollo de Fusarium spp.
... A study conducted by Audenaert et al. (2012) demonstrated that EW has potential to control Fusarium spp. in wheat grains during transport and storage although sublethal concentrations can result in increased deoxynivalenol (DON) biosynthesis. According to Zhang et al. (2012), soaking contaminated peanuts in an EW solution, the content of aflatoxin B1 (AFB 1 ) decreased of about 85%. ...
Disinfection after harvest is an essential step to maintain commodities and facilities free of fungal and bacterial postharvest pathogens, responsible of storage decay and economic losses. Electrolyzed water (EW) has gained considerable interest over the last decades as a novel broad-spectrum sanitizer. EW is sustainable and cost effective since it can be produced on-site utilizing tap water and different inexpensive salts and is healthy for both the environment and human beings. Its effectiveness in controlling fungi, yeasts, and bacteria within a wide range of pH is due to multiple mode of actions. Furthermore, its strong oxidizing potential is capable to reduce the amount of pesticide residues on fruit and vegetable surfaces and to avoid pathogen resistance. Properties of EW are related to salts employed for production, being those with low chlorine content preferable. Lastly, EW has no negative effect on the organoleptic properties and features of treated commodities. The present chapter highlights recent developments in EW generation, factors affecting its effectiveness for controlling postharvest decay of fruits and vegetables, mechanism of action on microbes and hosts, and advantages and disadvantages on its use.
... Other research showed that the use of neutralized electrolyzed water reduced the Fusarium microbial count on wheat, but partially increased the amount of produced deoxynivalenol (Audenaert et al., 2012). This was explained by the effect of reactive oxygen species (in this case hydrogen peroxide). ...
The application of novel, non-thermal technologies for the gentle preservation of foods is increasing. Some of the technologies, such as high hydrostatic pressure processing or pulsed electric fields, are already used in industrial scale. Others, such as cold plasma, ebeam, ultra high pressure homogenization or pulsed light, mainly exist in pilot scale and intensive research is performed in order to develop processes for the production of safe foods in industrial scale.
Conventional methods for food pasteurization or sterilization mainly rely on the thermal inactivation of microorganisms, in which microbial safety is usually only made possible by increasing the process intensity, with negative effects on the nutritional value and sensory properties. The aforementioned novel technologies aim to overcome these unwanted side effects by applying non-thermal inactivation mechanisms.
Although the basic inactivation mechanisms of these technologies have been described, further studies are performed in order to consider process combinations, matrix effects as well as structural and physiological effects on microbial cells. Furthermore, application concepts have been developed which require the selection of indicator microorganisms and treatment protocols for the validation and control of industrial scale processing.
The Research Topic aims to publish state of the art research about underlying inactivation mechanisms of microorganisms treated with novel decontamination technologies and their implication on the development of application and validation concepts.
... This fruit is one of the most consumed fruits, and is of greater importance in the family basket of Latin American countries-especially Colombia, Mexico, and Brazil-as well as in some countries in Africa and Asia [9,10]. However, harvested guava can exhibit fast ripening during storage periods due to their high respiration rate and decay incidence [11][12][13][14][15]. Reported methods that can be applied to control the decay of fruits caused by microorganisms correspond to microbial antagonists, such as yeast, fungi and bacteria [16], chlorine dioxide, hydrogen peroxide, citric acid, and ethanol application [17], polysorbates [18], ozone (O 3 ) [19], modified atmosphere packaging (MAP), ultraviolet-C (UV-C) light [20], electrolyzed water [21], gamma irradiation [22], and bioactive natural compounds such as essential oils [23,24], to avoid the use of synthetic fungicides in the control of fruit deterioration [25]. ...
Guava is a fruit appreciated worldwide for its high content of bioactive compounds. However, it is considered a highly perishable fruit, generally attacked by pathogenic species such as the fungi Colletotrichum gloeosporioides, which causes anthracnosis. To diminish the losses caused by pathogenic fungi, coatings of chitosan (CS) with Ruta graveolens essential oil (RGEO) in different concentrations (0.5, 1.0, 1.5% v/v) were applied in situ and their effects on the physical properties and microbiological quality of the guavas were studied. The CS+RGEO coated fruits exhibited better physicochemical behavior and lower microbiological decay as compared to the uncoated guavas, demonstrating the effectiveness of the coatings, especially those with 1.5% of RGEO content. All the fruits coated had greater acceptance and quality than the controls, being more those with essential oil incorporation. In situ investigation of C. gloesporioides infection of guavas demonstrated that the CS+RGEO coated guavas showed a high percentage of inhibition in the development of anthracnose lesions. In the present investigation, an alternative method has been proposed to extend the stability of the guavas fruit up to 12 days with application in the food industry.
... Other research showed that the use of neutralized electrolyzed water reduced the Fusarium microbial count on wheat, but partially increased the amount of produced deoxynivalenol (Audenaert et al., 2012). This was explained by the effect of reactive oxygen species (in this case hydrogen peroxide). ...
Ochratoxin A (OTA) is one of the most abundant food-contaminating mycotoxins. Besides their high toxicity, mycotoxins are highly stable to physical, chemical or biological detoxification. Therefore, the treatment with cold atmospheric plasma could be one approach to reduce the amount of mycotoxins in different products. The aim of this study was to determine the influence of cold atmospheric plasma on the inactivation of Aspergillus niger and Penicillium verrucosum inoculated on barley and their production of OTA. Inoculated barley was treated with plasma generated by dry air, CO2 or CO2 + O2 for 1 or 3 min and stored for up to two weeks at 9, 25, or 37°C. Three minutes of air plasma treatment effectively significantly reduced the total mold count of both microorganisms by 2.5–3 log cycles. The production of OTA from A. niger was only low, therefore the treatment effect was indistinguishable. The treatment of P. verrucosum on barley after an incubation of five days using a CO2 + O2 plasma resulted in a reduction of the OTA content from 49.0 (untreated) to 27.5 (1 min) and 23.8 ng/g (3 min), respectively. In contrast, CO2 plasma caused an increase of the OTA amount from 49.0 (untreated) to 55.8 (1 min) and 72.9 ng/g (3 min). Finally, the use of air plasma resulted likewise in a decrease of the OTA concentration from 56.9 (untreated) to 25.7 (1 min) and 20.2 ng/g (3 min), respectively. Reducing the incubation time before the treatment to 24 h caused in contrast an increase of the OTA content from 3.1 (untreated) to 29.1 (1 min) and 20.7 ng/g (3 min). Due to the high standard deviation, these changes were not significant, but the tendencies were clearly visible, showing the strong impact of the plasma gas on the OTA production. The results show, that even if the total mold count was reduced, under certain conditions the OTA amount was yet enhanced, probably due to a stress reaction of the mold. Concluding, the plasma gas and incubation conditions have to be considered to allow a successful inactivation of molds and in particular their toxic metabolites.
... Different strategies could be applied to reduce the incidence of postharvest decay, and among them, the temperature control of postharvest storage and disinfection procedures are the most common. In this context, several strategies have been reported to control fungal decay of postharvest vegetables, for example the use of microbial antagonists, as yeasts, fungi and bacteria (Sharma, Singh, & Singh, 2009), chlorine dioxide, hydrogen peroxide, citric acid and ethanol application (Spadoni, Neri, & Mari, 2016) polysorbates (Predmore & Li, 2011), ozone (O 3 ) (Tuffi, Lovino, Canese, Cafiero, & Vitali, 2012), modified atmosphere packaging (MAP), ultraviolet-C (UV-C) light (Allende, Marín, Buendía, Tomás-Barberán, & Gil, 2007) (Audenaert et al., 2012), gamma irradiation (Najafabadi, Sahari, Barzegar, & Esfahani, 2017) and bioactive natural compounds . ...
Background: Pesticides have a negative impact on the health of consumers and on the environment, and as a consequence, the use of naturally occurring antimicrobial agents have become more popular to prevent food spoilage. An alternative is the use of chitosan, because of its antimicrobial, antioxidant activities and its capacity to form films having good mechanical properties. Chitosan has been used in the preparation of films and coatings for the preservation of different food products, and the addition of essential oils have been shown to be a good strategy to improve its antimicrobial activity in situ. Scope and approach: This review compiles information related to studies and research that employ chitosan as matrix for films, coatings and nanogels with essential oils extracted from plants, as antifungal agent. A special emphasis has been addressed to the effect exerted on the most pathogenic fungi for crops, also highlighting the mechanisms of action that researchers attribute to the composite, together with inhibition data. Key Findings and Conclusion: Effective natural treatments, using chitosan-essential oils films or nano-emulsions, improve the preservation of fruit in terms of fungal decay. The effect is particularly dependent on the ability to release the antimicrobial compounds from the polymer matrix, the type of essential oils, the fungal species, and the incubation temperature. Several efforts are still required to understand in detail the mechanism of degradation of perishable food, how the chitosan-essential oils composites control or inhibit food decay, the effects on other pathogenic and non-pathogenic moulds as well as on the production of mycotoxins.
... Deoxynivalenol (DON) is one of major and most frequently detected mycotoxins in cereals (Audenaert et al., 2012;Binder, Tan, Chin, Handl, & Richard, 2007). It is mainly produced by Fusarium spp., especially by Fusarium graminearum (F. ...
... Toxins 2017, 9,255 8 of 18 ...
Fusarium head blight is a disease caused by a complex of Fusarium species. F. poae is omnipresent throughout Europe in spite of its low virulence. In this study, we assessed a geographically diverse collection of F. poae isolates for its genetic diversity using AFLP (Amplified Fragment Length Polymorphism). Furthermore, studying the mating type locus and chromosomal insertions, we identified hallmarks of both sexual recombination and clonal spread of successful genotypes in the population. Despite the large genetic variation found, all F. poae isolates possess the nivalenol chemotype based on Tri7 sequence analysis. Nevertheless, Tri gene clusters showed two layers of genetic variability. Firstly, the Tri1 locus was highly variable with mostly synonymous mutations and mutations in introns pointing to a strong purifying selection pressure. Secondly, in a subset of isolates, the main trichothecene gene cluster was invaded by a transposable element between Tri5 and Tri6. To investigate the impact of these variations on the phenotypic chemotype, mycotoxin production was assessed on artificial medium. Complex blends of type A and type B trichothecenes were produced but neither genetic variability in the Tri genes nor variability in the genome or geography accounted for the divergence in trichothecene production. In view of its complex chemotype, it will be of utmost interest to uncover the role of trichothecenes in virulence, spread and survival of F. poae.
... Since NEW is non-toxic, non-corrosive and safe due to its physicochemical properties and a reverting capacity to ordinary water when diluted with tap water [17], NEW could be used for the application of safer, healthier and more acceptable methods for aflatoxin detoxification. Mounting evidence suggests that EOW has strong antifungal activity [18,19] and it is also effective in detoxifying AFB 1 in peanuts and maize [20,21]; however, there are some challenges faced in the development of this technology, such as the quick loss of activity in the presence of organic matter. Nevertheless, the application of NEW to detoxify aflatoxin-contaminated maize and the confirmation of the detoxification process in an in vivo experimental model have not yet been reported. ...
Different in vitro and in silico approaches from our research group have demonstrated that neutral electrolyzed water (NEW) can be used to detoxify aflatoxins. The objective of this investigation was to evaluate the ability of NEW to detoxify B-aflatoxins (AFB1 and AFB2) in contaminated maize and to confirm detoxification in an in vivo experimental model. Batches of aflatoxin-contaminated maize were detoxified with NEW and mixed in commercial feed. A total of 240 6-day-old female large white Nicholas-700 turkey poults were randomly divided into four treatments of six replicates each (10 turkeys per replicate), which were fed ad libitum for two weeks with the following dietary treatments: (1) control feed containing aflatoxin-free maize (CONTROL); (2) feed containing the aflatoxin-contaminated maize (AF); (3) feed containing the aflatoxin-contaminated maize detoxified with NEW (AF + NEW); and (4) control feed containing aflatoxin-free maize treated with NEW (NEW). Compared to the control groups, turkey poults of the AF group significantly reduced body weight gain and increased feed conversion ratio and mortality rate; whereas turkey poults of the AF + NEW group did not present significant differences on productive parameters. In addition, alterations in serum biochemical constituents, enzyme activities, relative organ weight, gross morphological changes and histopathological studies were significantly mitigated by the aflatoxin-detoxification procedure. From these results, it is concluded that the treatment of aflatoxin-contaminated maize with NEW provided reasonable protection against the effects caused by aflatoxins in young turkey poults.
... In the anode, chloride ions and water molecules are transformed into chlorine oxidants such as hypochlorous acid (HOCl), hypochlorite ions (ClO´) and chlorine (Cl 2 ) [4]. The antimicrobial mechanism of NEW depends mainly on three physicochemical properties: pH, oxidation-reduction potential (ORP) and available chlorine concentration (ACC) [5]. ...
Theoretical studies of 8-chloro-9-hydroxy-aflatoxin B1 (2) were carried out by Density Functional Theory (DFT). This molecule is the reaction product of the treatment of aflatoxin B1 (1) with hypochlorous acid, from neutral electrolyzed water. Determination of the structural, electronic and spectroscopic properties of the reaction product allowed its theoretical characterization. In order to elucidate the formation process of 2, two reaction pathways were evaluated—the first one considering only ionic species (Cl⁺ and OH⁻) and the second one taking into account the entire hypochlorous acid molecule (HOCl). Both pathways were studied theoretically in gas and solution phases. In the first suggested pathway, the reaction involves the addition of chlorenium ion to 1 forming a non-classic carbocation assisted by anchimeric effect of the nearest aromatic system, and then a nucleophilic attack to the intermediate by the hydroxide ion. In the second studied pathway, as a first step, the attack of the double bond from the furanic moiety of 1 to the hypochlorous acid is considered, accomplishing the same non-classical carbocation, and again in the second step, a nucleophilic attack by the hydroxide ion. In order to validate both reaction pathways, the atomic charges, the highest occupied molecular orbital and the lowest unoccupied molecular orbital were obtained for both substrate and product. The corresponding data imply that the C9 atom is the more suitable site of the substrate to interact with the hydroxide ion. It was demonstrated by theoretical calculations that a vicinal and anti chlorohydrin is produced in the terminal furan ring. Data of the studied compound indicate an important reduction in the cytotoxic and genotoxic potential of the target molecule, as demonstrated previously by our research group using different in vitro assays.
... Therefore, it has been reported that EAW can be effectively used for the control of postharvest pathogen spores (OKULL and LABORDE, 2004;AL-HAQ and SUGİYAMA, 2004;KOSEKI et al., 2004). In their studies on a laboratory scale, Audenaert et al. (2012) demonstrated that electrolysed oxidising water (EOW) has the potential to control Fusarium spp. in wheat grains. It was observed that B. cereus endospores were substantially more resistant to the activity of NEW and temperature than fungi spores. ...
Problems with microorganism toxins in dried fig exports are becoming very important. Chlorine-based sanitizers are effective way of controlling microorganisms, but on the other hand their reaction with natural organic and inorganic matter may potentially form carcinogenic products. Therefore, different sanitizers for the disinfection of food and food contact surfaces are required as an alternative to chlorine-based sanitizers. Some earlier studies revealed that neutralised electrolysed water (NEW) may be a potential substitute for cleaning and sanitizing agents in packaged products. In order to make a contribution to solve toxins problems, the antibacterial and antifungal effect of neutralised electrolysed water (NEW) on the foodborne pathogens were evaluated in this study. Spores of Aspergillus flavus and Penicillium expansum were isolated from the surface of fig fruits. Escherichia coli and Bacillus cereus known to occur on the surface of figs were also evaluated. Vegetative cells and spores of bacterium and fungi were exposed to five different concentrations of NEW (100, 75, 25, 5 and 1%) at three different temperatures (22, 50 and 70°C) for 1, 3 and 5 min. According to the results, at 22°C, 1% neutralised electrolysed water exposure for 1 min effectively decreased the number of vegetative cells of E. coli and B. cereus by approximately 8.5 log cfu/ml and 6.3 log cfu/ml, respectively. At 50°C, 5% neutralised electrolysed water exposure for 1 min significantly reduced the A. flavus and P. expansum spore numbers by 5.54 log cfu/ml and 7 log cfu/ml, respectively. With the effect of mild temperature (22-50°C), low chlorine neutralised electrolysed water (9.22 mg/l-33.85 mg/l available chlorine concentrations) showed a strong antibacterial and antifungal activity against foodborne pathogens. As a conclusion, neutralised electrolysed water can be used widely as a sanitizer in fig enterprises, instead of high cost chlorine based disinfectants.
... Therefore, it has been reported that EAW can be effectively used for the control of postharvest pathogen spores (OKULL and LABORDE, 2004;AL-HAQ and SUGİYAMA, 2004;KOSEKI et al., 2004). In their studies on a laboratory scale, Audenaert et al. (2012) demonstrated that electrolysed oxidising water (EOW) has the potential to control Fusarium spp. in wheat grains. It was observed that B. cereus endospores were substantially more resistant to the activity of NEW and temperature than fungi spores. ...
Problems with microorganism toxins in dried fig exports are becoming very important. Chlorine-based sanitizers are effective way of controlling microorganisms, but on the other hand their reaction with natural organic and inorganic matter may potentially form carcinogenic products. Therefore, different sanitizers for the disinfection of food and food contact surfaces are required as an alternative to chlorine-based sanitizers. Some earlier studies revealed that neutralised electrolysed water (NEW) may be a potential substitute for cleaning and sanitizing agents in packaged products. In order to make a contribution to solve toxins problems, the antibacterial and antifungal effect of neutralised electrolysed water (NEW) on the foodborne pathogens were evaluated in this study. Spores of Aspergillus flavus and Penicillium expansum were isolated from the surface of fig fruits. Escherichia coli and Bacillus cereus known to occur on the surface of figs were also evaluated. Vegetative cells and spores of bacterium and fungi were exposed to five different concentrations of NEW (100, 75, 25, 5 and 1%) at three different temperatures (22, 50 and 70°C) for 1, 3 and 5 min. According to the results, at 22°C, 1% neutralised electrolysed water exposure for 1 min effectively decreased the number of vegetative cells of E. coli and B. cereus by approximately 8.5 log cfu/ml and 6.3 log cfu/ml, respectively. At 50°C, 5% neutralised electrolysed water exposure for 1 min significantly reduced the A. flavus and P. expansum spore numbers by 5.54 log cfu/ml and 7 log cfu/ml, respectively. With the effect of mild temperature (22-50°C), low chlorine neutralised electrolysed water (9.22 mg/l-33.85 mg/l available chlorine concentrations) showed a strong antibacterial and antifungal activity against foodborne pathogens. As a conclusion, neutralised electrolysed water can be used widely as a sanitizer in fig enterprises, instead of high cost chlorine based disinfectants.
... In the process, two types of water are generated: neutral electrolyzed water (NEW) and acidic electrolyzed water (AEW). The antimicrobial mechanism of both products depend mainly on three physicochemical properties: pH, oxidation-reduction potential (ORP) and available chlorine concentration (ACC) [11]. AEW has considerable biocidal activity, but rapidly loses ORP and Cl2-through the evolution of chlorine gas-thus reducing its effectiveness. ...
Aflatoxins, a group of extremely toxic mycotoxins produced by Aspergillus flavus, A. parasiticus and A. nomius, can occur as natural contaminants of certain agricultural commodities, particularly maize. These toxins have been shown to be hepatotoxic, carcinogenic, mutagenic and cause severe human and animal diseases. The effectiveness of neutral electrolyzed oxidizing water (NEW) on aflatoxin detoxification was investigated in HepG2 cells using several validation methodologies such as the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, the induction of lipid peroxidation, the oxidative damage by means of glutathione modulation, the Ames test and the alkaline Comet assay. Our results showed that, after the aflatoxin-contaminated maize containing 360 ng/g was soaked in NEW (60 mg/L available chlorine, pH 7.01) during 15 min at room temperature, the aflatoxin content did not decrease as confirmed by the immunoaffinity column and ultra performance liquid chromatography methods. Aflatoxin fluorescence strength of detoxified samples was similar to untreated samples. However, aflatoxin-associated cytotoxicity and genotoxicity effects were markedly reduced upon treatment. According to these results, NEW can be effectively used to detoxify aflatoxin-contaminated maize.
... Notably, intraculture differences have been observed by Ochiai et al. (2007) who demonstrated differential tri5 transcript levels in fungal hyphae. Moreover, a recent study by Audenaert et al. (2012) demonstrated the increased sensitivity of a tri5 knockout mutant compared to its wild-type parent strain, which indicated that biosynthesis of trichothecenes might also have a physiological meaning. ...
The effect of sublethal concentrations (below the recommended field doses) of propiconazole and tebuconazole on the amount of tri transcripts and accumulation of trichothecenes by three Fusarium graminearum isolates of 3ADON, 15ADON, and NIV chemotypes was examined on yeast extract sucrose agar (YES) medium. RT-qPCR analyses showed higher tri4, tri5, and tri11 transcript levels in cultures of all three F. graminearum isolates supplemented with sublethal concentrations of azoles as compared to those in nontreated control, although the fold changes in the amount of tri transcripts differed according to the type of azole used. Mycotoxin analysis revealed higher increase in trichothecene accumulation in most of the tebuconazole-treated samples of all chemotypes tested. A huge increase in all trichothecene compounds was revealed in samples of all F. graminearum isolates treated with 5 mg L(-1) of tebuconazole. An inducing effect of azoles on trichothecene accumulation in the grain was confirmed in an in planta experiment; however, the results obtained were inconsistent. A higher amount of trichothecenes and fungal DNA was quantitated in two grain samples treated with sublethal propiconazole concentrations. In contrast, no significant increase in trichothecene levels was revealed in grain samples treated with sublethal concentrations of tebuconazole.
Fresh seafood and agricultural products are susceptible to microbial contamination, leading to resource waste and
safety risks. Electrolyzed water (EW), an environmentally friendly agent, can inactivate microorganisms and prolong the shelf life of
food. Considerable attention has been devoted to its potential in guaranteeing food quality and safety. This review focused on the
effectiveness of both acidic electrolyzed water (AEW) and alkaline electrolyzed water (AIEW) in inactivating bacteria and fungi and
degrading mycotoxins. Additionally, newly developed acidic electrolyzed water ice (AEW ice) and its preservation effect were
evaluated. Notably, the AEW ice could greatly inhibit the growth of exogenous microorganisms and the activity of endogenous
enzymes, thereby preventing the deterioration of seafood. Additionally, the novel applications of AIEW combined with several
emerging technologies, including ultrasound and photodynamic inactivation (PDI) were also summarized. However, there are
several challenges regarding the future development of EW in the food industry, including constructing efficient technologies to
enhance the stability and durability of AEW, developing equipment for continuous production of AEW ice, improving the
inactivation efficiency of EW against microorganisms in food matrices, identifying action targets, and elucidating eradication
mechanisms of EW against bacterial biofilms, etc. This Perspective will provide new findings into the knowledge, deficiency, and
potential applications of EW in the food industry.
In this study, the sanitization efficacy of decontamination techniques was evaluated on lemon balm (Melissa officinalis). Dried aromatic herbs are minor food components with widespread use and, despite their low water activity, they are often contaminated with microorganisms, including toxigenic and pathogenic ones. Gaseous ozone (GO) and electrolyzed water (EW) treatments were applied on lemon balm after and before drying (traditional at 40 °C and cold at 20 °C), respectively. Microbiological and entomological decontamination aspects were assessed as well as the sensory quality and compositional properties of the product in terms of essential oil, total polyphenol and ascorbic acid contents, and antioxidant capacity. The most interesting results concerned EW treatment (400 ppm × 1 min dipping) reducing aerobic mesophilic bacteria, Enterobacteriaceae, moulds and yeasts of about 4.0, 2.5, 2.0 and 1.0 Log cfu/g, respectively, thus below law limits. Moreover, 200 ppm EW x 1 min dipping was enough for limiting Bacillus cereus growth. However, sanitization against the beetle species Tribolium castaneum and Lasioderma serricorne was less efficient with EW (less than 40% mortality) compared with GO (200,000 ppm × min) (more than 95% mortality). Noteworthy, sensory analysis highlighted that lemon balm exposed to EW treatment did not lose organoleptic quality, in particular the color even seemed to improve in brightness when the herbs were subsequently cold dried. Furthermore, the loss in essential oils was not significant in terms of the overall content as well as total polyphenol, ascorbic acid and antioxidant capacity in EW treated lemon balm then submitted to cold drying. Differently, the combination of EW treatment and traditional drying led to a significant detriment of compositional properties. The results obtained in this study are encouraging and deserve to be discussed with producers.
Mycotoxins are a significant threat to food safety and quality. Over the years, mycotoxins have been detected in almost all food and feed crops without any regional barrier. Conventional techniques for decontamination of mycotoxin involve physical, chemical, and biological methods, but these technologies often impact the quality of food in terms of changes in nutritional and sensory attributes. We examined the effects of nonthermal techniques on mycotoxins and their producing fungi to remove or reduce mycotoxin levels in food products without compromising food quality. Nonthermal technologies employ different lethal agents (including ozone, cold plasma, light, pressure, radiation, ultrasound, electric field, and magnetic field) to degrade mycotoxins while minimising product thermal exposure. However, the degradation pathway and toxicology of treated products need further research for a better understanding. With such food process development and optimisation efforts, food processors can employ various nonthermal technologies as tools for delivering consumer‐desired mycotoxin‐free food products with intact nutritional and sensory quality.
The aim of this study was to assess the antifungal effectiveness of neutral electrolyzed water (NEW) to inhibit the spore germination of post-harvest fungi common in fruits, determine the required available chlorine concentration (ACC) of NEW and to compare it with copper oxychloride (CO) and sterile distilled water (SDW) in vitro. This study evaluated the biological effectiveness of NEW to inactivate pure cultures of 11 different fungi obtained from post-harvest tropical fruits with anthracnose, rottenness or necrosis symptoms. A conidial solution of 1 × 104 spores/mL per culture was prepared and treated with a low, medium and high ACC of NEW (pH 7.0 ± 0.05, 12, 33 and 53 mg/L of ACC and ORP of 850 mV), CO at 0.3 g/L, or sterile distilled water as a control, for 3-, 5- and 10-min contact time. Spore germination of Alternaria alternata, Botrytis cinerea, Cladosporium australiense, Colletotrichum gloeosporioides and C. siamense, Fusarium solani and F. oxysporum, and Lasiodiplodia theobromae was inhibited in 100% by NEW at 12, 33 and 53 ppm ACC; 3,5 and 10 min contact time. Aspergillus niger and A. tamarii required 53 mg/L ACC to inhibit 100% of spore germination. NEW at 33 and 12 mg/L inhibited around 50% and
Electrolyzed oxidizing water (EOW) can be considered in the agrofood industry as a new antimicrobial agent with disinfectant, detoxifying, and shelf-life improvement properties. EOW is produced by electrolysis of water, with no added chemicals, except for sodium chloride. The antifungal and detoxifying mechanisms of EOW depend mainly on: pH, oxidation-reduction potential (ORP), and available chlorine concentration (ACC). EOW offers many advantages over other conventional chemical methods, including less adverse chemical residues, safe-handling, secure, energy-saving, cost-effective, and environmentally-friendly. As a result, EOW could be used for the development of safer and more socially acceptable methods for fungi decontamination and mycotoxin detoxification. This review contains an overview of EOW effectiveness to decontaminate non-toxigenic and mycotoxigenic fungi, its safety and efficacy for mycotoxin detoxification, the proposed mechanism of action of EOW on fungal cells, and the chemical mechanism of action of EOW on mycotoxins. Finally, conclusions and future research necessities are also outlined.
The disinfection efficacy of slightly acidic electrolyzed water (SAEW) has been recognized in food industry. However, the application of single SAEW limited its disinfection potential. The efficacy of the two-step disinfection with SAEW for the reduction of L. monocytogenes contamination on different food raw materials was evaluated compared to the one-step disinfection with SAEW in this study. Results demonstrated that SAEW could reduce both the natural aerobic bacterial count and inoculated L. monocytogenes population on endive and chicken immediately after processing and SAEW with approximately 60 mg/L of available chlorine concentration (ACC) had equal or higher antibacterial efficacy compared to NaClO solutions with approximately 150 mg/L of ACC. Moreover, SAEW treatments could control the growth of microbial populations of L. monocytogenes during storage and the efficacy on the microbial reduction was associated to the initial populations. In addition, the SAEW-treated food raw materials were stored and disinfected again after storage and the results showed that the two-step disinfection method could decrease the survival populations of L. monocytogenes by 24.8%∼99.6% compared to the one-step disinfection of SAEW. Therefore, considering storage habits, the two-step disinfection of SAEW may be a better choice in the disinfection of non-consumed-directly food raw materials.
As food industry flourished, the use of EW as a novel sanitizing agent has gained interest worldwide. The chapter reviews recent progress in the application of EW in fruits and vegetables industry, summarizing its efficacy on disinfection and pesticide removal during their processing, and disease control along with inhibiting moth infestation throughout storage as well as the effect on physiochemical properties, chemical components, and postharvest physiology. Furthermore, it specially generalized the application of EW in the field of sprouts vegetables (our researching focus) to open up a new way for the development of functional food. It indicated that EW has sufficient obliterating efficacy on spoilage or pathogenic microorganisms, pesticide residues, and some insect pests existing on fruits and vegetables without compromising sensory and nutritional quality of them in most occasions. Besides, the employment of EW to sprouts vegetables makes those healthful components such as CABA and flavonoids accumulated. However, optimal processing parameters such as washing time along with physiochemical properties of EW need further selection. And, hurdle technology should not be tolerated to maximize treatment efficacy and prolong the shelf life of fresh produce. In brief, EW has a promising prospect in future utilization of fruits and vegetables.
Economic losses due to post-harvest fungal spoilage and mycotoxin contamination of cereal crops is a frequently encountered issue. Typically, chemical preservatives are used to reduce the initial microbial load and the environmental conditions during storage are controlled to prevent microbial growth. However, in recent years the consumers’ desire for more naturally produced foods containing less chemical preservatives has grown increasingly stronger. This article reviews the latest advances in terms of novel approaches for chemical decontamination, namely application cold atmospheric pressure plasma and electrolysed water, and their suitability for preservation of stored cereal crops. In addition, the alternative use of bio-preservatives, such as starter cultures or purified antimicrobial compounds, to prevent the growth of spoilage organisms or remove in-field accumulated mycotoxins is evaluated. All treatments assessed here show potential for inhibition of microbial spoilage. However, each method encounters draw-backs, making industrial application difficult. Even under optimised processing conditions, it is unlikely that one single treatment can reduce the natural microbial load sufficiently. It is evident that future research needs to examine the combined application of several treatments to exploit their synergistic properties. This would enable sufficient reduction in the microbial load and ensure microbiological safety of cereal crops during long-term storage.
El agua electrolizada con pH neutro (7.0) es un novedoso agente antimicrobiano, que tiene efecto en una gran variedad de microorganismos, seguro para los seres humanos y el medio ambiente. Se determinó la eficacia del agua electrolizada de súper oxidación con pH neutro (SES) en la reducción de la germinación de esporas y desarrollo del tubo germinativo en hongos de importancia postcosecha. Una suspensión de 8X107esporas·mL-1 de los hongos Botrytis cinerea aislado de zarzamora, Colletotrichum gloeosporioides aislado de mango, guayaba y lichi, Fusarium solani aislado de chile y estevia, Monilinia fructicola aislado de durazno, Penicillium digitatum aislado de limón mexicano y limón persa, Penicillium sp. aislado de papaya y Rhizopus stolonifer aislado de yaca y guanábana, estuvieron en contacto con la SES por 5 minutos a concentraciones de 3, 5, 6, 8, 18, 24, 27, 29, 36 y 43 ppm de cloro libre, y agua destilada estéril (testigo). Las esporas se sembraron en medio de cultivo papa dextrosa agar (Bioxon®); las evaluaciones se realizaron a las 24 y 48 horas posteriores a la siembra. La inhibición del 100 % en la germinación de esporas y longitud del tubo germinativo de Botrytis se observó en el rango de concentración de 18-43 ppm, Colletotrichum (6-43 ppm), Fusarium (6-43 ppm), Monilinia (8 y 24-43 ppm), Penicillium (18-43 ppm), Rhizopus aislado de guanábana (5-24 y 29-43 ppm) y Rhizopus de yaca (18-43 ppm). Los resultados sugieren que la SES podría ser utilizada como alternativa de control de hongos postcosecha.
Coated Ti anodes have been prepared for producing acidic electrolyzed oxidizing water (AEOW). To improve the performance of anodes, the influence factors (sintering temperature, heat treatment time and dip-coating times) were systematically explored. The results show that the optimum sterilizing effect of AEOW is obtained in the case of sintering at 450 °C for 1 h with as many dip-coatings as possible. The sintering temperature is a critical factor. A lower temperature leads to better reaction selectivity, whereas a higher temperature results in a longer lifetime. A short heat treatment time leads to inadequate coating oxidation, a long heat treatment time prolongs the lifetime but results in high SEC. Increasing the number of dip-coatings could enhance the coating-substrate adhesion, thus extending the anode lifetime. The electrode prepared by optimization could replace the platinized Ti anode to produce AEOW. AEOW could be used as an effective disinfectant for eliminating Escherichia coli and Staphylococcus aureus. The sterilization ability is based on the combined effect of active chlorine concentration (ACC), low pH and high oxidation-reduction potential (ORP).
In this paper, a new type of controlled-release system was prepared by the covalent attachment of a volatile antifungal agent, hexanal, to the biodegradable polymer chitosan. Polysaccharide chitosan was reacted with hexyl aldehyde in Schiff base reaction to form iminated N-hexylimine-chitosan (NHIC). Physical and mechanical properties of the modified polymer films were studied and compared to those of unmodified chitosan. An aqueous solution of HCl (3M) was used to catalyze the hydrolysis of imine bonds, to yield regenerated chitosan and released hexanal. The release of hexanal was examined using headspace gas chromatography. The antifungal activity of N-hexylimine-chitosan film was demonstrated on harvested wheat. Acidic stimulation resulted in release of hexanal in the grain storage container and a significant (up to 10-fold) decrease in the mold occurrence on the grain.
The presented controlled-release system is based on dynamic covalent bonding. The formation of a stable covalent bond completely prevents the escape of active compound and can, however, be easily hydrolyzed. This approach may be a considerable tactic for the controlled release of volatile active agents.
The rhizospheric microbiome is comprised of many microbes, some of which reduce the virulence of their phytopathogenic neighbors; however, the mechanisms underlying these interactions are largely unknown. Rice soil isolate Pseudomonas chlororaphis EA105 strongly inhibits Magnaporthe oryzae's in vitro growth by restricting fungal diameter as well as inhibiting the formation of the appressorium, required for penetration. We were interested in elucidating M. oryzae's response to EA105 treatment, and utilized a microarray approach to obtain a global perspective of EA105 elicited changes in this pathogen. Based on this analysis, three genes of interest were knocked out in M. oryzae 70-15, and their sensitivity to EA105 treatment as well as their ability to infect rice was determined. Priming rice plants with EA105 prior to M. oryzae infection decreased lesion size, and the mutants were tested to see if this effect was retained. A null 70-15 mutant in a trichothecene biosynthesis gene showed less susceptibility to bacterial treatment, forming more appressoria than the parental type 70-15. A similar pattern was seen in a null mutant for a stress-inducible protein, MGG_03098. In addition, when this mutant was inoculated onto the leaves of EA105-primed rice plants, lesions were reduced to a greater extent than in 70-15, implicating the lack of this gene with an increased ISR response in rice. Understanding the global effect of biocontrol bacteria on phytopathogens is a key for developing successful and lasting solutions to crop loss caused by plant diseases and has the potential to greatly increase food supply.
This review is devoted to the study of the trichothecenes (group A and B) nature and properties. These compounds contaminate cereals all over the world. Important concentration of toxins can punctually be found; almost all kinds of feeds are contaminated with low concentrations. Physical sorting of contaminated and wholesome grains is the most practicable method on an industrial scale. The chemical and biological decontamination methods have not been evaluated enough to have actual applications. The main ways of struggle consist in the prevention of raw material contamination by toxigenic fungi, mainly Fusarium species.
Powdery mildew has been a major concern for greenhouse growers. Acidic electrolyzed oxidizing (EO) water was evaluated for the management of powdery mildew on gerbera daisy. EO water significantly reduced percent powdery mildew when sprayed twice a week and when sprayed every other week, alternating with fungicides. Studies were completed to determine if EO water could be used in an integrated management system. EO water was compatible with several fungicides and insecticides in an in vitro assay. However, EO water was not compatible with thiophanate methyl at the full rate and acephate at both the half and full rates. EO water is a viable option for controlling powdery mildew on gerbera daisies and provides growers an additional tool to reduce the use of traditional fungicides in greenhouses.
Recycled irrigation water is a primary source of inoculum for Phytophthora spp. and is capable of spreading propagules throughout nursery production. Chlorination commonly is used by the industry to disinfest recycled irrigation water; however, chlorine has not been fully researched as a disinfestant for this purpose. In this study, zoospores of seven species and eight isolates of Phytophthora were exposed for 2 min to free available chlorine at 0.25, 0.5, 1.0, 2.0, and 4.0 mg/liter. Zoospores, mycelial fragments, and culture plugs of P. nicotianae also were exposed to chlorine concentrations ranging from 0.25 to 8.0 mg/liter for periods ranging from 15 s to 8 min. In addition, chlorinated water was assayed monthly in 2000 and 2001 at two commercial nurseries, and quarterly in the first year at four other nurseries in Virginia, for chlorine and survival of pythiaccous species using a selective medium. No zoospores of any species tested survived endpoint free chlorine at 2 mg/liter, while limited mycelial fragments of P nicotianae survived at 8 mg/liter, and mycelial plugs treated at the same level of chlorine were able to produce few sporangia. Phytoplithora spp. were recovered only from nursery irrigation water with levels of free chlorine at 0.77 mg/liter or lower. The results of this study are essential for improving current chlorination protocols.
Definitive identification of free teliospores of Tilletia indica, causal agent of Karnal bunt of wheat, requires polymerase chain reaction (PCR)-based diagnostic tests. Since direct PCR amplification from teliospores has not been reliable, teliospores first must be germinated in order to obtain adequate DNA. We have routinely surface-sterilized teliospores for 2 min with 0.4% (vol/vol) sodium hypochlorite (NaOCl) to stimulate germination and produce axenic cultures. However, we observed that some spores were killed even with a 2-min NaOCl treatment, the shortest feasible duration. Decreasing the NaOCl concentration in our study from 0.4% to 0.3 and 0.2%, respectively, increased teliospore germination, but treatment times longer than 2 min still progressively reduced the germination percentages. In testing alternative methods, we found "acidic electrolyzed water" (AEW),generated by electrolysis of a weak solution of sodium chloride, also surface-sterilized and increased the rate of T. indica teliospore germination. In a representative experiment comparing the two methods, NaOCl (0.4%) for 2 min and AEW for 30 min increased germination from 19% (control) to 41 and 54%, respectively, by 7 days after treatment. Because teliospores can be treated with AEW for up to 2 h with little, if any, loss of viability, compared with 1 to 2 min for NaOCl, treatment with AEW has certain advantages over NaOCl for surface sterilizing and increasing germination of teliospores of suspect T. indica.
Acidic electrolyzed oxidizing (EO) water, generated by electrolysis of a dilute salt solution, recently gained attention in the food industry as a nonthermal method for microbial inactivation. Our objective was to determine if EO water has potential to control foliar diseases in greenhouses. Test fungi suspended in distilled water were combined with EO water (1:9 water:EO water) for various time periods, the EO water was neutralized, and germination was assessed after 24 h. Germination of all 22 fungal species tested was significantly reduced or prevented by EO water. All relatively thin-walled species (e.g., Botrytis, Monilinia) were killed by incubation times of 30 s or less. Thicker-walled, pigmented fungi (e.g., Curvularia, Helminthosporium) required 2 min or longer for germination to be reduced significantly. Dilution of EO water with tap water at ratios of 1:4 and 1:9 (EO:tap water) decreased efficacy against Botrytis cinerea. The presence of Triton X-100 (all concentrations) and Tween 20 (1 and 10%) eliminated the activity of EO water against B. cinerea. EO water did not damage geranium leaf tissue and inhibited lesion development by B. cinerea when applied up to 24 h postinoculation. EO water has a wide fungicidal activity which could facilitate its use as a contact fungicide on aerial plant surfaces and for general sanitation in the greenhouse.
Two years of field sampling aimed to establish the predominance and association among the fungal pathogens causing Fusarium ear blight (FEB) in four European countries (Hungary, Ireland, Italy and the UK). A PCR-based method was used to detect four Fusarium species and two varieties of Microdochium nivale present in the samples. The prevalence of FEB pathogens differed significantly between countries. Overall, all pathogens were commonly detected in Ireland and to a lesser extent in the UK. In contrast, only two species, F. graminearum and F. poae, were regularly detected in Italy and Hungary. Fusarium culmorum was rarely detected except in Ireland. Log-linear models were used to determine whether there is the independence of the six FEB pathogens at each sampling site. Significant two-pathogen interactions were frequently observed, particularly in harvest samples; all these significant two-pathogen interactions were of the synergistic type, except between F.
poae and F. culmorum, and were generally consistent over the 2 years and four countries. Fusarium graminearum and F. poae were least frequently involved in two pathogen interactions but were involved in most of the nine significant three-pathogen interactions. However, only the interaction between F. graminearum, F. avenaceum and F. poae was significant in both years. Potential implications of the present results in FEB management are discussed.
Fusarium head blight is a very important disease of small grain cereals with F. graminearum as one of the most important causal agents. It not only causes reduction in yield and quality but from a human and animal healthcare point of view, it produces mycotoxins such as deoxynivalenol (DON) which can accumulate to toxic levels. Little is known about external triggers influencing DON production.
In the present work, a combined in vivo/in vitro approach was used to test the effect of sub lethal fungicide treatments on DON production. Using a dilution series of prothioconazole, azoxystrobin and prothioconazole + fluoxastrobin, we demonstrated that sub lethal doses of prothioconazole coincide with an increase in DON production 48 h after fungicide treatment. In an artificial infection trial using wheat plants, the in vitro results of increased DON levels upon sub lethal prothioconazole application were confirmed illustrating the significance of these results from a practical point of view. In addition, further in vitro experiments revealed a timely hyperinduction of H2O2 production as fast as 4 h after amending cultures with prothioconazole. When applying H2O2 directly to germinating conidia, a similar induction of DON-production by F. graminearum was observed. The effect of sub lethal prothioconazole concentrations on DON production completely disappeared when applying catalase together with the fungicide.
These cumulative results suggest that H2O2 induced by sub lethal doses of the triazole fungicide prothioconazole acts as a trigger of DON biosynthesis. In a broader framework, this work clearly shows that DON production by the plant pathogen F. graminearum is the result of the interaction of fungal genomics and external environmental triggers.
Spacer-length (sl) variation in ribosomal RNA gene clusters (rDNA) was surveyed in 502 individual barley plants, including samples from 50 accessions of cultivated barley, 25 accessions of its wild ancestor, and five generations of composite cross II (CCII), an experimental population of barley. In total, 17 rDNA sl phenotypes, made up of 15 different rDNA sl variants, were observed. The 15 rDNA sl variants comprise a complete ladder in which each variant differs in length from adjacent variants by approximately equal to 115 nucleotide pairs. Studies of four rDNA sl variants in an F2 population showed that these variants are located at two unlinked loci, Rrn1 and Rrn2, each with two codominant alleles. Using wheat-barley addition lines, we determined that Rrn1 and Rrn2 are located on chromosomes 6 and 7, respectively. The nonrandom distribution of sl variants between loci suggests that genetic exchange occurs much less frequently between than within the two loci, which demonstrates that Rrn1 and Rrn2 are useful as new genetic markers. Frequencies of rDNA sl phenotypes and variants were monitored over 54 generations in CCII. A phenotype that was originally infrequent in CCII ultimately became predominant, whereas the originally most frequent phenotype decreased drastically in frequency, and all other phenotypes originally present disappeared from the population. We conclude that the sl variants and/or associated loci are under selection in CCII.
This study examined the efficacy of the following treatments to reduce selected fungal spore and mycotoxin levels on materials commonly found in home contents: (1) gamma irradiation at a 10-13 kiloGray exposure, (2) a detergent/bleach wash, and (3) a steam cleaning technique. A minimum of six replicates were performed per treatment. Paper, cloth, wood, and carpet were inoculated with either fungal spores (Stachybotrys chartarum, Aspergillus niger, Penicillium chrysogenum, or Chaetomium globosum) at 240,000 spores/2.54 cm2 of material or with the mycotoxins roridin A, T-2, and verrucarin A at 10 microg per 2.54 cm2 of material. Treatments were evaluated with an agar plating technique for fungal spores and a yeast toxicity culture assay for mycotoxins. Results showed that gamma irradiation inactivated fungal spores, but the treatment was not successful in inactivating mycotoxins. The washing technique completely inactivated or removed spores on all materials except for C. globosum, which was reduced on all items except paper (p < 0.05). Washing inactivated all mycotoxins on paper and cloth but not on carpet or untreated wood (p < 0.001). The steam cleaning treatment did not completely eliminate any fungal spores; however, it reduced P. chrysogenum numbers on all materials, C. globosum was reduced on wood and carpet, and S. chartarum was reduced on wood (p < 0.05). Steam cleaning was unsuccessful in inactivating any of the tested mycotoxins. These results show that the bleach/detergent washing technique was more effective overall in reducing spore and mycotoxin levels than gamma irradiation or steam cleaning. However, the other examined techniques were successful in varying degrees.
Fusarium head blight epidemics of wheat and barley cause heavy economic losses to farmers due to yield decreases and production of mycotoxin that renders the grain useless for flour and malt products. No highly resistant cultivars are available at present. Hyphae of germinating fungal spores use different paths of infection: After germination at the extruded tip of an ovary, the hyphae travel along the epicarp in the space between the lemma and palea. Infection of the developing kernel proceeds through the epicarp, successively destroying the layers of the fruit coat and finally the starch and protein accumulating endosperm. Hyphae reaching the rachis proceed to apically located developing kernels. Using a constitutively green fluorescence protein-expressing Fusarium wild-type strain, and its knockout mutant, preventing trichothecene synthesis, we demonstrate that trichothecenes are not a virulence factor during infection through the fruit coat. In the absence of trichothecenes, the fungus is blocked by the development of heavy cell wall thickenings in the rachis node of Nandu wheat, a defense inhibited by the mycotoxin. In barley hyphae of both wild-type and the trichothecene knockout mutant, are inhibited at the rachis node and rachilla, limiting infection of adjacent florets through the phloem and along the surface of the rachis. Effective resistance to Fusarium head blight requires expression of genes that combat these different pathways of infection.
Acidic electrolyzed water (AEW), known to have germicidal activity, was obtained after electrolysis of 0.045% aqueous solution of sodium chloride. Freshly prepared AEW (pH 2.3-2.6, oxidation-reduction potential 1007-1025 mV, and free active chlorine concentration 27-35 ppm) was tested in vitro and (or) on tomato foliage and seed surfaces for its effects on the viability of plant pathogen propagules that could be potential seed contaminants. Foliar sprays of AEW were tested against bacterial spot disease of tomato under greenhouse and field conditions. The viability of propagules of Xanthomonas campestris pv. vesicatoria (bacterial spot pathogen), Streptomyces scabies (potato scab pathogen), and Fusarium oxysporum f.sp. lycopersici (root rot pathogen) was significantly reduced 4-8 log units within 2 min of exposure to AEW. Immersion of tomato seed from infected fruit in AEW for 1 and 3 min significantly reduced the populations of X. campestris pv. vesicatoria from the surface of the seed without affecting seed germination. Foliar sprays of AEW reduced X. campestris pv. vesicatoria populations and leaf spot severity on tomato foliage in the greenhouse. In the field, multiple sprays of AEW consistently reduced bacterial spot severity on tomato foliage. Disease incidence and severity was also reduced on fruit, but only in 2003. Fruit yield was either enhanced or not affected by the AEW sprays. These results indicate a potential use of AEW as a seed surface disinfectant or contact bactericide.
The effect of electrolyzed oxidizing (EO) water in combination with ozone to control postharvest decay of tangerine cv. “Sai Num Pung” was investigated. The spore suspension containing 105 conidia ml−1 of Penicillium digitatum was prepared. EO water was generated by electrolysis of various concentrations of NaCl solution (5, 25, 50% and saturated NaCl). The spore suspension was inoculated into EO water and incubated at 27 °C for 1, 2, 4, 8 and 32 min. It was found that the EO water with saturated NaCl completely inhibited the spore germination of the fungus within 1 min. When the fruits inoculated with P. digitatum were washed in EO water at the same concentrations as previous experiment for 4, 8 and 16 min and stored at 5 °C for 18 days, it was found that immersion of the fruit in EO water for 8 min was the most effective to reduce disease incidences. Moreover, washing fruit in EO water and kept in a refrigerated chamber at 5 °C with continuous ozone exposure at a concentration of 200 mg l−1 for 2 h day−1 to extend storage life suppressed the disease incidence until 28 days. However, none of the treatments had any effect on the quality of fruit such as total soluble solids, titratable acidity, percent weight loss and peel color. Therefore EO water may be useful for surface sanitation and ozone has potential to control the recontamination of postharvest diseases in tangerine fruit in storage room.
Cereals contaminated by Fusarium spp. and their mycotoxins, e.g. deoxynivalenol (DON), are not only a risk to human and animal health but also show reduced technological properties. This study examines the influence of high Fusarium infection levels of wheat on its baking quality in relation to infection time. Nearly uninfected wheat, wheat inoculated with a spore-mixture of different Fusarium spp. at the time of flowering, and wheat inoculated with spores of Fusarium graminearum at different growth stages were investigated. Extension and baking tests, HPLC analyses of gluten proteins, and DON determination were performed as well as X-ray absorption spectroscopy to analyse the sulfur speciation of gluten proteins on a molecular level. Our results indicate that high Fusarium infection levels accompanied with high DON contents did not necessarily deteriorate baking quality. This finding was independent of infection time.
A defined medium was developed in which to monitor deoxynivalenol (DON) accumulation, fungal growth and expression of genes involved in trichothecene biosynthesis (designated Tri genes). In liquid culture, DON accumulated shortly after maximum expression of Tri6 and coincident with expression of Tri5. This was generally 96 h after inoculation. The effects of sublethal concentrations of the fungicides azoxystrobin, trifloxystrobin, kresoxim-methyl and tebuconazole on biosynthesis of the trichothecene DON by Fusarium culmorum were studied using this medium. The strobilurin fungicides trifloxystrobin and azoxystrobin significantly reduced the accumulation of DON in culture medium at a range of concentrations. Kresoxim-methyl, also a strobilurin, and tebuconazole, a triazole, did not significantly reduce the accumulation of DON, although levels were lower than those in nonamended cultures. Trifloxystrobin significantly reduced the accumulation of DON when added to cultures before initiation of trichothecene biosynthesis. RT-PCR assays of the expression of Tri6 and Tri5 genes indicated that trifloxystrobin acted by inhibiting the initiation of trichothecene biosynthesis.
Moulds and associated mycotoxins are important factors adversely affecting foods produced using contaminated plant products or animal products derived from animals fed on contaminated feeds. Mycotoxins are toxic to humans and animals, which explains the major concern of food and feed industries in preventing them from entering the food chain. Prevention is essential since there are few ways to completely overcome problems once mycotoxins are present. Toxin-producing moulds may invade plant material in the field before harvest, during post-harvest handling and storage and during processing into food and feed products. Thus, toxigenic fungi have been roughly classified into two groups (i) field fungi; (ii) storage fungi. The Fusarium genus, e.g. F. verticillioides (formerly F. moniliforme), F. roseus, F. tricinctum and F. nivale, are ubiquitous soil organisms, which may infect cereals directly in the field thereby, increasing fumonisins, trichothecene, and zearalenone levels (depending on the species) during growth, ripening of grain and at harvesting. Fusarium sp. can have deleterious effect on plants and decrease plant productivity. Many species can infect heads of wheat and other small grain cereals in fields causing head scab or blight (FHB). Ear rot also can be caused by Fusarium sp. growing on maize. Furthermore, fungi can grow on the non-grain part of plants producing large amounts of mycelium towards the stem where it colonizes the vascular bundles, which inhibits the transfer of nutrients in the upper part of the plant. On the contrary, Fusarium sp. does not significantly contribute to the storage fungi or to the fungal contaminants found only on damaged grains. Due to the multiple possible origins of fungal infection, any prevention strategy for fungal and mycotoxin contamination must be carried out at an integrative level all along the food production chain. Three steps of intervention have been identified. The first step in prevention should occur before Abbreviations: FHB, Fusarium head blight; HSCAS, hydrated sodium calcium aluminosilicates; QTLs, quantitative trait loci * Tel.: +33 4 73 62 40 54; fax: +33 4 73 62 46 59.
In this study, gaseous ozone was used as a fungicide to preserve stored wheat. The following operating parameters were investigated for their effects on the fungicidal efficacy of ozone: (1) the applied ozone dose; (2) ozonation time; (3) water activity of the wheat; and (4) temperature of the wheat. The effect of ozonation on germination of the wheat was also studied. Experimental results revealed that gaseous ozone was very effective in the inactivation of fungi associated with the wheat. Within 5 min of ozonation, 96.9% of the fungal spores were inactivated by applying 0.33 mg of ozone (g wheat)−1 min−1. It was also found that increases in both water activity and temperature of the wheat enhanced the fungicidal efficacy of ozone. In addition, results of this study indicated that the inactivation processes could be controlled by simply monitoring the ozone exiting from the reactor and, consequently, the time-consuming microbial examination processes could be avoided. This finding would make the application of ozone in the preservation of cereal grains easier, simpler, and more cost-effective. It was also found that although the applied ozone doses above certain thresholds may reduce the germination of wheat, the inactivation of fungi could be achieved using applied ozone doses far below those thresholds. Copyright © 2006 Society of Chemical Industry
Ninety samples of maize, chick-peas and groundnut seeds collected from the Egyptian market were found to be heavily contaminated by molds. Alternaria, Aspergillus, Cladosporium, Eurotium, Fusarium, Mucor, Penicillium and Rhizopus were the most common fungal genera isolated from nondisinfected seeds. Aspergillus alutaceus, A. flavus, Fusarium verticillioides and F. oxysporum were isolated from all surface-disinfected seeds and were reported to produce ochratoxin A, aflatoxin B1 and zearalenone, respectively. Irradiation at a dose 4.0 kGy reduced the mold growth greatly relative to unirradiated controls. There was no growth at dose 5.0 kGy. On the basis of the radiation survival data, the decimal reduction values D10 for A. alutaceus, A. flavus and F. verticilliodies were 0.70. 2.10 and 0.93 kGy in maize. A dose of 5 kGy inhibited the toxigenic molds and mycotoxin formation in seeds. Aflatoxin B1 and ochratoxin A were detected in maize and chick-peas, whereas zearalenone was detected in maize samples. Application of radiation at a dose of 6.0 kGy detoxified aflatoxin B1 by 74.3–76.7%, ochratoxin A by 51.3–96.2% and zearalenone by about 78%.
Fusarium head blight of wheat, often associated with mycotoxin contamination of food and feed is caused by various Fusarium species. The efficacy of fungicide sprays for the control of the disease and mycotoxins varies from being highly effective
to even increasing mycotoxin levels. The potential role of antagonistic fungi in this variability was investigated assessing
sensitivity of Fusarium species and saprophytic fungi colonizing wheat kernels to fungicides. Saprophytes were tested for their antagonistic activity
to the prevalent Fusarium species Fusarium avenaceum, Fusarium culmorum, Fusarium graminearum, and Fusarium poae. Fungal isolates from mature winter wheat kernels were Alternaria alternata, Arthrinium sp., Aspergillus niger, Epicoccum sp., Microdochium spp., Rhizopus oryzae and Trichoderma sp. In dual culture A. niger, R. oryzae and Trichoderma hamatum were more effective in reducing mycelial growth of Fusarium species than Microdochium majus; A. alternata and Epicoccum sp. were ineffective because of slow growth rates. Saprophytic fungi were sensitive to triazoles; however, prothioconazole
and tebuconazole had stronger effects on mycelial growth of Fusarium species. ED50 values also indicated significant differences in the sensitivity of Fusarium species to triazoles (range 0.1–1.7mg l−1). Azoxystrobin and fluoxastrobin were largely ineffective in inhibiting in vitro growth of Fusarium spp.; sensitivity of the other fungi was generally lower, except for M. majus which was highly sensitive. Due to differences in fungicide sensitivity among Fusarium spp. and ear-colonizing fungi antagonistic to Fusarium spp. fungicides are likely to modify the balance within the mycoflora of wheat ears which may also affect the mycotoxin contamination
of grain.
The Fusarium species predominantly found associated with Fusarium head blight (FHB) in wheat and other small-grain cereals all over Europe are F. graminearum, F. avenaceum and F. culmorum. Among the less frequently encountered species are several others which are less pathogenic or opportunistic, but also toxigenic. These include F. poae, F. cerealis
F. equiseti
F. sporotrichioides
F. tricinctum and, to a lesser extent, F. acuminatum
F. subglutinans
F. solani
F. oxysporum
F. verticillioides
F. semitectum and F. proliferatum. The species profile of FHB is due to several factors, primarily climatic conditions, particularly rain and the temperature at flowering stage, but also agronomic factors, such as soil cultivation, nitrogen fertilization, fungicides, crop rotation, and host genotype. The most frequently encountered Fusarium mycotoxins in FHB in Europe has proved to be deoxynivalenol and zearalenone produced by F. graminearum and F. culmorum with the former more common in southern (warmer) and the latter in northern (colder) European areas. Nivalenol was usually found associated with deoxynivalenol and its derivatives (mono-acetyldeoxynivalenols), together with fusarenone-X, formed by F. graminearum
F. cerealis
F. culmorum and, in northern areas, by F. poae. Moreover, from central to northern European countries, moniliformin has been consistently reported, as a consequence of the widespread distribution of F. avenaceum whereas the occurrence of T-2 toxin derivatives, such as T-2 toxin and HT-2 toxin, and diacetoxyscirpenol have been recorded in conjunction with sporadic epidemics of F. sporotrichioides and F. poae. Finally, beauvericin and various enniatins have recently been found in Finnish wheat colonized by F.avenaceum and F. poae.
Carbendazim-resistant (RS) and control (CS) strains ofFusarium sporotrichioides Sherb., previously developed in our laboratory, were exposed to graded concentrations of azoxystrob in in broth media under shake-culture conditions for 2, 3, 4 and 8 days. Azoxystrobin concentrations were 0, 1, 10 and 100 mg 1-1 broth and cultures were incubated at a constant 25°C. Mycelial growth was significantly affected by strain (P-1 mycelial growth was reduced (P0.05) at all three doses of azoxystrobin. Significant (P-1 addition of azoxystrobin stimulated T-2 toxin synthesis (P-1). Thus, the stimulation of T-2 toxin synthesis depended upon strain and azoxystrobin level. Production of diocetoxyscirpenol (DAS) was affected by a more complex set of interactions. Overall means showed that, in comparison with initial values (on day 2 or 3), DAS output maximized significantly(P on day 4 in RS cultures and on day 8 in CS. Marked strain effects were observed on exposure to the 10 mg 1-1 level of azoxystrobin. At this level, DAS production was enhanced in RS only after 4 (PF. sporotrichioides on exposure to a second fungicide. These results have been incorporated into a new classification scheme for fungicide efficacy which is also presented in this paper.
Samples artificially infected by Fusarium culmorum were analyzed to assess the effects of Fusarium infection on the protein quality of winter wheat (Triticum aestivum L.). The Fusarium infection did not noticeably influence either the crude protein content or the water absorption ability of the wheat flour. The protease activity found in the wheat flour was inversely correlated to the sedimentation value. In contrast, it was positively correlated to both the free amino acid content and the degree of infection as expressed in Fusarium protein equivalents (FPE) quantified by an enzyme-linked immunosorbent assay. A distinct reduction in the content of both total glutenin and high molecular weight glutenin subunits was detected in the seriously infected samples (FPE>20gg–1). The infection with Fusarium impaired the dough quality and led to a deformed loaf shape. The fungal protease was active over both a wide range of temperatures (from 10 to 100C) and a wide range of pH values (from 4.5 to 8.5). The maximum protease activity was displayed at 50C in the pH range 6.0–8.0. This property indicates that the protease produced by F. culmorum may impair storage proteins throughout all the processing procedures associated with wheat flour, thereby causing weak dough properties and, consequently, unsatisfactory bread quality.
The Hagberg falling number (HFN) is one of the most important quality characteristics of wheat. Six winter wheat cultivars
from three locations in Germany were analysed to assess the factors influencing the HFN. The cultivars and locations affected
significantly the HFN of all the samples. The infection with Fusarium culmorum, determined in another cultivar, also led to an increase in HFN, which suggested that the HFN method is not adequate enough
for the true determination of the alpha-amylase activity of fungus-infected, wheat flour. Furthermore, there was no clear correlation between HFN and thousand-kernel
weight, starch content or pentosan content. The crude protein content was positively related to the HFN, while the total dietary
fibre content depended on the cultivar and location.
Environmental microbiologists frequently use ergosterol, a fungal-specific membrane lipid, as an indicator of fungal infection in grain and other plant materials. Microbiological loading and technological quality of barley was determined directly after harvest, after post-harvest drying, and during storage. The conventional plate count method was used to measure fungal contamination (CFU). Ergosterol concentration (ERG) was determined by extraction, saponification and quantification using high-performance liquid chromatography (HPLC) with UV detection. The laboratory malting method was used to determine technological quality of the malt. Results showed a significant correlation between ERG and CFU (the coefficient of correlation was 0.92). Analyses also indicated that the high germinative energy and technological quality of the malt produced from dried barley was retained.
Electrolyzed oxidizing (EO) water has been regarded as a new sanitizer in recent years. Production of EO water needs only water and salt (sodium chloride). EO water have the following advantages over other traditional cleaning agents: effective disinfection, easy operation, relatively inexpensive, and environmentally friendly. The main advantage of EO water is its safety. EO water which is also a strong acid, is different to hydrochloric acid or sulfuric acid in that it is not corrosive to skin, mucous membrane, or organic material. Electrolyzed water has been tested and used as a disinfectant in the food industry and other applications. Combination of EO water and other measures are also possible. This review includes a brief overview of issues related to the electrolyzed water and its effective cleaning of food surfaces in food processing plants and the cleaning of animal products and fresh produce.
This study evaluated the potential use of near-neutral (pH=6.3-6.5) electrolyzed oxidizing water (EO water) to inactivate pure cultures of Botrytis cinerea and Monilinia fructicola and to mitigate fungal infection of these organisms on fruit surfaces. Treatment of these organisms, in pure culture, with EO water at concentrations of 25, 50, 75, and 100ppm total residual chlorine (TRC) and 10 min of contact time resulted in a 6 log(10) spores/mL reduction of both organisms. A dip treatment or a dip and daily spray treatment of EO water were used to evaluate its ability to prevent or delay the onset of surface infection on fruit during postharvest packaging and in retail shelf environments. A 10 minute dip treatment of surface inoculated peaches (M. fructicola) in EO water prevented infection for 3 days and resulted in a 12.5% incidence of infection and a disease severity rating of 6% after 5 days of storage at 25 degrees C. Dipping of green table grapes inoculated with B. cinerea into EO water prevented infection for 7 days and resulted in a 1% incidence of infection and a disease severity rating of 2% after 10 days of storage at 25 degrees C. A dip and daily spray of peaches with EO water prevented infection for 12 days and resulted in a 10% incidence of infection and a 6% disease severity after 14 days of storage at 25 degrees C. A dip and daily spray of grapes with EO water prevented infection for 24 days and resulted in a 2% incidence of infection and a disease severity rating of 2% after 26 days of storage at 25 degrees C. The results from this study suggest that these solutions may prove to be effective for postharvest sanitation of fruit surfaces prior to packaging and may increase the shelf life of the fruit in commercial settings.
Neutralized electrolyzed oxidizing water (NEW) and acidic electrolyzed oxidizing water (AcEW) are electrolyzed oxidizing waters (EOW) that have significantly different fungicidal efficiencies against Aspergillus flavus (A. flavus) (The actuation durations of no survival population to NEW and AcEW were 90s and 120s, respectively.), even when used at the same available chlorine concentration (30ppm). It has been verified by our previous research. This study hypothesized that this difference did not originate from the structure of water but based on the OH radical (OH). It was proved by the UV spectroscopy, (17)O-NMR spectroscopy and electron spin resonance analysis. NEW contains more OH compared with AcEW in the same available chlorine concentration level. The OH that exists in NEW and AcEW was found to have an important fungicidal factor that destroys the cellular structures of the A. flavus conidia. It also damages the cellular normal function of A. flavus conidia that brought about K+ and Mg2+ leakages. The levels of OH that exist in NEW and AcEW could be the important reason that leads to significant fungicidal efficiencies against A. flavus.
Fusarium species infect cereal crops worldwide and cause the important diseases Fusarium head blight and crown rot in wheat. Fusarium pathogens reduce yield and some species also produce trichothecene mycotoxins, such as deoxynivalenol (DON), during infection. These toxins play roles in pathogenesis on wheat and have serious health effects if present in grain consumed by humans or animals. In the present study, the response of wheat tissue to DON has been investigated. Infusion of wheat leaves with DON induced hydrogen peroxide production within 6 h followed by cell death within 24 h that was accompanied by DNA laddering, a hallmark of programmed cell death. In addition, real-time PCR analysis revealed that DON treatment rapidly induced transcription of a number of defence genes in a concentration-dependent manner. Co-treatment with DON and the antioxidant ascorbic acid reduced these responses, suggesting their induction may be at least partially mediated by reactive oxygen species (ROS), commonly known to be signalling molecules in plants. Wheat defence genes were more highly expressed in wheat stems inoculated with a DON-producing fungal strain than those inoculated with a DON-non-producing mutant, but only at a late stage of infection. Taken together, the results are consistent with a model in which DON production during infection of wheat induces ROS, which on the one hand may stimulate programmed host cell death assisting necrotrophic fungal growth, whereas, on the other hand, the ROS may contribute to the induction of antimicrobial host defences.
Microbial elicitors or attempted infection with an avirulent pathogen strain causes the rapid production of reactive oxygen intermediates. We report here that H2O2 from this oxidative burst not only drives the cross-linking of cell wall structural proteins, but also functions as a local trigger of programmed death in challenged cells and as a diffusible signal for the induction in adjacent cells of genes encoding cellular protectants such as glutathione S-transferase and glutathione peroxidase. Thus, H2O2 from the oxidative burst plays a key role in the orchestration of a localized hypersensitive response during the expression of plant disease resistance.
The occurrence of the mycotoxins deoxynivalenol (DON) and ochratoxin A (OTA) in the winter wheat of 1997 and 1998 grown under organic farming conditions was investigated using ELISAs (R-Biopharm) for quantification. The influence of delayed drying of the grain after harvest on the development of DON and OTA was determined in storage trials (moisture: 17% and 20%; temperature: 20 degrees C; duration: four and six weeks). The Tox5 PCR assay was used both to detect Fusarium species with the potential to produce trichothecenes and as a measure of their relative DNA content during the storage trials. The intensity of the PCR signals was correlated with the DON concentration. Fusarium species were identified microscopically by standard methods. All the freshly harvested grain samples were contaminated with DON and showed further increases in the DON concentration during storage. OTA contamination was found in 14.3% of the 1997 samples and in 24.1% of the 1998 samples. OTA increased during storage trials of the 1997 samples but not in the 1998 samples.
Of about 10 billion bushels of corn that are grown each year in the United States, less than 2% is processed directly into food products, and about 18% is processed into intermediates such as high-fructose corn syrup, ethanol, and cornstarch. The vast majority of the annual crop is used domestically for animal feed (60%), and about 16% is exported. Thus, any program for controlling residues of fumonisin (FB) in food must recognize that most of the crop is grown for something other than food. Studies on the effects of wet milling on FB residues found these residues nondetectable in cornstarch, the starting material for high-fructose corn syrup and most other wet-milled food ingredients. Similar effects are noted for the dry-milling process. FB residues were nondetectable or quite low in dry flaking grits and corn flour, higher in corn germ, and highest in corn bran. Extrusion of dry-milled products reduces FB concentrations by 30-90% for mixing-type extruders and 20-50% for nonmixing extruders. Cooking and canning generally have little effect on FB content. In the masa process measurable FB is reduced following the cooking, soaking, and washing steps, with little conversion of FB to the hydrolyzed form. Sheeting, baking, and frying at commercial times and temperatures generally have no effect. In summary, all available studies on the effects of processing corn into food and food ingredients consistently demonstrate substantial reductions in measurable FB. No studies have shown a concentration in FB residues in food products or ingredients.
Contamination of feed with trichothecenes, a group of Fusarium mycotoxins, leads to losses in performance due to their immunosupressive effects and the negative effect on the gastrointestinal system in animal production. A possible way of detoxification is microbial degradation, which was the focus of this study. A bacterial strain--BBSH 797--which can degrade some mycotoxins of the trichothecene group, has already been isolated. It transforms deoxynivalenol (DON) into its metabolite DOM-1, the non-toxic deepoxide of DON. Analogous to the microbial degradation of DON, the transformation of six different type A trichothecenes was observed. The metabolites appearing were characterized by GC-MS after derivatization with TRI-SIL TBT. Two metabolites were additionally, identified by liquid chromatography-mass spectrometry with particle beam interface (LC-PB-MS) with electron impact (EI)-ionization mode. The major finding was that scirpentriol was completely transformed into its non-toxic metabolite deepoxy scirpentriol, while the mycotoxin T-2 triol underwent a more complicated metabolism. According to the study, T-2-triol was degraded into its non-toxic deepoxy form and into T-2 tetraol, which was then further metabolized to deepoxy T-2 tetraol. GC-MS after derivatization with TRI-SIL TBT was suitable for the structural characterization of trichothecenes and their degradation products. Besides the mass spectra of already known degradation products, spectra of new metabolites could be recorded by LC-PB-MS.
A yeast strain isolated from the hindgut of the lower termite Mastotermes darwiniensis (Mastotermitidae) was found to represent a new member of the genus Trichosporon. Trichosporon mycotoxinivorans is closely related to T. loubieri on the basis of the phylogenetic trees based on the D1/D2 region of 26S rDNA, an approx. 600 bp fragment of the 18S rDNA and both ITS regions. However, the two species differ at nine positions in the D1/D2 region of 26S rDNA. The IGS1 region of T. mycotoxinivorans is 401 bp long. T. mycotoxinivorans is distinguished from T. loubieri by its ability to assimilate inulin and galactitol, and its inability to grow at 40 degrees C. The name of this newly isolated strain refers to an important characteristics of T. mycotoxinivorans to detoxify mycotoxins such as ochratoxin A and zearalenone. Therefore this strain can be used for the deactivation of the respective mycotoxins in animal feeds.
Liquid cultures of Fusarium graminearum were supplemented with H2O2 or other oxidative compounds. The accumulation kinetics of the resulting trichothecenes were monitored. At non-lethal concentrations, the H2O2 treatments modulated toxin accumulation, dependent on the method of supplementation. When H2O2 was added at the same time as the inoculation, higher levels of toxins accumulated 30 days later. Conversely, adding H2O2 2 or 7 days after inoculation had little effect. When H2O2 was added daily over the course of the culture, the accumulation of trichothecenes was rapidly and strongly enhanced. The fungus may adapt to oxidative stress when the first exposure to H2O2 occurs at the beginning of the culture course. The highest toxin levels were measured when the H2O2 was added daily. The importance of the first hours of culture was confirmed: pre-treating conidia with H2O2 does not affect their germination kinetics but leads to a reduction in the yield of trichothecenes 40 days later. The H2O2 regulation of this trichothecene accumulation may be specific, as paraquat, another pro-oxidant compound, inhibits their production. Since H2O2 is a major component of the oxidative burst occurring in pathogen/host interactions, these data support the theory that trichothecenes may act as virulence factors.
Effect of exogenous H(2)O(2) and catalase was tested in liquid cultures of the deoxynivalenol and 15-acetyldeoxynivalenol-producing fungus Fusarium graminearum. Accordingly to previous results, H(2)O(2) supplementation of the culture medium leads to increased toxin production. This study indicates that this event seems to be linked to a general up regulation of genes involved in the deoxynivalenol and 15-acetyldeoxynivalenol biosynthesis pathway, commonly named Tri genes. In catalase-treated cultures, toxin accumulation is reduced, and Tri genes expression is significantly down regulated. Furthermore, kinetics of expression of several Tri genes is proposed in relation to toxin accumulation. Biological meanings of these findings are discussed.
Fusarium graminearum was engineered for expression of enhanced green fluorescent protein gene (egfp) as a reporter regulated in a manner similar to Tri5, a key pathway gene in trichothecene biosynthesis. Using the transgenic fungus, it was found that the reporter gene was induced to express in aerial hyphae developed on trichothecene noninducing medium YG solidified by agar. Unexpectedly, the transcriptional activation of egfp was markedly suppressed by adding NaCl that does not significantly affect fungal growth. As suggested by these findings, wild-type F. graminearum that formed aerial hyphae on YG agar plates produced trichothecenes and the production was effectively suppressed by adding 1% NaCl to the agar. To evaluate the effects of abiotic stress on the expression of trichothecene biosynthesis (Tri) genes, a sensitive plate assay was established using GYEP medium (which very weakly induces trichothecene production) solidified with gellan gum. Using this assay, triazole fungicides were shown to cause transcriptional activation of egfp at sublethal concentrations. Indeed, trichothecene production significantly increased when F. graminearum was grown in rice medium (which moderately induces trichothecene) amended with low doses of tebuconazole. The real-time monitoring system described here may help predict the risks of trichothecene contamination by the fungus under various environmental conditions.
Investigation of gaseous ozone as an anti-fungal fumigant for stored wheat Differences in fungicidal efficiency against Aspergillus flavus for neutralized and acidic electrolyzed oxidizing waters
- J N Wu
- H Doan
- M A Cuenca
Wu, J. N., Doan, H., & Cuenca, M. A. (2006). Investigation of gaseous ozone as an anti-fungal fumigant for stored wheat. Journal of Chemical Technology and Biotechnology, 81, 1288e1293. Xiong, K., Liu, H. J., Liu, R., & Li, L. T. (2010). Differences in fungicidal efficiency against Aspergillus flavus for neutralized and acidic electrolyzed oxidizing waters. International Journal of Food Microbiology, 137, 67e75.
H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response. Cell, 79, 583e593 Trichosporon myco-toxinivorans sp nov., a new yeast species useful in biological detoxification of various mycotoxins
- A Levine
- R Tenhaken
- R Dixon
- C Lamb
- O Molnar
- G Schatzmayr
- E Fuchs
- H Prillinger
Levine, A., Tenhaken, R., Dixon, R., & Lamb, C. (1994). H2O2 from the oxidative burst orchestrates the plant hypersensitive disease resistance response. Cell, 79, 583e593. Molnar, O., Schatzmayr, G., Fuchs, E., & Prillinger, H. (2004). Trichosporon myco-toxinivorans sp nov., a new yeast species useful in biological detoxification of various mycotoxins. Systematic and Applied Microbiology, 27, 661e671. Mueller, D. S., Hung, Y. C., Oetting, R. D., van Iersel, M. W., & Buck, J. W. (2003).
) 515e521 quality and bread making properties of winter wheat
- Audenaert
Impact of the fungal protease produced by Fusarium culmorum on the protein K. Audenaert et al. / Food Control 23 (2012) 515e521 quality and bread making properties of winter wheat. European Food Research and Technology, 220, 552e559.