Article

Improvement of protein content and decrease of anti-nutritional factors in olive cake by solid-state fermentation: A way to valorize this industrial by-product in animal feed

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Abstract

The present work investigates the bioconversion of the olive cake (OC) generated by olive oil industries in Morocco through solid-state fermn. using selected filamentous fungi to increase its nutritional values for subsequent valorization as ruminants feed. The fungi -namely Beauveria bassiana, Fusarium flocciferum, Rhizodiscina cf. lignyota, and Aspergillus niger were cultured on OC for 15 days. Chem. compn. as well as enzymes activities were detd. Results showed (i) an increase in protein content of up to 94% for treated OC and (ii) significant (P < 0.05) decreases of phenolic compds., up to 43%, 70% and 42% for total phenolic content, total flavonoids content, and total condensed tannins, resp. Moreover, the RP-HPLC anal. of fermented OC confirmed the degrdn. of individual phenolic compds. by the strains. These findings demonstrate that F. flocciferum and Rhizodiscina cf. lignyota are efficient enzymes producers leading to a nutritive enhancement of this byproduct.

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... By deploying suitable microorganism in fermentation process using oil cake/meal as substrate, desired results can be achieved (Taiwo et al. 2012;Gupta et al. 2018;Chebaibi et al. 2019). By this method either the composition of the oil cake/meal can be altered (Taiwo et al. 2012;Gupta et al. 2018;Chebaibi et al. 2019) or its digestibility can be enhanced (Gosh and Mandal 2015). ...
... By deploying suitable microorganism in fermentation process using oil cake/meal as substrate, desired results can be achieved (Taiwo et al. 2012;Gupta et al. 2018;Chebaibi et al. 2019). By this method either the composition of the oil cake/meal can be altered (Taiwo et al. 2012;Gupta et al. 2018;Chebaibi et al. 2019) or its digestibility can be enhanced (Gosh and Mandal 2015). ...
... In oil cake, phenolic compounds, tannin and flavonoids were reduced and protein content was enhanced when subjected to fermentation by Fusarium flocciferum and Rhizodiscina cf. lignyota (Chebaibi et al. 2019). Gupta et al. (2018) deployed Aspergillus niger and Paecilomyces variotii to reduce cellulose content in jatropha oil cake by producing cellulase enzymes (Phulia et al. 2018). ...
Chapter
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Vegetable oil industry produces oil cakes or meals as byproducts after the expulsion and/or extraction of oil from oleaginous materials including oilseeds. The oil cakes or meals can serve various needs of humankind once utilized properly not only in the form of food, feed, and/or concentrated manures but also as sources of various nutraceutically, pharmaceutically, and/or industrially important compounds or phytochemicals. The presence of protein, mineral, and special constituents in oil cake or meal makes it an important component of food and/or feed formulations, provided it is enabled by scientific and technological information and methodologies and supported by enabling policy ecosystem. In this context, there exists a need to review the latest literature on various technological approaches for the valorization of the byproducts of vegetable oil industry. The present chapter is an attempt to bring to the readers an up-to-date and comprehensive information on research and technology in the area of utilizing vegetable oil cakes/meals by way of harnessing the nutritional components and alleviating the problems of antinutritional and/or toxic (or poisonous) components. Though various approaches are discussed, a special emphasis is laid on biotechnological approaches for enhancing the value of byproducts of vegetable oil industry. Also, a special effort is made for providing future prospects, highlighting the key area of research for the future pursuit and prosecution. This chapter is addressed to the researchers and research managers from both industry as well as academia interested or involved in promoting the byproduct utilization of vegetable oil industry in meeting nutritional and/or food/feed security at global level in the scenario of never receding human population and ever-changing climatic conditions.
... In general, most of the applications mentioned above use LAB to improve the nutritional value of several food matrices, or to isolate biologically active ingredients for functional food formulation. Nevertheless, bioconversion processes and fermentation strategies to increase digestibility, enhance nutritional value and decrease the levels of antinutritional factors in these substrates using other types of bacteria, as well as different yeasts and molds, have been described (Chebaibi et al., 2019;De Groof et al., 2019;Lücke et al., 2019;Vásquez et al., 2019). ...
... Thus, specific compounds produced through these processes are largely dependent on the raw material and the particular fungal species used. For instance, vegetable wastes are a rich source of nondigestible fibers and oligosaccharides which can confer improved technological , nutritional (Chebaibi et al., 2019), and functional properties when included in food preparations. Fungal fermentation of agri-food waste has been frequently used to produce prebiotic substrates, capable of beneficially modulating gut microbial populations (Gibson et al., 2011). ...
... In contrast, A. oryzae fermentations of maize-milling waste in co-culture with Pleurotus ostreatus and Hericium erinaceus to increase fiber content (+45%) (Acosta-Estrada et al., 2019) were performed under similar conditions to those processes using A. niger. Specifically, A. niger strains NRRL3, GH1 and enzymes isolated from CECT 2700 and 3T5B8 were used to treat mango, grape, soya and brewing by-products, and olive cake, leading to a high antioxidant activity (90%), release of xylo-oligosaccharides (887 mg/g), enzymes (soya 555 U/mL), xylose (6 g/L), and an increase in protein content (+94%) (Chebaibi et al., 2019;Costa et al., 2019;Paz et al., 2019;Taddia et al., 2019;Torres-León et al., 2019). Most of these processes were solid state-fermentations. ...
Article
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There is a general interest in finding new ways of valorizing fruit and vegetable processing by-products. With this aim, applications of industrial fermentation to improve nutritional value, or to produce biologically active compounds, have been developed. In this sense, the fermentation of a wide variety of by-products including rice, barley, soya, citrus, and milling by-products has been reported. This minireview gives an overview of recent fermentation-based valorization strategies developed in the last 2 years. To aid the designing of new bioprocesses of industrial interest, this minireview also provides a detailed comparison of the fermentation conditions needed to produce specific bioactive compounds through a simple artificial neural network model. Different applications reported have been focused on increasing the nutritional value of vegetable by-products, while several lactic acid bacteria and Penicillium species have been used to produce high purity lactic acid. Bacteria and fungi like Bacillus subtilis, Rhizopus oligosporus, or Fusarium flocciferum may be used to efficiently produce protein extracts with high biological value and a wide variety of functional carbohydrates and glycosidases have been produced employing Aspergillus, Yarrowia, and Trichoderma species. Fermentative patterns summarized may guide the production of functional ingredients for novel food formulation and the development of low-cost bioprocesses leading to a transition toward a bioeconomy model.
... So, unfiltered and unsupplemented OMWW were little used as microorganism's culture medium [12]. In a similar manner, the use of OP in the biotechnological processes was generally preceded by the individual or combined pretreatments such as ultrasounds, acidic hydrolysis, drying, stoning, grinding and sieving [13,14]. ...
... The production of laccase on OP by GS15 after 7 days (0.4 U/ml, equivalent to 5.0 U/g OP) was similar or slightly lower to those obtained after 15 days by several fungal strains as Beauveria bassiana, Fusarium flocciferum (respectively 1 and 1.5 U/ml) on unsupplemented OP [14]. Same work showed that Rhizodiscina lignyota produced an activity as 4 U/ml on supplemented OP whereas no laccase activity was mentioned with Aspergillus niger on supplemented or unsuplemented OP. ...
Article
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Enzymes from halophilic fungi offer interesting biotechnological applications, which lead us to explore novel producing strains. 23 fungi were isolated from Algerian saline soil. Among the three strains presenting laccase activities, one exhibited the high decolourising capacity of olive mill wastewaters. Identification showed that the efficient isolate GS15 belongs to Penicillium chrysogenum. This strain achieves optimal growth at 15% NaCl, 25 °C, pH 5, dark, aerobic and static conditions. The selected fungus is capable of producing extracellular enzymes as follows: caseinase, tannase, esterase and lipase. The laccase activities produced by P. chrysogenum on raw olive wastes are being reported here for the first time. GS15 produced 183.0 and 203.0 U/L of laccase activities in 10% and 20% unsupplemented olive mill wastewaters, respectively. The significant enzymatic activities can be correlated to the high ability of GS15 to decolourise industrial wastewater from the olive oil extraction. In these conditions no pre-treatment of olive wastewaters was needed. On the untreated grinded and non-grinded olive pomace, the laccase activity was 5.78 U/g and 5.36 U/g, respectively. Because the halophilic fungus has basic requirement for growth, this fungal strain is promising for saline biotechnological applications.
... Effective to produce enzymes [45] Low O 2 and CO 2 transfer ratio, it is difficult to monitor, control, and scale. There is no uniformity in culture [32] Effective to produce bioactive compounds [46] Slower microorganism's growth [3] Lower demand for water and energy, easy aeration in the medium [33] It is less efficient for the growth of microorganisms that require high water content [47] Most used for agro-industrial waste. ...
... In this process, the substrate and nutrients can be reused, although this type of fermentation does not apply to bacteria because they require a high-water content [30]. However, it is much more attractive because its chemical and physical processes are low cost, simpler, and have better yields; it allows reproducible conditions similar to the environment in which microorganisms live [45]. Solid-state fermentation has advantages in terms of the final product concentration, has a lower water expenditure, requires less sterile conditions, and has a low repression effect [50]. ...
Article
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Bacteria have been used in the food industry to produce flavors, dyes, thickeners, and to increase food value, because bacterial fermentations favor the obtention of different metabolites such as tannins and different nutritional compounds in food. Lactiplantibacillus plantarum was one the first species to be studied for industrial purposes, and its efficacy to obtaining tannins using fermentation processes. Bacterial fermentation helps to obtain a product with an added value of better quality and without the need to use strong solvents that can reduce their quality and safety. To release tannins, it is necessary to subject the substrate to different conditions to activate the enzyme tannin acyl hydrolase (tannase). The tannase-released compounds can have beneficial effects on health such as antioxidant, anticancer and cardioprotective properties, among others. Therefore, this review analyzes tannase release and other metabolites by fermentation processes.
... There is little evidence of the influence of an insect-based diet on the sensory qualities of meat. In broiler quail [46] and chickens [37,51], HI larva meals were provided, the sensory profile of the meat (smell, taste, aroma, texture, juiciness, and sensitivity) was unaltered. But, instead, Altmann et al. ...
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In this paper, we consider the conservation laws for the extended KdV equation in the form u_t+auu_x+bu_xxx+K(t) u_x=0 and for the extended KdV-B equation in the form u_t+auu_x+bu_xxx+K(t) u_x+cu_xx=0 where a,b and c are arbitrary constants. Conservation laws are of fundamental importance, especially in nonlinear sciences, and they indicate that a particular characteristic (such as mass, momentum, or charge) is measurable in an isolated physical system as the system evolves over time. In the field of differential equations there are many applications of conservation laws. For example, using conservation laws Lax proved theorems of global existence. In order to solve evolutionary equations, the study of conservation laws of the KdV equation was a milestone in the exploration of some techniques including Miura transformation, Lax pair, inverse scattering transformation and bi-Hamiltonian structures. By using a variational derivative approach, conservation laws for an extended KdV and extended KdV-B equations were constructed. The computations to derive multipliers and conservation law fluxes are conducted by using a Maple-based package which is called GeM.
... There is little evidence of the influence of an insect-based diet on the sensory qualities of meat. In broiler quail [46] and chickens [37,51], HI larva meals were provided, the sensory profile of the meat (smell, taste, aroma, texture, juiciness, and sensitivity) was unaltered. But, instead, Altmann et al. ...
Conference Paper
Feed prices is one of the most important constraint facing farming systems. Due to the fluctuation in price and constant raising feed prices, nutritionists have been searching alternative feed sources; especially agricultural based byproducts due to its huge nutritious potential which can make it an efficient way to improve animal production. Replacement of traditional feed sources with alternative sources in animal diets can alleviate human-livestock competition for feeds sources (e.g., soybean, wheat and corn), support the valorization of alternative local feed sources for animal production and help lower the price of feedstuff. However, the use of this alternative feeds comes with some limitations. The abundance of antinutritional factors is mainly reducing nutrient digestibility and there by restricting animal performance and feed utilization. To overcome this limitations, solid-state fermentation (SSF) has been reported as a great solution, actually it is utilized to boost nutrient bioavailability, limit gut pathogenic bacteria and decrease anti-nutritional factors in alternative sources. The use of SSF can improve the nutritive composition of feed, therefor the inclusion of SSF fermented products has a positive effect on animal performance, gut morphology and microbiota, carcass quality, animal hem-biochemical status and rumen fermentation of animals and poultry birds. This review aims to describe solid state fermentation (SSF) as a promising new method indicating the nutritional value of the solid-state fermented products, SSF’s effects on feed digestibility along with gut health, health status and ultimate performance of ruminants and birds. Keywords: Solid State Fermentation, Alternative Feed Sources, Agricultural Byproducts, Plant Feed Ingredients Anti-Nutritional Factors.
... This was due to the phenolic degradation by A. niger B60. Chebaibi et al. (2019) studied the bioconversion of the olive cake by different fungi and found significant decreases of phenolic compounds up to 43% of the initial phenolic content. ...
Article
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Citric acid production from dried and non-dried pomegranate peel wastes by the fungus Aspergillus niger B60 in solid-state fermentation (SSF) under non-aseptic conditions was investigated. The maximum amount of citric acid (278.5 g/kg dry peel) was achieved using dried (at 45 °C for 48 h) pulverized pomegranate peels with moisture content 75% and initial pH 8.0, after 8 days of fermentation at 25 °C. Under the same fermentation conditions, a higher amount of citric acid (306.8 g/kg dry peel) was observed during SSF of non-dried peels as a substrate. The addition of methanol as an inducer at a concentration of 3% (w/w) into the dried and non-dried pomegranate peel wastes increased the amount of citric acid to 300.7 and 351.5 g/kg dry peel, respectively. The non-dried pomegranate peel waste in SSF under non-aseptic conditions is a cheap and useful substrate for the commercial production of citric acid with low energy cost. The utilization of inexpensive agro-industrial wastes through SSF can contribute to achieve industrially feasible and environmentally sustainable bio-production of citric acid.
... Solid-state fermentation (SSF) of raw feed using microorganisms can significantly improve its quality by providing rich nutrients such as single-cell protein, minerals and growth factors (Chebaibi et al., 2019;Longo et al., 2008;Xiao et al., 2017). S. cerevisiae is not only the most commonly used strain in SSF (Hassaan et al., 2015;Shurson, 2018), but also a fantastic workhorse for bioproduction of various bio-based https://doi.org/10.1016/j.jbiotec.2020.06.001 ...
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Over the past decade, 5-aminolevulinic acid (5-ALA) has been highlighted as a promising functional feed additive and immunomodulator for improving the general health, immune response, and resistance to disease of livestock and poultry. However, it is very costly to produce 5-ALA using conventional chemical synthesis methods. Classical microbial fermentation fulfills the criteria of environmental friendliness, but the unsatisfactory titers still hinder actual industrial production. This study aimed to develop a solid-state fermentation (SSF) process that can be used to efficiently enrich feed with 5-ALA at a low cost. First, the endogenous 5-ALA synthase was overexpressed in Saccharomyces cerevisiae via integrating a copy of HEM1 gene into the chromosome and introducing a multi-copy plasmid pRS416-HEM1 which constitutively overexpresses HEM1 gene. The resulting strain ScA3 was able to produce 63.82 mg/L 5-ALA in shake-flask fermentation. After process optimization, a titer of 225.63 mg/kg dry materials, exceeding the usual effective dosage reported in animal trials, was achieved within 48 h through SSF of 20 kg feed in a 90-L steel drum. To our knowledge, this is the first report on combining microbial 5-ALA production with SSF in feed processing, which will hopefully promote the application and popularization of 5-ALA in the feed industry.
... lignyota, Aspergillus niger and Fusarium flocciferum) for 15 days. Results showed a significant (p < 0.05) increase in proteins (94%) and decrease in phenolic compounds (43%), flavonoids (70%) and condensed tannins (42%) due to the production of enzymes (oxidases, peroxidases) by fungi [176]. ...
Article
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The food industry generates a large amount of waste every year, which opens up a research field aimed at minimizing and efficiently managing this issue to support the concept of zero waste. From the extraction process of oilseeds results oil cakes. These residues are a source of bioactive compounds (protein, dietary fiber, antioxidants) with beneficial properties for health, that can be used in foods, cosmetics, textile, and pharmaceutical industries. They can also serve as substrates for the production of enzymes, antibiotics, biosurfactants, and mushrooms. Other applications are in animal feedstuff and for composites, bio-fuel, and films production. This review discusses the importance of oilseed and possible valorization methods for the residues obtained in the oil industry.
... On the other hand, solid-state fermentation using selected filamentous fungi is a promising biological technique that improves olive cake nutritional value and is characterized by its low cost, simplicity, and efficiency. At the same time, a more stable product is obtained, the requirements for energy are less, and smaller levels of effluents are produced compared to submerged fermentation systems [44]. ...
Article
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The olive oil industry has a leading position in the Mediterranean countries, resulting in the production of considerable quantities of the respective by-products (OB) that constitute an important environmental issue. OB contain valuable nutrients and bioactive components that can be re-used under the bioeconomy strategy, and several chemical, physical, and biological processes have been evaluated with the intention to improve their nutritional value. One feasible application of OB is their incorporation in the diets of livestock and especially ruminants due to their high fiber content. As indicated by numerous studies, OB dietary supplementation increases the levels of monounsaturated fatty acids (MUFAs) and decreases that of saturated fatty acids (SFAs) in the milk and meat of ruminants with beneficial effects for consumers’ health. At the same time, environmental impact and feeding costs are reduced without detrimental effects on ruminal fermentation, nutrients utilization, growth performance, carcass traits, milk yield and composition.
... Recently, some investigations have been performed to show new uses for olive cake. For example, Chebaibi et al. [2], Dorbane et al. [3], Ferrer et al. [4], Marcos et al. [5], and Symeou et al. [6] studied the use of olive cake as animal feed. Particularly, Symeou et al. [6] demonstrated desirable changes in ovine milk lipids. ...
Article
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Olive cake obtained as a by-product from the olive oil industry has been evaluated as biosorbent of heavy metals from aqueous solutions in batch and continuous systems (fixed-bed columns). First, a complete study of effect of hydrothermal treatment with water on biosorption capacity of resulting solid was performed. Results showed that the values of biosorption capacity increased when the particle size of material decreased and the temperature of treatment increased. Then, hydrolyzed olive cake was treated by common chemicals (hot water, nitric acid, and sodium hydroxide) and the impact of chemical treatment was analyzed. The results were well reproduced by Langmuir and Freundlich isotherm models, getting maximum experimental biosorption capacities that changed between 42.34 mg/g obtained for the solid material modified by NaOH and 14.27 mg/g obtained for the solid material modified by nitric acid. Finally, laboratory tests in fixed-bed columns were performed with four different heavy metals and at three different inlet concentrations. The biosorption capacity increased from 2.83 mg/g (Cr), 4.51 mg/g (Cu), 12.30 mg/g (Pb), and 4.10 mg/g (Zn) to 3.08 mg/g (Cr), 5.17 mg/g (Cu), 13.21 mg/g (Pb), and 5.51 mg/g (Zn) when the concentration of metal ions increased, from 50 mg/L to 200 mg/L, respectively. Also, the experimental data obtained was successfully correlated with the Thomas, Yoon–Nelson, and dose–response models.
... Numerous breakthroughs have been proposed to improve the affordability and nutrient availability of aquafeed. Olive oil and olive byproducts have great value especially in Mediterranean countries [5]. To the best of our knowledge, olive fruit products have complex micro-constituents such as phenolic compounds, which have antioxidant and cardioprotective properties [6][7][8]. ...
Article
Fermentation strategy is well documented to improve the nutritional value of agricultural waste by-products such olive cake (OC), which, in turn, provides healthy, safe, and affordable feedstuff. This study assessed the combined impact of Aspergillus oryzae-fermented OC (AFOC) on the growth performance, intestinal morphometry, blood biochemistry, lysozyme activity, gut immune-related genes, and flesh quality of Nile tilapia. We divided 225 fish into five groups further subdivided into three replicates (n = 15 each) and fed them five diets (Control, AFOC5, AFOC10, AFOC15, AFOC20) to determine AFOC nutritional value and its optimized incorporation level in the diet. The trial continued for 3 months. The crude protein content of OC improved by 7.77% after A. oryzae fermentation, while lipid content decreased by 14.19%. In addition, growth and feed utilization significantly improved at (10.8–11.2) % AFOC dietary level. High-density lipoprotein (HDL) significantly improved, and the serum lysozyme level was significantly higher in the AFOC10 group compared to other groups. Interestingly, gut-related inflammatory cytokines tumor necrosis factor alpha (TNF- α) and interleukin 1 beta (IL-1β) revealed higher relative mRNA expression in the AFOC10 group compared to other groups. The histomorphometric parameters was greatly influenced by the AFOC incorporation level (10%–20%). These findings suggested that A. orzae fermentation modifies the nutritional quality of OC, as seen through its positive impact on the growth performance, local and systemic immunity, and intestinal absorptive capacity of Nile tilapia. The recommended dose for dietary AFOC was around 11%
... The authors stated that at the end of the procedure the crude protein content was significantly increased. Finally, an investigation concerning the bioconversion of olive cake through SSF was carried out by Chebaibi et al. [34]. Some filamentous fungi were employed in order to upgrade olive cake's nutritional content by crude proteins' concentration displaying a significant increment. ...
Article
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The study herein concerns the application of the solid-state fermentation (SSF) bioprocess of agro-industrial wastes as a means to improve their nutritional composition, targeting their utilization as proteinaceous animal feed. The fermentation outcome resulted from the mixtures of Olive Mill Stone Waste (OMSW) with Pistachio Shell (PS) and PS with Lathyrus clymenum pericarp (LP) at various proportions via SSF initiated by P. ostreatus. The addition of 20% w/w of LPs to PS recorded the highest crude protein content (%) increase of 33.87% while concerning cellulose content, 50% w/w addition presented the highest value (37.68%). Concerning lignin presence, PS and its additions to OMSW recorded a reduction, the ratio of 100% w/w of PS was found to be decreased by 14.22% whereas, 20% w/w of LP additions to PS displayed an increment of 38.25%. Regarding β-glucans content, the mixture of 50% w/w of LP to PS recorded the highest value (5.19%) while 100% w/w of PS presented a vast increment exceeding 480-folds. The OMSW, PS and LP mixtures revealed their potential as supplements in animals’ diets after their nutritional upgrade through SSF. Such studies highlight the contribution to the confrontation of the unavailability of proteinaceous animal feed in the terms of a circular economy.
... The majority of this waste is thrown out in the nearby environment. This waste decomposes over a long period of time (years) and still presents economical (i.e. the cost of getting rid of the waste) and environmental problems in soil and groundwater (Molina-Alcaide and Yáñez-Ruiz, 2008; Dermeche et al., 2013;Fadel and El-Ghonemy, 2015;Berbel and Posadillo, 2018;Chebaibi et al., 2019). The fresh or well preserved waste of olive oil production can be utilized in ruminant feeding with no adverse effects on animal health (Awawdeh and Obeidat, 2013;Fadel and El-Ghonemy, 2015;Mannelli et al., 2018;Abid et al., 2020). ...
Article
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Olive mill waste is low-quality feed and rarely used in ruminant nutrition because of its high lignocellulose content, the existence of anti-nutritional factors such as total polyphenol and condensed tannin, and low protein contents. This in vitro research was conducted to valorize this waste (crude olive cake, extracted olive cake, and olive leaves) using an exogenous fibrolytic enzyme produced from Trichoderma longibrachiatum in ruminal nutrition. The enzymatic activity of this additive was 1161 units of endoglucanase per millilitre, 113 units of exoglucanase per millilitre, and 2267 units of xylanases per millilitre. This treatment was applied by spraying substrates with four doses: 0 (control), 1 (low), 2 (medium), and 4µL g−1 µL g−1 (high) of dry matter olive mill waste in an air-conditioned room at 26 ∘C for 12 h before in vitro incubation. For the crude olive cake, this additive at high doses increased degradation of 14 % of cellulose and 8 % of hemicellulose compared with the control at 12 h before the in vitro incubation. Consequently, it increased dry matter solubility and reduced sugars at this period compared to the control. Upon ruminal incubation, the high dose of exogenous fibrolytic enzyme increased the gas production from the immediately soluble fraction and insoluble fraction, the rate of gas production for the insoluble fraction, the dry matter degradability by 26 %, the organic matter degradability by 24 %, the metabolizable energy value by 28 %, and the microbial crude protein production by 24 % compared with the control. For olive leaves, an exogenous fibrolytic enzyme at medium dosage can also hydrolyse the hemicellulose compound, release fewer sugars, and increase dry matter solubility compared with the control at 12 h before the in vitro incubation. Upon in vitro incubation, the medium dose increased the gas production from immediately soluble and insoluble fractions, the rate of gas production for the insoluble fraction, the dry matter degradability by 13 %, the organic matter degradability by 11 %, the metabolizable energy value by 12 %, and the microbial crude protein production by 12 % compared with the control. However, the highest dose altered the gas production from insoluble fractions and decreased microbial crude protein production by 6 % compared with the control. Under the same conditions, an exogenous fibrolytic enzyme applied to extracted olive cake did not produce any effect in the chemical composition and nutritional value. These results showed clearly that effectiveness of exogenous fibrolytic enzyme varied with incubated waste. Increasing the nutritional value of crude olive cake and olive leaves using an exogenous fibrolytic enzyme can encourage breeders to use this waste as feed at a low cost in animal nutrition. This valorization of waste is a good solution to reduce pollution of soils and groundwater caused by throwing out this polluted waste into the environment.
... In fact, the extraction of phenolic compounds before the use of forced witloof chicory roots (FR) as a feed supplement can be beneficial since phenolic compounds are considered antinutritional and must be eliminated. Similar valorizations of food byproducts by the extraction of phenolic compounds have been reported in the literature for mustard seed meal [13,14], wood bark [15], grape pomace [16], brewer's spent grains [17], wheat bran [18], apple pomace [19], olive cake [20] and food processing by-products [21]. ...
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Chlorogenic acids are major phenolic constituents in many herbal medicines and exhibit various bioactivities that explain the growing interest in extracting chlorogenic acids from biomass. In this context, the present study aims to maximize 3-O-Caffeoylquinic acid (3-CQA) and 3,5-O-di-caffeoylquinic acid (3,5-diCQA) contents from forced witloof chicory roots and to analyze the extraction kinetic modelling. First, the solid–liquid ratio, ethanol concentration, extraction time and temperature were studied. The extraction conditions were optimized to maximize the extraction of these compounds. The maximum yields reached 5 ± 0.11 and 5.97 ± 0.30 mg/g dry matter (DM) for 3-O-Caffeoylquinic acid and 3,5-O-di-caffeoylquinic acid, respectively, in less than 6 min at 70 °C. Extraction with water as a solvent was assessed with the aim of proposing a second greener and less-expensive solvent. This extraction is very fast from 90 °C, with a maximum of 6.22 ± 0.18 mg/gDM of 3-O-Caffeoylquinic acid, and instantaneous for 3,5-O-di-caffeoylquinic acid with a maximum of 6.44 ± 0.59 mg/gDM. In the second step, response surface methodology was employed to optimize the ultrasound-assisted extraction of antioxidants. The higher antioxidant activities were found at temperatures from 40 °C and at percentages of ethanol in the range of 35–70%.
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Residual biomass is acknowledged as a key sustainable feedstock for the transition towards circular and low fossil carbon economies to supply whether energy, chemical, material and food products or services. The latter is receiving increasing attention, in particular in the perspective of decoupling nutrition from arable land demand. In order to provide a comprehensive overview of the technical possibilities to convert residual biomasses into edible ingredients, we reviewed over 950 scientific and industrial records documenting existing and emerging waste-to-nutrition pathways, involving over 150 different feedstocks here grouped under 10 umbrella categories: (i) wood-related residual biomass, (ii) primary crop residues, (iii) manure, (iv) food waste, (v) sludge and wastewater, (vi) green residual biomass, (vii) slaughterhouse by-products, (viii) agrifood co-products, (ix) C1 gases and (x) others. The review includes a detailed description of these pathways, as well as the processes they involve. As a result, we proposed four generic building blocks to systematize waste-to-nutrition conversion sequence patterns, namely enhancement, cracking, extraction and bioconversion. We further introduce a multidimensional representation of the biomasses suitability as potential as nutritional sources according to (i) their content in anti-nutritional compounds, (ii) their degree of structural complexity and (iii) their concentration of macro- and micronutrients. Finally, we suggest that the different pathways can be grouped into eight large families of approaches: (i) insect biorefinery, (ii) green biorefinery, (iii) lignocellulosic biorefinery, (iv) non-soluble protein recovery, (v) gas-intermediate biorefinery, (vi) liquid substrate alternative, (vii) solid-substrate fermentation and (viii) more-out-of-slaughterhouse by-products. The proposed framework aims to support future research in waste recovery and valorization within food systems, along with stimulating reflections on the improvement of resources’ cascading use.
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The growth of the world population has caused an increase in the demand for food of animal origin, where cattle have become one of the most important species economically speaking, due to the high costs of concentrates, interest has been generated in the search for feeding alternatives. The objective of this work was to determine the behavior of some zoo technical parameters in calves supplemented with different of FES potato-carrot inclusions. Four groups were established with a basic diet of milk and forage, two groups were supplemented with 6 and 9 g/kg/PV of FES-carrot feed, one group with 6 g of balanced concentrate and the control group. The variables evaluated were weight gain, height at the withers and food consumption. The animals of T2 and T3 reached a statistically higher final weight (p <0,05) in relation to the animals of the control group; the highest height at the withers was achieved with the T2, reporting a height of 85 cm. Supplementation with 6 g of FES feed turns out to be a feeding alternative, obtaining better results in zoo technical parameters and being more economical.
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Solid-state fermentation (SSF) using mixed strains can increase the nutritional value and antioxidant content of Moringa oliefera Lam. leaf flour (MLF). However, little is known about the chemical composition and metabolite profiles of MLF during the fermentation process. In this work, mixed strains of Aspergillus Niger, Candida utilis and Bacillus subtilis were inoculated into MLF for SSF. The MLF's contents of crude protein (CP), crude fiber (CF), water soluble carbohydrate (WSC), reducing sugar, tannin and phytic acid all changed significantly as fermentation proceeded. A metabolomic analysis was performed using GC-TOF-MS, resulting in the identification of 347 metabolites. Fermentation with mixed strains significantly affected levels of amino acids, sugars, and organic acids; concentrations of most amino acids, oligosaccharides, organic acids, nucleosides, γ-aminobutyric acid (GABA), and myo-inositol were higher after 3 d of SSF than at the start. Additionally, several intermediate metabolites were detected in 3 d fermented MLF. The mixed microorganisms' metabolic activity thus seems to peak after 3 d of fermentation under the tested conditions. These results provide new insights into the changes in the chemical composition and metabolite content of MLF during SSF and reveal possibilities for producing valuable compounds via this process.
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Although Trametes versicolor is one of the most investigated white-rot fungi, the industrial application of this fungus and its metabolites is still far from reaching its full potential. This review aims to highlight the opportunities and challenges for the industrial use of T. versicolor according to the principles of circular bioeconomy for interventions. The use of this fungus can contribute significantly to the success of efforts to valorize lignocellulosic waste biomass and industrial lignocellulosic byproducts. Various techniques of T. versicolor cultivation for enzyme production, food and feed production, wastewater treatment, and biofuel production are listed and critically evaluated, highlighting bottlenecks and future perspectives. Applications of T. versicolor crude laccase extracts in wastewater treatment, removal of lignin from lignocellulose, and in various biotransformations are analyzed separately.
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Background: The increase of peptides yield contributed to reducing the usage of antibiotics in solid-state fermented feed. Ultrasound technology was used in field of liquid-state fermentation to improve yield of fermented products but never utilized in field of solid-state fermentation (SSF). The main objective of this study was to investigate the feasibility of improving peptides yield in solid-state fermentation (SSF) products through ultrasound-treated bacterial strain. Results: The highest peptides content in soybean meal SSF products reached 153.28 mg/g, which increased by 15.05% compared with the control. This content value was acquired through treating the bacteria of Bacillus amyloliquefaciens by ultrasound before inoculating into soybean meal under the optimized mode and parameters (simultaneous dual-frequency ultrasound mode, frequency combination of 40/60 kHz, total power density of 40 W/L, time of 20 min, pulse-on and -off time of 40 s and 60 s, delayed inoculation time of 0 h). Fermenting with ultrasound-treated bacterial strain can effectively increase peptides yield, biomass and protease activity of soybean meal fermented products during the SSF prophase. After treating by ultrasound, the latent phase and logarithmic phase of the bacterial strain shortened by 1 h and 3 h while the generation time reduced by 23.64%. In qualitative test of protease activity, DR value of ultrasound-treated bacterial cells enlarged by 12.0% compared with the control. Conclusion: Peptides yield of soybean meal SSF products can be improved through ultrasound-treated bacterial inoculum, which attributed to the promoting effect of ultrasound treatment on growth activity and protease production capability of bacterial cells. This article is protected by copyright. All rights reserved.
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The present investigation evaluated the effect of processing on nutrient composition of pumpkin seed flour. The pumpkin seed flour was subjected to two types of fermentations i. e. natural and controlled single culture. The controlled single culture fermentations were carried out with two different probiotic strains viz., L. acidophilus and L. rhamnosus at 37°C for 36 h. The unprocessed pumpkin seed flour contained 6.08, 30.31, 2.87 and 21.09 g/100 g ash, crude fat, crude fiber and crude protein, respectively. The three types of fermentations significantly increased ash (14.31 to 19.08%) and crude protein content (6.83 to 12.57%). A significant reduction was observed in total carbohydrate content (8.29 to 17.79%). Natural as well as both the controlled fermentations significantly decreased soluble fiber content (6.67, 8.89 and 6.67%, respectively).
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The application of traditional Chinese medicine has a long history in China with unique advantages and functions. With the rapid development of separation and purification technologies, more and more polypeptide compounds with specific biological activity and medicinal value were isolated from natural plants. The plant polypeptides have a lot of biological activities, such as antitumor effect, antioxidize effect, antibacterial effect, hypoglycemic effect, blood pressure lowering effect, lipid-lowering effect, and anti-fatigue effect, and so on. This review summarized the extraction method, purification method, biological activities, and prospects of plant polypeptides, providing a basis for further study of plant polypeptides.
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It has now passed more than forty years since solid-state fermentation (SSF) research developments have gained importance for the scientific community. After so many years, numerous processes and equipment for SSF were studied and designed focusing on the production of different commercially relevant bioproducts such as enzymes, fermented food, such as Chinese daqu and koji, organic acids, pigments, phenolic compounds, aromas, biosorbents and so many others. However, no review paper has been focused yet specifically on agricultural and animal feed bioproducts obtained through SSF techniques. This review comprises the description of agricultural sub-products that have been employed in most important developed processes concerning the production of animal feed products and agricultural products such as spores, probiotics, biofungicides, bioinsecticides and other biopesticides, biofertilizers and plant growth hormones. Major designed SSF bioreactors are also described and the most important related cases of successful employment of the technique are reported. Finally, a summary of patents and innovations regarding SSF products and processes in this area is presented, showing that the main involved countries are China, South Korea, India and the USA. It is clear that the interest in this theme is increasing and that scientific and technological developments are still needed.
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The main objective of this study concerns the bioconversion of agro-industrial wastes into high added value products, such as proteinaceous animal feed, using Solid State Fermentation process (SSF). For this purpose, the Olive Mill Stone Waste (OMSW) which is known to contain low amounts of proteins and a high concentration of anti-nutritional substances was used as substrate. Subsequently, OMSW was fermented with Oat Bran (OB) or Lathyrus clymenum pericarp (LP) in proportions varying from 10 %w/w to 30 %w/w, applying SSF process initiated by Pleurotus ostreatus utilizing latter’s secreted enzymes for their degradation. The respective results indicated that the addition of 30 %w/w of OB, resulted in a 39% increase of the protein content at the end of fermentation (Day 21). In addition, we observed a 5-fold increase of 1,3–1,6 β-glucan content and a simultaneous decrease of unwanted lignin of 24%. The addition of 20 %w/w of LP afforded, at the end of fermentation (Day 21), an increased protein content of 57%, a 3-fold increase in 1,3–1,6 β-glucans and a decrease in lignin concentration of 13%. These findings demonstrate the potential of the LP utilization by using SSF process, for the production of high nutritional value dietary supplements for animal feed. This endeavor constitutes the first literature report for the utilization of the agro-industrial waste LP. The developed methodology herein is considered as crucial for the circular economy since it refers to the reuse of agro-industrial wastes and the production of a high added-value product.
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The purpose of the study was to investigate the feasibility and mechanisms of increasing peptide yield of soybean meal solid-state fermentation (SSF) products by ultrasound-treated Bacillus amyloliquefaciens. Under the optimal parameters level (frequency of 40 kHz, power density of 40 W/L, time of 17.5 min), peptide content of SSF soybean meal in ultrasonic treatment group reached 150.68 mg/g, which increased by 13.10% compared to the control. Ultrasound-treated B. amyloliquefaciens enhanced peptide yield, biomass and protease activity at early stage of SSF. Analysis of omics and qRT-PCR validated that ultrasound treatment did not promote protease secretion but facilitated the germination of endospores. The germination rate increased from 15.67% to 67.33%. According to growth curve determination, ultrasound-treated B. amyloliquefaciens had shorter lag times due to increased vegetative cell content in the inoculum. In conclusion, peptide yield of soybean meal SSF products can be effectively increased by ultrasound-treated B. amyloliquefaciens, which is because of the facilitation effect of ultrasound on endospores germination.
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In this work we present the study of bioconversion of cowpea shells in solid state fermentation with edible mushrooms, Pleurotus ostreatus and Pleurotus pulmonarius so as to upgrade its nutritional values and digestibility for its use as ruminants feed. The results obtained showed an increase in the crude protein (CP) from 12.25% for the control to 17.04% for P. ostreatus degraded cowpea husk (POT) and 15.41% for the P. pulmunarius degraded cowpea husk (PPT). A significant (P<0.05) decrease in the values of neutral detergent fiber (hemicellulose. Cellulose and lignin) and acid detergent fiber (lignin and cellulose) were detected. The estimated organic matter digestibility (OMD) improved from 45.65% (control) 62.14% for POT and 59.52% for PPT. Similar trend was also observed in the estimated ME from 6.97 MJ/Kg DM to 9.41MJ/Kg DM for POT and 9.103 MJ/Kg DM for PPT, respectively. Wide variations also exist in the factional rate of gas production (c) and fermentation of the insoluble fraction (b).
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Enzymes are among the most important products, obtained for human needs through microbial sources. A large number of industrial processes in the areas of industrial, environmental and food biotechnology utilize enzymes at some stage or the other. Current developments in biotechnology are yielding new applications for enzymes. Solid state fermentation (SSF) holds tremendous potential for the production of enzymes. It can be of special interest in those processes where the crude fermented products may be used directly as enzyme sources. This review focuses on the production of various industrial enzymes by SSF processes. Following a brief discussion of the microorganisms and the substrates used in SSF systems, and aspects of the design of fermenter and the factors affecting production of enzymes, an illustrative survey is presented on various individual groups of enzymes such as cellulolytic, pectinolytic, ligninolytic, amylolytic and lipolytic enzymes, etc.
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Five strains were screened out from 120 strains of Fusarium Oxysporum Schl. isolated from different regions. Based on ITS analyses, the strains were determined as Fusarium Oxysporum Schl. The strain named as H57-1 produce the highest cellulase, which activity reach at 1.43 IU/mL. The most suitable reactive pH of the CMCase was 4.5 similar to 5.5, and the most suitable reactive temperature is 60 similar to 65 degrees C. Its activity is stable at pH 5.3 degrees 9.5 and 4 similar to 50 degrees C. (C) 2011 Published by Elsevier B.V. Selection and/or peer-review under responsibility of National University of Singapore.
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2 Abstract: The ability of Aspergillus niger to improve the nutritional status of Cassava Root Sieviate (CRS) and peels was assessed for ten days through biodegradation. The biodegradation within this time had several effects on the proximate content of the substrates. The protein content of CRS recorded for 0, 5 and 10 days were 2.09, 5.21 and 7.34% while these 5.35, 10.70 and12.64% were values for cassava peels. From the results it was obvious that Aspergillus niger was able to enrich the protein content of both sieviate and the peels, i.e. there was significant effect (p
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Orange waste consisting of both peel and pulp is highly susceptible to hydrolysis by mixtures of cellulolytic and pectinolytic enzymes which give it potential as feedstock for biological conversion to value added products. Whereas the pulp is relatively rich in carbohydrate, the peel consists of 16.9% soluble sugars, 9.21% cellulose, 10.5% hemicellulose and 42.5% pectin as the most important components. Thus, Aspergillus niger (KA-06) and Chaetomium spp (KC-06) isolated from municipal waste were investigated for their ability to degrade orange waste under solid substrate fermentation (SSF). This study evaluated the influence of various fermentation parameters such as substrate concentration, initial moisture content, Nitrogen source supplementation, inoculum concentration, temperature and pH on the biodegradation of orange waste into protein enriched biomass using A. niger (KA-06) and Chaetomium spp (KC-06). The production of protein enriched biomass from orange waste as a substrate for the fermentation process was found to be optimized by moisture content of 40% and substrate concentration of 10 g with inoculum of 10 6 to 10 8 spores/ml at 25 ° ° ° ° C for both Chaetomium spp (KC-06) and A. niger (KA-06). The maximum protein content of 39.64% was obtained with Chaetomium spp (KC-06) at inoculum load of 10 8 spores/ml. A. niger (KA-06) give a protein yield of 31.7% with inoculum load of 10 6 spores/ml. This research has demonstrated the potential for protein production from orange waste under solid substrate fermentation.
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Among 12 bacterial and fungal isolates from a phenol-containing effluent, an Acinetobacter sp. and a Fusarium flocciferum strain could be adapted to growth on up to lg/1 of phenol.
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Crude Manganese Peroxidase (MnP) preparations from the fungus Bjerkandera sp. BOS55 were tested for their abilities to bleach and delignify oxygen delignified Eucalyptus Kraft pulp in a sequence combining a chelating and a peroxide stage. The inclusion of the enzymatic treatment in the bleaching sequence helped considerably to improve the final brightness. Other interesting results included moderate Kappa reduction, slight yield loss and paper sheets with an acceptable breaking length and burst index.
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Twenty laboratories participated in a collaborative investigation of assays for endo-1,4-β-xylanase activity based on production of reducing sugars from polymeric 4-O-methyl glucuronoxylan. The substrates and methods already in use in the different laboratories were first recorded and the apparent activities obtained using these methods in the analysis of a distributed enzyme sample were compared. The standard deviation of the results reported in this analysis was 108% of the mean. Significant reduction in interlaboratory variation was obtained when all the participants used the same substrate for activity determination, each with their own assay procedure. The level of agreement was further improved when both the substrate and the method procedure were standardized.In a round robin testing of a single substrate and method, including precise instructions for enzyme dilution, the standard deviation between the results after the rejection of two outliers was 17% of the mean. This figure probably reflects the inherently poor reproducibility of results when using only partially soluble, poorly defined and rather impure polymeric substrates. The final level of variation was however low enough to allow meaningful comparison of results obtained in different laboratories when using the standardized assay substrate and method procedure.Fifteen laboratories also participated in preliminary testing of an assay based on the release of dyed fragments from 4-O-methyl glucuronoxylan dyed with Remazol Brilliant Blue dye. High values of the coefficients of correlation indicated good linearity between the amount of dyed fragments released and enzyme concentration. The relative standard deviations of the results obtained by fifteen laboratories were about 30% for an optimum range of xylanase activity in the reaction mixture.
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The mycelium of Fusarium flocciferum was assayed for its ability to degrade aromatic compounds, namely, gallic, protocatechuic, vanillic, syringic, caffeic, and ferulic acids and syringic aldehyde, commonly found in agro-industrial wastes. The biodegradation assays were performed in liquid medium with the phenolic compounds as single substrates and as a synthetic mixture containing the seven aromatic compounds. The results with single substrates indicated that in 24 hrs of incubation the fungus was able to reduce the phenolic concentration from 200 mg/l to below detection limits, except for syringic acid, being the lowest degradation rates found for this acid and its aldehyde. The biodegradation experiments with the mixture of phenolic compounds showed that after 8 hrs the total phenolic concentration was reduce from 350 mg/l to below the detection limits of all the tested compounds. In all the experiments a rise in the pH and an effective detoxification of the phenolic solutions were also observed.
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The genus Olea contains the economically important European olive tree (Olea europaea L.). This species is also of chemotaxonomic interest because of the presence of various phenol-conjugated oleosidic secoiridoids or oleosides. The chemistry of these phenolic oleosides is diverse and complicated, and it is only in recent years that attention has been given to their biosynthesis and the biotransformations during the processing and storage of olive products. Many questions regarding these processes remain unanswered, and yet these have significant impact on the quality and value of olive products such as olive oil.
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The discovery in 1983 of fungal "ligninases" capable of catalyzing the peroxidation of nonphenolic aromatic lignin components has been seen as a major advance in understanding how certain basidiomycete fungi can completely degrade lignin. The ability of these lignin-type peroxidases to covert millimolar concentrations of veratryl alcohol to veratraldehyde, indicated by a change in the A310 of veratraldehyde, has become the standard assay for routine quantitation of LP activity. A new assay based on the oxidation of micromolar concentrations of the dye Azure B is presented. Although it is as simple and rapid as the veratryl alcohol assay, it appears to overcome some of the shortcomings of that assay. In particular, interference from UV- and short-wavelength visible-light-absorbing materials is greatly reduced and assay specificity is improved.
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The relative contributions of lignin peroxidase (LiP) and manganese peroxidase (MnP) to the decolorization of olive mill wastewaters (OMW) by Phanerochaete chrysosporium were investigated. A relatively low level (25%) of OMW decolorization was found with P. chrysosporium which was grown in a medium with a high Mn(II) concentration and in which a high level of MnP (0.65 (mu)M) was produced. In contrast, a high degree of OMW decolorization (more than 70%) was observed with P. chrysosporium which was grown in a medium with a low Mn(II) concentration but which resulted in a high level of LiP activity (0.3 (mu)M). In this culture medium, increasing the Mn(II) concentration resulted in decreased levels of OMW decolorization and LiP activity. Decolorization by reconstituted cultures of P. chrysosporium was found to be more enhanced by the addition of isolated LiP than by the addition of isolated MnP. The highest OMW decolorization levels were obtained at low initial chemical oxygen demands combined with high levels of extracellular LiP. These data, plus the positive effect of veratryl alcohol on OMW decolorization and LiP activity, indicate that culture conditions which yield high levels of LiP activity lead to high levels of OMW decolorization.
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Laccase-catalyzed oxygen delignification of kraft pulp offers some potential as a replacement for conventional chemical bleaching and has the advantage of requiring much lower pressure and temperature. However, chemical mediators are required for effective delignification by laccase, and their price is currently too high at the dosages required. To date, most studies have employed laccase from Trametes versicolor. We have found significant differences in reactivity between laccases from different fungi when they are tested for pulp delignification in the presence of the mediators 2,2(prm1)-azinobis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) and 1-hydroxybenzotriazole (HBT). A more detailed study of T. versicolor laccase with ABTS and HBT showed that HBT gave the most extensive delignification over 2 h but deactivated the enzyme, and therefore a higher enzyme dosage was required. Other mediators, including 1-nitroso-2-naphthol-3,6-disulfonic acid, 4-hydroxy-3-nitroso-1-naphthalenesulfonic acid, promazine, chlorpromazine, and Remazol brilliant blue, were also tested for their ability to delignify kraft pulp. Studies with dimeric model compounds indicated that the mechanisms of oxidation by ABTS and HBT are different. In addition, oxygen uptake by laccase is much slower with HBT than with ABTS. It is proposed that the dication of ABTS and the 1-oxide radical of HBT, with redox potentials in the 0.8- to 0.9-V range, are required for pulp delignification.
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The expression of laccase in the white rot fungus Trametes versicolor is regulated at the level of gene transcription by copper and nitrogen. We used reverse transcription-PCR to demonstrate that as the concentration of copper or nitrogen in fungal cultures was increased, an increase in laccase activity, corresponding to increased laccase gene transcription levels, was observed. In addition, we demonstrated that the amounts of laccase mRNA and laccase activity in 10-day-old cultures were a direct function of the concentration of either 1-hydroxybenzotriazole, a previously described laccase substrate, or 2,5-xylidine, a well-known laccase inducer, in the medium. No induction was observed after the addition of two aromatic acids, ferulic acid and veratric acid, which have been shown to induce laccase production in other white rot fungi. When either copper, 2,5-xylidine, or both compounds were added to cultures grown in the absence of copper, increased laccase transcript levels were detected within 15 min. Corresponding increases in laccase activity were observed after 24-h incubation only when copper was present.
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Continuous phenol degradation was studied in a completely mixed reactor, at steady state conditions, using the mycelium of Fusarium Floociferum immobilized in Polyurethane foam. Experiments at different dilution rates, 0.069, 0.118 and 0.196h−1 with an influent phenol concentration of 1g/l, showed a virtually complete substrate utilization over a period of four months. Low biomass productivity values of suspended cells were found, 0.21, 0.34 and 1.81g d.w./l. day, especially when compared with those obtained with the free cell system at similar conditions: 0.955 and 6.73g d.w./l.day for 0.063 and 0.116h dilution rates. The immobilized cells behaviour at different feed substrate concentrations was studied at D=0.196h.−1 corresponding to a retention time of 5.1h. The results indicate that above 1g/l the complete phenol removal is not achieved. A progressive increase in the outlet concentration was observed, attaining a value of 284mg/l at 1.5g/l. Respiratory experiments made with the immobilized cells taken from the reactor along with these experiment, indicate that the viability is retained by the mycelium, pointing out its ruling part in the phenol degradation. Culture fluid viscosity measurements were made and the rheological characteristics of the two systems were investigated. A non-Newtonian fluid was observed in the free cell system, with a shear-thinning behaviour. The immobilization had a beneficial effect on the rheology of the fluid i.e. the viscosity was much lower,1.2 c.p.s. and there was a tendency to approach Newtonian behaviour.
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In order to screen for novel fungus with powerful delignification capability on rice straw, fungal samples found on woody surfaces were collected from several regions in China and were isolated and screened for their lignin-degrading properties on rice straw. After the individual isolates were cultivated on rice straw as the sole carbon substrate for 10 days, gravimetric fiber extraction analysis was used to determine the change in holocellulose and lignin content. Isolate 812 exhibited a high degree of lignin degradation at 34.7% while maintaining low holocellulose degradation at 2.1%, which performed better than the traditional white-rot fungus Phanerochaete chrysosporium with 28.3% lignin degradation and 28.4% holocellulose degradation. Isolate 812 was identified as Fusarium moniliforme based on its 18S rDNA gene sequence and its morphological characteristics. Ligninolytic enzyme assay indicated that the fungus produced lignin peroxidase and manganese peroxidase during solid-state and liquid fermentation. Above results indicated that we had screened a F. moniliforme isolate with highly efficient delignification capability and very slight damage to holocellulose. The newly isolated fungus could be used in biodegradation of lignocellulosic feedstock.
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Fungi are considered good producers of industrially valuable enzymes with higher enzymatic activities. Among these cellulases are group of extracellular enzymes commonly employed in many industries for the hydrolysis of cellulolytic material. Aspergillus fumigatus produced exoglucanase having high enzymatic activity (83 U/gds) during the solid-state fermentation of wheat straw under optimum physical and nutritional conditions. Maximum production was obtained after 72 h of fermentation, at 55 °C temperature, pH 5.5, 80 % moisture level, and 2 mL fungal inoculum. Production was further increased by the addition of fructose (0.3 %) as additional carbon source, peptone (0.4 %) as nitrogen source, Tween-80 (0.3 %) as surfactant, and ammonium sulfate (0.2 %) in media. Exoglucanase was 2.30-folds purified by adding 40 % ammonium sulfate with volumetric activity 95.4 U/gds and specific activity 14.74 U/mg. Further, it was 5.18-folds purified by gel filtration chromatography with volumetric activity 115.2 U/gds and specific activity 33.10 U/mg. Purified exoglucanase has maximum activity at 55 °C and pH 4.8 using 1 % Avicel aqueous solution as substrate. The K m and V max were 4.34 mM and 7.29 μM/min, respectively. Calcium, magnesium, and zinc ions have positive effect on exoglucanase activity.
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Background and purpose: Napiergrass (Pennisetum purpureum Schumacher) and pangolagrass (Digitaria decumbens Stent) are two major forage grasses for cow feeding. They possess high yields and high regeneration properties. Inoculation of cellulolytic microbes on herbage could enhance the protein content of herbage and promote digestibility in chickens. Methods: Cellulolytic microbes were isolated from various sources and cultivated on napiergrass and pangolagrass with solid-state fermentation for protein enrichment and in vitro digestion improvement.The fermented napiergrass and pangolagrass were used as the main protein source in chicken diets to assess the feasibility for non-ruminants feed. Results: After a 42-day fermentation period, napiergrass showed higher protein contents (13.4-13.9%) than those of pangolagrass(11.1-11.7%). The in vitro digestibility of pangolagrass increased from 5.29% to 20.4%, whereas that of napiergrass increased from 5.29% to 19.0%. The average feed conversion efficiencies of chickens were close to the traditional fodder using corn as the main ingredient. Conclusion: Inoculation of appropriate cellulolytic microbes to enrich protein content and improve in vitro digestibility of herbage with solid-state fermentation for chicken feed is the prospective technique for agriculture, animal husbandry, and substantial management.
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Several parameters mostly affecting the precision and accuracy of vanillin assay were reexamined and optimized. The reexamination was performed both by vanillin reaction with catechins and by vanillin reaction with purified proanthocyanidins. In addition to the acid nature and concentration, the reaction time, the temperature, and the vanillin concentration, other factors such as the water content, the presence of interfering substances, and the standard utilized, for both vanillin reaction with catechins and vanillin reaction with proanthocyanidins, were also important. However, the kinetics of the two types of reactions were markedly different. For estimating accurately catechins or proanthocyanidins that exist simultaneously in plant tissues, it is necessary to preliminarily separate them from each other. Keywords: Catechins; proanthocyanidins; vanillin assay
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Publisher Summary This chapter discusses the analysis of total phenols and other oxidation substrates and antioxidants by means of Folin-Ciocalteu reagent. Analyses of the Folin-Ciocalteu (FC) type are convenient, simple, and require only common equipment and have produced a large body of comparable data. Under proper conditions, the assay is inclusive of monophenols and gives predictable reactions with the types of phenols found in nature. Because different phenols react to different degrees, expression of the results as a single number—such as milligrams per liter gallic acid equivalence—is necessarily arbitrary. Because the reaction is independent, quantitative, and predictable, analysis of a mixture of phenols can be recalculated in terms of any other standard. The assay measures all compounds readily oxidizable under the reaction conditions and its very inclusiveness allows certain substances to also react that are either not phenols or seldom thought of as phenols (e.g., proteins). Judicious use of the assay—with consideration of potential interferences in particular samples and prior study if necessary—can lead to very informative results. Aggregate analysis of this type is an important supplement to and often more informative than reems of data difficult to summarize from various techniques, such as high-performance liquid chromatography (HPLC) that separate a large number of individual compounds .The predictable reaction of components in a mixture makes it possible to determine a single reactant by other means and to calculate its contribution to the total FC phenol content. Relative insensitivity of the FC analysis to many adsorbents and precipitants makes differential assay—before and after several different treatments—informative.
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Biophenolic compounds constitute a complex mixture in olives and derived products. In this work, ion-spray tandem mass spectrometry coupled with liquid chromatography is applied to the identification and quantification of biophenols present in complex matrices such as olives and vegetation waters. The extraction and purification method for the biophenol present in both the matrices is reported. Using this approach the main biophenols found, in three different variety of olives, were: tyrosol, hydroxytyrosol, oleoside methyl ester, oleoside dimethyl ester, and oleuropein. In vegetation water the biophenols are present in lower amounts than in olives.
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Treatment of crop residues with some species of white-rot fungi can enhance digestibility. This study was conducted to investigate changes in in-vitro dry matter disappearance (IVDMD) and degradation of cell wall constituents in maize (Zea maize L) stover treated with three white-rot fungi: Cyathus stercoreus, Phlebia brevispora and Phanerochaete chrysosporium. Solid fermentation of maize stover for 28 days at 27°C improved IVDMD from 409 g kg−1 (control) to 514 g kg−1 for P brevispora and 523 g kg−1 for C stercoreus. In contrast, growth of P chrysosporium reduced IVDMD from 409 to 298 g kg−1. All fungi degraded cell wall p-coumaric acid (PCA) and ferulic acid (FA), but P chrysosporium was the least effective in degrading PCA and FA. Conversely, P chrysosporium degraded lignin 1·6 times more effectively than C stercoreus and 1·4 times more than P brevispora, indicating that lignin degradation alone cannot account for the IVDMD enhancement and that degradation of PCA and FA may be important. Hemicelluloses were preferentially and highly utilized by all the fungi. Cellulose was extensively degraded only by P chrysosporium (69% lost after 28 days of incubation), while substrate colonized by the other two fungi retained more than 84% original cellulose. Incubation of C stercoreus and P brevispora decreased the concentrations of both xylose and arabinose, but increased glucose concentration, whereas P chrysosporium removed less xylose and decreased glucose concentration. Preferential removal of arabinose over xylose by the fungi caused an increase in the xylose to arabinose ratio of the treated residues. Enhanced digestibility may have resulted from cleavage of lignin-carbohydrate bonds. Results of this study suggest that digestibility enhancement of maize stover colonized by white-rot fungi is regulated by a complex combination of various factors, including the degradation of structural carbohydrates, cell wall phenolic acids and lignin.
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A β-O-4 lignin substructure model compound, 2-(2,6-dimethoxy-4-formylphenoxy)-1,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)propane, was oxidized by Coriolus versicolor laccase in the presence of 1-hydroxybenzotriazole to form four products: 2,3-dihydroxy-1-(4-ethoxy-3-methoxyphenyl)propanone, 1-(4-ethoxy-3-methoxyphenyl)-3-hydroxypropanone, 4-ethoxy-3-methoxybenzoic acid, and 2,6-dimethoxy-p-benzoquinone. The results show that three types of the reactions, β-ether cleavage, Cα-Cβ cleavage, and Cα-oxidation are catalyzed by laccase–1-hydroxybenzotriazole couple. Furthermore, depolymerization of a polymeric guaiacyl lignin model compound prepared from [β-14C]coniferyl alcohol was also caused by this system.
Article
Several white rot fungi were evaluated for their ability to decolorize olive mill waste-waters (OMW). Among these, Phanerochaete chrysosporium showed the highest potential for the biological depollution of OMW. Approximately 65% of the color and 73% of the chemical oxygen demand (COD) were removed by P. chrysosporium strain HD. Phlebia radiata, Dichomitus squalens, Polyporus frondosus and Coriolus versicolor could also decolorize the OMW but to a lesser extent. The different abilities of these white rot fungi to decolorize OMW correlated with their rates of depolymerization of high molecular weight aromatics and the degradation of the low molecular weight aromatic compounds. Fourteen strains of P. chrysosporium were compared on the basis of their lignin peroxidase (LiP) production, OMW decolorization and residual material dry weight. High lignin peroxidase producer strains, such as strains HD and BKM-F-1767, showed the highest rates of OMW decolorization, P. chrysosporium strains 79–36 and FP 104297 (low LiP producer strains) did not exhibit any decolorization activity.
Article
Aspergillus niger KKS, a laboratory isolate, has previously been shown to have considerable cellulolytic and hemicellulolytic activity when grown on rice-straw. In the present work, we have compared the activities, yields and productivities of cellulase and xylanase obtained in shake-flask, stirred-tank, bubble-column, and air-lift reactors. In general, better yield and productivity were shown in a bubble-column and an external-loop air-lift than in the stirred-tank reactor. The highest yield and productivity of cellulase were 84 FPA IU/g and 9.7 FPA IU/l.h, obtained by fed-batch mode in the bubble-column and in the stirred-tank reactor, respectively. In the case of β-glucosidase, the highest yield and productivity were 370 U/g and 26 U/l.h in an external-loop air-lift reactor. For xylanase, the highest yield was 9100 U/g in a bubble-column, and the highest productivity was 823 U/l.h in an external-loop air-lift reactor with fed-batch mode.
Article
A thermostable cellulase-producing fungus, HML 0278, was identified as Fusarium chlamydosporum by morphological characteristics and ITS rDNA sequence analysis. HML 0278 produced extracellular cellulases in solid-state fermentation using sugar cane bassage as the carbon source. Native-PAGE analysis demonstrated that this fungus strain was capable of producing the three major components of cellulases and xylanase, with a yield of 281.8IU/g for CMCase, 182.4IU/g for cellobiohydrolase, 135.2IU/g for β-glucosidase, 95.2IU/g for filter paper activity, and 4,720IU/g for xylanase. More importantly, the CMCase and β-glucosidase produced by HML 0278 showed stable enzymatic activities within pH 4–9 and pH 4–10, and at temperatures below 70 and 60°C, respectively. KeywordsBeta-glucosidase-CMCase- Fusarium chlamydosporum -Identification-Thermostable cellulase
Article
Various agricultural and kitchen waste residues were assessed for their ability to support the production of a complete cellulase system by Aspergillus niger NS-2 in solid state fermentation. Untreated as well as acid and base-pretreated substrates including corn cobs, carrot peelings, composite, grass, leaves, orange peelings, pineapple peelings, potato peelings, rice husk, sugarcane bagasse, saw dust, wheat bran, wheat straw, simply moistened with water, were found to be well suited for the organism's growth, producing good amounts of cellulases after 96 h without the supplementation of additional nutritional sources. Yields of cellulases were higher in alkali treated substrates as compared to acid treated and untreated substrates except in wheat bran. Of all the substrates tested, wheat bran appeared to be the best suited substrate producing appreciable yields of CMCase, FPase and β-glucosidase at the levels of 310, 17 and 33 U/g dry substrate respectively. An evaluation of various environmental parameters demonstrated that appreciable levels of cellulases could be produced over a wide range of temperatures (20-50 °C) and pH levels (3.0-8.0) with a 1:1.5 to 1:1.75 substrate to moisture ratio.
Article
The recent information regarding the healthy properties of virgin olive oil phenols and the interest in increasing the value of byproducts from the oil extraction processs support the standardized development of phenol-enriched olive oil. Accordingly, the aim of this research work was to evaluate strategies for the development of a virgin olive oil enriched with phenolic compounds obtained from olive cake to increase phenolic ingestion without the drawback of a higher calorie intake. For this proposal, different combinations of phenolic extracts were evaluated at a range of concentrations to obtain the best prototype of enriched olive oil. To study the functionality of the phenol enrichments, the total phenolic content and the oxidative stability were determined by the Folin-Ciocalteu and Rancimat tests, respectively. In addition, the phenolic composition and antioxidant capacity (ORAC assay) of the oils were studied. Finally, the stability and potential bioaccesibility of the phenolic fraction of the enriched oils were tested by an in vitro gastrointestinal digestion model. Results of the study showed different strategies to select the best prototype of enriched olive oil, taking into consideration not only their phenolic content but also other important factors such as the feasibility of implementing the preparation process in the food industry.
Article
In order to improve the digestibility and nutrient availability in rumen, wheat straw was subjected to solid state fermentation (SSF) with white-rot fungi (i.e. Pleurotus ostreatus and Trametes versicolor) and the fermented biomass (called myco-straw) was evaluated for biochemical, enzymatic and nutritional parameters. The fungal treatment after 30 days led to significant decrease (P < 0.05) in cell wall constituents viz, acid detergent fiber (ADF), neutral detergent fiber (NDF), hemicellulose, lignin and cellulose to the extent of 35.00, 38.88, 45.00, 37.48 and 37.86%, respectively in P. ostreatus fermented straw, while 30.04, 33.85, 39.90, 31.29 and 34.00%, respectively in T. versicolor fermented straw. However, maximum efficiency of fermentation in terms of low carbohydrate consumption per unit of lignin degradation, favoring cattle feed production was observed for P. ostreatus on the 10th day (17.12%) as compared with T. versicolor on the 30th day (16.91%). The myco-straw was found to contain significantly high (P < 0.05) crude protein (CP; 4.77% T. versicolor, 5.08% P. ostreatus) as compared to control straw (3.37%). Metabolizable energy (ME, MJ/kg DM), percent organic matter digestibility (OMD) and short chain fatty acids (SCFAs; mmol) production also increased considerably from control straw (4.40, 29.91 and 0.292) to a maximum up to P. ostreatus fermented straw (4.92, 33.39 and 0.376 on 20th day) and T. versicolor fermented straw (4.66, 31.74 and 0.334 on 10th day), respectively. Moreover, the myco-straw had lower organic carbon and was rich in nitrogen with lower C/N ratio as compared to control wheat straw. Results suggest that the fungal fermentation of wheat straw effectively improved CP content, OM digestibility, SCFAs production, ME value and simultaneously lowered the C/N ratio, thus showing potential for bioconversion of lignin rich wheat straw into high energy cattle feed.
Article
To produce high laccase activities from the white-rot fungus Fomes fomentarius. Different culturing methods, viz, cell immobilization on stainless steel sponges and plastic material and solid-state fermentation (SSF) using wheat bran as substrate were used for laccase production by the white-rot fungus F. fomentarius. The SSF study expresses the highest laccase activities, nearly to 6400 U l(-1) after 13 days of laboratory flasks cultivation. When the wheat bran medium was supplemented with 2 mmol l(-1) copper sulfate, laccase activity increased by threefold in comparison to control cultures, reaching 27 864 U l(-1). With the medium thus optimized, further experiments were performed in a 3 l fixed-bed bioreactor (working volume 1.5 l) leading to a laccase activity of about 6230 U l(-1) on day 13. The results obtained clearly showed the superiority of wheat bran for laccase production over stainless steel sponges and plastic material. Supplementing the wheat bran solid medium with 2 mmol l(-1) copper sulfate allowed obtaining high activities at flask scale. The system was scaled to fixed-bed laboratory reactor. The high enzyme production along with the low-cost of the substrate, showed the suitability of the system F. fomentarius- SSF for industrial purposes.
Article
This study describes the production of xylanases from Aspergillus niveus, A. niger, and A. ochraceus under solid-state fermentation using agro-industrial residues as substrates. Enzyme production was improved using a mixture of wheat bran and yeast extract or peptone. When a mixture of corncob and wheat bran was used, xylanase production from A. niger and A. ochraceus increased by 18%. All cultures were incubated at 30 degrees C at 70-80% relative humidity for 96 h. For biobleaching assays, 10 or 35 U of xylanase/g dry cellulose pulp were incubated at pH 5.5 for 1 or 2 h, at 55 degrees C. The delignification efficiency was 20%, the brightness (percentage of ISO) increased two to three points and the viscosity was maintained confirming the absence of cellulolytic activity. These results indicated that the use of xylanases could help to reduce the amount of chlorine compounds used in cellulose pulp treatment.
Article
A laccase, the only ligninolytic enzyme produced by the basidiomycete Pleurotus ostreatus strain RK 36 was purified to homogeneity and characterized. The enzyme is a monomeric protein with a molecular weight of 67 000 Da and an isoelectric point of 3.6. Type I and type III Cu(2+) centers were identified by spectrophotometry. With syringaldazine as substrate laccase showed the highest oxidation rates at pH 5.8, 50 degrees C, and in 40 mM phosphate buffer. Among the tested stabilization parameters laccase retained most of its activity in high ionic buffer, pH 10, -20 degrees C, in the presence of 10 mM benzoic acid and with 35% ethylene glycol respectively. Crude laccase was covalently immobilized to Eupergit((R))C. Benzoate was found to stabilize the enzyme during the immobilization process. The activity loss of laccase during 10 days at 25 degrees C storage was 2% on average. Continuous elimination of 2,6-dimethoxyphenol by immobilized laccase was carried out in a packed bed reactor followed by filtration of the formed precipitate. The solubility of the polymerisates of oxidized syringaldazine, o-dianisidine, and 2,6-dimethoxyphenol with respect to temperature, pH-value and organic solvents were examined. The precipitates were found to be insoluble under non-extreme environmental conditions.
Article
In the used media mainly consisting of steam-exploded wheat straw, the straw, which could replace expensive veratryl alcohol, might act not only as nutrient, but also as inducer of lignin enzymes. The activities of the enzymes lignin peroxidase (LiP) and manganese peroxidase (MnP) in solid-state fermentation (SSF) were far higher than in submerged fermentation (SmF). Under optimal conditions of SSF, the maximum activities of the enzymes Lip and MnP were 2600 and 1375 U/L, respectively. Thus, this would pave the way for production and application of lignin enzymes on a large scale.
Article
The partition coefficient (K(p)) of the natural phenolic antioxidant compounds in the olive fruit between aqueous and olive oil phases was determined. The antioxidants of olive oil are either present in the olive fruit or formed during the olive oil extraction process. The antioxidants impart stability to and determine properties of the oil and are valuable from the nutritional point of view. The olive oil antioxidants are amphiphilic in nature and are more soluble in the water than in the oil phase. Consequently, a large amount of the antioxidants is lost with the wastewater during processing. The determination of antioxidants was performed using HPLC, and the K(p) was estimated to be from as low as 0.0006 for oleuropein to a maximum of 1.5 for 3,4-DHPEA-EA (di-hydroxy-phenyl-ethanol-elenolic acid, oleuropein aglycon). Henry's law fitted very well to the experimental data. The partition coefficients were also estimated by applying the activity coefficients of the antioxidants in the two phases using a predictive group contribution method, the UNIFAC equation. The K(p) values estimated with UNIFAC method were of the same order of magnitude but varied from the experimental values. Nevertheless, this method may be a rough predictive tool for process optimization or design. Because the K(p) values were very low, some changes in the process are recommended in order to achieve a higher concentration of antioxidants in the oil. A temperature increase may lead to increasing the partition coefficient. Also, limiting the quantity of water during oil extraction could be a basis for designing alternative processes for increasing the antioxidant concentration in the olive oil.
Article
Processed fruits and vegetables have been long considered to have lower nutritional value than their fresh commodities due to the loss of vitamin C during processing. This research group found vitamin C in apples contributed < 0.4% of total antioxidant activity, indicating most of the activity comes from the natural combination of phytochemicals. This suggests that processed fruits and vegetables may retain their antioxidant activity despite the loss of vitamin C. Here it is shown that thermal processing elevated total antioxidant activity and bioaccessible lycopene content in tomatoes and produced no significant changes in the total phenolics and total flavonoids content, although loss of vitamin C was observed. The raw tomato had 0.76 +/- 0.03 micromol of vitamin C/g of tomato. After 2, 15, and 30 min of heating at 88 degrees C, the vitamin C content significantly dropped to 0.68 +/- 0.02, 0.64 +/- 0.01, and 0.54 +/- 0.02 micromol of vitamin C/g of tomato, respectively (p < 0.01). The raw tomato had 2.01 +/- 0.04 mg of trans-lycopene/g of tomato. After 2, 15, and 30 min of heating at 88 degrees C, the trans-lycopene content had increased to 3.11+/- 0.04, 5.45 +/- 0.02, and 5.32 +/- 0.05 mg of trans-lycopene/g of tomato (p < 0.01). The antioxidant activity of raw tomatoes was 4.13 +/- 0.36 micromol of vitamin C equiv/g of tomato. With heat treatment at 88 degrees C for 2, 15, and 30 min, the total antioxidant activity significantly increased to 5.29 +/- 0.26, 5.53 +/- 0.24, and 6.70 +/- 0.25 micromol of vitamin C equiv/g of tomato, respectively (p < 0.01). There were no significant changes in either total phenolics or total flavonoids. These findings indicate thermal processing enhanced the nutritional value of tomatoes by increasing the bioaccessible lycopene content and total antioxidant activity and are against the notion that processed fruits and vegetables have lower nutritional value than fresh produce. This information may have a significant impact on consumers' food selection by increasing their consumption of fruits and vegetables to reduce the risks of chronic diseases.
Article
The oil palm sector is one of the major plantation industries in Malaysia. Palm kernel cake is a byproduct of extracted palm kernel oil. Mostly palm kernel cake is wasted or is mixed with other nutrients and used as animal feed, especially for ruminant animals. Recently, palm kernel cake has been identified as an important ingredient for the formulation of animal feed, and it is also exported especially to Europe, South Korea, and Japan. It can barely be consumed by nonruminant (monogastric) animals owing to the high percentages of hemicellulose and cellulose contents. Palm kernel cake must undergo suitable pretreatment in order to decrease the percentage of hemicellulose and cellulose. One of the methods employed in this study is fermentation with microorganisms, particularly fungi, to partially degrade the hemicellulose and cellulose content. This work focused on the production of enzymes by Aspergillus niger and profiling using palm kernel cake as carbon source.
Article
Solid-state fermentation (SSF) has developed in eastern countries over many centuries, and has enjoyed broad application in these regions to date. By contrast, in western countries the technique had to compete with classical submerged fermentation and, because of the increasing pressure of rationalisation and standardisation, it has been widely superseded by classical submerged fermentation since the 1940s. This is mainly because of problems in engineering that appear when scaling up this technique. However, there are several advantages of SSF, for example high productivities, extended stability of products and low production costs, which say much about such an intensive biotechnological application. With increasing progress and application of rational methods in engineering, SSF will achieve higher levels in standardisation and reproducibility in the future. This can make SSF the preferred technique for special fields of application such as the production of enzymes and food.
Article
The effects of biological pretreatment of rice straw using four white-rot fungi (Phanerochaete chrysosporium, Trametes versicolor, Ceriporiopsis subvermispora, and Pleurotus ostreatus) were evaluated on the basis of quantitative and structural changes in the components of the pretreated rice straw as well as susceptibility to enzymatic hydrolysis. Of these white-rot fungi, P. ostreatus selectively degraded the lignin fraction of rice straw rather than the holocellulose component. When rice straw (water content of 60%) was pretreated with P. ostreatus for 60 d, the total weight loss and the degree of Klason lignin degraded were 25% and 41%, respectively. After the pretreatment, the residual amounts of cellulose and hemicellulose were 83% and 52% of those in untreated rice straw, respectively. By enzymatic hydrolysis with a commercial cellulase preparation for 48 h, 52% holocellulose and 44% cellulose in the pretreated rice straw were solubilized. The net sugar yields based on the amounts of holocellulose and cellulose of untreated rice straw were 33% for total soluble sugar from holocellulose and 32% for glucose from cellulose. The SEM observations showed that the increase in susceptibility of rice straw to enzymatic hydrolysis by pretreatment with P. ostreatus is caused by partial degradation of the lignin seal. When the content of Klason lignin was less than 15% of the total weight of the pretreated straw, enhanced degrees of enzymatic solubilization of holocellulose and cellulose fractions were observed as the content of Klason lignin decreased.
Article
F(3) and F(4) strains of Aspergillus niger were screened from five strains of fungi to produce multienzyme preparations (containing cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase) as dietary supplementation. Enzyme activities indicated that 1:4 (F(3) to F(4)) was the optimum mixture proportion, and 0.3% (W/W) was the preferable pitching rate. In bran mash containing 54.5% (W/W) water, F(3) and F(4) could produce the supplementation better when cultured 30 to 36 h at 30 degrees C. Monofactorial and orthogonal experiments were performed to optimize media. Results of the variance and range analysis showed that the optimum medium contained 80 g of bran, 20 g of cottonseed powder, 1 g of (NH(4))(2)SO(4), and 0.1 g of KH(2)PO(4). When F(3) and F(4 )strains were cultured in the optimum medium containing 54.5% (W/W) water, the activity of cellulase, hemicellulase, glucoamylase, pectinase, and acidic proteinase reached 996; 15,863; 13,378; 7,621; and 5,583 U/g, respectively.
Article
The process parameters influencing the production of extracellular laccases by Streptomyces psammoticus MTCC 7334 were optimized in submerged fermentation. Coffee pulp and yeast extract were the best substrate and nitrogen source respectively for laccase production by this strain. The optimization studies revealed that the laccase yield was maximum at pH 7.5 and temperature 32 degrees C. Salinity of the medium was also observed to be influencing the enzyme production. An agitation rate of 175 rpm and 15% inoculum were the other optimized conditions for maximum laccase yield (5.9 U/mL). Pyrogallol and para-anisidine proved to be the best inducers for laccase production by this strain and the enzyme yield was enhanced by 50% with these inducers. S. psammoticus was able to decolourize various industrial dyes at different rates and 80% decolourization of Remazol Brilliant Blue R (RBBR) was observed after 10 days of incubation in dye based medium.
Article
Compared with batch systems, flowthrough and countercurrent reactors have important potential advantages for pretreating cellulosic biomass, including higher hemicellulose sugar yields, enhanced cellulose digestibility, and reduced chemical additions. Unfortunately, they suffer from high water and energy use. To better understand these trade-offs, comparative data are reported on xylan and lignin removal and enzymatic digestibility of cellulose for corn stover pretreated in batch and flowthrough reactors over a range of flow rates between 160 degrees and 220 degrees C, with water only and also with 0.1 wt% sulfuric acid. Increasing flow with just water enhanced the xylan dissolution rate, more than doubled total lignin removal, and increased cellulose digestibility. Furthermore, adding dilute sulfuric acid increased the rate of xylan removal for both batch and flowthrough systems. Interestingly, adding acid also increased the lignin removal rate with flow, but less lignin was left in solution when acid was added in batch. Although the enzymatic hydrolysis of pretreated cellulose was related to xylan removal, as others have shown, the digestibility was much better for flowthrough compared with batch systems, for the same degree of xylan removal. Cellulose digestibility for flowthrough reactors was related to lignin removal as well. These results suggest that altering lignin also affects the enzymatic digestibility of corn stover.
Article
Thermophilic aerobic digestion (TAD) of heteroxylan waste was implemented at waste load of 30gL(-1) with mineral nitrogen supplementation to study effect of the process on waste degradation, protein accretion and quality. Digestions were carried out at 45 50, 55, 60 and 65 degrees C using Bacillusstearothermophilus in a CSTR under batch conditions at 1.0vvm aeration rate, pH 7.0 for a maximum of 120h. Amylase and xylanase activities appeared rapidly in the digest, while basal protease activity appeared early in the digestion and increased towards end of the processes. Highest degradation of volatile suspended solid, hemicellulose and fibre occurred at 55 degrees C while highest degradation of total suspended solid occurred at 60 degrees C. Highest protein accretion (258.8%) and assimilation of mineral nitrogen and soluble protein occurred at 55 degrees C. The % content of amino acids of digest crude protein increased relative to raw waste and with digestion temperature. Quality of digest protein was comparable to the FAO standard for feed use. TAD has potentials for use in the protein enrichment of waste.
Article
To investigate the production of cellulases and hemicellulases from Aspergillus niger KK2, solid state fermentation (SSF) was performed by using different ratios of rice straw and wheat bran. When A. niger KK2 was grown on rice straw alone as a solid support in SSF, the maximum FPase activity was 19.5 IU g(-1) in 4 days. Also, CMCase (129 IU g(-1)), beta-glucosidase (100 IU g(-1)), xylanase (5070 IU g(-1)) and beta-xylosidase (193 IU g(-1)) activities were concurrently obtained after 5-6 days of fermentation. The higher enzyme activities produced by A. niger KK2 is a significant advantage from the viewpoint of practical saccharification reaction. Cellulases and hemicellulases produced by A. niger KK2 might be applied to pulp and paper industry, feed industry and chemical industry.