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Aspergillus flavus is a well-known ubiquitous fungus able to contaminate, both in pre- and postharvest period, different feed and food products. During their growth, these fungi can synthesize aflatoxins, secondary metabolites highly hazardous for animal and human health. Aflatoxins represent a serious problem in cattle breeding. They can have negative influence on animal health, like impaired growth or lower immunity and the intake of contaminated feed could result in production of milk and milk products unsuitable for market and human consumption due to high content of aflatoxin M1. Climatic changes make aflatoxins occurring contaminant of maize and other cereals also in EU countries. Even if different strategies for prevention and control of aflatoxins in food and feed are applied, the complete control still has not been achieved. The mitigation of mycotoxin content via enzymatic degradation could be a promising strategy to ensure safer food and feed, and to address the forthcomin g issues in view of the global trade and sustainability. Results obtained with mushroom oxidases in in vitro and in vivo experiments are encouraging, the degradation rate was up to 90%. Nevertheless, the search for active enzymes is still challenging and time-consuming.

Food and feed safety, due to their direct influence on human health, becomes every day the more and more important issue. The awareness that different chemicals, largely used in agriculture to control pests, could present both environmental problems and health hazard, led to large limitation of their use. Since 2014 European Community has banned about 50% of chemicals used in agriculture. In plant production systems chemicals were also the main tool used against fungal pathogens and against the contamination of food/feed stuff with fungal highly toxic secondary metabolites, mycotoxins. Today the EC push the research to investigate for preventive and/or detoxification strategies using more environmental friendly “green” approaches and eco-compatible tools also in control of plant fungal diseases. Different mushroom metabolites showed the potential to become a control agent for fungal growth and mycotoxin production. One of the most promising biocontrol producers is Trametes versicolor an edible and nontoxic basidiomycete, considered “healing mushroom” for its bioactivity towards some pathologies. Biocontrol agents from T. versicolor, such as polysaccharide Trametano®, oligosaccharides from its partial hydrolysis and protein fractions, are proposed to counteract the growth of some mycotoxigenic fungal species (Aspergillus flavus, A. carbonarius, A. ochraceus) and the mycotoxins synthesis (aflatoxin B1, AF ; ochratoxin A, OTA). The inhibiting effect on germination, fungal growth and toxin synthesis of these compounds was evaluated. Furthermore, some aspects of their mechanism of action is proposed and discussed. The goal of this research is to evaluate an environmental friendly tool for a significant control of mycotoxin production, in order to improve food and feed safety quality. Results indicated that biocontrol agents from T. versicolor could be considered new eco- compatible tools for mycotoxins control, in line with EU directives.

Mycotoxins are secondary metabolites produced by fungi toxic for humans and animals. Due to their toxicity, the legislations of almost all the countries have limited the concentration of most important mycotoxins in food and feed commodities. The awareness that different chemicals, largely used in agriculture to control pests, could present both environmental problems and health hazard, led to large limitation of their use. Since 2014 European Community has banned about 50% of chemicals used in agriculture. In plant production systems chemicals were also the main tool used against fungal pathogens and against the contamination of food/feed by mycotoxins. Today the EC incourage the research to investigate for control and/or detoxification strategies using more environmental friendly “green” approaches and eco-compatible tools. Prefered methods for controlling mycotoxins contamination are largely preventive and use of biocontrol agents is one of the strategies. Different mushroom metabolites showed the potential to become a control agent for fungal growth and mycotoxin production. Particularly the exo-polysaccharides from medicinal mushroom Trametes versicolor, an edible and nontoxic basidiomycete, showed some interesting potential in mycotoxin control. Biocontrol agents from T. versicolor, such as polysaccharide Tramesan®, oligosaccharides from its partial hydrolysis and protein fractions, are proposed to counteract the growth of some mycotoxigenic fungal species (Aspergillus flavus, A. carbonarius, A. ochraceus), and the mycotoxins synthesis (aflatoxin B1, AF ; ochratoxin A, OTA). The inhibiting effect on germination, fungal growth and toxin synthesis of these compounds was evaluated. Furthermore, some aspects of their mechanism of action is proposed and discussed. Results indicated that biocontrol agents from T. versicolor could be a new more eco-compatible tools for the control of biosynthesis of several mycotoxins in food and feed chain.

Aspergillus flavus is a well-known ubiquitous fungus able to contaminate, both in pre- and postharvest period, different feed and food products. During their growth, these fungi can synthesize aflatoxins, secondary metabolites highly hazardous for animal and human health. Aflatoxins represent a serious problem in cattle breeding. They can have negative influence on animal health, like impaired growth or lower immunity and the intake of contaminated feed could result in production of milk and milk products unsuitable for market and human consumption due to high content of aflatoxin M1. Climatic changes make aflatoxins occurring contaminant of maize and other cereals also in EU countries. Even if different strategies for prevention and control of aflatoxins in food and feed are applied, the complete control still has not been achieved. The mitigation of mycotoxin content via enzymatic degradation could be a promising strategy to ensure safer food and feed, and to address the forthcomin g issues in view of the global trade and sustainability. Results obtained with mushroom oxidases in in vitro and in vivo experiments are encouraging, the degradation rate was up to 90%. Nevertheless, the search for active enzymes is still challenging and time-consuming.

Aflatoxins are bioactive compounds, which are toxic and carcinogenic for humans and animals, and are produced mainly by Aspergillus flavus and A. parasiticus. We studied the effect of some bioactive compounds produced into the culture filtrates of the basidiomycete Trametes versicolor on A. flavus growth and aflatoxin synthesis. Some aspects of the mechanism of action of different filtrate fractions were investigated. The results showed that these compounds stimulate the antioxidant system of the Aspergillus mycelia by the induction of a transient and modulated oxidative burst (peroxides and superoxide anions formation) perceived by Afyap1 transcription factor. T. versicolor culture filtrate fractions, significantly inhibited aflatoxin biosynthesis (A: 75% and B: 55%) apparently by stimulating endogenous antioxidant system. In conclusion, bioactive compounds present in the T. versicolor filtrates probably act by modulating the fungal antioxidant system, eventually leading to aflatoxin inhibition. T. versicolor could represent a novel promising tool to control aflatoxins in foods and feeds.

Contamination of feed and feed stuff with aflatoxins is a worldwide problem. Probably due to climatic changes the contamination of maize with aflatoxins has become more frequent problem also in some European countries. These toxic secondary metabolites of some filamentous fungi belonging to genera Aspergillus can severely impair animal production both due to their health hazardous effects and possibility of transmission along the food chain. Along the years different control strategies were applied but none of them has solved the problem of aflatoxin contamination. The ongoing researches often focus on detoxification strategies. In this work the effect of the basidiomycete Trametes versicolor metabolites on the aflatoxin production by Aspergillus flavus in maize, was investigated. The addition of fine powder, obtained by milling 14 days old T. versicolor cultures grown on pure sugar beet pulp, to maize kernels (moistened up to aw 0.85) at 1% w/v significantly (p

Aspergillus flavus are well known ubiquitous fungi able to contaminate both in pre- and postharvest period different feed and food commodities. During their growth these fungi can synthesise aflatoxins, secondary metabolites highly hazardous for animal and human health. These mycotoxins can enter the human food chain by the direct ingestion of contaminated food and by the consumption of animal products coming from livestock fed with contaminated silages. In this work the effect of the basidiomycete Trametes versicolor on the aflatoxin production by A. flavus in maize, was investigated. T. versicolor was grown on pure sugar beet pulp for 14 days at 25°C in dark conditions. The obtained compost was dehydrated at 40°C o/n and powdered. The addition of this fine powder at 1% w/v in maize kernels (moistened up to aw 0.85) significantly (Mann- Whitney test, p

An analysis of biodeterioration on different kind of materials.

Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic).