Biological Control of Molds and Mycotoxins in Foods

Growth and mycotoxin production by molds is influenced by the environment, including other microorganisms. Lactic acid bacteria (LAB), Bacillus species and sourdough bread cultures have been reported to inhibit mold growth which may result from competition for space and nutrients in general, competition for nutrients required for mycotoxin production but not for growth, and production of antimycotic and antimycotoxigenic metabolites. Changes in the pH of the substrate through production of organic acids, such as lactic, propionic and acetic, along with hydroxyl fatty acids, reuterin and low-molecular-weight peptides may account in part for this activity. LAB have also been reported as capable of binding mycotoxins, which shows promise for the possible use of these organisms as sequestering agents in fermented and other processed foods, as well as in the gut. In the literature there is also evidence of microbial degradation of mycotoxins, and while this area of research is promising, there are some risks associated with potential production of toxic by-products or only partial detoxification that need further study. In general, the "generally recognized as safe"(GRAS) status of LAB and sourdough cultures enhances the potential of this group of bacteria to be used in commercial applications as biological control agents in processed foods to prevent mold growth, to improve the shelf life of fermented products and to reduce potential health hazards associated with mycotoxins.