The most frequently used approach to deactivate mycotoxins in animal feeds is the application of adsorbents which bind toxins and reduce the absorption in the gastrointestinal tract. However, the drawback of this method is that only a group of bentonite clays with a high smectite content work against aflatoxins and ergot alkaloids, but have limitations against other relevant mycotoxins. Microorganisms or their enzymes with the capability to detoxify mycotoxins by degradation or biotransformation can be used to overcome the limitations of binding agents. Such microorganisms can be found in the environment where they prevent any significant accumulation of fungal toxins by utilizing them as carbon- or energy source. Our objective is to isolate microorganisms or their enzymes which catabolize mycotoxins and apply those as additives in food and feed. One of these microorganisms designated as BBSH 797 originates from the rumen of a cow and was identified as genus novus of family Coriobacteriacae. This bacterium is capable of detoxifying trichothecenes by reduction of their epoxide rings. We also isolated several microorganisms for catabolizing and detoxifying fumonisins. For several reasons none of these strains was useful as a direct fed microbial type of mycotoxin detoxifying additive. Therefore we explored the catabolic pathway of fumonisin degradation and identified the key gene of detoxification, which was a carboxylesterase. Then we cloned and expressed this gene in a yeast strain, purified the enzyme and tested it in swine for its gastrointestinal detoxification capacity. Based on various parameters like sphinganine/sphingosine biomarker and expression of immune genes we could confirm that this enzyme works in the gastrointestinal environment. Recently the European Food Safety Authority (EFSA) provided a positive opinion on BBSH797 and the carboxylesterase to the European Commission based on efficacy- and safety data.

Mycotoxin deactivation strategies – past, presence and future

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.