Aerobic and anaerobicin vitrotesting of feed additives claiming to detoxify deoxynivalenol and zearalenone

Abstract

Deoxynivalenol (DON) and zearalenone (ZEN) are mycotoxins produced by fungi of the genus Fusarium which frequently contaminate maize and grain cereals. Mycotoxin-contaminated feed endangers animal health and leads to economic losses in animal production. Several mycotoxin elimination strategies, including the use of commercially available DON and ZEN detoxifying agents, have been developed. However, frequently there is no scientific proof of the efficacy of such adsorbents and degrading products. We therefore tested 20 commercially available products claiming to detoxify DON and/or ZEN either by biodegradation (4 products) or a combination of degradation and adsorption (16 products) under aerobic and anaerobic conditions at approx. pH 7. Under the applied conditions, a complete reduction of DON and consequent formation of the known non-toxic metabolite DOM-1 was exclusively observed in samples taken from the anaerobic degradation experiment of one product. For all other products, incubated under aerobic and anaerobic conditions, a maximum DON reduction of 17% after 72 h of incubation was detected. Aerobic and anaerobic incubation of only one tested product resulted in complete ZEN reduction as well as in the formation of the less-toxic metabolites DHZEN and HZEN. With this product, 68-97% of the toxin was metabolised within 3 h. After 24 h, a ZEN reduction ≥ 60% was obtained with four additional products during aerobic incubation only. Six of the 20 investigated products produced α- and/or β-ZEL, which are metabolites showing similar oestrogenic activity compared to ZEN. Aerobic and anaerobic degradation to unknown metabolites with unidentified toxicity was obtained with 10 and 3 products, respectively. The results of our study demonstrate the importance of in vitro experiments to critically screen agents claiming mycotoxin detoxification.

Masked trichothecene and zearalenone mycotoxins withstand digestion and absorption in the upper GI tract but are efficiently hydrolyzed by human gut microbiota in vitro

“…In the present study we propose zearalanol, zearalenol, zearalanone (ZAN), hydrolyzed zearalenone (HZEN), and decarboxylated hydrolyzed zearalenone (DHZEN) as potential metabolites using HRMS and accurate mass detection. HZEN and DHZEN have been identified recently and described as anaerobic microbial ZEN degradation products in a study comparing several microbial feed additives . Other microbial additives tested produced a range of unidentified metabolites under both aerobic and anaerobic conditions.…”

Detoxification of Mycotoxins through Biotransformation

“…Indeed, not all converted products are nontoxic. Some converted products are still toxic or even more toxic [170,171]. Some mycotoxins are converted into the masked forms such as ZEN 14-O-glucoside (107) and ZEN 16-O-glucoside (108), which can be accumulated in organisms and cannot be eliminated [81,172,173].…”

Strategies and Methodologies for Developing Microbial Detoxification Systems to Mitigate Mycotoxins

“…For physical strategies, the application of adsorption agents has become popular since the European Union (EU) allowed substrates that suppress or reduce the absorption, promote the excretion of mycotoxins or modify their mode of action to be used as feed additives [10]. However, the efficacy of adsorption agents in reducing mycotoxin contamination is variable, and most of the commercial binding agents presented no sufficient effect against DON [11]. Compared with chemical and physical approaches, biological detoxification methods, which biotransform mycotoxins into less toxic metabolites, are generally more specific, efficient and environmentally friendly.…”