Enzymatic Detoxification of Zearalenone-Contaminated Wheat and Corn Grain Using a Recombinant Zearalenone Hydrolase from Clonostachys rosea

Zearalenone (ZEN) produced by some Fusarium fungi is one of the most prevalent mycotoxins in forage. Due to restrictions in the organic agriculture, biodegradation of this and other mycotoxins is more preferable way to control these contaminants. Here, a purified recombinant ZEN-specific lactonohydrolase (rZHD) from Clonostachys rosea expressed in Penicillium canescens PCA-10 was evaluated for its ZEN-degrading activity in both model solutions and artificially infected wheat and corn grain under optimal conditions (30 °C, pH 8.5). ZEN degradation dynamics in a model solution containing purified rZHD showed the most part of the toxin was degraded after 3 h of incubation; no residual ZEN was revealed after 12 h of incubation. Inoculation of wheat and corn grain with toxigenic F. culmorum strain BR-03–21 resulted in ZEN accumulation up to 15‒25 mg/kg. The subsequent 12-h enzymatic treatment provided degradation of 63 (wheat) and 55% (corn) of accumulated ZEN; to the end of a 24-h treatment, only 2.0 and 9.5% of ZEN remained in these samples, respectively. A complete ZEN removal from both samples was revealed after 48 h of the treatment. Due to such activity and the earlier revealed ability to work at low-temperature (10 °C) conditions, the enzyme is promising for practical application.