Transformation of trichothecene mycotoxins by microorganisms from fish digesta

Trichothecene mycotoxins are commonly found in cereals worldwide and bring significant threats to the food industry and animal production. The aim of this research was to search for microbes from fish guts capable of transforming trichothecenes into less toxic compounds. Digesta of 62 fishes from nine species were screened for their ability to transform 4-deoxynivalenol (DON). Liquid chromatography-mass spectrometry was used to determine the reduction of DON concentrations and structures of DON-transformation products. The microbial community from one catfish Ameiurus nebulosus, namely microbial culture C133, completely transformed DON to deepoxy DON (dE-DON) at 15 °C in full medium after 96 h incubation. Various media and culture conditions were tested to evaluate their effect on DON transformation. Microbial culture C133 maintained high transformation ability over a broad range of temperatures from 4 to 25 °C and pH values from 4.5 to 10.4. The transformation of DON to dE-DON was enhanced in a rich medium such as full medium, nutrient broth and corn meal broth. Microbial culture C133 was then tested for its ability to transform other trichothecene mycotoxins; most of the toxins were transformed to deacetyl and/or deepoxy products. This is the first report on trichothecene transformation by microbes from the intestinal tract of fish.