The Detoxification Of Deoxynivalenol By Probiotic Bacteria

Deoxynivalenol (DON) was a kind of mycotoxin and belongs to trichothecenes produced by Fusarium, leading to anorexia, emesis, immunosuppression or immunostimulation, teratogeny, cytotoxicity, reproductive toxicity and human cancers. DON was mainly a common contaminant of wheat, corn and relevant products. Physical or chemical methods for detoxification of DON resulted in losses of nutrients, incomplete detoxification of mycotoxin and the residue of chemical components. Microbiological approach, especially treatment with probiotic bacteria, did not have such disadvantages and was an ideal method for detoxification due to its gentle reaction, efficiency and no contamination to environment.The aim of this study was to screen out strains that can efficiently detoxify DON from our collections of probiotic bacteria, study the detoxification mechanism and characterize the properties of those detoxified strains. All of our approach was to set up a basis for applying the detoxification method in traditional food fermentation, reducing the contaminant of mycotoxin in food chains and ensuring the food safety.The whole research work was described as follows:1. The interference effect of MRS or BA on the determination of DON by competitive indirect ELISA was eliminated maximally, by dilution and regulating pH value of the broth. Bacillus subtilis ZZ and Bacillus licheniformis DY were screened out for detoxification of DON from 59 probiotic bacteria.2. The impact of temperature, incubation time and rotation speed of revolution on the detoxification efficiency was determined. The optimal condition for detoxification of DON by Bacillus subtilis ZZ and Bacillus licheniformis DY was incubation at 37℃, 180 rpm for 12 h.3. The detoxification mechanism of Bacillus subtilis ZZ and Bacillus licheniformis DY was analyzed preliminarily. It was found that the spent culture supernatant (SCS) of two strains was involved into the detoxification of DON, the detoxification components in SCS was deduced to be the second metabolic substances and sensitive to the heating treatment above 75℃.