Isolation, identification of a zearalenone degradated strain and the properties of its producing enzymes

Abstract:

[Objective] To screen and identify a microorganism with zearalenone (ZEN) detoxification ability from fermented foods, and determine its decomposing efficiency and the properties of producing enzymes. [Methods] Solid media with toxin analogue (PL) were used to obtain toxin analogue resistant strains from 25 materials of fermented foods. Through the second screening of ZEN as the selective stress, a ZEN detoxified microorganism with high decomposition efficiency was confirmed. Its degradation efficiency was further evaluated in analysis of ZEN residue of bacteria suspension using high performance liquid chromatography (HPLC). Then we analysed the properties of producing cellulase, xylanase and β-glucosidase separately. The strain was identified for the taxonomical position using morphological observation and molecular identification. [Results] A ZEN detoxified strain BF-B-3 was screened and identified as Bacillus subtilis. Its degradation rate reached 62.48%. The cellulase, xylanase and β-glucosidase activity of Bacillus subtilis BF-B-3 reached 160.38 U/mL, 84.51 U/mL and 4.14 U/mL separately. [Conclusion] Bacillus subtilis is a kind of feed microorganism. Bacillus subtilis BF-B-3 has favorable security for detoxifying ZEN, and could grow under different carbon sources. Bacillus subtilis BF-B-3 has potential values for preventing mould pollution of crops and feed.