Recombinant Expression of Trametes versicolor Aflatoxin B1-Degrading Enzyme (TV-AFB1D) in Engineering Pichia pastoris GS115 and Application in AFB1 Degradation in AFB1-Contaminated Peanuts

Aflatoxins seriously threaten the health of humans and animals due to their potential carcinogenic properties. Enzymatic degradation approach is an effective and environmentally friendly alternative that involves changing the structure of aflatoxins. In this study, Trametes versicolor aflatoxin B-1-degrading enzyme gene (TV-AFB(1)D) was integrated into the genome of Pichia pastoris GS115 by homologous recombination approach. The recombinant TV-AFB(1)D was expressed in engineering P. pastoris with a size of approximately 77 kDa under the induction of methanol. The maximum activity of TV-AFB(1)D reached 17.5 U/mL after the induction of 0.8% ethanol (v/v) for 84 h at 28 degrees C. The AFB(1) proportion of 75.9% was degraded using AFB(1) standard sample after catalysis for 12 h. In addition, the AFB(1) proportion was 48.5% using AFB(1)-contaminated peanuts after the catalysis for 18 h at 34 degrees C. The recombinant TV-AFB(1)D would have good practical application value in AFB(1) degradation in food crops. This study provides an alternative degrading enzyme for the degradation of AFB(1) in aflatoxin-contaminated grain and feed via enzymatic degradation approach.