Aflatoxins Degradation Enzyme In Saccharomyces Cerevisiae Cells On The Surface Of The Display And Enzyme Activity Of Qualitative Research

Aflatoxin (AFT), the secondary metabolites of aspergillus flavus and aspergillusparasiticus, belongs to a category of mycotoxins which causes carcinogenic, teratogenic andmutagenic effects, and it is also ranked by WHO as the Group I carcinogens. The traditionalphysical and chemical detoxification methods of aflatoxin are both unstable and can lead tosignificant loses of nutrition, biological methods which are highly efficient and relatively stableattracted much attention from scientific researchers in recent years.In this pater, the gene encoding of ADTZ is cloned from the total RNA of armillariellatabescens, and the genes are connected to the pYD1vector of the surface displaying plasmid.Then, pYD1-ADTZ, the recombinant plasmid is successfully structured. After it beingtransformed into saccharomyces cerevisiae EBY100, positive transformants are screened byPCR and double digestion, and this proves that aflatoxin detoxifying enzyme genes have beenintegrated into the genome of saccharomyces cerevisiae. Primary qualitative detection is madeby measuring fluorescence reaction, and then through ELISA, the quantitative detection ofdegradation of aflatoxin B1by aflatoxin detoxifying enzyme is conducted, when the inductiontime is48hours, and the optimum reaction temperature is28℃, reaction time is3hour,Detoxification rate of the AFB1is13.1%and avtivity of recombinant protein is0.93U/L.This study on enzymatic properties of aflatoxin detoxifying enzyme on surface displayshows that when the induction time is48hours, the enzymatic properties reach the highest level,etoxification rate of the AFB1is24.2%, Moreover, when the optimum reaction time of ADTZon surface display with aflatoxin B1is3hours, the avtivity of recombinant protein reach thehighest level. Detoxification rate of the AFB1is27.3%, and the optimum reaction temperature is28°C. Comparing the activity of different induction time and reaction time, this study played animportant and basic role in production of enzymic preparations of rADTZ.