黄曲霉毒素B_(1)降解菌株的鉴定及降解产物研究

Screening and identification of an AFB_(1)-dergrading strain and product analysis

为开发有效降解黄曲霉毒素B_(1)(aflatoxin B_(1),AFB_(1))的生物菌剂,筛选降解率高的菌株进行分离鉴定,并分析降解产物,以前期筛选到AFB 1降解率高达83.5%的菌株WTX1为研究对象,通过形态学、生理生化特征及菌株16S rRNA基因测序对菌株进行鉴定,通过超高效液相色谱-串联四级杆质谱(ultra-performance liquid chromatography-MS/MS,UPLC-MS/MS)测定菌株各组分降解率,将降解液产物质谱图与软件中标准质谱库比对,分析菌株降解AFB_(1)产物结构。菌株WTX1被鉴定为枯草芽孢杆菌(Bacillus subtilis)。菌株降解AFB_(1)起主要作用的是生长过程产生的次级代谢产物。菌株WTX1降解AFB_(1)机制是破坏AFB_(1)的毒性结构即呋喃环二氢双键,香兰素内脂环结构,达到脱毒效果。较目前筛选到降解AFB_(1)的菌株,菌株WTX1更具有食品安全优势。

Aflatoxin seriously threatens human health and causes serious economic losses and arouses widespread concern in food safety.In order to develop effective biological bacterium agent against aflatoxin contamination,this study used preliminary screened strain WTX1 as the research object,the AFB_(1) degradation rate was up to 83.5%.Through morphological,physiological and biochemical analysis and the evolution of 16S rRNA system,the bacterial strain was screened as Bacillus subtilis.By UPLC-MS/MS determination of degradation rate of strain component parts,the degradation liquid mass spectrum was analyzed by software.The secondary metabolites produced during the growth process played a major role in the degradation of AFB_(1).The mechanism of AFB_(1) degradation by strain WTX1 is to destroy the toxic structure of AFB_(1),namely,furan ring dihydrogen double bond and the lipid ring structure of vanillin to achieve the detoxification effect.The experiment will further analyze the effects of the degradation products of the strain WTX1 on human and animal metabolism.