宏基因组学揭示AFB1对牦牛瘤胃微生物多样性及CAZy谱影响

Metagenomics Reveals the Effect of AFB1 on Rumen Microbial Diversity and CAZy of Yak

采用宏基因组学方法探讨黄曲霉毒素B1(AFB1)对牦牛瘤胃微生物多样性及碳水化合物酶类(CAZy)功能谱的影响。试验设E1、E2两个试验组和对照组C,日粮中添加AFB1量分别为20μg·kg^(-1)、60μg·kg^(-1)和0。采集瘤胃液,提取DNA,进行宏基因组分析。结果表明,AFB1降低拟杆菌门及厚壁菌门的丰度,在属水平上较高水平的AFB1对普雷沃氏菌具有抑制作用。牦牛瘤胃中降解植物纤维素主要的CAZy是糖苷水解酶(GH)和糖基转移酶(GT)。AFB1对CAZy中6类酶以及3种纤维小体构成组分均产生影响,且高水平影响更大。研究揭示,AFB1降低瘤胃细菌多样性,影响CAZy功能。研究结果有利于探讨AFB1影响反刍动物瘤胃微生态的机制,为饲料安全使用及牦牛健康养殖和产品安全生产提供参考。

The effect of aflatoxin B1(AFB1)on the rumen microbial diversity and the function profile of carbohydrate enzymes(CAZy)in calf are investigated by using metagenomics.The experiment is divided into AFB1 treatment,the first group(E1,20μg·kg^-1),the second group(E2,60μg·kg^-1),and the control group(C).Rumen fluid is collected and DNA is extracted for metagenomic analysis.The results show that AFB1 decreases the abundance of Bacteroidetes and Firmicutes,and the level of AFB1 has inhibitory effect on Prevotella.The main carbohydrate enzymes in degradation of plant cellulose in calf rumen microorganisms are glycoside hydrolase(GH)and glycosyltransferase(GT).AFB1 has effects on six enzymes in CAZy and three fibrous body constituents,and the higher levels,the greater effect.It is concluded that AFB1 can reduce the diversity of rumen bacteria and affect the function of carbohydrate enzymes(CAZy).The results of the study will help to explore the mechanism of AFB1 affecting the rumen microecology,and provide references for the safe use of feed and healthy breeding of yaks and safe production of products.