Characterization of a novel bifunctional enzyme from buffalo rumen metagenome and its effect on in vitro ruminal fermentation and microbial community composition  

作　　者：Zhenxiang Meng Jing Ma Zhanying Sun Chengjian Yang Jing Leng Weiyun Zhu Yanfen Cheng 

机构地区：[1]Laboratory of Gastrointestinal Microbiology,National Center for International Research on Animal Gut Nutrition,Nanjing Agricultural University,Nanjing 210095,China [2]State Key Laboratory of Grassland Agro-Ecosystems,Center for Grassland Microbiome,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730000,China [3]Buffalo Research Institute,Chinese Academy of Agricultural,Nanning 530000,China [4]Key Laboratory of Animal Nutrition and Feed Science of Yunnan Province,Yunnan Agricultural University,Kunming 650000,China

出　　处：《Animal Nutrition》2023年第2期137-149,共13页动物营养（英文版）

基　　金：supported by the Carbon Peak&Carbon Neutralization Innovation Project of Jiangsu Province(BE2022309);Natural Science Foundation of China(32061143034,32161143028);the Fundamental Research Funds for the Central Universities(lzujbky-2022-ct04);the National Modern Agricultural Industry Technology System Guangxi Dairy Buffalo Innovation Team Project(nycytxgxcxtd-2021-21).

摘　　要：To efficiently use lignocellulosic materials in ruminants,it is crucial to explore effective enzymes,especially bifunctional enzymes.In this study,a novel stable bifunctional cellulase-xylanase protein from buffalo rumen metagenome was expressed and characterized,CelXyn2.The enzyme displayed optimal activity at pH 6.0 and 45℃.The residual endoglucanase and xylanase activities were 90.6%and 86.4%after a 60-min pre-incubation at 55℃.Hydrolysis of rice straw,wheat straw,sheepgrass and sugar beet pulp by CelXyn2 showed its ability to degrade both cellulose and hemicellulose polymers.Treatment with CelXyn2 improved the hydrolysis of agricultural residues with an evident increase in production of total gas,lactate and volatile fatty acids.The results of 16S rRNA and real-time PCR showed that the effect on in vitro ruminal microbial community depended on fermenta-tion substrates.This study demonstrated that CelXyn2 could strengthen lignocellulose hydrolysis and in vitro ruminal fermentation.These characteristics of CelXyn2 distinguish it as a promising candidate for agricultural application.

关 键 词：Bifunctional enzyme In vitro ruminal fermentation LIGNOCELLULOSE Microbial communit 

分 类 号：S823.83[农业科学—畜牧学]