Production,purific tion,characterization and application of two novel endoglucanases from buffalo rumen metagenome  

作　　者：Zhenxiang Meng 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]Buffalo Research Institute,Chinese Academy of Agricultural,Nanning 530000,China [3]Key Laboratory of Animal Nutrition and Feed Science of Yunnan Province,Yunnan Agricultural University,Kunming 650000,China

出　　处：《Journal of Animal Science and Biotechnology》2023年第3期1235-1251,共17页畜牧与生物技术杂志（英文版）

基　　金：supported by the Carbon Peak&Carbon Neutralization Innovation Project of Jiangsu Province (BE2022309);Natural Science Foundation of China (32161143028,32061143034);the National Modern Agricultural Industry Technology System Guangxi Dairy Buffalo Innovation Team Project (nycytxgxcxtd-2021-21)。

摘　　要：Background Lignocellulose biomass is the most abundant and renewable material in nature.The objectives of this study were to characterize two endoglucanases Trep Cel3 and Trep Cel4,and determine the effect of the combination of them(1.2 mg Trep Cel3,0.8 mg Trep Cel4)on in vitro rumen fermentation characteristics.In this study,three nature lignocellulosic substrates(rice straw,RS;wheat straw,WS;leymus chinensis,LC)were evaluated for their in vitro digestibility,gas,NH3-N and volatile fatty acid(VFA)production,and microbial protein(MCP)synthesis by adding enzymatic combination.Methods Two endoglucanases’genes were successfully expressed in Escherichia coli(E.coli)BL21(DE3),and enzymatic characteristics were further characterized.The combination of Trep Cel3 and Trep Cel4 was incubated with lignocellulosic substrates to evaluate its hydrolysis ability.Results The maximum enzymatic activity of Trep Cel3 was determined at p H 5.0 and 40℃,while Trep Cel4 was at p H 6.0 and 50℃.They were stable over the temperature range of 30 to 60℃,and active within the p H range of 4.0 to 9.0.The Trep Cel3 and Trep Cel4 had the highest activity in lichenan 436.9±8.30 and 377.6±6.80 U/mg,respectively.The combination of Trep Cel3 and Trep Cel4 exhibited the highest efficiency at the ratio of 60:40.Compared to maximum hydrolysis of Trep Cel3 or Trep Cel4 separately,this combination was shown to have a superior ability to maximize the saccharification yield from lignocellulosic substrates up to 188.4%for RS,236.7%for wheat straw WS,222.4%for LC and 131.1%for sugar beet pulp(SBP).Supplemental this combination enhanced the dry matter digestion(DMD),gas,NH3-N and VFA production,and MCP synthesis during in vitro rumen fermentation.Conclusions The Trep Cel3 and Trep Cel4 exhibited the synergistic relationship(60:40)and significantly increased the saccharification yield of lignocellulosic substrates.The combination of them stimulated in vitro rumen fermentation of lignocellulosic substrates.This combination has the potential to be a

关 键 词：ENDOGLUCANASE In vitro Lignocellulosic substrates Rumen fermentation 

分 类 号：S823.83[农业科学—畜牧学]