期刊
EXTREMOPHILES
卷 23, 期 4, 页码 479-486出版社
SPRINGER JAPAN KK
DOI: 10.1007/s00792-019-01099-3
关键词
Biogas plant; metagenomic library; Cellulase; Thermostability
A metagenomic library from DNA isolated from a biogas plant was constructed and screened for thermoactive endoglucanases to gain insight into the enzymatic diversity involved in plant biomass breakdown at elevated temperatures. Two cellulase-encoding genes were identified and the corresponding proteins showed sequence similarities of 59% for Cel5A to a putative cellulase from Anaerolinea thermolimosa and 99% for Cel5B to a characterized endoglucanase isolated from a biogas plant reactor. The cellulase Cel5A consists of one catalytical domain showing sequence similarities to glycoside hydrolase family 5 and comprises 358 amino acids with a predicted molecular mass of 41.2kDa. The gene coding for cel5A was successfully cloned and expressed in Escherichia coli C43(DE3). The recombinant protein was purified to homogeneity using affinity chromatography with a specific activity of 182 U/mg, and a yield of 74%. Enzymatic activity was detectable towards cellulose and mannan containing substrates and over a broad temperature range from 40 degrees C to 70 degrees C and a pH range from 4.0 to 7.0 with maximal activity at 55 degrees C and pH 5.0. Cel5A showed high thermostability at 60 degrees C without loss of activity after 24h. Due to the enzymatic characteristics, Cel5A is an attractive candidate for the degradation of lignocellulosic material.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据