Characterization of a Thermostable Lichenase from Bacillus subtilis B110 and Its Effects on β-Glucan Hydrolysis

• Published in: Journal of microbiology and biotechnology Vol. 32; no. 4; pp. 484 - 492
• Main Authors: Huang, Zhen, Ni, Guorong, Wang, Fei, Zhao, Xiaoyan, Chen, Yunda, Zhang, Lixia, Qu, Mingren
• Format: Journal Article
• Language: Korean
• Published: 한국미생물생명공학회 30.04.2022
• Subjects: Bacillus subtilis; characterization; expression; lichenase; oligosaccharide; β-glucan; oligosaccharide; expression; Bacillus subtilis; lichenase; characterization; {\beta}-glucan
• ISSN: 1017-7825; 1738-8872

Lichenase is an enzyme mainly implicated in the degradation of polysaccharides in the cell walls of grains. Emerging evidence shows that a highly efficient expression of a thermostable recombinant lichenase holds considerable promise for application in the beer-brewing and animal feed industries. Herein, we cloned a lichenase gene (CelA203) from Bacillus subtilis B110 and expressed it in E. coli. This gene contains an ORF of 729 bp, encoding a protein with 242 amino acids and a calculated molecular mass of 27.3 kDa. According to the zymogram results, purified CelA203 existed in two forms, a monomer, and a tetramer, but only the tetramer had potent enzymatic activity. CelA203 remained stable over a broad pH and temperature range and retained 40% activity at 70℃ for 1 h. The K m and V max of CelA203 towards barley β-glucan and lichenan were 3.98 mg/ml, 1017.17 U/mg, and 2.78 mg/ml, 198.24 U/mg, respectively. Furthermore, trisaccharide and tetrasaccharide were the main products obtained from CelA203-mediated hydrolysis of deactivated oat bran. These findings demonstrate a promising role for CelA203 in the production of oligosaccharides in animal feed and brewing industries.