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Gene cloning and expression of a new acidic family 7 endo-β-1,3-1,4-glucanase from the acidophilic fungus Bispora sp. MEY-1
- Luo, Huiying, Yang, Jun, Yang, Peilong, Li, Jiang, Huang, Huoqing, Shi, Pengjun, Bai, Yingguo, Wang, Yaru, Fan, Yunliu, Yao, Bin
- Applied microbiology and biotechnology 2010 v.85 no.4 pp. 1015-1023
- trypsin, barley, pepsin, Komagataella pastoris, complementary DNA, fermenters, gene overexpression, oats, xylan, fungi, pH, sodium, molecular cloning, temperature, endo-1,4-beta-glucanase, beta-glucans, glycosides, carboxymethylcellulose
- Most reported microbial β-1,3-1,4-glucanases belong to the glycoside hydrolase family 16. Here, we report a new acidic family 7 endo-β-1,3-1,4-glucanase (Bgl7A) from the acidophilic fungus Bispora sp. MEY-1. The cDNA of Bgl7A was isolated and over-expressed in Pichia pastoris, with a yield of about 1,000 U ml⁻¹ in a 3.7-l fermentor. The purified recombinant Bgl7A had three activity peaks at pH 1.5, 3.5, and 5.0 (maximum), respectively, and a temperature optimum at 60°C. The enzyme was stable at pH 1.0-8.0 and highly resistant to both pepsin and trypsin. Belonging to the group of non-specific endoglucanase, Bgl7A can hydrolyze not only β-glucan and cellulose but also laminarin and oat spelt xylan. The specific activity of Bgl7A against barley β-glucan and lichenan (4,040 and 2,740 U mg⁻¹) was higher than toward carboxymethyl cellulose sodium (395 U mg⁻¹), which was different from other family 7 endo-β-glucanases.