Construction and characterization of a fusion beta-1,3-1,4-glucanase to improve hydrolytic activity and thermostability.

摘要

A new fusion gene (Bgl-licMB), encoding beta-1,3-1,4-glucanase from both Bacillusamyloliquefaciens (Bgl) and Clostridium thermocellum (licMB), was constructed via end-to-end fusion and expressed in Escherichia coli to improve hydrolytic activity and thermostability of beta-1,3-1,4-glucanase. The results of enzymatic properties showed that the catalytic efficiency (k_cat/K_m) of the fusion enzyme for oat beta-glucan was 2.7 and 20-fold higher than that of the parental Bgl and licMB, respectively, and that the fusion enzyme can retain more than 50% of activity following incubation at 80 degrees C for 30 min, whereas the residual activities of Bgl and licMB were both less than 30%. These properties make this particular beta-1,3-1,4-glucanase a good candidate for application in brewing and animal-feed industries