A variant of Orpinomyces joyonii 1,3-1,4-beta-glucanase with increased thermal stability obtained by random mutagenesis and screening.

Abstract

A thermostable variant of an Orpinomyces joyonii beta-glucanase was identified by screening a mutant library constructed using error-prone PCR products. The mutant, designated 2011D, had one amino acid substitution (Val replaced Asp-70). 2011D showed similar catalytic efficiency to its wild-type enzyme, LicA. The temperature at which 50% inactivation occurred after heat treatment for 10 min was increased by 14 degrees C for 2011D, in comparison to those of wild-type enzyme.