Biochemical characteristics of Myceliophthora thermophila recombinant β-glucosidase (MtBgl3c) applicable in cellulose bioconversion

The GH3 beta-glucosidase gene of Myceliophthora thermophila (MtBgl3c) has been cloned and heterologously expressed in E. coli for the first time. This study highlights the important characteristics of recombinant MtBgl3c (rMtBgl3c) which make it a promising candidate in industrial applications. Optimization of the production of rMtBgl3c led to 28,000 U L-1. On purification, it has a molecular mass of similar to 100 kDa. It is a broad substrate specific thermostable enzyme that exhibits pH and temperature optima at 5.0 and 55 degrees C, respectively. The amino acid residues Asp287 and Glu514 act as nucleophile and catalytic acid/base, respectively in the enzyme catalysis. Its low K-m value (1.28 mM) indicates a high substrate affinity as compared to those previously reported. The rMtBgl3c displays a synergistic action with the commercial enzyme cocktail in the saccharification of sugarcane bagasse suggesting its utility in the cellulose bioconversion. Tolerance to solvents, detergents as well as glucose make this enzyme applicable in wine, detergent, paper and textile industries too.

Automated summary

The GH3 beta-glucosidase gene of Myceliophthora thermophila has been successfully cloned and expressed in E. coli. The recombinant enzyme rMtBgl3c shows promising characteristics for industrial applications, with a high production yield of 28,000 U L-1 and a thermostable nature. It exhibits optimal activity at pH 5.0 and 55 degrees C, and has a low K-m value indicating high substrate affinity. Additionally, rMtBgl3c demonstrates synergistic effects in saccharification and has potential applications in various industries.