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Updated: Oct 25, 2025
Determination of the Glycogen Content in Cyanobacteria
Published on: July 17, 2017
Characterization of a glucose-stimulated β-glucosidase from Microbulbifer sp. ALW1
Zedong Jiang1, Liufei Long2, Meifang Liang2
1College of Food and Biological Engineering, Jimei University, Xiamen, 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, 361021, China; Research Center of Food Biotechnology of Xiamen City, Xiamen, 361021, China.
Abstract:
Glucose-tolerant and/or glucose-stimulated β-glucosidase is of great interest for its industrial utilization in enzymatic digestion of lignocellulosic biomass for biofuel production. In this study, a new gene of β-glucosidase MaGlu1A was cloned from an alginate-degrading marine bacterium Microbulbifer sp. ALW1. The gene of MaGlu1A encoded a 472-amino acid protein classified into the glycosyl hydrolase family 1 (GH1). The recombinant β-glucosidase was overexpressed and purified from Escherichia coli with a molecular mass of 65.0 kDa. Structure analysis illustrated the catalytic acid/base residue Glu186 and nucleophilic residue Glu370 in the enzyme. MaGlu1A displayed optimal activity at 40 °C and pH 4.5, respectively. It had substrate preference to the aryl-β-glycosidic bonds with glucose, fucose, and galactose moieties, in addition to cellobiose. MaGlu1A demonstrated strong stimulation to the supplemental glucose. Site-directed mutagenesis suggested an essential role of Asn242 in glucose stimulation. The enzymatic characterization of MaGlu1A provides general information about its catalytic properties facilitating its practical applications.
