A Novel Neutral and Mesophilic beta-Glucosidase from Coral Microorganisms for Efficient Preparation of Gentiooligosaccharides

beta-glucosidases can produce gentiooligosaccharides that are lucrative and promising for the prebiotic and alternative food industries. However, the commercial production of gentiooligosaccharides using beta-glucosidase is challenging, as this process is limited by the need for high thermal energy and increasing demand for the enzyme. Here, a putative beta-glucosidase gene, selected from the coral microbial metagenome, was expressed in Escherichia coli. Reverse hydrolysis of glucose by Blg163 at pH 7.0 and 40 & DEG;C achieved a gentiooligosaccharide yield of 43.02 & PLUSMN; 3.20 g & BULL;L-1 at a conversion rate of 5.38 & PLUSMN; 0.40%. Transglycosylation of mixed substrates, glucose and cellobiose, by Blg163 consumed 21.6 U/0.5 g glucose/g cellobiose, achieving a gentiooligosaccharide yield of 70.34 & PLUSMN; 2.20 g & BULL;L-1 at a conversion rate of 15.63%, which is close to the highest yield reported in previous findings. Blg163-mediated synthesis of gentiooligosaccharides is the mildest reaction and the lowest beta-glucosidase consumption reported to date.