Enzymatic Bioconversion of Cycloastragenol-6-O-β-D-glucoside into Cycloastragenol by a Novel Recombinant β-Glucosidase from Phycicoccus sp. Soil748

摘要

Cycloastragenol (CA), the genuine sapogenin of astragaloside from Astragalus membranaceus, exhibits diverse pharmaceutical activities. Recently, the efficient production of CA has received considerable attention due to rapidly increasing market demands. In this study, enzyme mining was conducted, based on skeleton and glycosyl similarity, to explore an efficient beta-glucosidase for CA preparation. A novel beta-glucosidase from Phycicoccus sp. Soil748 (Bgps) was discovered, possessing the efficient conversion rate for cycloastragenol-6-O-beta-D-glucoside (CMG) into CA. The optimum temperature and pH value of Bgps were determined as 45 degrees C and 7.0. The results of kinetic analysis suggested that Bgps catalyzed deglycosylation of CMG more efficiently than other substrates. Furthermore, the optimal substrate concentration of Bgps was up to 80 mg/mL with the conversion rate as 99.2%, suggesting its potential application in CA industrial production by biotransformation.