청국장에서 분리한 바실러스종으로부터 베타-글루코시다제의 분석 및 분리정제

Identification and Partial Purification of the Extracellular β-Glucosidase of Bacillus Species Isolated from Cheonggukjang, Fermented Bean Paste

The strain obtained from Cheonggukjang produced a protein showing β-glucosidase activity in the experimental data of column chromatography and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. An extracellular β-glucosidase of Bacillus species isolated from Cheonggukjang was identified and partially purified through 75% ammonium sulfate precipitation, High Q anion exchange chromatography, and Bio-Gel P-30 and P-60 size exclusion chromatography. The molecular weight of 45,000 was estimated by SDS-PAGE. β-Glucosidase was produced in the culture medium containing cellobiose, but not glucose. implying an inhibitor. Assay of β-glucosidase activity was performed by measuring the release of p-nitrophenol from the substrate p-nitrophenyl-β-D-glucopyranoside.