Purification and characterization of an extracellular beta-glucanase from Bacillus IMET B 376.

beta-1.3-1.4-glucanase (E.C. 3.2.1.73) was obtained in highly purified form from the culture fluid of Bacillus IMET B 376 by precipitation with ammonium sulfate, adsorption on CM-cellulose and then affinity chromatography on lichenan-Sepharose 4B. The purified enzyme was active on lichenan and barley glucan but not on laminarin and on CM-cellulose. The molecular weight of the enzyme was estimated to be 26,000 daltons. The Km values for lichenan and barley glucan were determined to be 1.43 and 1.15 mg/ml, respectively. The beta-glucanase has a broad pH optimum between 6 to 8, and was particularly thermostable in presence of Ca++.