| 摘要 |
PURPOSE:To enable to produce an alkali protease APG 501 having physicochemical properties such as a protease activity especially high against sericin by culturing Bacillus S.P 9111-5B strain. CONSTITUTION:Bacillus S.P 9111-5B strain (FERM 8520) separated from soil is cultured in a liquid medium containing starch, etc., as a carbon source, soybean residues, etc., as a nitrogen source and inorganic salts at 20-40 deg.C under an aerobic condition. After the culture is finished, the cells and the residues of the medium are removed and the filtrate is concentrated by an ultrafiltration method at a fraction mol.wt. of 5000 to provide a liquid crude enzyme. The crude enzyme is purified by an ion exchange chromatography, etc., and lyophilized to provide pure alkali protease APG 501 having physicochemical properties: (a) the enzyme has the protease action in an alkaline region, (b) the enzyme has an especially high peculiar protease action on sericin, the optimal pH thereof being 6.5-9 and the optimal temperature thereof being 60-65 deg.C. |
