Screening of a high yield protease producing strain and studies on its fermentation conditions / 中国海洋药物

ABSTRACT

A1 strain with fibrinolytic activity was isolated from sea water in Qingdao. After combination treatment with ultraviolet light and MNNG, a mutant C22 producing 2947.60 u?mg -1 protein of fibrinolytic enzyme in culture broth was obtained.Its enzyme activity was 4.23 fold of wild stain A1.The optimum medium for fermentation consisted of 2.5% soy bean cake meal, 0.1% yeast extract,0.2%NaCl,0.05%MgSO 4?7H 2O,0.001%FeSO 4?7H 2O.They were dissolved with 0.05mol?L -1 ,pH7.4 phosphoric buffer.The strain producing maximum fibrnolytic activity after growth at 25℃ for 40h on a rotary shaker.The initial optimum pH was 7.0~7.5.