核酸P＿1酶产生菌选育及其生理生态学研究

Selection of Nuclease P_1-Pfodudng Strain and Studies of Physiolocal Ecology

采用改良的菌选育方法选育到一株高活性磷酸二酯酶产生菌。通过生理生态双向选择方法，确定了适合于该菌株产酶的优化条件．在营养因子筛选中发现一种廉价的产酶促进因子，添加该物质可使酶活提高２～４倍。在最佳工艺条件下，摇瓶酶活可达５００ｕ／ｍｌ，对该菌株进行了３０Ｌ发酵罐发酵试验，酶活达６４０ｕ／ｍｌ。

A fine strain Penicillium citrinum producing nuclease P_1 was selected,and, its suitable cultural conditions were determined by some ameliorative methods ofphysiological microorganism ecology.A nutriational factor,which stimulates produtionof the enzyme nulcease P_1was found,adding it into the medium the enzyme activity can beincreased by 2-4 times.The level of enzyme activity is achieved to 500-600 μ/ml in aver-age. The studies proved that strain has a good genetic stability ofproducing enzyme after many times fermentation in 30 L fermenter.