低温蛋白酶产生菌的筛选及其酶学性质的初步研究

摘要

从南印度洋深海沉积物中筛选获得1株产低温蛋白酶的嗜冷菌株11815，经16S rDNA鉴定，结合菌株的形态结构特征和生理生化特性分析，确定其为动性球菌属(Planococcus sp.)．该菌株的最适生长温度及最佳产酶温度均为20,℃，经发酵条件初步优化后，48,h内摇瓶水平的蛋白酶产量可达280,U/mL；酶学性质分析结果显示：该菌株所产蛋白酶的最适作用温度为37,℃，最适pH为8.0，30,℃条件下可保持最高催化活力的80%以上，而在25～30,℃仍具有较高的催化活力(保持最高催化活力的50%以上)．该菌株所产蛋白酶属于典型的低温蛋白酶，在常温下具有较好的催化活性，因此在食品加工业及冷水洗涤剂开发等方面具有较高的研究价值．%A psychrophilic bacterium 11815 was isolated from the deep sea mud of southern Indian ocean to produce cold-adapted protease and the product was identified asPlanococcussp. according to its morphological and physiochemical char-acteristics as well as 16S rDNA sequence analysis. The optimal temperature for its growth and protease production was 20,℃and the protease production reached 280 U/mL after 48 h fermentation in shake flask. The optimal pH and temperature for producing protease were 8.0 and 37,℃. At 30,℃,the relative activity reached 80% of the highest activity. Even at lower tem-peratures from 25,℃ to 30,℃,the relative activity still reached more than 50% of the highest activity. These enzymatic prop-erties indicate that the protease produced by the newly isolated psychrophilic strain belongs to the class of cold-adapted pro-teases and possesses a high application potential in food processing and cold-water detergents.