一株产低温蛋白酶菌株的筛选、鉴定及生长特性的研究

Screening, identification and growth characteristics of a low-temperature proteinase producing strain

摘要: 以新疆阿勒泰地区的冻土为原材料,采用平板分离法初筛,测蛋白酶活性法复筛,筛选出9株低温蛋白酶产生菌株,其中菌株A29-2蛋白酶活性最高,为31.88U/mL,且该菌在初始pH 7.0,NaCl质量分数为1.00%,22℃条件下繁殖量最大。通过形态学观察、生理生化鉴定及16S rDNA序列鉴定,鉴定为:该菌属于沙雷氏菌（Serratia sp.）,该菌株所产的蛋白酶在4℃条件下保存48h,酶活力基本保持不变,表明该低温耐冷菌所产的蛋白酶为低温酶。

Abstract: Through the plate separation and the proteinase activity determination, nine low- temperature proteinase producing strains were obtained from the permafrost in the region of Altai, Xinjiang, in which the strain A29-2 had the highest proteinase activity, reaching to 31.88U /mL.The growth of A29-2 reached the maximum level under the condition of initial pH7.0, mass fraction of NaCl 1.00%, temperature 22℃.Based on the morphological observation, physiological and biochemical identification and 16S rDNA sequence analysis, the strain A29- 2 was identified as Serratia sp..The activity of proteinase produced by A29-2 remained mostly unchanged after 48h of stored at 4℃.The results indicated that proteinase produced by cold-adapted strains was low-temperature enzyme.