1株脱毛蛋白酶生产菌株的选育和鉴定

[目的]筛选鉴定脱毛蛋白酶生产菌株。[方法]通过菌株分离、筛选与鉴定试验筛选并鉴定出了1株脱毛蛋白酶生产菌株,命名为Bacillus cereus SZ-4。[结果]经初筛得到11株脱毛蛋白酶生产菌株,经复筛得到菌株SZ-4。SEM观察结果表明,蜡状芽孢杆菌1.230与待鉴定菌株的细胞形态非常相似。菌株SZ-4的菌体细胞革兰氏染色呈阳性;荚膜染色呈阴性;芽孢呈椭圆形,中生或次端生。生理试验结果表明,葡萄糖、L-鼠李糖、肌醇、甘露醇及蔗糖均可用作菌株SZ-4的碳源;以葡萄糖为碳源时,菌株的生长状况最佳。该菌株是1株嗜盐菌。DNA序列分析表明,蜡状芽孢杆菌和苏云金芽孢杆菌同处于一个最小的分支,与已知菌株Bacillus cereus strain CCM2010的遗传距离最近,同源性达到99.8%。确定该菌株为蜡状芽孢杆菌,将其命名为Bacillus cereus SZ-4。[结论]该试验从盐腌原料皮中分离得到1株脱毛蛋白酶生产菌株SZ-4。

Screening and Identification of A Producing Strain of Dehairing Protease

[Objective] The research aimed to screen and identify producing strains of dehairing protease. [Method] A producing strain of dehairing protease was screened out and identified through strain isolation,screening and identification experiments and named Bacillus cereus SZ-4. [Result] 11 producing strains of dehairing protease were obtained through primary screening and SZ-4 was obtained through secondary screening. The results from SEM observation showed that the cell shapes of B. cereus 1.230 and identified strain were very similar. The somatic cells of the strain SZ-4 showed positive results in Gram's staining; the stained capsule sula showed negative results; the gemma was oval and grown on middle part or secondary end. The results from physiological experiments showed that all of glucose,L-rhamnose,phaseomannite,mannite and sucrose could be used as carbon source for the strain SZ-4; when the carbon source was selected as glucose,the strain grew best. This strain was obligate halophile. The DNA sequence analysis showed that B. cereus and B. thuringiensis were on the same smallest branch,its genetic distance from known B. cereus strain CCM 2010 was shortest and their homology reached 99.8%. This strain was ascertained as B. cereus and it was named B. cereus SZ-4. [Conclusion] A producing strain SZ-4 of dehairing protease was isolated from salted raw hide in this experiment.