摘要
通过酪蛋白平板法从实验室极地微生物资源库中筛选到130株在低温条件(4℃)下具有蛋白酶活性的菌株,并对部分酪蛋白水解圈较大的菌株进行了酶活测定和系统发育分析。发现酶活较高的8株菌分别属于假交替单胞菌属(Pseudoalteromonas)、科尔韦尔氏菌属(Colwellia)、希瓦氏菌属(Shewanella)、嗜冷杆菌属(Psychrobacter)。选择低温蛋白酶活性较高的菌株Pseudoalteromonas sp.QI-1为研究对象,以酪蛋白为反应底物对其所产低温蛋白酶粗酶酶性质进行初步研究。结果表明:QI-1低温蛋白酶酶活最适反应温度为40℃,在0℃时保持10%的相对酶活,酶活最适反应pH为10.0;其催化作用不需要金属离子的参与;热稳定性极差,在60℃放置15 min即完全失活。
One hundred and thirty strains of polar bacteria producing extracellular protease were screened from the polar microbial resources by a casein plate method,and the phylogenetic analysis of the strains with larger casein hydrolyzation halos was carried out.The results showed that 8 isolates with higher protease activity belonged to Pseudoalteromonas,Colwelli,Shewanella and Psychrobacter,respectively.By using casein as the substrate,the characteristics of the crude protease produced by QI-1 with high activities at the low temperature than other strains was preliminarily studied.The results showed that the optimal temperature and pH were 40 ℃ and 10.0,respectively.The protease activity was insensitive to divalent metal cations and was susceptible to heat but lost its activity completely after incubating at 60 ℃ for 15 min.
出处
《生物加工过程》
CAS
CSCD
2010年第2期55-60,共6页
Chinese Journal of Bioprocess Engineering
基金
国家高技术研究发展计划(863计划)资助项目(2007AA091905)
国家海洋局第一海洋研究所基本科研业务费专项资金资助项目(2007T11)
关键词
低温蛋白酶
酶学性质
系统发育分析
极地微生物
cold-active protease
enzymatic characteristics
phylogenetic analysis
polar microorganism
