摘要
为鉴定金黄杆菌属(Chryseobacterium)菌株vv8及分析其胞外蛋白酶的酶学特性,首先,通过分子及生理生化特性对菌株vv8进行鉴定;然后,采用明胶平板筛选法和Lowry法对菌株vv8进行产酶筛选和蛋白酶活性测定;最后,研究pH值、温度、金属离子和抑制剂对该蛋白酶活性的影响.研究结果表明:菌株vv8的16S rDNA与比目鱼黄杆菌(C.scophthalmum)具有98.24%的序列相似性,属于Chryseobacterium属;菌株vv8的最适生长条件是温度为22℃,NaCl质量浓度为0 mg·mL^-1,pH值为6.0;菌株vv8的胞外蛋白酶在pH值为5.0~10.0,温度为0~90℃范围内均具有酶活性,其最适酶活温度和pH值分别为40℃,8.5;在最适条件下,蛋白酶具有较高的稳定性,在冻干过程中,添加葡萄糖具有明显的酶活保护作用;Fe^3+,Fe^2+,Cu^2+等金属离子及乙二胺四乙酸(EDTA)对酶活性有明显的抑制作用,该酶对洗衣液和尿素具有较好的耐受性.
To identify Chryseobacterium sp. vv8 and analyze the enzymatic properties of its extracellular protease, the strain vv8 was firstly identified by molecular, physiological and biochemical characteristics. Secondly, the enzyme screening and protease activity of strain vv8 were determined by gelatin plate screening method and Lowry method. Last, the effects of pH value, temperature, metal ions and inhibitors on the protease activity were studied. The results showed that the 16 S rDNA of strain vv8 had 98.24% sequence similarity with C. scophthalmum and was phylogenetically assigned as genus Chryseobacterium. The optimum culture conditions of strain were 22 ℃, the mass concentration of NaCl 0 mg·mL^-1 and pH value 6.0. The extracellular protease of strain vv8 presented enzyme activity at the range of pH 5.0-10.0 and 0-90 ℃, with the highest activity at pH 8.5 and 40 ℃.Under the optimal conditions,the protease exhibited good stability,and glucose had obvious enzyme activity protection during lyophilization.Fe^3+,Fe^2+,Cu^2+and ethylenediaminetetraacetic acid(EDTA)showed obvious inhibitory effects on enzyme activity,but the protease exhibited good tolerance to laundry detergent and urea.
作者
何小玉
刘承忠
陈明霞
李和阳
HE Xiaoyu;LIU Chengzhong;CHEN Mingxia;LI Heyang(College of Chemical Engineering,Huaqiao University,Xiamen 361021,China;Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China)
出处
《华侨大学学报（自然科学版）》
CAS
北大核心
2019年第5期646-652,共7页
Journal of Huaqiao University(Natural Science)
基金
国家自然科学基金资助项目(41506179)
国家海洋局全球变化与海气相互作用专项资助项目(GASI-03-01-03-01)
中央级公益性科研院所基本科研业务费专项资金资助项目(海三科2014003)
福建省自然科学基金资助项目(2015J01613)
华侨大学研究生科研创新能力培育计划资助项目(17013087002)
关键词
冷适碱性蛋白酶
金黄杆菌属
生长特性
酶特性
cold-adapted alkaline protease
Chryseobacterium
growth characteristics
enzymatic characteristics
