发酵海产品中产蛋白酶菌株多样性及其酶学特性

Diversity of Cultivable Protease-producing Strains from Fermented Seafoods and Their Enzymatic Characteristics

从自制发酵海产品中筛选分离到10株具有产蛋白酶能力的菌株,经分子生物学鉴定分别为贝莱斯芽孢杆菌S1YBB、S1YB,黏质沙雷氏菌S2DD、S2DB、C2Y3、M1B、C2J2,藤黄色微球菌C1Y1,海藻希瓦氏菌C2J1和海氏肠球菌M1R,选择不同种的5株分泌蛋白酶活力较高菌株S1YB、S2DB、C1Y1、C2J1、M1R进行生物学和酶学特性研究。结果表明,5株菌生长最适温度37℃、最适pH值6.0、最适盐质量浓度20 g/L,所产蛋白酶在50℃、pH 6.0~8.0时活性最高。在Na^(+)、K^(+)、Ca^(2+),Fe^(2+),Fe^(3+)、Zn^(2+)、Cu^(2+)等不同金属离子和乙二胺四乙酸(EDTA)的影响下相对酶活力呈下降趋势,并与金属离子质量浓度有一定关系。本研究为海产品发酵优良菌株的开发以及发酵过程中杂菌的控制提供理论参考。

A total of 10 protease-producing strains were isolated from homemade fermented seafoods,and were identified as Bacillus velezensis S1YBB,S1YB,Serratia marcescens S2DD,S2DB,C2Y3,M1B,C2J2,Micrococcus luteus C1Y1,Shewanella alga C2J1,and Enterococcus hirae M1R.The biological and enzymatic characteristics of S1YB,S2DB,C1Y1,C2J1,and M1R from different species with relatively higher enzyme activities were evaluated.The optimum growth temperature,pH and salinity of the strains were 37℃,6.0,and 20 g/L,respectively.The optimum temperature and pH for the enzyme activities were 50℃and 6.0-8.0,respectively.Relative enzyme activities of the strains were decreased under the treatment of Na^(+),K^(+),Ca^(2+),Fe^(2+),Fe^(3+),Zn^(2+),Cu^(2+) and ethylene diamine tetraacetic acid(EDTA)and in response to their concentrations.The results provided theoretical supports for exploring strains with excellent fermentation performance in seafood fermentation and controlling unexpected protease-producing strains in seafood fermentation processes.