【摘要】 目的从海洋生物双齿围沙蚕消化道筛选产蛋白酶菌株,并对其胞外蛋白酶的性质进行分析。方法用脱脂奶粉平板溶圈法及改良Lowry法进行产蛋白酶菌株的筛选和蛋白酶活力测定;Bradford法测定蛋白含量;UVP GDS8000型凝胶成像系统和VisionWorks、Bandscan4·03软件进行相对分子质量和纯度分析,并对酶的各项性质进行检测。结果筛选出高蛋白水解活性菌株D2,其胞外蛋白酶比活性为156·0U/mg,相对分子质量约为42000,纯度大于97%,最适作用温度60℃,最适pH为9,在pH6～10及0～55℃具有较好的稳定性。结论D2株分泌的胞外蛋白酶有望成为一种新型的海洋微生物蛋白酶资源。更多还原

【Abstract】 Objective To isolate and screen proteinase-hyperproducing strain D2 from the digestive tract of Perinereis aibuhitensis grube and analyze its enzymatic property.Methods Isolate 9 bacterial strains from the digestive tract of Perinereis aibuhitensis grube by using 2216E medium,screen strain D2 using skim milk powder plate.Determine the activity of screened strain by modified Lowry method,the protein content by Bradford method,and analyze the relative molecular mass and purity by UVP GDS8000 gel imaging system as well as VisionWorks and Bandscan4.03 software.Test the screened strain for enzymatic property.Results Protenase-hyperproducing strain D2 of Perinereis aibuhitensis grube was screened.The specific activity,relative molecular mass and purity of extracellular proteinase secreted were 156.0 U/mg,about 42 000 and more than 97% respectively.The optimal temperature and pH value for hydrolysis of substrate with proteinase secreted by D2 strain were 60℃ and 9 respectively.The proteinase showed good stability at pH 6-10 and 0-55℃.Conclusion The extracellular proteinase secreted by D2 strain might be a new source of proteinase of marine microorganisms.更多还原