长蛸胃肠道产蛋白酶菌的筛选及粗酶性质研究
Screening of protease producing bacterium from the gastrointestinal tract of ？？Octopus variabilis？？ and enzymatic properties

通过透明圈法从长蛸胃肠道内筛选出4株产蛋白酶的菌株, L 1、L 2、L 3、L 5, 采用偶氮酪蛋白法测定粗酶液蛋白酶活力, 采用SDS PEAG活性电泳测定粗酶液中具有蛋白水解活性的蛋白酶的种类及分子量. 菌株L 2产蛋白酶比酶活最高, 达到4.80U/μg, 菌株L 1比酶活最低为3.31 U/μg. 菌株L 2粗酶液中含有4种酶活较高的蛋白酶, 分子量分别为105.2、86.9、69.3、37.8kD, 其他3株菌株的粗酶液中各蛋白酶分子量相近. 菌株L 1和L 2蛋白酶最佳反应温度为40℃, 最佳反应pH为8.0; L 3产蛋白酶的最佳反应温度为50℃, 最佳pH为7.0; 菌株L 5产蛋白酶在温度为60℃, pH为8.5时有最大酶活力.
Four strains with high yield and strong hydrolase activity protease were isolated from the gastrointestinal tract of the ？？Octopus variabilis？？ by transparent circle method.The activity of protease was determined by azocasein method. The protease produced by strain L 2 has the highest hydrolase activity, 4.80U/μg. Besides, the activity of proteases produced by strain L 1 was up to 3.31 U/μg, which was the lowest of the four strains. The molecular weights of proteases produced by strain L 2 were estimated at 105.2, 86.9, 69.3, 37.8 kD by SDS PAGE. Moreover, the optimal reaction temperature and pH of the proteases from strain L 1, L 2 were 40℃ and 8.0. The proteases produced by strain L 3 and L 5 have the highest activity at 50, 60 ℃ and 8.5, 7.0, respectively