深海适冷菌Pseudomonas sp.SM9913的适冷生长机制探讨

Preliminary Study on the Cold-adapted Growth Mechanism of a Deep-sea Psychrotrophic Strain Pseudomonas sp SM9913

研究了温度对适冷菌Pseudomonassp SM 9913的生长与适冷蛋白酶合成的影响 ,结果表明 ,P sp SM 9913的最适生长温度为 15℃ ,最适产酶温度为 10℃ ,是一典型的适冷菌。P sp SM 9913分泌的适冷蛋白酶在低温下与底物的亲和力增大 ,反应的活化能降低 ,表明在低温下较中温蛋白酶有更高的催化效率。深海产适冷蛋白酶的适冷菌P SM 9913可能是通过提高菌株在低温下的生长速率和增加酶分子在低温下的催化效率两条途径增加低温环境中蛋白质的分解效率 。

Effects of temperature on the growth of Pseudomonas sp SM9913 and the synthesis of the cold adapted protease were determined The optimum growth temperature was at 15℃, and the optimum temperature for protease synthesis was at 10℃, which was far lower than that of mesophiles The cold adapted protease excreted by P sp SM9913 catalyzed more efficiently than the mesophilc protease because of the higher affinity the substrate and lower activation energy P sp SM9913 might adapted the cold temperature by two ways: increased the growth rate of the bacterium and increased the catalytic efficiency of the protease at low temperature