嗜热菌的耐热 L-乳酸脱氢酶的研究  

STUDIES ON THE THERMOSTABLE L-LACTATE DEHYDROGENASE FROM THERMOPHILIC BACTERIA

作　　者：杨寿钧[1] 蔡妙英[1] 刘俊凤 顾雅君 王政一[1] 张树政[1] 

机构地区：[1]中国科学院微生物研究所 [2]河北省微生物研究所

出　　处：《微生物学报》1991年第6期438-442,共5页Acta Microbiologica Sinica

基　　金：国家自然科学基金

摘　　要：从广东各地的热温泉(55—95℃)水样中,分离到200余株最适生长温度高于70℃的极端嗜热菌。其中一株编号为 HG25,具有耐热胞内 L-乳酸脱氢酶(L-Lactate dehydrogenase EC.1.1.1.27.,简称 LDH),有栖热菌属(Thermus)的特征,革兰氏阴性,无芽孢,好氧,不运动,产黄色素,最适生长温度为65—75℃,最高生长温度为85℃,最低为40℃,不水解淀粉,不从葡萄糖产酸,DNA 的 G+C 百分含量为65mol%,L-乳酸脱氢酶经硫酸铵分级沉淀、DEAE-纤维素柱层析作了初步提纯,比活提高7倍,LDH 还原丙酮酸反应的最适温度为60℃,最适pH为8.0,酶在70℃稳定,保温10分钟后,仍保留85%的原始酶活力。失活半寿期(t_(1/2))为85℃10分钟。About 200 strians of extereme thermophilic bacteria were isolated from hot springs in Guandong province.A strian,HG25,was found to produce thermostable intracellular L- lactate dehydrogenase (EC.1.1.1.27).It has the characteristic of Thermus sp..The cells were gram-negative,nonsporulating,nonmo- tile,arobic rods containing yellow pigment. The optimum temperature for growth was be- tween 65℃ to 75℃,the maximum 85℃,and minimum 40℃.The generation time at the optimum was about 80 min.Starch was not hydrolized.Acid was not produced from glucose.The G+C content in DNA was 62— 65mol%(T_m).As the properties of strian HG25 is similar to those of Thermus aquaticus and T.thermophilus HB 8 belonging to the genus Thermus. The thermostable L-lactate dehydrogenase was partially purified by ammonium sulfate fractionation and DEAE-cellulose column chromatography.For pyruvate reduction,the optimum temperature of the enzyme was 60℃ and pH 8.0.After incubation in 0.1 mol/L phosphate buffer pH 7.4 at 70℃ for 10min, the enzyme retained about 85% of its original activity.The half-live time (t_(1/2)) at 85℃ was 10 min.

关 键 词：嗜热菌 栖热菌属 L-乳酸脱氢酶 

分 类 号：Q939.106[生物学—微生物学]