【作者】 曲艳洪；

【导师】 刘东波；

【作者基本信息】 东北师范大学 ， 微生物学， 2010， 硕士

【摘要】 本论文采用传统的微生物稀释平板法从我国内蒙古自治区吉兰泰盐湖(东经105°42′,北纬39°45′)中分离筛选出23株最适生长盐浓度在12%左右的细菌菌株。对其中6株具有产酶活性的嗜盐菌株进行了表型特征(形态学观察、生理生化试验)分析。在此基础上,对其中一株JLT-15菌株进行了菌株系统鉴定及产蛋白酶特性的初步研究。结果如下:1.分离筛选得到的23株嗜盐菌株中有6株产酶菌株,其中产淀粉酶2株,产脂肪酶3株,产蛋白酶2株,产甘露聚糖酶1株,产其它酶的菌株未筛到。其中JLT-6与JLT-15产生较低酶活性的脂肪酶和蛋白酶两种酶。2.对其中一株JLT-15进行了菌株鉴定及产蛋白酶特性研究。该菌株呈杆状,革兰氏阴性,无芽孢,无荚膜,无鞭毛;菌落呈乳白色,圆形,表面光滑且边缘整齐。甲基红和V.P.测定阴性,柠檬酸盐试验阳性;产生吲哚,产H2S,不能利用硝酸盐及亚硝酸盐;能利用葡萄糖、蔗糖、半乳糖作为唯一碳源生长。蛋白酶、酯酶、氧化酶、过氧化氢酶、盐酸联苯胺阳性,不液化明胶,不具淀粉酶、纤维素酶、脲酶活性。通过生长限制因子实验得到该菌株最适生长盐浓度为12%左右,最适生长Mg2+浓度为2%,最适生长pH为7.5,最适培养温度为37℃。结合16S rDNA序列分析初步鉴定该菌株为海杆菌属Marinobacter的一个新菌株,被命名为Marinobacter lipolyticus JLT-15。3.对JLT-15产生的蛋白酶的特性进行了初步的质研究。JLT-15在pH 7.5～8.5,温度32℃～37℃,接种量1%～4%,盐浓度(NaCl)8%～12%范围内,均具有较高的蛋白酶产量,最适产酶条件为pH 8.0、37℃、12% NaCl和4%接种量。JLT-15所产粗蛋白酶酶液具有以下一般性质:酶的最适pH为8.5,酶的最适作用温度为40℃,该蛋白酶在温度超过60℃时基本丧失了酶活力。更多还原

【Abstract】 By traditional dilution plate method,the 23strains halophiles, Optimal growth occuring in the presence of 12%(w/v) total salt, are isolated from Jilantai Salt Lake (longitude 105°42 ’, latitude 39°45’). we had identified 6 strains halophiles ,having enzyme activity,by phenotype (morphological, physiological and biochemical tests).On this basis, the JLT-15 strain is identified on taxology and studying protease Characteristics from it.The results were reported as follows:1.There are 6 strains having enzyme activity in 23 strains halophiles:2 strains having amylase,3 strains having lipase,2 strains protease, 1 strains mannandse.JLT-06 and JLT-15 have lipase and protease activity.2.Identifing JLT-15:it is rod shaped, Gram-negative.The bacterial colony is rotundity, ivory-white and glossy. Methyl red and Voges-Proskauer are negative. Simmons′citrate test is positive. Indole and H2S are positive. Benzidine hydrochloride is positive,Gelatin liquefaction is negative. Protease, esterase,oxidase, catalase, hydrochloric acid and benzidine are positive, but it had non-amylase, cellulose, urease activity. The following compounds are utilized as sole carbon and energy sources: glucose, sucrose, galactose. Optimal growth occurs in the presence of 12%(w/v) total salt, in the presence of 2%(w/v)Mg2+, at 37℃, at pH 7.5.Combining with 16s rDNA sequence analysis, JLT-15 was identified a new strain of Marinobacter and named Marinobacter lipolyticus JLT-15.3.The results of fermentation showed that The optimal conditions for enzyme production was pH 8.0、37℃、12% NaCl and 4% inoculum rate. And the enzyme production was to follow the growth. The crude enzyme activity was optimal at pH 8.5 and 40℃,and actually, above 60℃,the enzyme lost activity.更多还原