Study On Biological Characteristics Of Moderately Halophilic Bacteria In Jilantai Salt Lake In Inner Mongolia

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.