中文摘要：

采用高盐选择性培养基从20份青海湖水样中筛选分离获得35株青海湖嗜盐微生物.耐盐梯度实验分析表明：水体中以中度嗜盐菌为主,约占65.7%;弱嗜盐菌次之,约占25.7%;非嗜盐菌与耐盐菌相对较少,约占8.5%.其中优势菌QHL5的生长盐度耐受范围为0.04～3.0 mol/L,最适生长范围为0.3～0.9 mol/L,隶属于中度嗜盐菌.菌体形态和生长特性分析表明：QHL5菌落大小为4～6 mm,圆形或椭圆形,边缘整齐厚实,乳白色,中间微隆起,不透明,革兰氏染色阴性.显微形态呈杆状,最适生长pH为8.5～9.5,最适生长温度为35℃.生理生化、16S rRNA的全序列Blast和系统发育分析表明：QHL5菌株分类定位于γ变形菌纲海洋螺菌目盐单胞菌属樊氏盐单胞菌（Halomonas ventosae）.通过80%乙醇法抽提胞内相溶物质,采用TLC法检测出该菌积聚四氢嘧啶.

英文摘要：

Thirty-five strains of halophiles were isolated from 20 water samples of Qinghai Lake,China by a high saline medium.In all strains tested,the proportion of the moderate halophile was 66.7%,as a dominate group,and the percentage of the slight halophile was 25.7.The nonhalophile plus halotolerant was however only 8.5%.The dominant strain QHL5 was a moderate halophile,which could grow in a salt concentration from 0.04 to 3.0 mol/L,and its optimal concentration was 0.3～0.9 mol/L.According to colonial morphology and growth characteristics,QHL5 was round or oval,4.0～6.0 mm,white,gram negative and opaque as a single cell.The optimum pH and cultural temperature were 7.5～8.0 and 35 ℃,respectively.Based on the physiological and biochemical characteristics of bacteria,and phylogenetic analysis using 16S rDNA sequence comparison,QHL5 was primarily identified as a Halomonas ventosae species of Holomonas genus,in Oceanospirillales order of Gammaproteobacteria class.The intracellular compatible solute of QHL5 was extracted with 80% ethanol,then the ectoine accumulated in cell was tested by a TLC method.