【摘要】 对天山乌鲁木齐河源1号冰川末端融水细菌进行分离,检测了分离菌株的生理生化表型特征,通过16S rRNA基因序列分析确定分离菌株的系统进化地位.结果表明:天山乌鲁木齐河源1号冰川融水中分离的36株代表菌株分属于5个系统发育类群、8个属,其中,Bacteroidetes和γ-Proteobacteria为优势类群,分别占41.7%和38.9%;在属水平上,假单胞菌属(Pseudomonas)菌株占39%.依据菌株最适生长温度,36株分离菌株80%以上属于耐冷菌;产酶实验显示,大多数菌株同时产蛋白酶和脂肪酶,仅3株菌不产酶,6株菌同时产脂肪酶、淀粉酶、蛋白酶.耐药性试验表明,36株分离菌株对各种抗生素有不同程度的耐药,其中,7株菌对测试的10种抗生素均具有耐药性.研究结果将有助于了解天山乌鲁木齐河源1号冰川微生物物种多样性、生理多样性,同时为评估气候变化、人类活动对冰川微生物生理特性潜在的影响提供依据.更多还原

【Abstract】 In this study,it is aimed to characterize the physiological and phylogenetic diversity of bacteria isolated from the meltw ater of the Glacier No. 1 at headw ater of the rümqi River in Tianshan Mountains,China. Using culture medium of R2 A,10% and full strength tryptic soy agar,a total of 36 aerobic bacteria strains were isolated from the meltw ater of the Glacier No. 1. Phenotypic characteristics of the isolated strains were examined,including the tolerance to Na Cl,temperature range for grow th,enzyme activity and antibiotic resistance. 16 S rRNA gene sequence analysis and microscopy indicated that the isolated strains were dominated by Gram-negative bacteria. Based on 16 S rRNA gene sequences,it is found that the isolates are members of α,β and γ of Proteobacteria,Actinobacteria and Bacteroides group. The most abundant and diverse isolates are within the Bacteroidetes( 41. 7%) and γ-Proteobacteria( 38. 9%). More than one-third of the isolates could be tentatively identified as Pseudomonas spp. According to the temperature range for grow th,it is believed that most of the isolates( 80%) are psychrotrophic ones. Among 36 isolates,seven are resistant to all antibiotics. In addition,thirty-three isolates have potentially useful cold-active enzymes,including those with proteolytic,amylolytic,lipolytic,and cellulose-hydrolyzing activities. The results will enrich the know ledge of the phylogenetic and physiological diversity of cold-adapted strains in cold environments.更多还原