摘要
冰川作为地球主要的冰冻圈要素之一,蕴藏着丰富的微生物资源.本文通过培养和16S rRNA基因序列鉴定,研究了新疆北部木斯岛冰川的表层雪、表层冰、深层冰、表层融水和前沿土壤生境中的可培养细菌群落结构.结果表明,从木斯岛冰川中培养的细菌属于拟杆菌门(Bacteroidetes)、变形菌门(Proteobacteria)、奇异球菌-栖热菌门(Deinococcus-Thermus)和放线菌门(Actinobacteria),优势门为变形菌门和放线菌门,占所有分离菌株数量的78%.优势属为黄杆菌属(Flavobacterium)、假单胞菌属(Pseudomonas)和冷杆菌属(Cryobacterium),有15株细菌为潜在新种.在10℃和25℃下培养的菌落数分别为6.0×101～5.3×103 CFU·mL-1(CFU·g-1)和3.1×101～5.1×103 CFU·mL-1(CFU·g-1).木斯岛冰川不同生境物种多样性差异较大,前沿土壤生境物种多样性最高,表层融水生境物种多样性最低.可培养细菌具有生境特异性,表层雪、表层冰、深层冰和前沿土壤生境分别有2、2、1和19个特有的属,假单胞菌属是五种生境的共有属,许多源自雪的细菌类群可以在不同生境中保存下来.在10℃和25℃下共培养出16个共有属,分别有9个和7个特有属.木斯岛冰川蕴含丰富的菌株多样性,可为开发冰川微生物资源提供数据支持和菌株资源.
Abstract
As one of the major cryospheric environments of the Earth,glaciers harbor rich microbial resources.One of the unique features of glacial ecosystems compared to other terrestrial biomes is that they are entirely driv-en by microorganisms,which are well adapted to the glacial environment and play important ecological roles.The glacier reserves in Xinjiang rank first in China,and the total area and number of glacier resources rank sec-ond in China.With climate warming and intensified human activities,the ablation of glaciers in Xinjiang,Chi-na,has intensified,and the microorganisms in the glacier ecosystems have been lost continuously,so the exca-vation and protection of microbial resources in the glacier ecosystems have been shown to be very necessary.In this study,samples of surface snow,surface ice,deep ice,surface meltwater and foreland soil at different alti-tudes were collected from Muz Taw Glacier in northern Xinjiang,China.Bacteria in different habitats were cul-tured using six media and two culture temperatures,combined with 16S rRNA gene sequence homology identifi-cation,the community structure and distribution characteristics of culturable bacteria in different habitats of Muz Taw Glacier were studied.The results showed that culturable bacteria from Muz Taw Glacier belonged to Bacte-roidetes,Proteobacteria,Deinococcus-Thermus,and Actinobacteria,with Proteobacteria and Actinobacteria be-ing the dominant phyla,which accounted for 78%of the total number of isolated strains,Flavobacterium,Pseu-domonas and Cryobacterium were the dominant genera,and 15 bacteria were potential new species.The number of culturable bacteria ranged from 6.0×101～5.3×103(Colony Forming Units)CFU⋅mL-1(CFU⋅g-1)and 3.1×101～5.1×103 CFU·mL-1(CFU⋅g-1)at the incubation temperatures of 10℃ and 25℃,respectively.There was a sig-nificant negative correlation(P<0.05)between the number of culturable bacteria in aquatic habitats and conduc-tivity,pH,Mg2+,K+and Na+at 10 ℃,and a significant positive correlation between the number of culturable bacteria in aquatic habitats and pH at 25 ℃;the number of culturable bacteria in foreland soil habitats did not show any significant correlation with the environmental factors at both temperatures.Habitats varied consider-ably in species diversity,with the highest species diversity in the foreland soil habitat and the lowest in the sur-face meltwater,and habitat specificity existed in the culturable bacteria.There were 2,2,1 and 19 unique gen-era of culturable bacteria in surface snow,surface ice,deep ice and foreland soil,respectively,Pseudomonas strains existed in each habitat,many snow-derived bacterial groups can be preserved in different habitats.There were 16 shared genera and 9 and 7 unique genera at the incubation temperatures of 10 ℃ and 25 ℃,respectively.The present study has generated abundant resources of glacier culturable bacteria and potential new species,which can help conserve glacier ecosystem strain resources,lay the foundation for further investigation of strain-specif-ic functions,and provide data support and strain resources for the development of glacier microbial resources.
维普
万方数据