Characteristics of bacterial community structure cultured in Muz Taw Glacier,northern Xinjiang
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.
Muz Taw Glacierculturable bacteriacommunity structure
万方数据
维普
