Differences in community composition of bacteria in four glaciers in western China
- 1Key Laboratory of Arid and Grassland Agroecology (Ministry of Education) School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, China
- 2Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Science, Beijing, 100085, China
- 3State Key Laboratory of Cryospheric Science, Cold and Arid Regions Environmental Engineering Research Institute, Chinese Academy of Science, Lanzhou, Gansu, 730000, China
- 4Department of Plant Pathology, Gansu Agricultural University, Lanzhou, Gansu, 730070, China
Abstract. Microbial community patterns vary in glaciers worldwide, presenting unique responses to global climatic and environmental changes. Four bacterial clone libraries were established by 16S rRNA gene amplification from four ice layers along the 42-m-long ice core MuztB drilled from the Muztag Ata Glacier. A total of 151 bacterial sequences obtained from the ice core MuztB were phylogenetically compared with the 71 previously reported sequences from three ice cores extracted from ice caps Malan, Dunde, and Puruogangri. Six phylogenetic clusters Flavisolibacter, Flexibacter (Bacteroidetes), Acinetobacter, Enterobacter (Gammaproteobacteria), Planococcus/Anoxybacillus (Firmicutes), and Propionibacter/Luteococcus (Actinobacteria) frequently occurred along the Muztag Ata Glacier profile, and their proportion varied by seasons. Sequence analysis showed that most of the sequences from the ice core clustered with those from cold environments, and the sequence clusters from the same glacier more closely grouped together than those from the geographically isolated glaciers. Moreover, bacterial communities from the same location or similarly aged ice formed a cluster, and were clearly separate from those from other geographically isolated glaciers. In summary, the findings provide preliminary evidence of zonal distribution of microbial community, and suggest biogeography of microorganisms in glacier ice.