Differences in community composition of bacteria in four glaciers in western China

Abstract

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 similarlyCorrespondence to: S.-R. Xiang (srxiang@ns.lzb.ac.cn) 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.

Changes of the Bacterial Abundance and Communities in Shallow Ice Cores from Dunde and Muztagata Glaciers, Western China

“…The phenomena of Polaromonas sp. from the same location readily grouping together was also found in the Muztagata and Puruogangri glaciers (An et al, 2010; Xiang et al, 2010). Although Polaromonas sp.…”

“…(B1–B4) Dominant bacteria in four Muztagata ice columns dated in 1970, 1972, 1984–1985, and 1988, respectively. Muztagata ice core dada was adapted from our previous report (An et al, 2010). …”

“…Previous studies have shown the prevalence of specific bacteria in certain local glaciers (Zhang et al, 2008; Xiang et al, 2009; An et al, 2010; Franzetti et al, 2013; Miteva et al, 2015). However, our findings demonstrate that the members of bacterial genus-related groups are highly similar in the related ice cores at a historical scale, whereas the composition of the prevalent genus-related groups is largely different across the geographically different glaciers.…”

“…Some of the glacier bacteria have been found to be phylogenetically distinct from those found in temperate environments, demonstrating the biogeography of individual microorganisms in the glacier ice (Christner et al, 2003; Xiang et al, 2010; Anesio and Laybourn-Parry, 2012; Franzetti et al, 2013; Knowlton et al, 2013). Previous studies have also shown apparent geographic patterns of microbial communities across the snow slope surfaces of mountain glaciers Kuytun 51, Qiangyong, and Rongbuk and among the mountain ice cores Dunde (140-m-long, drilled in 1987), Malan (102-m-long, drilled in 1999), Muztagata (37-m-long, drilled in 2003), and Puruogangri (89-m-long, drilled in 2000), and deep ice cores Greenland GISP2D and Antarctic Vostok 5G and Byrd, which illustrates the various microbial responses to climatic and environmental changes of glaciers and ice sheets (Xiang et al, 2009, 2010; An et al, 2010; Knowlton et al, 2013). The micro-biogeography of whole communities may be influenced by the dynamics of taxonomic groups.…”

“…Only a few taxonomic groups are able to colonize and dominate in the snow, although numerous microorganisms are trapped in the surface snow (Zhang et al, 2008, 2009; Xiang et al, 2009, 2010; An et al, 2010). Previous limited data of glacier surface snow have shown that the bacteria Comamonadaceae and Flavisolibacter sp.…”