Change of microbial communities in glaciers along a transition of air masses in western China

Abstract

[1] Microbial community dynamics across glaciers in different climatic zones provide important information about the sources, transportation pathways, and deposition of microorganisms. To better understand the possible driving forces of microbial community shifts in glacier ice at a large spatial scale, 16S rRNA gene amplification was used to establish clone libraries containing 95 bacterial sequences from three different habitats in the Qiangyong Gacier in 2005. The libraries were used in phylogenetic comparison with 149 previously reported sequences from the surface samples collected from the Kuytun 51, and East Rongbuk glaciers in the same year. The results showed the presence of cosmopolitan and endemic species, and displayed a tendency of zonal distribution of bacterial communities at genera and community levels, corresponding to the geographic placement of the three glaciers. Data also showed a significant difference in the proportion of dominant phylogenetic groups in the three glaciers. Comamonadaceae/Polaromonas (Betaproteobacteria) and Flexibacteraceae (Bacteroidetes) were dominant in the Qiangyong Glacier, Cyanobacteria, Comamonadaceae/Polaromonas, and Rhodoferax (Betaproteobacteria) were dominant in the Kuytun 51 Glacier, and Acinetobacteria (Gammaproteobacteria) were dominant in the Rongbuk Glacier. In conclusion, the current study provides evidence of microbial biogeography in glacier ice at both the fine lineage and whole community levels. The biogeographical patterns were generally associated with the hydrological transition over the glaciers in the northern periphery and southern part of the Tibetan plateau. This supports our hypothesis of air mass behavior being one of the main drivers determining the zonal distribution of microbial communities across the mountain glaciers in western China.

Activity and bacterial diversity of snow around Russian Antarctic stations

“…Members of the genus Corynebacterium were detected in the permafrost and Antarctic soils (Cherbunina et al, 2011;Horowitz et al, 1972). Genera which were detected in significant amounts in both DNA and cDNA libraries (Aquabacterium, Aquaspirillum, Comamonas, Janthinobacterium, Acinetobacter) were also detected previously (as evidenced by rDNA library analyses) in cold different environments, such as Tibetan glaciers and coastal Antarctic waters Bej and Mojib, 2009;Garrison et al, 1986;Gentile et al, 2006;Junge et al, 2004;Liu et al, 2006;Segawa et al, 2005;Xiang et al, 2010). Some of the genera, which we found only in DNA libraries, have been previously detected in cold environments.…”

“…Variovorax paradoxus grows at low temperatures and is likely an indigenous member of snow microbiota (Segawa et al, 2005). Sphingomonas, Pseudomonas, Methylobacterium, Flavisolibacter, and Stenotrophomonas were found multiple times in snow and glaciers in Tibet Christner et al, 2002;Liu et al, 2006;Miteva, 2008;Segawa et al, 2005;Xiang et al, 2010). Members of the genus Corynebacterium were detected in the permafrost and Antarctic soils (Cherbunina et al, 2011;Horowitz et al, 1972).…”

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

“…Bacteria are the most dominant life forms in extremely cold, oligotrophic, and frozen water environments. 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).…”

“…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.…”

“…Previous limited data of glacier surface snow have shown that the bacteria Comamonadaceae and Flavisolibacter sp. are common in both the Kuytun 51 and Qiangyong glaciers but only Rhodoferax ( Betaproteobacteria ) is dominant in the Kuytun 51 glacier (Xiang et al, 2010). The changes of the dominant bacteria in glaciers are mainly influenced by processes such as wind deposition (airborne or aerosol-associated microorganisms by prevailing winds and dust-associated microorganisms by dust storm events), precipitation deposition (microbial deposition with snow, wet-deposition), and post-deposition by microbial growth in the warming seasons on the glacier surface snow (Xiang et al, 2009; Price and Bay, 2012; Bottos et al, 2014; Peter et al, 2014; Meola et al, 2015; Miteva et al, 2015; Pearce et al, 2016).…”