Differences in Bacterial Diversity and Communities Between Glacial Snow and Glacial Soil on the Chongce Ice Cap, West Kunlun Mountains.

A detailed understanding of microbial ecology in different supraglacial habitats is important due to the unprecedented speed of glacier retreat. Differences in bacterial diversity and community structure between glacial snow and glacial soil on the Chongce Ice Cap were assessed using 454 pyrosequencing. Based on rarefaction curves, Chao1, ACE, and Shannon indices, we found that bacterial diversity in glacial snow was lower than that in glacial soil. Principal coordinate analysis (PCoA) and heatmap analysis indicated that there were major differences in bacterial communities between glacial snow and glacial soil. Most bacteria were different between the two habitats; however, there were some common bacteria shared between glacial snow and glacial soil. Some rare or functional bacterial resources were also present in the Chongce Ice Cap. These findings provide a preliminary understanding of the shifts in bacterial diversity and communities from glacial snow to glacial soil after the melting and inflow of glacial snow into glacial soil.

Bacterial community in the East Rongbuk Glacier, Mt. Qomolangma (Everest) by culture and culture-independent methods.

The abundance of total and culturable bacteria deposited into the East Rongbuk ice core was investigated, and the bacterial content was examined through culture and culture-independent approaches. Total counts of bacteria in the ice core ranged from 0.02 x 10(3) to 6.4 x 10(3) cells ml(-1). Viable bacteria varied between 0 and 5.6 CFU ml(-1) on PYGV and R2A media. The phylogenetic trees placed the culturable bacteria into four major groups: Actinobacteria, Firmicutes, Proteobacteria and Deinococcus-Thermus, with Firmicutes being the most prevalent. They exhibited unique phenotypic properties with large and non-pigmented cells. The diversity revealed by H' index of DGGE analysis was 0-0.75, and closer sections showed higher similarity of bacterial DNA structure. Members of two major lineages were found: Firmicutes and Proteobacteria. The combined culture and culture-independent methods indicated layer distribution of bacterial community in the ice core section, which might reflect the ecological environments on glacier at time of their deposition.

[Study on microbial diversity and community in Miaoergou snow of East Tianshan Mountains and their relation to climatic and environmental changes].

The different depth snow samples were collected from the Miaoergou glacier in East Tianshan Mountains regions, China. Total bacteria counts were established by 4',6- diamino-2-phenylindole (DAPI). Both culture-dependent and culture-independent methods, denaturing gradient gel electrophoresis (DGGE), were used to examine the bacterial diversity and community structure. The microbial abundance and diversity index have a close relationship with mineral particle concentration. These mineral particles, such as Ca2+ , Mg2+, and Cl- etc, are good indicators of climate and environment. The 16S rDNA gene both of cultured bacteria and DGGE band sequenced belong to following groups: proteobacteria (alpha-, beta-, gamma-), Cytophaga- Flavobacterium-Bacteroides (CFB), High GC and Low GC. Among these, Proteobacteria and CFB are dominant groups. Compare with bacteria revealed from ice and snow in Qinghai-Tibet Plateau, South Pole and North Pole which have been reported, Paracoccu sp. and Aquasalina sp. are especially exist in this study area as far as we know. The microbial abundance and community structure are all changed obviously in different depth snow samples. It indicates that the snow bacteria community is influenced by many factors. The results show that because the special geographical position of the East Tianshan Mountains, microorganism in ice and snow of this area has its particularity.