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

Abstract

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.