http://www.sciencedirect.com/science/article/pii/S1674987112000023

Ice melt water from a 22.27 m ice core which was drilled from the East Rongbuk Glacier,Mt. Everest was incubation in two incubation ways: plate melt water directly and enrichment melt waterprior plate, respectively. The abundance of cultivable bacteria ranged from 0e295 CFU mL 1 to0e1720 CFU mL 1 in two incubations with a total of 1385 isolates obtained. Comparing to direct cultivation,enrichment cultivation recovered more bacteria. Pigment-producing bacteria accounted for anaverage of 84.9% of total isolates. Such high percentage suggested that pigment production may be anadaptive physiological feature for the bacteria in ice core to cope with strong ultraviolet radiation onthe glacier. The abundances of cultivable bacteria and pigment-producing isolates varied synchronouslyalong depth: higher abundance in the middle and lower at the top and bottom. It indicated that the middlepart of the ice core was hospitable for the microbial survival. Based on the physiological properties ofthe colonies, eighty-nine isolates were selected for phylogenetic analysis. Obtained 16S rRNAgene sequences fell into four groups: Firmicutes, Alpha-Proteobacteria, Gamma-Proteobacteria,and Actinobacteria, with the Firmicutes being dominant. Microbial compositions derived from directand enrichment cultivations were not overlapped. We suggest that it is a better way to explore the culturable microbial diversity in ice core by combining the approaches of both direct and enrichmentcultivation.