Diversity and distribution of the prokaryotic community in near-surface permafrost sediments in the Tianshan Mountains, China

• Published in: Canadian Journal of Microbiology
• Main Authors: Yang, Daqun, Wang, Jianhui, Bai, Yu, Xu, Shijian, An, Lizhe
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 2008
• Subjects: permafrost
• Online Access: http://dx.doi.org/10.1139/w08-004; http://www.nrcresearchpress.com/doi/full-xml/10.1139/W08-004; http://www.nrcresearchpress.com/doi/pdf/10.1139/W08-004

The community structures and diversity of bacteria and archaea were investigated at 4 depths (1.5, 2.0, 2.5, and 3.0 m) in permafrost sediments in the Tianshan Mountains, using denaturing gradient gel electrophoresis of 16S rRNA gene amplified by polymerase chain reaction. Phylogenetic analysis of the dominant bands sequenced revealed the presence of rich diversity of bacteria, which could be related to the Proteobacteria, Actinobacteria, Acidobacteria, Gemmatimonadetes, Bacteroidetes, Firmicutes, and Chloroflexi. The Proteobacteria, consisting of the α, β, γ, and ε subdivisions, were clearly the dominant group at all depths studied. Archaeal diversity was relatively low and archaeal 16S rRNA gene sequences were grouped into 3 phylogenetic clusters within the 2 kingdoms Euryarchaeota and Crenarchaeota. Within the Euryarchaeota, methanogen-related group II was most abundant at shallow depth (1.5 m), whereas halobacterium-related group I dominated at greater depths. The low-temperature Crenarchaeota group was detected only at 2.5 and 3.0 m. Specific-depth distribution of methanogen-related Euryarchaeota group II and denitrifying bacteria of the genus Pseudomonas dominated at 1.5 m depth, accompanied by a distinct peak in the ratio of NH 4 -N to NO 3 /NO 2 -N, implying the potential capacity of these organisms in near-surface permafrost to release the greenhouse gases N 2 O and CH 4 .