title: Phylogenetic diversity of bacteria isolates from the Qinghai-Tibet Plateau permafrost region.
abstract: The Qinghai-Tibet Plateau in east Asia is a unique and important permafrost environment. However, its microbiology remains largely unexplored to date. In this study, sediment samples were collected from the Qinghai-Tibet Plateau permafrost region, bacteria isolation procedures were performed 8 times, and the samples incubated at 4 degrees C for nearly 3 months. The number of colony forming units (cfu) ranged from 0 to 10(7)/(g dry soil). The quantity of culturable bacteria grew exponentially within the first few weeks, and then slowed gradually to a plateau. Phylogenetic analyses indicated that all the isolates fell into 6 categories: high G+C Gram-positive bacteria, low G+C Gram-positive bacteria, alpha-Proteobacteria, beta-Proteobacteria, gamma-Proteobacteria, and Cytophaga-Flavobacterium-Bacteroides group bacteria. The isolates belong to 19 genera, but the genera Arthrobacter and Pseudomonas were predominant. With the increase in incubation time, the isolated populations changed in terms of both species and their respective quantities. Of the 33 analyzed isolates, 9 isolates related to 8 genera might be new taxa. These results suggest that the Qinghai-Tibet Plateau permafrost region is a specific ecologic niche that accommodates an original microbial assemblage.
authors: School of Life Sciences, Key Laboratory of Arid and Grassland Agrioecology of Ministry of Education, Lanzhou University, Lanzhou, 730000, China.
authors: Gaosen
authors: G
authors: Zhang
authors: Fujun
authors: F
authors: Niu
authors: Xiaojun
authors: X
authors: Ma
authors: Wei
authors: W
authors: Liu
authors: Maoxing
authors: M
authors: Dong
authors: Huyuan
authors: H
authors: Feng
authors: Lizhe
authors: L
authors: An
authors: Guodong
authors: G
authors: Cheng
mesh_terms: D000531:Altitude; D001419:Bacteria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D044822:Biodiversity; D014644:Genetic Variation; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D018609:Tibet
chemical_list: D012336:RNA, Ribosomal, 16S