Phylogenetic diversity of culturable bacteria from alpine permafrost in the Tianshan Mountains, northwestern China
Phylogenetic diversity of culturable bacteria from alpine permafrost in the Tianshan Mountains, northwestern China
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DOI：
10.1016/j.resmic.2006.03.006
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发表时间：
2006-10-01
影响因子：
2.6
通讯作者：
An, Lizhe
中科院分区：
文献类型：
--
作者：
Bai, Yu;Yang, Daqun;An, Lizhe
近一个世纪以来，在永久冻土沉积物中发现了微生物。然而，高山永久冻土的微生物分析非常稀少。本研究首次对中国西北部天山高寒冻土中分离到的可培养细菌群落的系统发育多样性进行了描述。从4℃高山冻土样品中回收了改良PYGV培养基需氧2.5-6.0×10(5)CFU/GDW(每克干重CFU)，对其中91株不同形态的细菌菌株进行了形态、菌落着色、革兰氏染色、内孢子形成和生长温度范围等表型特征的研究。根据扩增的rDNA限制性内切酶分析(ARDRA)对这些菌株进行了进一步的分类，从中选出了51株具有不同ARDRA带型的代表性菌株，并进行了16S rDNA测序和系统发育分析。系统进化树将51株细菌分为4大类群：高G+C革兰氏阳性菌、低G+C革兰氏阳性菌、变形杆菌和胞噬-黄杆菌-类杆菌(CFB)门。最丰富和多样化的分离株是革兰氏阳性菌，特别是节杆菌，作为高山冻土可培养种群中的优势类群。Jukes-Cantor进化距离矩阵的结果表明，绝大多数菌株是已知物种的不同菌株，其中3个可能代表CFB门的金杆菌属的新种。这项研究表明，天山高山冻土沉积物为延长不同微生物谱系的生存提供了独特的生态位。(C)2006年爱思唯尔公司。版权所有。
Microbes have been discovered in permafrost sediments for nearly a century. However, microbiological analyses of alpine permafrost are very scarce. This study is a first attempt to describe the phylogenetic diversity of a culturable bacterial community isolated from alpine permafrost in the Tianshan Mountains in northwestern China. Aerobic 2.5-6.0 x 10(5) CFU/gdw (CFU per 1 gram of dry weight) on modified PYGV medium were recovered from alpine permafrost samples at 4 degrees C; among these, 91 bacterial isolates with different morphotypes were characterized by phenotypic properties, such as morphology, colony pigmentation, Gram staining, endospore formation and temperature range of growth. The isolates were further categorized based on amplified rDNA restriction analysis (ARDRA), and 51 representative isolates possessing distinct ARDRA patterns selected for subsequent 16S rDNA sequencing and phylogenetic analysis. The phylogenetic trees placed the 51 isolates in four major groups: the high-G + C Gram-positives, the low-G + C Gram-positives, Proteobacteria and the Cytophaga-Flavobacterium-Bacteroides (CFB) phylum. The most abundant and diverse isolates were members of Gram-positive bacteria, particularly the Arthrobacter as a dominant group in alpine permafrost culturable populations. Results of the Jukes-Cantor evolutionary distance matrix suggested that the vast majority of the isolates were different strains of known species, and three may represent new species within the genus Chryseobacterium of the CFB phylum. From this study, it is proposed that alpine permafrost sediments in the Tianshan Mountains provide a specific ecological niche for prolonging survival of diverse microbial lineages. (c) 2006 Elsevier SAS. All rights reserved.