极地研究2017，Vol.29Issue(4)：496-505,10.DOI:10.13679/j.jdyj.2017.4.496
北极斯瓦尔巴群岛冰川流域可培养细菌的系统发育多样性及固氮菌初步研究
PRELIMINARY STUDY ON PHYLOGENETIC DIVERSITY OF CULTURABLE BACTERIA AND NITROGEN-FIXING BACTERIA IN THE SVALBARD GLACIERS OF THE ARCTIC
摘要
Abstract
Five different samplesof representative soil and meltwater (MT, AT, TN, BT, MS) were collected from the upstream, midstream and downstream of the Arctic Svalbard glaciers. The culturable bacteria and poten-tial nitrogen-fixing bacteria were counted, enriched and isolated by using LB medium and strict nitro-gen-free medium at the low temperature, respectively. After colony observation, preliminary 16S rRNA gene sequencing andnifH-PCR, 48 culturable bacterial strains and 31 potential nitrogen-fixing bacterial strains were selected to examine the phylogenetic diversity based on the almost full-length 16S rRNA gene se-quences. The purpose was to obtain a preliminary understanding of the diversity and distribution of these bacteria in this special area, and to provide a basis for further research on their ecological functions. The results showed that the populations of the culturable bacteria in the five samples were ordered as BT > TN > AT > MT=MS. The populations of potential nitrogen-fixing bacteria were ordered as BT > AT > MT > TN > MS. Forty-eight culturable bacteria belonged to 4 phyla (Proteobacteria, Actinobacteria, Bacteroidetes, Fir-micutes), 7 classes and 14 genera, and their degrees of diversity were ordered as BT(6 classes, 6 genera)> MT(4 classes, 6 genera)> AT=MS(3 classes, 3 genera)> TN(2 classes, 3 genera).Meanwhile, the majority of culturable bacterial isolates were composed ofPseudomonas ofγ-proteobacteria (20.8%, isolated from the AT, BT and MS samples) andJanthinobacterium ofβ-proteobacteria(35.4%, isolated from the MS sample). The experimental results of the potential nitrogen-fixing bacteria showed that the diversity of 31 strains iso-lated from the five samples was very low. Of the strains, 90.32% belonged mainly toPseudomo-nas(γ-proteobacteria), only 3 strains isolated from the MT and MS samples belonged toRhizobium (α-proteobacteria),Janthinobacterium(β-proteobacteria) andArthrobacter (Actinobacteria C), respectively. There was high 16S rRNA gene homology among these potential nitrogen-fixing strains and some related standard-type strains isolated from other extreme environment. In addition, eight strains that showed less than 98.6% 16S rRNA gene-sequence similarity with strains of related type may represent potential novel species in this special ecological environment.关键词
北极/斯瓦尔巴冰川流域/可培养细菌/潜在固氮菌/系统发育多样性/分布状况Key words
Arctic/Svalbard glaciers/culturable bacteria/potential nitrogen-fixing bacteria/phylogenetic diversity/distribution引用本文复制引用
刘杰,李胜男,郭昱东,张丹丹,王能飞..北极斯瓦尔巴群岛冰川流域可培养细菌的系统发育多样性及固氮菌初步研究[J].极地研究,2017,29(4):496-505,10.基金项目
南北极环境综合考察与评估专项(CHINARE-2015-02-01)、中央级公益性科研院所基本科研业务专项(2015T04)和山东省重点研发计划(2015GSF115004)资助 （CHINARE-2015-02-01）
