今天是2018年12月18日

云南腾冲两条热泉溪流的固氮细菌群落多样性

DOI:10.3799/dqkx.2018.911

作者:冯灿, 杨渐, 蒋宏忱

联系地址:中国地质大学生物地质与环境地质国家重点实验室,湖北武汉 430074

摘要:探究云南腾冲热泉溪流中固氮细菌群落多样性及其对温度变化的响应.在云南腾冲地热区选取两个热泉 (水热爆炸区和蛤蟆嘴) 及沿其溪流选取共9个采样点,测量样点的温度和pH,针对水体样品中的nifH基因进行系统发育分析、聚类分析和多样性分析,并分析水体理化性质与固氮细菌群落组成和多样性的关系. 克隆文库分析显示:本研究中腾冲热泉水体样品中固氮细菌主要由 Chloroflexi (26.7\%)、Firmicutes(5.5\%)、Nitrospirae (9.4\%)、 Cyanobacteria(32.5\%) 和 Proteobacteria} (25.9\%) 5个门的细菌组成.沿着水热爆炸区热泉溪流,温度从高到低的过程中, Chloroflexi}逐渐取代Cyanobacteria成为主要的固氮细菌群落. 然而在蛤蟆嘴溪流中,随着温度的降低,其主要固氮细菌群落由 Firmicutes和 Nitrospirae变成为 Cyanobacteria. 聚类分析和典范对应分析均显示,温度对本文研究的热泉样品固氮微生物群落组成有重要影响. 另外,多样性分析表明不同样点间固氮微生物群落多样性差异较小. 温度是影响本研究中腾冲热泉固氮微生物群落结构组成的重要因素.

关键字:热泉; 固氮细菌; nifH基因; 种群构成; 温度; 环境地质

Diversity and Distribution of Nitrogen-Fixing Bacteria in Two Geothermal Channels in Tengchong Geothermal Zone, Yunnan~Province

Author:Feng Can, Yang Jian, Jiang Hongchen

Author Address:State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan

Abstract:To investigate the composition and diversity of nitrogen-fixing bacteria community and their responses to temperature gradients along two hot spring channels in Tengchong, Yunnan Province, China. Five sampling locations in the Hmzfj channel and four sampling locations in the Srbz channel were selected along outflows of each corresponding channel. The temperature and pH of the sampled waters were measured. The diversity of nitrogen-fixing bacteria community was studied through phylogenetic analyses of {\it nifH} genes. Temperatures of the nine sampling sites in the two hot spring channels in Tengchong range from 40.7 $^\circ$\hspace{-0.8pt}C to 86.8 $^\circ$\hspace{-0.8pt}C with a pH gradient of 6.5-8.7. Seven {\it nifH} gene clone libraries were constructed, and a total of 255 clones were randomly picked and subjected to phylogenetic analysis. The obtained {\it nifH} gene clones were grouped into 25~OTUs (operational taxonomic unit) at the cutoff of 97\% similarity. The nitrogen-fixing bacteria are mainly composed of {\it Chloroflexi}, {\it Cyanobacteria} and {\it Proteobacteria} in the two studied geothermal channels. Diversity indices of nitrogen-fixing bacteria community show no distinct differences among the studied sites. The PCoA (principal coordinates analysis) and cluster analyses illustrate that temperature played an important role in shaping the community structures of nitrogen-fixing bacteria in the studied samples. Temperature was the major factor influencing the composition of nitrogen-fixing bacteria community in Tengchong hot~springs

Keyword:hot spring; nitrogen-fixing bacteria; nifH; community composition;~temperature; environmental geology

 

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作者简介:冯灿(1993—),女,硕士研究生,主要从事地质微生物等方面研究工作, ORCID: 0000-0001-5907-2162. E-mail: 475717554@qq.com

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