Dominance of a clonal green sulfur bacterial population in a stratified lake
Dominance of a clonal green sulfur bacterial population in a stratified lake
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DOI：
10.1111/j.1574-6941.2009.00737.x
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发表时间：
2009-10-01
影响因子：
4.2
通讯作者：
Frigaard, Niels-Ulrik
中科院分区：
文献类型：
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作者：
Gregersen, Lea H.;Habicht, Kirsten S.;Frigaard, Niels-Ulrik
多年来，瑞士卡达尼奥湖的化学跃层以紫色硫磺细菌为主。然而，随着近年来群落的重大转变，绿色硫磺细菌(GSB)开始占据主导地位。我们通过使用鱼类细胞计数和种群多位点序列分型[GSB的小亚基(SSU)rRNA基因座和参与光合作用的两个基因座的克隆文库序列分析：fmoA和csmCA]进行微生物多样性调查来调查这个群落。根据水柱化学，所有细菌种群明显分层。GSB种群在化学跃层达到峰值(约8×10(6)GSB细胞毫升(-1))，约占水柱缺氧区细胞总数的50%。至少99.5%的GSB细胞具有SSU rRNA、fmoA和csmCA序列，与以前分离的和基因组测序的GSB Clathatiforme菌株BU-1(DSM 5477)的序列基本相同。在GSB盛开之前，在卡达诺湖没有检测到这种核型。这些观察结果表明，在卡达诺湖稳定下来的笼形扇贝种群是克隆的。我们推测，这种克隆水华可能是由环境干扰、突变适应或入侵引起的。
For many years, the chemocline of the meromictic Lake Cadagno, Switzerland, was dominated by purple sulfur bacteria. However, following a major community shift in recent years, green sulfur bacteria (GSB) have come to dominate. We investigated this community by performing microbial diversity surveys using FISH cell counting and population multilocus sequence typing [clone library sequence analysis of the small subunit (SSU) rRNA locus and two loci involved in photosynthesis in GSB: fmoA and csmCA]. All bacterial populations clearly stratified according to water column chemistry. The GSB population peaked in the chemocline (c. 8 x 10(6) GSB cells mL(-1)) and constituted about 50% of all cells in the anoxic zones of the water column. At least 99.5% of these GSB cells had SSU rRNA, fmoA, and csmCA sequences essentially identical to that of the previously isolated and genome-sequenced GSB Chlorobium clathratiforme strain BU-1 (DSM 5477). This ribotype was not detected in Lake Cadagno before the bloom of GSB. These observations suggest that the C. clathratiforme population that has stabilized in Lake Cadagno is clonal. We speculate that such a clonal bloom could be caused by environmental disturbance, mutational adaptation, or invasion.