Diversity and abundance of sulfate-reducing microorganisms in the sulfate and methane zones of a marine sediment, Black Sea
Diversity and abundance of sulfate-reducing microorganisms in the sulfate and methane zones of a marine sediment, Black Sea
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DOI：
10.1111/j.1462-2920.2006.01122.x
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发表时间：
2007-01-01
影响因子：
5.1
通讯作者：
Jorgensen, Bo Barker
中科院分区：
文献类型：
--
作者：
Leloup, Julie;Loy, Alexander;Jorgensen, Bo Barker
黑海，其高硫化物水柱，是世界上最大的缺氧盆地。在其沉积物中，有机物的矿化主要通过硫酸盐还原和甲烷生成发生。在这项研究中，硫酸盐还原社区进行了调查，以了解这些微生物分布相对于化学地带性：在上硫酸盐区，在硫酸盐-甲烷过渡区，并深入甲烷区。通过16 S rRNA基因的实时PCR定量总细菌，而硫酸盐还原微生物（SRM）通过靶向其代谢关键基因，异化（二）亚硫酸盐还原酶（dsrA）进行定量。硫酸盐还原微生物在硫酸盐区占优势，但在甲烷区也有分布，在硫酸盐-甲烷转化前后相对比例最大。30%，硫酸盐和甲烷区同样高，5- 10%。硫酸盐-甲烷过渡带的dsrAB克隆文库显示出与脱硫杆菌科相关的大部分序列。而来自上层硫酸盐富集区和深层硫酸盐贫乏区的dsrAB克隆文库以相似的、新的深分支序列为主，这些序列可能代表革兰氏阳性孢子形成硫酸盐和/或亚硫酸盐还原微生物。因此，我们假设，终端碳矿化在黑海的表层沉积物中，主要是由于硫酸盐还原活性的先前隐藏的SRM。虽然这些新的SRM也丰富的硫酸盐贫乏，产甲烷地区的黑海沉积物，其活动和可能非常多才多艺的代谢能力仍然是进一步研究的主题。
The Black Sea, with its highly sulfidic water column, is the largest anoxic basin in the world. Within its sediments, the mineralization of organic matter occurs essentially through sulfate reduction and methanogenesis. In this study, the sulfate-reducing community was investigated in order to understand how these microorganisms are distributed relative to the chemical zonation: in the upper sulfate zone, at the sulfate-methane transition zone, and deeply within the methane zone. Total bacteria were quantified by real-time PCR of 16S rRNA genes whereas sulfate-reducing microorganisms (SRM) were quantified by targeting their metabolic key gene, the dissimilatory (bi)sulfite reductase (dsrA). Sulfate-reducing microorganisms were predominant in the sulfate zone but occurred also in the methane zone, relative proportion was maximal around the sulfate-methane transition, c. 30%, and equally high in the sulfate and methane zones, 5-10%. The dsrAB clone library from the sulfate-methane transition zone, showed mostly sequences affiliated with the Desulfobacteraceae. While, the dsrAB clone libraries from the upper, sulfate-rich zone and the deep, sulfate-poor zone were dominated by similar, novel deeply branching sequences which might represent Gram-positive spore-forming sulfate- and/or sulfite-reducing microorganisms. We thus hypothesize that terminal carbon mineralization in surface sediments of the Black Sea is largely due to the sulfate reduction activity of previously hidden SRM. Although these novel SRM were also abundant in sulfate-poor, methanogenic areas of the Black Sea sediment, their activities and possibly very versatile metabolic capabilities remain subject of further study.