Accelerated sulfur cycle in coastal marine sediment beneath areas of intensive shellfish aquaculture
Accelerated sulfur cycle in coastal marine sediment beneath areas of intensive shellfish aquaculture
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DOI：
10.1128/aem.71.6.2925-2933.2005
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发表时间：
2005-06-01
影响因子：
4.4
通讯作者：
Watanabe, K
中科院分区：
文献类型：
--
作者：
Asami, H;Aida, M;Watanabe, K
采用不依赖培养的分子系统发育方法，结合化学分析和活性分析，对日本三陆海岸两个相邻的半封闭海湾（山田湾和釜石湾）的海洋沉积物中的原核生物进行了研究。这两个海湾的水文地质和化学特征相似，但使用方式不同；山田湾被用于密集的贝类养殖，而釜石湾有一个商业港口，不用于水产养殖。在山田和釜石沉积物中构建的16S rRNA基因克隆文库在系统发育组成上存在较大差异。在Yamada文库中，与delta-Proteobacteria相关的种型最多，与gamma-Proteobacteria相关的种型次之。相比之下，Kamaishi文库被plantomycetes、gamma-Proteobacteria、delta-Proteobacteria和Crenarchaeota所属的种型所占据。在γ -变形菌门中，许多Yamada型与自由生活和共生硫氧化剂有关，而Kamaishi型与假单胞菌属有关。这些结果使我们假设硫酸盐还原和硫氧化细菌在山田沉积物中已经变得丰富。这一假设得到了具有群体特异性引物的定量竞争PCR （qcPCR）的支持。qcPCR还表明，与desulfobulbacae中Desulfotalea密切相关的生物是这些沉积物中主要的硫酸盐还原菌。此外，测定了沉积物样品中潜在的硫酸盐还原速率和硫氧化速率，表明在贝类集约化养殖区域下方的山田沉积物中，硫循环已经开始活跃。
Prokaryotes in marine sediments taken from two neighboring semienclosed bays (the Yamada and Kamaishi bays) at the Sanriku coast in Japan were investigated by the culture-independent molecular phylogenetic approach coupled with chemical and activity analyses. These two bays were chosen in terms of their similar hydrogeological and chemical characteristics but different usage modes; the Yamada bay has been used for intensive shellfish aquaculture, while the Kamaishi bay has a commercial port and is not used for aquaculture. Substantial differences were found in the phylogenetic composition of 16S rRNA gene clone libraries constructed for the Yamada and Kamaishi sediments. In the Yamada library, phylotypes affiliated with delta-Proteobacteria were the most abundant, and those affiliated with gamma-Proteobacteria were the second-most abundant. In contrast, the Kamaishi library was occupied by phylotypes affiliated with Planctomycetes, gamma-Proteobacteria, delta-Proteobacteria, and Crenarchaeota. In the gamma-Proteobacteria, many Yamada phylotypes were related to free-living and symbiotic sulfur oxidizers, whereas the Kamaishi phylotype was related to the genus Pseudomonas. These results allowed us to hypothesize that sulfate-reducing and sulfur-oxidizing bacteria have become abundant in the Yamada sediment. This hypothesis was supported by quantitative competitive PCR (qcPCR) with group-specific primers. The qcPCR also suggested that organisms closely related to Desulfotalea in the Desulfobulbaceae were the major sulfate-reducing bacteria in these sediments. In addition, potential sulfate reduction and sulfur oxidation rates in the sediment samples were determined, indicating that the sulfur cycle has become active in the Yamada sediment beneath the areas of intensive shellfish aquaculture.