Coral-Associated Bacteria and Their Role in the Biogeochemical Cycling of Sulfur
Coral-Associated Bacteria and Their Role in the Biogeochemical Cycling of Sulfur
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DOI：
10.1128/aem.02567-08
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发表时间：
2009-06-01
影响因子：
4.4
通讯作者：
Bourne, David G.
中科院分区：
文献类型：
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作者：
Raina, Jean-Baptiste;Tapiolas, Dianne;Bourne, David G.
海洋细菌在将二甲基磺基丙酸酯降解为二甲基硫醚和丙烯酸的过程中发挥着核心作用，二甲基硫醚对云的形成至关重要，从而对气候产生冷却作用。高浓度的DMSP和DMS已报告在石珊瑚组织，虽然，到目前为止，还没有调查这些有机硫化合物对珊瑚相关细菌的影响。两个珊瑚物种，Montipora aequituberculata和鹿角珊瑚，采样，其细菌群落的特征在于文化依赖和分子技术。四个属，Rosebellum，海绵状，弧菌，Alteromonas，这是分离的媒体与DMSP或DMS作为唯一的碳源，包括大多数的克隆检索珊瑚粘液和组织16S rRNA基因克隆库。蔷薇属的无性系占M. aequituberculata组织文库中的克隆数为59%，而来自A.aequituberculata组织文库的克隆数为59%。millepora文库与海绵属相关的序列有关。弧菌属通常从二甲基硫醚和丙烯酸富集物中分离出来，也存在于珊瑚粘液的16S rRNA基因文库中，这表明在“正常”环境条件下，它们是珊瑚相关群落的天然组成部分。与dddD和dddL同源的基因，以前涉及DMSP降解，也从分离的菌株，其特征在于，证实与珊瑚相关的细菌有可能代谢这种硫化合物时，存在于珊瑚组织中。我们的研究结果表明，DMSP，DMS和丙烯酸可能作为营养源的珊瑚相关的细菌，这些硫化合物可能发挥作用，在珊瑚中构建细菌群落，珊瑚和珊瑚礁生态系统的健康具有重要的后果。
Marine bacteria play a central role in the degradation of dimethylsulfoniopropionate ( DMSP) to dimethyl sulfide (DMS) and acrylic acid, DMS being critical to cloud formation and thereby cooling effects on the climate. High concentrations of DMSP and DMS have been reported in scleractinian coral tissues although, to date, there have been no investigations into the influence of these organic sulfur compounds on coral-associated bacteria. Two coral species, Montipora aequituberculata and Acropora millepora, were sampled and their bacterial communities were characterized by both culture-dependent and molecular techniques. Four genera, Roseobacter, Spongiobacter, Vibrio, and Alteromonas, which were isolated on media with either DMSP or DMS as the sole carbon source, comprised the majority of clones retrieved from coral mucus and tissue 16S rRNA gene clone libraries. Clones affiliated with Roseobacter sp. constituted 28% of the M. aequituberculata tissue libraries, while 59% of the clones from the A. millepora libraries were affiliated with sequences related to the Spongiobacter genus. Vibrio spp. were commonly isolated from DMS and acrylic acid enrichments and were also present in 16S rRNA gene libraries from coral mucus, suggesting that under "normal" environmental conditions, they are a natural component of coral-associated communities. Genes homologous to dddD, and dddL, previously implicated in DMSP degradation, were also characterized from isolated strains, confirming that bacteria associated with corals have the potential to metabolize this sulfur compound when present in coral tissues. Our results demonstrate that DMSP, DMS, and acrylic acid potentially act as nutrient sources for coral-associated bacteria and that these sulfur compounds are likely to play a role in structuring bacterial communities in corals, with important consequences for the health of both corals and coral reef ecosystems.