Microbial community structure and function on sinking particles in the North Pacific Subtropical Gyre.
Microbial community structure and function on sinking particles in the North Pacific Subtropical Gyre.
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DOI：
10.3389/fmicb.2015.00469
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发表时间：
2015
影响因子：
5.2
通讯作者：
DeLong EF
中科院分区：
文献类型：
--
作者：
Fontanez KM;Eppley JM;Samo TJ;Karl DM;DeLong EF
下沉颗粒介导碳和能量向深海的运输，但与海洋内部沉积颗粒相关的特定微生物在很大程度上仍然没有特征。在这项研究中，我们使用颗粒拦截器陷阱（PITs），以评估在北太平洋亚热带环流的各种深度收集的颗粒相关的微生物群落的性质。比较宏基因组学被用来评估微生物分类群和功能基因库的差异，在PIT含有防腐剂（中毒陷阱）相比，无防腐剂陷阱，其中生长被允许继续原位（活陷阱）。活陷阱微生物群落与先前报道的富含溶解有机物（DOM）微宇宙的细菌（例如，交替单胞菌属和嗜甲基菌属），以及其他颗粒和真核生物相关细菌（例如，黄杆菌目（Flavobacteriales）和假交替单胞菌属（Pseudoalteromonas）。中毒陷阱微生物组合富集弧菌和弯曲杆菌可能与真核生物表面和肠道的共生体，病原体，或satellites。中毒陷阱中的微生物组合的功能基因内容包括参与毒力，厌氧代谢，附着到chitinaceaous表面，和几丁质降解的各种基因。几丁质表面的存在还伴随着编码附着、运输和代谢几丁质及其衍生物的能力的细菌的共存。明显不同的微生物组合占主导地位的活陷阱，这在很大程度上是由共生生物和真核生物相关的细菌群落。主要沉积物陷阱相关的真核生物门包括甲藻，后生动物（主要是桡足类），Protalveolata，Retaria，和Straveliles。这些数据表明真核生物类群在构建下沉颗粒微生物组合中的核心作用，以及土著微生物物种在海洋内部原位降解海洋颗粒有机物（POM）中的快速反应。
Sinking particles mediate the transport of carbon and energy to the deep-sea, yet the specific microbes associated with sedimenting particles in the ocean's interior remain largely uncharacterized. In this study, we used particle interceptor traps (PITs) to assess the nature of particle-associated microbial communities collected at a variety of depths in the North Pacific Subtropical Gyre. Comparative metagenomics was used to assess differences in microbial taxa and functional gene repertoires in PITs containing a preservative (poisoned traps) compared to preservative-free traps where growth was allowed to continue in situ (live traps). Live trap microbial communities shared taxonomic and functional similarities with bacteria previously reported to be enriched in dissolved organic matter (DOM) microcosms (e.g., Alteromonas and Methylophaga), in addition to other particle and eukaryote-associated bacteria (e.g., Flavobacteriales and Pseudoalteromonas). Poisoned trap microbial assemblages were enriched in Vibrio and Campylobacterales likely associated with eukaryotic surfaces and intestinal tracts as symbionts, pathogens, or saprophytes. The functional gene content of microbial assemblages in poisoned traps included a variety of genes involved in virulence, anaerobic metabolism, attachment to chitinaceaous surfaces, and chitin degradation. The presence of chitinaceaous surfaces was also accompanied by the co-existence of bacteria which encoded the capacity to attach to, transport and metabolize chitin and its derivatives. Distinctly different microbial assemblages predominated in live traps, which were largely represented by copiotrophs and eukaryote-associated bacterial communities. Predominant sediment trap-assocaited eukaryotic phyla included Dinoflagellata, Metazoa (mostly copepods), Protalveolata, Retaria, and Stramenopiles. These data indicate the central role of eukaryotic taxa in structuring sinking particle microbial assemblages, as well as the rapid responses of indigenous microbial species in the degradation of marine particulate organic matter (POM) in situ in the ocean's interior.