Prokaryotic niche partitioning between suspended and sinking marine particles
Prokaryotic niche partitioning between suspended and sinking marine particles
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DOI：
10.1111/1758-2229.12692
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发表时间：
2019-06-01
影响因子：
3.3
通讯作者：
Lam, Phyllis
中科院分区：
文献类型：
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作者：
Duret, Manon T.;Lampitt, Richard S.;Lam, Phyllis
悬浮颗粒是中远洋（100-1000米）异养微生物的主要有机碳基质。尽管如此，与下沉颗粒相比，与这些颗粒相关的群落被忽视了，后者通常被认为是向深海输送碳的主要载体。这项研究首次区分了与悬浮颗粒和下沉颗粒相关的原核生物群落，这些原核生物群落是用海洋捕雪器在斯科舍海的四个环境不同的站点收集的。16S rRNA基因扩增子测序显示，在混合层（0-100 m）和中上层区，两种颗粒类型存在明显的原核生物群落（平均差异为42.5% +/- 15.2%）。虽然在两种颗粒类型中都存在共同的再矿化分类群，但发现γ变形菌属假单胞菌属和弧菌属以及α变形菌属红杆菌属的下沉颗粒富集高达32倍，而黄杆菌属（拟杆菌属）则倾向于悬浮颗粒。我们提出，这种生态位划分可能是由两种颗粒类型中发现的有机物性质驱动的：k -战略型，专门降解复杂有机化合物，在半不稳定的悬浮颗粒上茁壮成长，而通才r-战略型则适应下沉颗粒的瞬时不稳定有机含量。两种粒子相关群落之间的差异在中上层比表层海洋更为明显，这可能是由更强的湍流导致的粒子池之间的交换造成的。
Suspended particles are major organic carbon substrates for heterotrophic microorganisms in the mesopelagic ocean (100-1000 m). Nonetheless, communities associated with these particles have been overlooked compared with sinking particles, the latter generally considered as main carbon transporters to the deep ocean. This study is the first to differentiate prokaryotic communities associated with suspended and sinking particles, collected with a marine snow catcher at four environmentally distinct stations in the Scotia Sea. Amplicon sequencing of 16S rRNA gene revealed distinct prokaryotic communities associated with the two particle-types in the mixed-layer (0-100 m) and upper-mesopelagic zone (mean dissimilarity 42.5% +/- 15.2%). Although common remineralising taxa were present within both particle-types, gammaproteobacterial Pseudomonadales and Vibrionales, and alphaproteobacterial Rhodobacterales were found enriched in sinking particles up to 32-fold, while Flavobacteriales (Bacteroidetes) favoured suspended particles. We propose that this niche-partitioning may be driven by organic matter properties found within both particle-types: K-strategists, specialised in the degradation of complex organic compounds, thrived on semi-labile suspended particles, while generalists r-strategists were adapted to the transient labile organic contents of sinking particles. Differences between the two particle-associated communities were more pronounced in the mesopelagic than in the surface ocean, likely resulting from exchanges between particle-pools enabled by the stronger turbulence.