Variation in abundance and community structure of particle-attached and free-living bacteria in the South China Sea
Variation in abundance and community structure of particle-attached and free-living bacteria in the South China Sea
复制标题
南海颗粒附着细菌和自由生活细菌丰度和群落结构的变化
DOI：
10.1016/j.dsr2.2015.07.006
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发表时间：
2015-12-01
影响因子：
3
通讯作者：
Fang, Jiasong
中科院分区：
文献类型：
--
作者：
Li, Jiangtao;Wei, Bingbing;Fang, Jiasong
细菌在海洋碳的生物转移中起着至关重要的作用，特别是在颗粒有机碳（POC）向溶解有机碳（DOC）的转化中，然而关于其在中层和深层沃茨中的丰度和群落结构的信息却很少。在这里，我们提出了我们的调查结果的丰度和社区组成的颗粒附着（PA）和自由生活（FL）的细菌组合在不同深度（500米，800米，1500米）在中国南海（SCS）的空间变化。结果表明，FL细菌的丰度比PA细菌的丰度高一个数量级。FL细菌的相对丰度从500 m处的82%增加到1500 m处的93%。在所有情况下，FL细菌组合比PA组分更多样化。PA细菌组合主要由α-变形菌门的Rhododocalales和γ-变形菌门的Alteromonadales的成员组成。与此相反，FL细菌组合显示出明显的空间异质性，并在不同深度的不同的细菌类型占主导地位。然而，某些细菌类群的α-和γ-变形菌共同发生在FL和PA部分，比例随深度而变化。这些结果突出了颗粒附着和自由生活的细菌专家和通才的共存，并提供了有价值的信息，了解不同的细菌组合在深海碳循环中的作用。(C)2015爱思唯尔有限公司版权所有。
Bacteria play a crucial role in the biological transfer of carbon in the ocean, especially in the transformation of particulate organic carbon (POC) to dissolved organic carbon (DOC), yet little information is available for their abundance and community structures in mesopelagic and bathypelagic waters. Here we present results of our investigation on the spatial variations of abundance and community composition of the particle-attached (PA) and free-living (FL) bacterial assemblages at different depths (500 m, 800 m, and 1500 m) in the South China Sea (SCS). Our results showed that the abundance of FL bacteria was an order of magnitude higher than that of PA bacteria. The relative abundance of FL bacteria increased from 82% at 500 m to 93% at 1500 m. In all cases, the FL bacteria assemblages were more diverse than the PA fraction. The PA bacterial assemblage was dominated by members of the Rhodobacterales of the alpha-Proteobacteria and the Alteromonadales of the gamma-Proteobacteria. In contrast, the FL bacteria assemblages displayed distinctive spatial heterogeneity and were dominant by different phylotypes at different depths. However, certain bacterial taxa of the alpha- and gamma-Proteobacteria co-occurred in both the FL and PA fractions, with proportions being varied with depth. These results highlight the coexistence of particle-attached and free-living bacteria specialists and generalists, and provide valuable information in understanding the role of different bacterial assemblages in the deep-ocean carbon cycle. (C) 2015 Elsevier Ltd. All rights reserved.