Qiao Yanlu, Liu Jiwen, Zhao Meixun, Zhang Xiao-Hua
Laboratory of Marine Microbiology, College of Marine Life Sciences, Ocean University of China, Qingdao, China.
Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Front Microbiol. 2018 May 31;9:1128. doi: 10.3389/fmicb.2018.01128. eCollection 2018.
The mud sediments of the eastern China marginal seas (ECMS) are deposited under different hydrodynamic conditions with different organic matter sources. These events have been demonstrated to exert significant influences on microbial communities and biogeochemical processes in surface sediments. However, the extent to which such effects occur in subsurface microbial communities remains unclear. In this study, both horizontal and vertical (five sites, each for eight layers) distributions of bacterial abundance and community composition in mud deposits of the South Yellow Sea (SYS) and East China Sea (ECS) were investigated by quantitative PCR and Illumina sequencing of the 16S rRNA gene. Both bacterial abundance and diversity were higher in the ECS than in the SYS, and tended to be higher in up than in deep layers. (JTB255 marine benthic group), and were dominant in the upper layers, whereas , , and were enriched in the deep layers. The bacterial communities in surface and subsurface sediments showed different inter-taxa relationships, indicating contrasting co-occurrence patterns. The bacterial communities in the upper layer samples clustered in accordance with mud zones, whereas those in the deep layer samples of all sites tended to cluster together. TOC δC and TON δN significantly affected the bacterial community composition, suggesting that the abundance and composition of organic matter played critical roles in shaping of sedimentary bacterial communities. This study provides novel insights into the distribution of subsurface bacterial communities in mud deposits of the ECMS, and provides clues for understanding the biogeochemical cycles in this area.
中国东部边缘海（ECMS）的泥质沉积物是在不同的水动力条件下沉积的，且有机质来源不同。这些情况已被证明会对表层沉积物中的微生物群落和生物地球化学过程产生重大影响。然而，这种影响在次表层微生物群落中发生的程度仍不清楚。在本研究中，通过对16S rRNA基因进行定量PCR和Illumina测序，研究了南黄海（SYS）和东海（ECS）泥质沉积物中细菌丰度和群落组成的水平和垂直分布（五个站点，每个站点八个层）。东海的细菌丰度和多样性均高于南黄海，且浅层的细菌丰度和多样性往往高于深层。（JTB255海洋底栖生物群）在上层占主导地位，而 、 和 在深层富集。表层和次表层沉积物中的细菌群落显示出不同的类群间关系，表明共现模式存在差异。上层样品中的细菌群落根据泥质区域聚类，而所有站点深层样品中的细菌群落则倾向于聚集在一起。TOC δC和TON δN显著影响细菌群落组成，这表明有机质的丰度和组成在塑造沉积细菌群落方面发挥了关键作用。本研究为了解中国东部边缘海泥质沉积物中次表层细菌群落的分布提供了新的见解，并为理解该区域的生物地球化学循环提供了线索。
