An Liyun, Yan Ying-Chun, Tian Hai-Long, Chi Chang-Qiao, Nie Yong, Wu Xiao-Lei
College of Architecture and Environment, Sichuan University, Chengdu, China.
College of Agriculture, Henan University, Kaifeng, China.
Front Microbiol. 2023 Aug 10;14:1218828. doi: 10.3389/fmicb.2023.1218828. eCollection 2023.
Microbes play central roles in ocean food webs and global biogeochemical processes. Yet, the information available regarding the highly diverse bacterial communities in these systems is not comprehensive. Here we investigated the diversity, assembly process, and species coexistence frequency of bacterial communities in seawater and sediment across ∼600 km of the eastern Chinese marginal seas using 16S rRNA gene amplicon sequencing. Our analyses showed that compared with seawater, bacterial communities in sediment possessed higher diversity and experienced tight phylogenetic distribution. Neutral model analysis showed that the relative contribution of stochastic processes to the assembly process of bacterial communities in sediment was lower than that in seawater. Functional prediction results showed that sulfate-reducing bacteria (SRB) were enriched in the core bacterial sub-communities. The bacterial diversities of both sediment and seawater were positively associated with the relative abundance of SRB. Co-occurrence analysis showed that bacteria in seawater exhibited a more complex interaction network and closer co-occurrence relationships than those in sediment. The SRB of seawater were centrally located in the network and played an essential role in sustaining the complex network. In addition, further analysis indicated that the SRB of seawater helped maintain the high stability of the bacterial network. Overall, this study provided further comprehensive information regarding the characteristics of bacterial communities in the ocean, and provides new insights into keystone taxa and their roles in sustaining microbial diversity and stability in ocean.
微生物在海洋食物网和全球生物地球化学过程中发挥着核心作用。然而，关于这些系统中高度多样化的细菌群落的现有信息并不全面。在这里，我们使用16S rRNA基因扩增子测序技术，对中国东部边缘海约600公里范围内海水和沉积物中的细菌群落的多样性、组装过程和物种共存频率进行了调查。我们的分析表明，与海水相比，沉积物中的细菌群落具有更高的多样性，并且经历了紧密的系统发育分布。中性模型分析表明，随机过程对沉积物中细菌群落组装过程的相对贡献低于海水。功能预测结果表明，硫酸盐还原菌（SRB）在核心细菌亚群落中富集。沉积物和海水的细菌多样性均与SRB的相对丰度呈正相关。共现分析表明，海水中的细菌比沉积物中的细菌表现出更复杂的相互作用网络和更紧密的共现关系。海水中的SRB位于网络中心，在维持复杂网络中起着至关重要的作用。此外，进一步分析表明，海水中的SRB有助于维持细菌网络的高稳定性。总体而言，本研究提供了关于海洋中细菌群落特征的进一步全面信息，并为关键类群及其在维持海洋微生物多样性和稳定性中的作用提供了新的见解。
