舟山群岛不同功能区划海域细菌群落结构分析

Bacterial community structure in different functional sea areas of Zhoushan archipelago

摘要:

浮游细菌在海洋生态系统中不可或缺，在海洋生物地球化学循环过程中起着关键性作用。[目的]为了解舟山群岛不同功能区划海域细菌群落结构及丰度变化，探索海洋生态因子对细菌群落结构的影响。[方法]于2016年夏季（8月）在舟山群岛不同功能区划海域共设置8个典型站位采集表层海水，基于细菌16S rRNA基因进行高通量测序；利用流式细胞术揭示各海域细菌丰度；利用典范对应分析（Canonical correspondence analysis，CCA）探讨海洋生态因子与细菌多样性之间的关系。[结果]共获取到305487条原始序列，基于97%相似性水平进行OTU （Operational Taxonomic Units）聚类分析，共得到1088个OTUs，包括29个门、62个纲、138个目、239个科、416个属。细菌群落组成在各个站位之间不尽相同，但都主要包括Flavobacteria、Alphaproteobacteria、Gammaproteobacteria三大优势菌纲。CCA结果表明细菌群落结构和多样性情况与站位分布和所在站位的环境因子息息相关，Cyanobacteria受硝酸盐影响显著，Parcubacteria受温度影响最大，而磷酸盐对本实验海域菌群影响甚微。对海洋菌群潜在功能进行预测的结果显示，各海域菌群在氨基酸代谢、碳水化合物代谢、膜运输等方面功能较为突出，为今后舟山海洋微生物研究提供了新的方向。[结论]高通量测序分析可以更精确地揭示海洋菌群的群落结构信息。该研究为细菌群落结构与环境因素的关联提供参考。本研究所取得的大量数据既可以作为对舟山市海洋功能区划施行情况的响应，又将为舟山及其邻近海域浮游细菌群落结构的进一步研究奠定基础。

Abstract:

Planktonic bacteria are indispensable in marine ecosystems and play a key role in the process of marine biogeochemical cycling. [Objective] The aim of this study was to analyze the bacterial community structure in different functional sea areas of Zhoushan archipelago.[Methods] Samples were collected in surface seawater from Zhoushan Archipelago of the East China Sea in 8 typical sites representative of 8 functional zones in the summer (August) of 2016. We used high throughput sequencing to study bacterial diversity and community structure in seawater of the of Zhoushan archipelago based on the bacterial 16S rRNA gene. Flow cytometry was used to reveal the abundance of bacteria in each site. The technique of Canonical correspondence analysis was used to analyze the effects of the environmental factors on bacterial community composition.[Results] In this research, 305487 raw reads were obtained. OTU cluster analysis was performed at the 97% similarity level, and all the sequences were grouped into 1088 OTUs, including 29 phyla, 62 classes, 138 orders, 239 families, and 416 genera. The bacterial community structure of each station were different, but they all included three dominant strains of Flavobacteria, Alphaproteobacteria and Gammaproteobacteria. A canonical correspondence analysis showed that different stations and different Phyla were affected by different ecological factors, Cyanobacteria was most affected by nitrate, Parcubacteria was most affected by temperature, and phosphate had little effect on all bacteria in this study area. The prediction of the potential function of marine microflora showed that the sea areas of each site were more prominent in Amino Acid Metabolism, Carbohydrate Metabolism, Membrane Transport and so on, which provided a new direction for marine microbial research in the future.[Conclusion] High throughput sequencing analysis can accurately reveal the bacterial structure information of marine bacteria. This research provides references for the association of bacterial composition and diversity with environmental factors. The large amount of data that was obtained not only as a response of Zhoushan marine function zoning purposes of the case but also lay foundations for further bacterial community structure research in the east China sea.