福建东吾洋海域海水和沉积物菌群结构及其与环境因子相关性

Structure of seawater and sediment bacterial community and its correlation with environmental factors in Fujian Dongwuyang Bay

中文关键词: 东吾洋海域  刺参吊笼养殖  环境评价  菌群结构分析

英文关键词: Dongwuyang Bay  Sea cucumber cage culture  Environmental evaluation  Bacterial community structure analysis

中文摘要:

      福建东吾洋海域是我国刺参(Apostichopus japonicus)吊笼养殖的核心产区，但目前该地区的水域环境现状和环境菌群结构相关研究匮乏。本研究以东吾洋海域东安、马坑、雷江和沙湾4个主要养殖区域为对象，完成了海参养殖高峰期1月的水质环境因子调查和评价分析，采用高通量测序方法完成了水体和沉积物菌群多样性和差异特征菌群分析，解析了环境因子与菌群结构相关性。结果表明，马坑海域的富营养化指数为21.60，属于严重富营养化；东安和雷江海域属于重度富营养，只有沙湾海域处于中度富营养的水平。东安和沙湾海域水质属于轻度有机污染，而马坑和雷江海域属于中度有机污染。高通量测序共获得1 520个操作分类单元(operational taxonomic units, OTUs)，归属于28门、57纲、163目、322科、581属。菌群结构多样性分析表明，各区域沉积物的菌群多样性水平均显著高于相应海域水体菌群多样性，且具有较强的空间异质性。沙湾海域环境菌群多样性与丰度最高。PCoA分析表明，沉积物和水体中细菌群落结构差异极显著，水体交换和海域位置对其水体和沉积物菌群结构的影响较大。具有潜在致病性的弧菌科(Vibrionaceae)在所有水体和沉积物样本中均为优势种类之一。对水体样品和沉积物样品的LEFSe (line discriminant analysis effect size)分析筛选到处于不同分类水平的74个特异菌群。基因功能的预测和COG分类统计表明，水体与沉积物样品在12个代谢途径上存在显著差异(P<0.05)。对4个海区的水体菌群LEFSe分析筛选到处于不同分类水平的30个特异菌群。水体的菌群与环境因子的RDA分析揭示，温度、溶氧、叶绿素a浓度是影响不同海域水体菌群结构的主要环境因子，相关研究将为福建刺参养殖管理提供基础数据和科学参考。

英文摘要:

      The Dongwuyang Bay of Fujian Province is the core production area for sea cucumber culture in South China; however, research on the environmental status and bacterial community structure in this area is still limited. In this study, we investigated and evaluated the seawater quality in January, which is the peak culture period for sea cucumber in this area, and analyzed the diversity and differential characteristics of seawater and sediment bacterial community structure using the high-throughput sequencing method and analyzed the correlation between environmental factors and bacterial community structure. The following results were obtained: The Makeng eutrophication index reached 21.60, which indicated that this area was experiencing serious eutrophication. Dong´an and Leijiang were experiencing severe eutrophication, and only the Shawan sea area was experiencing moderate eutrophication. The organic pollution assessment showed that Dong´an and Shawan had light organic pollution, while Makeng and Leijiang had moderate organic pollution. A total of 1 520 OTUs were obtained via high-throughput sequencing, belonging to 28 phyla, 57 orders, 163 families, 322 families, and 581 genera. The diversity analysis revealed that the level of bacterial community diversity in the sediment of each region was significantly higher than that of the corresponding seawater diversity and presented stronger spatial heterogeneity. The diversity and abundance in Shawan were the highest. The results of the principal coordinate analysis and similarity analysis showed that there were significant differences in the bacterial community composition between sediment and seawater. The cluster analysis revealed that the cluster was influenced by water exchange and site location. Vibrionaceae, a family with potential pathogenicity, was one of the dominant species in all seawater and sediment samples. LEFSe (line discriminant analysis effect size) analysis of seawater column samples and sediment samples screened 74 specific OTUs (operational taxonomic units) of bacteria at different taxonomic levels. Prediction of gene function and COG (clusters of orthologous groups of proteins) classification statistics showed significant differences in 12 metabolic pathways between seawater and sediment samples (P<0.05). LEFSe analysis of bacterial community structure from four sites screened 30 specific OTUs at different taxonomic levels. The RDA (redundancy analysis) of the seawater bacterial community structure with environmental factors revealed that temperature, dissolved oxygen, and chlorophyll-a concentration were the major environmental factors affecting the structure in the four sites. Related studies should provide basic data and scientific reference for the management of sea cucumber culture in Fujian Province.