虾-贝-红树林耦合循环水养殖系统中微生物群落分析

海水循环水养殖系统是重要的生态养殖模式发展趋势之一, 为了深入了解循环水养殖生态系统, 通过对系统各功能区水体中细菌16S rRNA基因V4V5区进行高通量测序和生物信息学分析, 从微生物生态学角度分析了循环水养殖系统不同功能区的细菌群落结构动态。测序分析结果显示, 海水循环水养殖系统中优势细菌种群分别属于变形菌门(Proteobacteria)、蓝藻门(Cyanobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)和浮霉菌门(Planctomycetes)。红树林湿地水体中变形菌门和厚壁菌门丰度较高, 而对虾养殖池的拟杆菌门和浮霉菌门丰度较高。在不同优势类群中, 变形菌门多样性指数平均值最高, 其次是拟杆菌门, 厚壁菌门最低。在各功能区中, 红树林细菌多样性最高, 虾池最低。MDS分析结果显示虾池、贝池和红树林湿地水体中细菌群落结构有明显差异, 虾池与其他功能区差异最大。研究表明, 高密度对虾养殖对虾池水体中细菌群落有显著影响, 但其影响在循环水养殖系统后续功能区中逐渐减弱。

ANALYSIS OF MICROBIAL COMMUNITY STRUCTURE IN MANGROVE CONSTRUCTED WETLAND-MARICULTURE COUPLING SYSTEM

Bacteria play a key role in the biological geochemical cycle and degradation of organic contamination in pond ecosystem. It is important to understand the dynamics of bacterial community structure in recirculating aquaculture system during shrimp and shellfish rearing. In this study, bacterioplankton community structure in mangrove constructed wetland-mariculture coupling system was investigated by using high-throughput sequencing with 16S rDNA. High-throughput sequencing analysis indicated that the dominant OTUs were Proteobacteria, Cyanobacteria, Bacteroidetes, Firmicutes, Actinobacteria and Planctomycetes. Proteobacteria and firmicutes were the most dominant phyla in mangrove wetland, while bacteroidetes and planctomycetes were the most abundant in shrimp pond. The analysis of Shannon-Wiener indices inferred that proteobacteria communities were the highest, whereas firmicutes were the lowest. The diversity of bacterial phyla in shrimp pond was lower than that of the other station (except firmicutes), whereas the diversity of bacterial phyla in mangrove wetland was higher than that of the other station (except actinobacteria). Multidimensional scaling revealed the changes in the microbial community structure of different stations. The microbial community structure in shrimp pond was markedly different from other stations in recirculating mariculture system, suggesting that shrimp farming has a great influence on bacterioplankton community structure.