大连长山群岛海岸带沉积物微生物群落结构特征

Microbial diversity of sediments from the coasts of Dalian Changshan Islands

摘要:

摘要：【目的】为揭示海岸带微生物群落结构在人类活动影响下的分布差异及对环境因子变化的响应趋势，【方法】本实验采用t-RFLP和DGGE技术，对大连长山群岛不同功能类型海岸潮间带沉积物中的微生物群落结构特征进行比对和分析，并通过16S rRNA基因文库解析养殖污染站位的微生物群落结构特征。【结果】T-RFLP的t-RF分析显示，养殖污染严重站位的微生物丰度、香农指数和均匀度明显高于其它站位。通过对t-RFLP色谱峰和DGGE图谱聚类分析发现，处于旅游区的2个站位微生物群落结构相似度较高，养殖区随污染程度加重与旅游区的群落结构差异增大。对污染严重站位建立的克隆文库显示变形菌门（Proteobacteria）为优势菌群，其中γ-变形菌门是主要存在的亚门微生物。【结论】T-RFLP和DGGE技术从不同方面反映了环境中的微生物群落结构特征，研究结果表明养殖污染区的微生物群落结构发生明显变化，其影响大于地理隔离效应，污染严重区域的微生物群落中存在大量肠杆菌属，且多个物种与富营养化和赤潮相关联，如拟杆菌门和α-变形细菌红细菌目的细菌。

Abstract:

Abstract：[Objective] To understand the impacts of anthropogenic activities on structure and composition of bacterial communities and to evaluate how bacterial communities respond to environmental gradients at coastal sediments. [Methods] The diversity of bacterial communities in sediments form tourist and mariculture zones at coastal area of Dalian Changshan Islands was assessed using terminal restriction fragment length polymorphism (t-RFLP) and denaturing gradient gel electrophoresis(DGGE) approaches. Meanwhile, 16S rRNA clone library was constructed to reveal the composition and structure of bacterial communities in the most seriously polluted site (D4). [Results] There were much higher values of richness, Shannon-wiener and evenness index at D4 site by the analysis of terminal restriction fragments (t-RFs). The clustering result on the t-RFs areas and DGGE patterns showed that the bacterial diversity of tourist zone were more similar, while the distinction was increased with pollution levels among the tourist and mariculture zones. The 16S rRNA clone of D4 revealed that the Proteobacteria were the dominant phylum, and γ-proteobacteria was the main class within Proteobacteria. [Conclusion] The study documented changes in bacterial community structure by human impacts of mariculture than geographical location.