近海沉积物与水体中天然大分子聚合物降解菌的原位富集与多样性分析

In situ enrichment and diversity analysis of natural macromolecular polymer degrading bacteria in offshore sediments and water bodies

本研究选取5种海洋动植物大分子高聚物或其天然组织,包括虾壳、鱼鳞、海带叶片、几丁质和壳聚糖,分别在海水表层和沉积物环境中进行富集,定期取样,通过高通量测序分析菌群多样性。结果发现,不同有机物原位富集的细菌多样性存在较大的差异,而且同种底物在海水表层与沉积物中的降解菌菌群差异较大。从物种多样性看,在海水表层环境中富集的鱼鳞样品种群最丰富,而沉积物环境中富集的海带叶片样品菌群多样性最低,除其优势菌群为热袍菌门外,其他所有富集物中优势菌均为变形菌门。其中脱硫杆菌科、黄杆菌科、脱硫弧菌科和弧菌科占有较大比例,脱硫杆菌科在所有样品中优势较大,黄杆菌科在海水表层环境样品中为优势菌群,弧菌科在沉积物样品几丁质和壳聚糖样品中占比较高。本研究通过对同种海洋环境中不同富集样品之间以及同种底物不同环境中富集菌群之间的比较,分析结果得到了原位条件下参与大分子聚合物降解的菌群种类,但有待于在更多不同的海域富集物中进行验证。

In this study we selected five marine animal and plant macromolecular polymers or their natural tissues,including shrimp shells,fish scales,kelp blades,chitin and chitosan,which were enriched in the surface seawater and sediment environments and sampled regularly.The diversity of bacteria was analyzed with high-throughput sequencing.The results showed that significant differences were found in the diversity of bacteria in the in situ enrichment of organic compounds and in the degrading bacteria in the surface seawater and sediments of the same organic substrates.For species diversity,it is the most abundant on the fish scales enriched in the surface seawater environment in contrast to the lowest diversity of bacterial flora on the kelp blades enriched in the sediment environment.Besides thermophore,the dominant bacteria in all the other enrichments were Proteobacteria.Among them,Desulfobacteraceae,Flavobacteriaceae,Desulfovibrionaceae and Vibrioaceae accounted for a large proportion with dominant Desulfobacteraceae in all samples.Flavobacteriaceae dominated in bacterial flora in the samples in surface seawater environment.Vibrioaceae had a high abundance in chitin and chitosan samples in the sediments.With comparisons of the different enrichment samples in the same marine environment and the enriched bacteria on the same organic substrate in different environments,it shows the types of bacterium flora involved in the in situ degradation process of macromolecular polymers.However,it needs to be further verified with more marine enrichment samples.