镉离子污染条件下微生物群落中细菌与藻类的相互作用

Interactions between bacteria and phytoplankton in microbial communities under cadmium contamination conditions

【背景】水体微生物有着丰富的多样性,不同种类的微生物之间的相互作用对水体生态系统的组成结构与功能具有重要影响。水体内的藻类与某些微生物可以发生多种相互作用,然而人们对逆境条件下的菌藻有益相互作用尚缺乏深入研究。【目的】为了研究镉对水体微生物群落的影响以及镉胁迫下菌藻之间可能的相互作用。【方法】本研究运用了基于16S rRNA基因的高通量测序技术,分析在不同Cd^2+条件下微生物群落结构的变化,利用微生物相互作用网络分析菌藻之间可能发生的相互作用。【结果】通过分离培养筛选出了与集胞藻PCC6803互作抗Cd^2+的关键细菌Y9菌株。【结论】研究结果表明Y9菌株属于Phyllobacteriaceae科,与微生物群落组成和微生物互作网络的分析结果相符。本研究为探索水体环境中微生物种间相互作用、菌藻互作抗Cd2+的生态效应提供参考依据。

[Background] Microorganisms in water are rich in diversity, and various interspecific relationships occur among different microorganisms, which have an important influence on the composition structure and function of water ecosystem. Phytoplankton (microalgae and cyanobacteria) and some microbes in aquatic environment can interact with each other in various formats. However, the beneficial interactions between bacteria and phytoplankton under stress conditions remain unclear.[Objective] Studying the effects of Cd^2+ on the microbial community of water samples and possible interactions between bacteria and phytoplankton.[Methods] Based on the high throughput sequencing of 16S rRNA gene, we analyzed the changes of microbial community structure under Cd^2+ stress. We used the microbial interaction network to analyze the possible interaction between bacteria and phytoplankton.[Results] By isolation and culture, we found that the strain Y9 could interact with Synechocystis sp. PCC6803 and help the algae to resist the toxicity of Cd^2+.[Conclusion] The results showed that strain Y9 belonged to Phyllobacteriaceae family, which was consistent with the results of microbial community composition and microbial interaction network. This study will provide a new scientific basis for exploring the interactions between microorganisms in aquatic environment and the ecological effects of interactions between bacteria and phytoplankton for cadmium resistance.