厦门海域2011年中肋骨条藻和血红哈卡藻赤潮期间细菌群落结构变化

Dynamics of bacterial community during the bloom caused by Skeletonema costatum and Akashiwo sanguinea in Xiamen sea area

摘要:

摘要:【目的】研究2011 年8 月厦门海域爆发的由中肋骨条藻和血红哈卡藻共同引发的赤潮生消过程中细菌群落结构变化。【方法】应用变性梯度凝胶电泳技术(Denaturing gradient gel electrophoresis，DGGE)对两个赤潮站位和一个非赤潮站位的细菌群落结构进行研究。通过DGGE 图谱分析确定赤潮生消过程中细菌群落中的关键菌群，借助Canoco 软件分析细菌菌群与环境因子的相关性。【结果】在赤潮起始阶段细菌的群落结构与pH、N/P的相关性较大，在赤潮消亡阶段细菌的群落结构与盐度、温度呈明显的正相关。γ变形杆菌(Gammaproteobacteria) (47.7%)在赤潮期间处于主导位置，假交替单胞菌属(Pseudoalteromonas)、假单胞菌属(Pseudomonas)、交替单胞菌属( Alteromonas)、噬氢菌属(Hydrogenophaga)、Actibacter、Oleibacter 等属均为优势菌群。香农-威列多样性指数表明，赤潮站位细菌多样性随着赤潮生消呈先升高后降低趋势，而非赤潮站位细菌多样性基本保持不变。通过Canoco 对细菌菌群的主成分分析发现，在赤潮开始阶段Hydrogenophaga 属为优势菌群，而在赤潮消退阶段则以Pseudomonas 和Pseudoalteromonas 属为主。赤潮站位藻际细菌和游离细菌群落多样性在藻密度较大时均达到最大值，然而两者与环境因子的相关性有较大差别。 【结论】研究结果表明赤潮站位细菌群落多样性远高于非赤潮站位，细菌丰度随着赤潮藻密度的升高而增加，细菌与赤潮藻有着密切的关系。本文首次研究了多种优势藻引发的赤潮环境下细菌群落结构的变化，这对于多种藻引发的赤潮生消过程中细菌菌群结构有了深入的了解，为赤潮调控的研究提供了理论依据。

Abstract:

Abstract:［Objective］To investigate the dynamics of bacterial community in Xiamen sea during the bloom mainly caused by Skeletonema costatum and Akashiwo sanguine in August 2011． ［Methods］Bacterial community structures of samples from two bloom sites and one non-bloom site were evaluated by PCR-DGGE ( Denaturing gradient gel electrophoresis，DGGE)．The genetic diversity of bacterial community was analyzed based on the DGGE fingerprint． The correlation between bacterial community and environmental parameters was studied by Canoco． ［Results］The bacterial community was largely related to pH and N /P during the start-up stage of the bloom; while in the demise stage，it was mostly correlated to salinity and temperature． According to the results of sequence analysis of DGGE dominant bands，Gammaproteobacteria accounted for 47. 7% during the bloom and Pseudoalteromonas，Pseudomonas，Alteromonas，Hydrogenophaga，Actibacter and Oleibacter were dominant genus in bacterial community． The Shannon-Weaver diversity index showed that the diversity of bacterial community in bloom site increased firstly and then decreased during this bloom．Hydrogenophaga was dominant in the start-up stage of bloom，while Pseudomonas and Pseudoalteromonas were dominant in the demise stage of bloom． The diversity of attached bacteria and free-living bacteria in bloom sites reached maximum in the same day ( the concentration of algae was high)，both of them changed greatly during the bloom while the environment factors which correlated with the two communities were different． ［Conclusion］It is the first report about dynamics of bacterial community during the bloom caused by several algae together． This work is helpful to understand the dynamics of bacterial community during the bloom，and provides a theoretical basis for bloom's control in the future．