中文摘要：

细菌是浮游藻类群落结构重要的生物调节因子之一.采用PCR-DGGE技术研究太湖梅梁湾水域的菌群结构,主要分析水华发展阶段和暴发阶段该水域附生细菌和游离细菌的群落结构,以获得富营养化水体更丰富的微生态信息,探讨附生细菌和游离细菌在水华过程中可能具有的重要生态功能.结果表明,附生菌群结构简单,具有较高的时空稳定性,是水华发展阶段的优势菌群,其优势种群主要为α-proteobacteria和γ-proteobacteria;比较而言,游离菌群具有明显的时间差异性,水华发展阶段的种群多样性非常低,水华暴发阶段的则相当高,从而成为这一时期的优势菌群,以Actinobacteria和α-proteobacteria为主.此外,在水华发展与暴发阶段均发现淡水水体中较为罕见的SAR11种群,且这类细菌在附生菌群和游离菌群中均可检测到.

英文摘要：

Bacteria are one of the important biologic regulators for phytoplankton community structure.Here,PCR-DGGE（Polymerase chain reaction-denaturing gradient gel electrophoresis） technology is employed to study the bacterial community structure in the Meiliang Bay of the Taihu Lake in Jiangsu,China.The community structures of the attached and free-living bacteria in two typical water bloom periods（proceeding period and outbreak period,respectively） were analyzed to obtain more detail micro-ecological information and explore the ecological functions of both the attached bacteria and free-living bacteria in algal bloom.The results indicated that the attached bacterial community was simple and displayed high spatio-temporal stability,and the community mainly composed of α-proteobacteria and γ-proteobacteria was dominant in the proceeding period of the algal bloom.Comparatively,the community of the free-living bacteria greatly differed in the two different periods.The population diversity of the free-living bacteria in the proceeding period was apparently smaller than that of the outbreak period,in which Actinobacteria and α-proteobacteria are dominant members.In addition,the SAR11 bacteria,a rare population in fresh water body,were detected both in the attached and free-living bacteria.