玄武湖微囊藻水华暴发及衰退期细菌群落变化分析  

Variation of Bacterial Community Composition in the Outbreak and Decline of Microcystis spp. Bloom in Lake Xuanwu

作　　者：郑小红[1] 肖琳[1] 任晶[1] 杨柳燕[1] 

机构地区：[1]南京大学环境学院、污染控制与资源化研究国家重点实验室,南京210093

出　　处：《环境科学》2008年第10期2956-2962,共7页Environmental Science

基　　金：国家自然科学基金项目(40371102,30770414);国家重点基础研究发展规划(973)项目(2002CB412307)

摘　　要：为探索微囊藻水华期间细菌群落的变化及了解水华的动态变化提供线索,采集玄武湖水华暴发及衰退期3个湖区内的水样,采用微生物传统方法,对水体中可培养细菌进行了分离鉴定,并通过变性梯度凝胶电泳技术(DGGE),对水体中细菌16S rDNA V3可变区的PCR扩增片段进行分离,分析了所得到的细菌群落特征DNA指纹图谱,并对其中的优势细菌进行16S rDNA序列系统发育分析.结果表明,玄武湖微囊藻水华期间水体内细菌主要属于3大类群,包括Proteobacteria、Firmicutes和Bacteroides;水华暴发期,Firmicutes、Bacteroides、α-、β-、γ-Proteobacteria分别占总数的31.25%、25%、18.75%、12.5%、12.5%,优势菌为16种,生物多样性高;水华衰退期γ-Proteobacteria菌群比例上升至50%,其次为Firmicutes和α-Proteobacteria,分别占总数的33.3%和16.7%,水体内原有的Hydrogenophaga、Vogesella、Sphingomonas、Exiguobacterium等菌属消亡,优势菌种数减少至6种,但细菌数量增大;Pseudomonas与Bacillus在水华暴发和衰退期一直处于优势,但优势菌的种类发生改变;同一时期内,藻华相对密集的湖区优势菌种数相对较少,生物多样性相对较低.微囊藻水华暴发与衰退期水体中细菌群落的变化,可能与藻体聚集与消散而引起的水体中有机物浓度及形态等环境因子的变化有关,此外,藻体密集程度也可能对细菌群落生物多样性有一定影响.Water samples were collected in the outbreak and decline of Microcystis spp. bloom in three different lake areas of Lake Xuanwu for studying the bacterial community composition during the bloom to provide clew for understanding the dynamics of water bloom. Traditional microbiological methods were used for cuhurable bacterial analysis, while the amplified products of variable V3 region of bacterial 16S rDNA were used for bacterial community DNA finger print by using denaturing gradient gel electrophoresis （DGGE）, and the 16S rDNA sequences of predominant bacteria in the community were used for phylogenetic analysis. Results showed three groups of bacteria were detected during Microcystis spp. bloom, including Proteobacteria, Firmicutes and Bacteroides. In the outbreak of the boom, the propotion of Firmicutes, Bacteroides and α-、β-、γ-Proteobacteria in total bacteria account for 31.25 %, 25 %, 18.75 %, 12.5 % and 12.5 % respectively, and sixteen genera of bacteria are predominant in the bacterial community. While in the decline of the bloom, the proportion of γ-Proteobacteria increases up to 50%, followed by Firmicutes and α-Proteobacteria, with the proportion of 33.3% and 16.7% respectively. Some species including Hydrogenophaga, Vogesella, Sphingomonas, and Exiguobacterium disappear when the bloom declining, but the abundance of total bacterial goes up. Pseudomonas and Bacillus are always the leading genera but with changing in species. During the same stage of the bloom, bacterial diversity in the lake area with more Microcystis spp. aggregates is lower. The variation in bacterial community composition may be correlated with changes of organic matters and other environmental factors that affected directly by wax and wane of Microcystis spp. aggregates, and the density of the aggregates may have effect on bacterial diversity.

关 键 词：微囊藻 水华 细菌群落 微生物传统分析 PCR-DGGE 

分 类 号：X172[环境科学与工程—环境科学] X524