沉水植物附着细菌群落结构及其多样性研究进展

Research progress of diversity and community structure of epiphytic bacteria on submerged macrophytes

与陆生植物类似，沉水植物的n十表也存在着大量的附着细菌。附着细菌拥有独特的生态位和显著的生态功能，与沉水植物构成了复杂的共生体系。针对附着细菌的群落结构及其多样性进行了简单的综述。在方法学上，“表面活性剂＋超声处理”的方式能够比较有效地洗脱叶表的附着细菌。显微计数和分离培养的方法分别发现，某些沉水植物附着细菌的多度存10^5～10^7个／cm2以及10^6CFU／cm左右。克隆测序的研究表明沉水植物附着细菌的OTU在几十到上百的范围内。在群落结构上，Betaproteobacteria、Bacteroidetes、Alphaproteobacteria、Actinobacteria、Planctomycetes、Cyanobacteria等门类的细菌较为常见。先锋物种在附着细菌生物膜的形成过程中发挥着关键作用，环境条件和植物体都会对附着细菌的多样性造成影响。富营养化水体观察到较高的附着细菌丰度，溶解性有机物比无机营养物更加适合附着细菌的利用。植物体的叶片化学组成、渗出物以及物理结构等会影响附着细菌的多样性及群落结构。对沉水植物附着细菌群落结构形成的机理进行了假说性质的总结，并对附着细菌的研究前沿进行了展望。

Similar to terrestrial plants, aquatic submerged plants habor abundant epiphytic bacteria on their leaves. With unique ecololgical niche and significant ecological function, epiphytic bacteria develop complex symbiotic relationship with submerged plants. This paper focused on diversity and community structure of epiphytic bacteria on submerged plants. In methodology, the surfactant ＋ ultrasonic processing way can wash epiphytic bacteria effectively. Based on microscopic count and cultivation methods, it＇s found that on some submerged plants, the number of eiphytic bacteria ranges 10^5-10^7 cells/cm2 and 10^6 CFU/cm, respectively. Cloning sequencing studies indicate that OTU numbers of epiphytic bacteria on submerged plants are in the range of tens to hundreds. Betaproteobacteria, Bacteroidetes, Alphaproteobacteria, Actinobaeteria, Planctomycetes, Cyanobacteria are the common bacreria phyla found on the surface of submerged macrophytes. Pioneering species of baceria play key roles in the process of biofilm development of epiphytic bacteria. Environmental characteristics and plant types can affect the diversity of epiphytic bacteria. Higher epiphytic bacteria abundance is observed in eutrophic waterbody. And dissolved organic matter is more suitable for epiphytic bacteria than inorganic nutrients. Chemical composition, leachs or exudates and physical structure of plant leaves are likely to affect epiphytic bacteria diversity and structure. Here we proposed several hypotheses on the mechanism of epiphytic bacterial community sructure moulding. At last we bad an overall envisage about the study of epiphytic bacteria on submerged macrophytes.