福州左海湖细菌群落的季节性变化特征及典范对应分析

摘要

To determine the seasonal changes on and the environmental factors that affected the bacterial community at Zuohai Lake in Fuzhou,a survey was conducted at 4 sampling sites on the lake from February to August in 2012. A genetic library of their 1 6S rRNA gene clones was established.Canonical correspondence analysis (CCA)was used to examine the correlation between the bacterial diversity and the environmental factors.The results indicated thatβ-Proteobacteria and Cyanobacteria were the predominate lineages in the water,followed byα-Proteobacteria , Bacteroidetes ,and Actinobacteria.A significant seasonal variation in composition of the bacterial community was detected.Among various categories of bacteria,Cyanobacteria appeared most dominant in the spring and summer;whileβ-Proteobacteria ,in the autumn and winter.The results of CCA showed that the bacterial community in the water was mainly affected by pH,chlorophyll a (Chla),transparency (SD),and total nitrogen (TN)in the spring;pH,Chla,SD,and total phosphate (TP),in the summer;TP,Chla,and TN in the fall;and,water temperature, pH,and SD,in the winter.Thus,in general,the bacterial growth in the lake closely related to the temperature as well as the nutrients available in the water.%为揭示福州左海湖细菌群落的季节变化及其与环境因子的关系,通过构建16S rRNA 基因克隆文库对全湖水体细菌群落进行了调查,应用典范对应分析(Canonical correspondence analysis,CCA)探讨影响细菌群落季节性变化的环境因素。结果表明：左海湖细菌群落组成中β-变形菌门β-Proteobacteria 和蓝细菌门Cyanobacteria 为优势类群,α-变形菌门α-Proteobacteria 、拟杆菌门 Bacteroidetes 和放线菌门 Actinobacteria 为亚优势类群。细菌群落结构具有明显的季节性变化特征,春、夏季 Cyanobacteria 为优势类群,秋、冬季β-Proteobacteria 为优势类群。春季水体细菌群落结构主要受 pH、叶绿素 a (Chla)、透明度(SD)和总氮(TN)的影响,夏季水体受 pH、Chla、SD、总磷(TP)影响较大,秋季水体受 TP、Chla、TN 影响较大,冬季水体则受水温(WT)、pH、SD 影响较大。本研究发现,左海湖细菌群落结构的季节动态与水温及营养状况密切相关。