title: Response of bacterial communities to environmental changes in a mesoscale subtropical watershed, Southeast China.
abstract: This study used 16S rRNA gene-based pyrosequencing (16S-pyrotag) to investigate both planktonic and benthic bacterial communities in two main tributaries (North River and West River) of the Jiulong River Watershed (JRW), a mesoscale subtropical watershed that has experienced intensive human perturbation in recent decades. The results of 16S-pyrotag showed that benthic bacterial communities were clearly more diverse and uniform than surface bacterioplankton communities. The results of taxonomic assignments indicated that Betaproteobacteria, Actinobacteria and Firmicutes were significantly more abundant in planktonic than in benthic communities, whereas the relative abundances of Acidobacteria, Delta-, Gammaproteobacteria, Chloroflexi and Nitrospira were higher in sediment than in water samples. In particular, several sewer- and fecal-pollution bacterial indicators were observed in water samples, implying that the water bodies of the JRW were contaminated by fecal pollution. Using the typical freshwater bacteria (TFB) taxonomic framework, 57.6 ± 10%, 27.6 ± 10.9% and 10.4 ± 6.9% of sequences recovered from planktonic communities could be assigned to lineages, clades and tribes of TFB, respectively. The relatively lower abundance of TFB implied that some unknown or unique autochthonous bacterioplankton populations occurred in the JRW. The principal coordinate analysis (PCoA) and one way analysis of similarity (ANOSIM) analysis demonstrated that planktonic bacterial community structures were significantly different between North River and West River, whereas benthic communities from these two tributaries were grouped together. Multivariate statistical analysis revealed that nutrient concentrations and stoichiometry were the key drivers of both α- and β-diversity patterns of bacterioplankton communities. Overall, our results indicate that the diversity, composition and structure of planktonic bacterial communities are sensitive to water chemistry (e.g., nutrient concentrations and stoichiometry) in the JRW, and therefore can serve as a good sentinel of environmental changes in this watershed.
authors: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors: Anyi
authors: A
authors: Hu
authors: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Life Sciences, Xiamen University, Xiamen 361005, China.
authors: Xiaoyong
authors: X
authors: Yang
authors: College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
authors: Nengwang
authors: N
authors: Chen
authors: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
authors: Liyuan
authors: L
authors: Hou
authors: Fisheries College, Jimei University, Xiamen 361021, China.
authors: Ying
authors: Y
authors: Ma
authors: Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China. Electronic address: cpyu@iue.ac.cn.
authors: Chang-Ping
authors: CP
authors: Yu
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D044822:Biodiversity; D002681:China; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000382:microbiology; D010933:Plankton; D012623:Seawater / Q000382:microbiology*; D014871:Water Microbiology
keywords: 16S-pyrotag; Bacterial community; Environmental change; Jiulong River watershed; Typical freshwater bacteria