title: Dynamics of size-fractionated bacterial communities during the coastal dispersal of treated municipal effluents.
abstract: Everyday huge amount of treated municipal wastewater is discharged into the coastal seawater. However, microbial biomarkers for the municipal effluent instead of the fecal species from raw sewage have not been proposed. Meanwhile, bacterial taxa for degrading large amounts of input organics have not been fully understood. In this study, raw effluent and serial water samples were collected from the coastal dispersal of two sewage treatment plants in Xiamen, China. Free-living (FL) and particle-associated (PA) bacterial communities were analyzed via high-throughput sequencing of 16S rRNA gene and quantitative PCR to measure bacterial abundance. The PA bacterial communities in our samples exhibited higher cell abundance, alpha diversity, and population dynamics than the FL bacterial communities, which supports greater environmental significance of the PA bacterial communities. Two non-fecal but typical genera in activated sludge, Zoogloea and Dechloromonas, exhibited decreased but readily detectable abundance along the effluent dispersal distance. Furthermore, the dominating microbial species near the outfalls were related to well-known marine indigenous taxa, such as SAR11 clade, OM60 clade, low-GC Actinobacteria, and unclassified Flavobacteriales, as well as the less understood taxa like Pseudohongiella and Microbacteriaceae. It is interesting that these taxa exhibited two types of correlation patterns with COD concentration. Our study suggested Zoogloea as a potential indicator of municipal effluents and also proposed potential utilizers of residual effluent COD in marine environments.
authors.affiliation: Fujian Provincial Key Laboratory of Coastal Ecology and Environmental Studies, Xiamen University & Fujian Institute of Oceanography, Xiamen, 361005, China.|Laboratory of Marine Chemistry, Fujian Institute of Oceanography, Xiamen, 361000, China.
authors.forename: SiGuang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Fujian Provincial Key Laboratory of Coastal Ecology and Environmental Studies, Xiamen University & Fujian Institute of Oceanography, Xiamen, 361005, China. lyr@xmu.edu.cn.|Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361005, China. lyr@xmu.edu.cn.
authors.forename: YuanRong
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Fujian Provincial Key Laboratory of Coastal Ecology and Environmental Studies, Xiamen University & Fujian Institute of Oceanography, Xiamen, 361005, China.|Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, College of the Environment and Ecology, Xiamen University, Xiamen, 361005, China.
authors.forename: LingFeng
authors.initials: L
authors.lastname: Huang
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D044822:Biodiversity; D002681:China; D004269:DNA, Bacterial / Q000235:genetics; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*; D018508:Water Purification / Q000295:instrumentation
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: Bacterial indicator; Community structure; Diversity; Marine environment; Pollutant