title: Abundance and composition of indigenous bacterial communities in a multi-step biofiltration-based drinking water treatment plant.
abstract: Indigenous bacterial communities are essential for biofiltration processes in drinking water treatment systems. In this study, we examined the microbial community composition and abundance of three different biofilter types (rapid sand, granular activated carbon, and slow sand filters) and their respective effluents in a full-scale, multi-step treatment plant (Zürich, CH). Detailed analysis of organic carbon degradation underpinned biodegradation as the primary function of the biofilter biomass. The biomass was present in concentrations ranging between 2-5 × 10(15) cells/m(3) in all filters but was phylogenetically, enzymatically and metabolically diverse. Based on 16S rRNA gene-based 454 pyrosequencing analysis for microbial community composition, similar microbial taxa (predominantly Proteobacteria, Planctomycetes, Acidobacteria, Bacteriodetes, Nitrospira and Chloroflexi) were present in all biofilters and in their respective effluents, but the ratio of microbial taxa was different in each filter type. This change was also reflected in the cluster analysis, which revealed a change of 50-60% in microbial community composition between the different filter types. This study documents the direct influence of the filter biomass on the microbial community composition of the final drinking water, particularly when the water is distributed without post-disinfection. The results provide new insights on the complexity of indigenous bacteria colonizing drinking water systems, especially in different biofilters of a multi-step treatment plant.
authors.affiliation: Eawag, Swiss Federal Institute for Aquatic Science and Technology, Überlandstr. 133, CH-8600 Dübendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, CH-8092 Zürich, Switzerland.
authors.forename: Karin
authors.initials: K
authors.lastname: Lautenschlager
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Chiachi
authors.initials: C
authors.lastname: Hwang
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Fangqiong
authors.initials: F
authors.lastname: Ling
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA.
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Ghent University, Faculty of Bioscience Engineering, Laboratory of Microbial Ecology and Technology (LabMET), Gent, Belgium.
authors.forename: Nico
authors.initials: N
authors.lastname: Boon
authors.affiliation: Zürich Water Supply (WVZ), Hardhof 9, P.O. Box 1179, CH-8021 Zürich, Switzerland.
authors.forename: Oliver
authors.initials: O
authors.lastname: Köster
authors.affiliation: Eawag, Swiss Federal Institute for Aquatic Science and Technology, Überlandstr. 133, CH-8600 Dübendorf, Switzerland; ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, CH-8092 Zürich, Switzerland.
authors.forename: Thomas
authors.initials: T
authors.lastname: Egli
authors.affiliation: Eawag, Swiss Federal Institute for Aquatic Science and Technology, Überlandstr. 133, CH-8600 Dübendorf, Switzerland. Electronic address: Frederik.Hammes@eawag.ch.
authors.forename: Frederik
authors.initials: F
authors.lastname: Hammes
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000254:growth & development*; D001673:Biodegradation, Environmental; D044822:Biodiversity; D018533:Biomass; D002244:Carbon / Q000302:isolation & purification; D002606:Charcoal / Q000737:chemistry; D060766:Drinking Water / Q000382:microbiology*; D005374:Filtration / Q000379:methods*; D009930:Organic Chemicals / Q000302:isolation & purification; D010933:Plankton / Q000254:growth & development; D013557:Switzerland; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods*; D060753:Water Quality
chemical_list: D060766:Drinking Water; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical; D002606:Charcoal; D002244:Carbon
keywords: 454 pyrosequencing; Adenosine tri-phosphate (ATP); Biofilter; Drinking water; Microbial communities