title: Proteobacteria become predominant during regrowth after water disinfection.
abstract: Disinfection processes aim at reducing the number of viable cells through the generation of damages in different cellular structures and molecules. Since disinfection involves unspecific mechanisms, some microbial populations may be selected due to resilience to treatment and/or to high post-treatment fitness. In this study, the bacterial community composition of secondarily treated urban wastewater and of surface water collected in the intake area of a drinking water treatment plant was compared before and 3-days after disinfection with ultraviolet radiation, ozonation or photocatalytic ozonation. The aim was to assess the dynamics of the bacterial communities during regrowth after disinfection. In all the freshly collected samples, Proteobacteria and Bacteroidetes were the predominant phyla (40-50% and 20-30% of the reads, respectively). Surface water differed from wastewater mainly in the relative abundance of Actinobacteria (17% and <5% of the reads, respectively). After 3-days storage at light and room temperature, disinfected samples presented a shift of Gammaproteobacteria (from 8 to 10% to 33-65% of the reads) and Betaproteobacteria (from 14 to 20% to 31-37% of the reads), irrespective of the type of water and disinfection process used. Genera such as Pseudomonas, Acinetobacter or Rheinheimera presented a selective advantage after water disinfection. These variations were not observed in the non-disinfected controls. Given the ubiquity and genome plasticity of these bacteria, the results obtained suggest that disinfection processes may have implications on the microbiological quality of the disinfected water.
authors: LEPABE, Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal; Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal.
authors: Cristina
authors: C
authors: Becerra-Castro
authors: Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal.
authors: Gonçalo
authors: G
authors: Macedo
authors: Laboratory of Separation and Reaction Engineering, Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors: Adrian M T
authors: AMT
authors: Silva
authors: Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal. Electronic address: cmanaia@porto.ucp.pt.
authors: Célia M
authors: CM
authors: Manaia
authors: LEPABE, Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
authors: Olga C
authors: OC
authors: Nunes
mesh_terms: D004203:Disinfection; D020560:Proteobacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology / Q000592:standards*; D018508:Water Purification / Q000379:methods*
chemical_list: D012336:RNA, Ribosomal, 16S; D062065:Wastewater
keywords: Ozonation; Photocatalytic ozonation; Selective advantage; Surface water; UV radiation; Wastewater