title: Evidence for bacteriophage activity causing community and performance changes in a phosphorus-removal activated sludge.
abstract: Bacteria are known to play important roles in biogeochemical cycles and biotechnology processes, but little is known about the influence of bacteriophage on these processes. A major impediment to the study of host-bacteriophage interactions is that the bacteria and their bacteriophage are often not available in a pure culture. In this study, we detected an unexpected decline in the phosphorus-removal performance of a granular laboratory-scale wastewater treatment reactor. Investigations by FISH, transmission electron microscopy and proteomics led us to hypothesize that a bacteriophage infection of the uncultured Candidatus 'Accumulibacter phosphatis' was responsible for the decline in performance. Further experiments demonstrated that the addition of a putative bacteriophage-rich supernatant, obtained from the previous failed reactor to phosphorus-removal reactors, caused a decrease in the abundance of Accumulibacter in both granular and floccular activated sludges. This coincided with increases in bacteriophage-like particles and declining phosphorus-removal performance. The granular sludge did not recover after the attack, but the floccular sludge regained Accumulibacter numbers and phosphorus-removal performance. These findings suggest that bacteriophage may play a significant role in determining the structure and function of bacterial communities in activated sludges.
authors.affiliation: Advanced Water Management Centre (AWMC), The University of Queensland (UQ), Brisbane, Qld, Australia.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Barr
authors.forename: Frances R
authors.initials: FR
authors.lastname: Slater
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Fukushima
authors.forename: Philip L
authors.initials: PL
authors.lastname: Bond
mesh_terms: D001435:Bacteriophages / Q000254:growth & development*; D020562:Betaproteobacteria / Q000378:metabolism / Q000821:virology*; D019149:Bioreactors; D017404:In Situ Hybridization, Fluorescence; D046529:Microscopy, Electron, Transmission; D010758:Phosphorus / Q000378:metabolism*; D040901:Proteomics; D012722:Sewage / Q000382:microbiology* / Q000821:virology*; D014865:Waste Disposal, Fluid
chemical_list: D012722:Sewage; D010758:Phosphorus