title: Newly isolated Nodularia phage influences cyanobacterial community dynamics.
abstract: Cyanophages, that is, viruses infecting cyanobacteria, are a key component driving cyanobacterial community dynamics both ecologically and evolutionarily. In addition to reducing biomass and influencing the genetic diversity of their host populations, they can also have a wider community-level impact due to the release of nutrients by phage-induced cell lysis. In this study, we isolated and characterized a new cyanophage, a siphophage designated as vB_NpeS-2AV2, capable of infecting the filamentous nitrogen fixing cyanobacterium Nodularia sp. AV2 with a lytic cycle between 12 and 18 hours. The role of the phage in the ecology of its host Nodularia and competitor Synechococcus was investigated in a set of microcosm experiments. Initially, phage-induced cell lysis decreased the number of Nodularia cells in the cultures. However, around 18%-27% of the population was resistant against the phage infection. Nitrogen was released from the Nodularia cells as a consequence of phage activity, resulting in a seven-fold increase in Synechococcus cell density. In conclusion, the presence of the cyanophage vB_NpeS-2AV2 altered the ecological dynamics in the cyanobacterial community and induced evolutionary changes in the Nodularia population, causing the evolution from a population dominated by susceptible cells to a population dominated by resistant ones.
authors.affiliation: Department of Food and Environmental Sciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: S E
authors.initials: SE
authors.lastname: Coloma
authors.affiliation: Department of Biosciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: A
authors.initials: A
authors.lastname: Dienstbier
authors.affiliation: Department of Biosciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.|Institute of Biotechnology, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: D H
authors.initials: DH
authors.lastname: Bamford
authors.affiliation: Department of Food and Environmental Sciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Sivonen
authors.affiliation: Department of Biosciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.|Institute of Biotechnology, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: E
authors.initials: E
authors.lastname: Roine
authors.affiliation: Department of Food and Environmental Sciences, Viikinkaari 9, 00014 University of Helsinki, Helsinki, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Hiltunen
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D044822:Biodiversity; D005075:Biological Evolution; D014644:Genetic Variation; D009584:Nitrogen / Q000378:metabolism; D046932:Nodularia / Q000254:growth & development / Q000378:metabolism / Q000821:virology*; D046940:Synechococcus / Q000254:growth & development / Q000378:metabolism / Q000821:virology
chemical_list: D009584:Nitrogen