title: Life-style and genome structure of marine Pseudoalteromonas siphovirus B8b isolated from the northwestern Mediterranean Sea.
abstract: Marine viruses (phages) alter bacterial diversity and evolution with impacts on marine biogeochemical cycles, and yet few well-developed model systems limit opportunities for hypothesis testing. Here we isolate phage B8b from the Mediterranean Sea using Pseudoalteromonas sp. QC-44 as a host and characterize it using myriad techniques. Morphologically, phage B8b was classified as a member of the Siphoviridae family. One-step growth analyses showed that this siphovirus had a latent period of 70 min and released 172 new viral particles per cell. Host range analysis against 89 bacterial host strains revealed that phage B8b infected 3 Pseudoalteromonas strains (52 tested, >99.9% 16S rRNA gene nucleotide identity) and 1 non-Pseudoaltermonas strain belonging to Alteromonas sp. (37 strains from 6 genera tested), which helps bound the phylogenetic distance possible in a phage-mediated horizontal gene transfer event. The Pseudoalteromonas phage B8b genome size was 42.7 kb, with clear structural and replication modules where the former were delineated leveraging identification of 16 structural genes by virion structural proteomics, only 4 of which had any similarity to known structural proteins. In nature, this phage was common in coastal marine environments in both photic and aphotic layers (found in 26.5% of available viral metagenomes), but not abundant in any sample (average per sample abundance was 0.65% of the reads). Together these data improve our understanding of siphoviruses in nature, and provide foundational information for a new 'rare virosphere' phage-host model system.
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Lara
authors.affiliation: University of Arizona, Department of Ecology and Evolutionary Biology, 1007 E. Lowell St., Tucson, AZ, United States of America.
authors.forename: Karin
authors.initials: K
authors.lastname: Holmfeldt
authors.affiliation: University of Arizona, Department of Ecology and Evolutionary Biology, 1007 E. Lowell St., Tucson, AZ, United States of America.
authors.forename: Natalie
authors.initials: N
authors.lastname: Solonenko
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Elisabet Laia
authors.initials: EL
authors.lastname: Sà
authors.affiliation: University of Arizona, Department of Molecular and Cellular Biology, 1007 E. Lowell St., Tucson, AZ, United States of America.
authors.forename: J Cesar
authors.initials: JC
authors.lastname: Ignacio-Espinoza
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Cornejo-Castillo
authors.affiliation: Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, United States of America.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Verberkmoes
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Dolors
authors.initials: D
authors.lastname: Vaqué
authors.affiliation: University of Arizona, Department of Ecology and Evolutionary Biology, 1007 E. Lowell St., Tucson, AZ, United States of America; University of Arizona, Department of Molecular and Cellular Biology, 1007 E. Lowell St., Tucson, AZ, United States of America.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Sullivan
authors.affiliation: Department of Marine Biology and Oceanography, Institut de Ciències del Mar (CSIC), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Silvia G
authors.initials: SG
authors.lastname: Acinas
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification*; D004279:DNA, Viral / Q000235:genetics; D016679:Genome, Viral; D008522:Mediterranean Sea; D054892:Metagenome; D010802:Phylogeny; D031161:Pseudoalteromonas / Q000235:genetics / Q000302:isolation & purification*; D012623:Seawater / Q000382:microbiology
chemical_list: D004279:DNA, Viral