title: Vertical distribution and characterization of aerobic phototrophic bacteria at the Juan de Fuca Ridge in the Pacific Ocean.
abstract: The vertical distribution of culturable anoxygenic phototrophic bacteria was investigated at five sites at or near the Juan de Fuca Ridge in the Pacific Ocean. Twelve similar strains of obligately aerobic phototrophic bacteria were isolated in pure culture, from depths ranging from 500 to 2,379 m below the surface. These strains appear morphologically, physiologically, biochemically, and phylogenetically similar to Citromicrobium bathyomarinum strain JF-1, a bacterium previously isolated from hydrothermal vent plume waters. Only one aerobic phototrophic strain was isolated from surface waters. This strain is morphologically and physiologically distinct from the strains isolated at deeper sampling locations, and phylogenetic analysis indicates that it is most closely related to the genus Erythrobacter. Phototrophs were cultivated from three water casts taken above vents but not from two casts taken away from active vent sites. No culturable anaerobic anoxygenic phototrophs were detected. The photosynthetic apparatus was investigated in strain JF-1 and contains light-harvesting I and reaction center complexes, which are functional under aerobic conditions.
authors.affiliation: Department of Microbiology, The University of Manitoba, 422 Buller Building, Winnipeg, MB, Canada, R3T 2N2.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rathgeber
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lince
authors.forename: Jean
authors.initials: J
authors.lastname: Alric
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Lang
authors.forename: Elaine
authors.initials: E
authors.lastname: Humphrey
authors.forename: Robert E
authors.initials: RE
authors.lastname: Blankenship
authors.forename: André
authors.initials: A
authors.lastname: Verméglio
authors.forename: F Gerald
authors.initials: FG
authors.lastname: Plumley
authors.forename: Cindy L
authors.initials: CL
authors.lastname: Van Dover
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Beatty
authors.forename: Vladimir
authors.initials: V
authors.lastname: Yurkov
mesh_terms: D001420:Bacteria, Aerobic / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D002338:Carotenoids / Q000378:metabolism; D008858:Microscopy, Phase-Contrast; D010140:Pacific Ocean; D010788:Photosynthesis / Q000502:physiology*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000378:metabolism; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013053:Spectrophotometry; D014871:Water Microbiology
chemical_list: D045322:Photosynthetic Reaction Center Complex Proteins; D012336:RNA, Ribosomal, 16S; D002338:Carotenoids