title: Rhodoferax antarcticus sp. nov., a moderately psychrophilic purple nonsulfur bacterium isolated from an Antarctic microbial mat.
abstract: A new species of purple nonsulfur bacteria isolated from an Antarctic microbial mat is described. The organism, designated strain ANT.BR, was mildly psychrophilic, growing optimally at 15-18 degrees C with a growth temperature range of 0-25 degrees C. Cells of strain ANT.BR were highly motile curved rods and spirals, contained bacteriochlorophyll a, and showed a multicomponent in vivo absorption spectrum. A specific phylogenetic relationship was observed between strain ANT.BR and the purple bacterium Rhodoferax fermentans FR2T, and the two organisms shared several physiological and other phenotypic properties, with the notable exception of growth temperature optimum. Tests of genomic DNA hybridization, however, showed Rfx. fermentans FR2T and strain ANT.BR to be genetically distinct bacteria. Because of its unique set of properties, especially its requirement for low growth temperatures, we propose to recognize strain ANT.BR as a new species of the genus Rhodoferax, Rhodoferax antarcticus, named for its known habitat, the Antarctic.
authors.affiliation: Department of Microbiology and Center for Systematic Biology, Southern Illinois University, Carbondale 62901-6508, USA. madigan@micro.siu.edu
authors.forename: M T
authors.initials: MT
authors.lastname: Madigan
authors.forename: D O
authors.initials: DO
authors.lastname: Jung
authors.forename: C R
authors.initials: CR
authors.lastname: Woese
authors.forename: L A
authors.initials: LA
authors.lastname: Achenbach
mesh_terms: D000864:Antarctic Regions; D001419:Bacteria / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification*; D018407:Bacterial Physiological Phenomena; D001429:Bacteriochlorophylls / Q000378:metabolism; D001482:Base Composition; D020562:Betaproteobacteria / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification / Q000502:physiology; D002244:Carbon / Q000378:metabolism; D002338:Carotenoids / Q000378:metabolism; D003470:Culture Media; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020459:Genes, rRNA; D008969:Molecular Sequence Data; D009584:Nitrogen / Q000378:metabolism; D010802:Phylogeny; D012335:RNA, Ribosomal / Q000235:genetics; D017422:Sequence Analysis, DNA; D013696:Temperature; D014871:Water Microbiology
chemical_list: D001429:Bacteriochlorophylls; D003470:Culture Media; D004269:DNA, Bacterial; D012335:RNA, Ribosomal; D002338:Carotenoids; D002244:Carbon; D009584:Nitrogen