title: Erythrobacter citreus sp. nov., a yellow-pigmented bacterium that lacks bacteriochlorophyll a, isolated from the western Mediterranean Sea.
abstract: Two facultatively oligotrophic, intensely yellow-pigmented bacterial strains, RE35F/1T and RE10F/45, have been previously isolated from the western Mediterranean Sea (Bay of Calvi, Corsica, France) by 0.2 microm membrane filtration. The organisms were gram-negative, catalase- and oxidase-positive, strictly aerobic, rod-shaped and non-motile. Their respiratory lipoquinone profiles consisted exclusively of ubiquinone-10 (Q-10) and the G+C contents of their DNAs were 62.0 and 62.4 mol%, respectively. Among the cellular fatty acids, octadecenoic acid (18:1omega7c) was the major component. Both isolates also contained hydroxy fatty acids (14:0 2-OH, 18:1 2-OH and 16:0 iso 3-OH) and branched fatty acids (15:0 anteiso, 16:0 anteiso and 17:0 anteiso). Polar lipid fingerprints were characterized by the presence of a sphingoglycolipid. Comparative analyses of their 16S rRNA gene sequences indicated that both isolates were phylogenetically closely related (sequence similarity of 99.9%) and formed a coherent cluster with aerobic bacteriochlorophyll a-containing species of the Erythrobacter/Porphyrobacter/Erythromicrobium cluster within the family Sphingomonadaceae. The closest relative was Erythrobacter litoralis DSM 8509T (97.4 and 97.5% 16S rRNA gene sequence similarity between this strain and RE35F/1T and RE10F/45, respectively). DNA-DNA reassociation studies confirmed that strains RE35F/1T and RE10F/45 represent a single species (79.6% DNA homology), but also demonstrated that they do not belong to the species Erythrobacter litoralis (25.2 and 34.2% DNA homology, respectively). Notably, both RE35F/1T and RE10F/45 lacked bacteriochlorophyll a. Based upon phenotypic and molecular evidence, a novel species of the genus Erythrobacter, Erythrobacter citreus sp. nov., is proposed. Strain RE35F/1T (= CIP 107092T = DSM 14432T) is the type strain.
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D008522:Mediterranean Sea; D008969:Molecular Sequence Data; D010641:Phenotype; D010802:Phylogeny; D010858:Pigmentation; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S