title: Sphingomonas astaxanthinifaciens sp. nov., a novel astaxanthin-producing bacterium of the family Sphingomonadaceae isolated from Misasa, Tottori, Japan.
abstract: A red-pigmented, Gram-negative, motile, strictly aerobic, mesophilic, oval- or short rod-shaped bacterium (TDMA-17(T)) was isolated from fresh water collected at Misasa, a radioactive site in Japan. TDMA-17(T) was slightly tolerant against gamma-ray irradiation, and effectively produced carotenoids (2.8 mg g(-1) dry cells) including, astaxanthin and astaxanthin isomers. Phylogenetic analysis based on 16S rRNA gene sequences placed TDMA-17(T) in a distinct lineage in the family Sphingomonadaceae, and the highest degree of sequence similarity determined were to Sphingomonas aerolata NW12(T) (94.5%), Sphingomonas aurantiaca MA101b(T) (94.0%), Sphingomonas melonis DAPP-PG 224(T) (94.0%), Sphingomonas asaccharolytica IFO 15499(T) (93.9%) and Sphingomonas abaci C42(T) (93.9%). The major fatty acids were C(17 : 1)omega6c (33.0%) and C(18 : 1)omega7c (20.8%). The DNA G+C content was 67.7 mol%. The presence of Q-10 as the main ubiquinone, the presence of Sphingomonadaceae-specific sphingoglycolipid in the polar lipid profiles, the presence of 2-hydroxy fatty acids and the absence of 3-hydroxy fatty acids supported the identification of this strain as a member of the genus Sphingomonas sensu stricto. Phylogenetic distinctiveness and unique phenotypic characteristics differentiated strain TDMA-17(T) from the closely related Sphingomonas species. The results of polyphasic taxonomic analyses suggested that TDMA-17(T) represents a novel Sphingomonas species, for which the name Sphingomonas astaxanthinifaciens sp. nov. is proposed. The type strain is TDMA-17(T) (=NBRC 102146=CCUG 53608).
authors.affiliation: Life Science Research Center, College of Bioresource Sciences, Nihon University, Fujisawa, Japan. dasker@brs.nihon-u.ac.jp
authors.forename: Dalal
authors.initials: D
authors.lastname: Asker
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Beppu
authors.forename: Kenji
authors.initials: K
authors.lastname: Ueda
mesh_terms: D002338:Carotenoids / Q000737:chemistry / Q000145:classification; D005618:Fresh Water / Q000382:microbiology*; D007564:Japan; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000145:classification; D017422:Sequence Analysis, DNA; D020578:Sphingomonas / Q000145:classification* / Q000302:isolation & purification / Q000378:metabolism; D024341:Xanthophylls / Q000096:biosynthesis
chemical_list: D012336:RNA, Ribosomal, 16S; D024341:Xanthophylls; D002338:Carotenoids; C005948:astaxanthine