Sphingomonas astaxanthinifaciens sp. nov., a novel astaxanthin-producing bacterium of the family Sphingomonadaceae isolated from Misasa, Tottori, Japan

• Published in: FEMS microbiology letters Vol. 273; no. 2; pp. 140 - 148
• Main Authors: Asker, Dalal, Beppu, Teruhiko, Ueda, Kenji
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-08-2007; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Astaxanthin; Bacteria; Bacteriology; Biological and medical sciences; Carotenoids; Carotenoids - chemistry; Carotenoids - classification; Deoxyribonucleic acid; DNA; Dry cells; Fatty acids; Fresh water; Fresh Water - microbiology; Fundamental and applied biological sciences. Psychology; Gamma rays; Gene sequencing; Irradiation; Isomers; Japan; Lipids; Microbiology; Molecular Sequence Data; New species; Phylogenetics; Phylogeny; RNA, Ribosomal, 16S - chemistry; RNA, Ribosomal, 16S - classification; rRNA 16S; Sequence Analysis, DNA; Sphingomonadaceae; Sphingomonas; Sphingomonas - classification; Sphingomonas - isolation & purification; Sphingomonas - metabolism; Sphingomonas astaxanthinifaciens; Sphingomonas melonis; Systematics; Ubiquinone; Xanthophylls - biosynthesis; Asia; Japan; carotenoids; Astaxanthin; Ribosomal RNA; Sphingomonas astaxanthinifaciens; Morphology; Sphingomonadaceae; Bacteria; Isolate; Sphingomonas; Biochemistry; Physiology; Carotenoid
• ISSN: 0378-1097; 1574-6968
• DOI: 10.1111/j.1574-6968.2007.00760.x

A red-pigmented, Gram-negative, motile, strictly aerobic, mesophilic, oval- or short rod-shaped bacterium (TDMA-17T) was isolated from fresh water collected at Misasa, a radioactive site in Japan. TDMA-17T 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-17T in a distinct lineage in the family Sphingomonadaceae, and the highest degree of sequence similarity determined were to Sphingomonas aerolata NW12T (94.5%), Sphingomonas aurantiaca MA101bT (94.0%), Sphingomonas melonis DAPP-PG 224T (94.0%), Sphingomonas asaccharolytica IFO 15499T (93.9%) and Sphingomonas abaci C42T (93.9%). The major fatty acids were C₁₇ : ₁ω6c (33.0%) and C₁₈ : ₁ω7c (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-17T from the closely related Sphingomonas species. The results of polyphasic taxonomic analyses suggested that TDMA-17T represents a novel Sphingomonas species, for which the name Sphingomonas astaxanthinifaciens sp. nov. is proposed. The type strain is TDMA-17T (=NBRC 102146=CCUG 53608).