Sphingomonas jaspsi sp. nov., a novel carotenoid-producing bacterium isolated from Misasa, Tottori, Japan

Abstract

A yellow-pigmented, Gram-negative, motile, strictly aerobic, pleomorphic bacterium (strain TDMA-16(T)) was isolated from a freshwater sample collected at Misasa (Tottori, Japan). Strain TDMA-16(T) was slightly tolerant to gamma-ray irradiation and produced carotenoids, including zeaxanthin, nostoxanthin and an unknown carotenoid, effectively [1.7 mg (g dry cells)(-1)]. The DNA G+C content of strain TDMA-16(T) was 63.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed strain TDMA-16(T) in a distinct lineage in the family Sphingomonadaceae; sequence data showed that strain TDMA-16(T) was most closely related to Sphingomonas mali IFO 15500(T) (95.1 %), Sphingomonas aquatilis JSS7(T) (95.0 %), Sphingomonas pruni IFO 15498(T) (94.9 %), Sphingomonas melonis DSM 14444(T) (94.9 %) and Sphingomonas asaccharolytica IFO 15499(T) (94.5 %). The major fatty acids of strain TDMA-16(T) were C(17 : 1) omega 6c (34.5 %) and C(18 : 1) omega 7c (29.3 %). The presence of Q-10 as the main ubiquinone, the Sphingomonadaceae-specific sphingoglycolipid in the polar lipid profile and 2-hydroxy fatty acids, plus the absence of 3-hydroxy fatty acids, supported identification of this strain as a member of the genus Sphingomonas sensu stricto. Phylogenetic distinctiveness and unique phenotypic characteristics differentiated strain TDMA-16(T) from closely related Sphingomonas species. The results of polyphasic taxonomic analyses suggest that strain TDMA-16(T) represents a novel Sphingomonas species, for which the name Sphingomonas jaspsi sp. nov. is proposed. The type strain is strain TDMA-16(T) (=NBRC 102120(T)=DSM 18422(T)=CCUG 53607(T)).