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-16T) was isolated from a freshwater sample collected at Misasa (Tottori, Japan). Strain TDMA-16T 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-16T was 63.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed strain TDMA-16T in a distinct lineage in the family Sphingomonadaceae; sequence data showed that strain TDMA-16T was most closely related to Sphingomonas mali IFO 15500T (95.1 %), Sphingomonas aquatilis JSS7T (95.0 %), Sphingomonas pruni IFO 15498T (94.9 %), Sphingomonas melonis DSM 14444T (94.9 %) and Sphingomonas asaccharolytica IFO 15499T (94.5 %). The major fatty acids of strain TDMA-16T were C17 : 1 ω6c (34.5 %) and C18 : 1 ω7c (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-16T from closely related Sphingomonas species. The results of polyphasic taxonomic analyses suggest that strain TDMA-16T represents a novel Sphingomonas species, for which the name Sphingomonas jaspsi sp. nov. is proposed. The type strain is strain TDMA-16T (=NBRC 102120T=DSM 18422T=CCUG 53607T).