Description of Gelidibacter japonicus sp. nov., isolated from the Inland Sea (Setonaikai) in Japan

摘要

A novel Gelidibacter strain, JCM 31967(T), was isolated from seawater collected from the Inland Sea (Setonaikai) in Japan. It was characterized as a Gram-negative, halophilic, oxidase-negative, catalase-positive, aerobic, nonmotile, but gliding, rod-shaped bacterium without flagella. Based on 16S rDNA gene identity, strain JCM 31967(T) is closely related to Gelidibacter mesophilus (DSM 14095(T), 96.6% identity), G. gilvus (IC158(T), 96.4%), G. algens (DSM 12408(T), 96.1%), G. sediminis (S11-41(T), 94.7%), and G. salicanalis (IC162(T), 94.7%). The G + C content of strain JCM 31967(T) DNA was found to be 39.1%. The average nucleotide identity (ANI) values of JCM 31967(T) against G. algens DSM 12408(T) and G. mesophilus DSM 14095(T) were 79.1% and 80.9%, respectively. Strain JCM 31967(T) phenotypically differed from the closest related Gelidibacter species in its utilization of methyl alpha-d-mannopyranoside, methyl alpha-d-glucopyranoside, and d-ribose and in its lack of utilization of l-arginine and d-arabinose. It was further differentiated based on its fatty acid composition, specifically properties of C-18:0 and C-20:2 omega 6c, 9c, which were significantly different from those of G. algens, G. gilvus, G. mesophilus, G. salicanalis, and G. sediminis type strains. Overall, the results of DNA-DNA hybridization and physiological and biochemical analyses differentiated strain JCM 31967(T) from a previously described species of Gelidibacter. Based on these polyphasic taxonomic findings, it was concluded that strain JCM 31967(T) is a novel Gelidibacter species, for which the name Gelidibacter japonicus sp. nov. is proposed, with JCM 31967(T) (= LMG 30063(T)) as the type strain.