Shewanella dokdonensis sp. nov., isolated from seawater

A novel bacterial strain, designated UDC329(T), was isolated from a sample of seawater collected at Dong-do, on the coast of Dokdo Island, in the East Sea of the Republic of Korea. The Gram-staining-negative, motile, facultatively anaerobic, non-spore-forming rods of the strain developed into dark orange-yellow colonies. The strain grew optimally between 25 and 30 °C, with 1% (w/v) NaCl and at pH 7. It grew in the absence of NaCl, but not with NaCl at >7% (w/v). The predominant menaquinone was MK-7, the predominant ubiquinones were Q-7 and Q-8, and the major fatty acids were iso-C(15:0) (33.52%) and C(17:1)ω8c (11.73%). The genomic DNA G+C content of strain UDC329(T) was 50.2 mol%. In phylogenetic analyses based on 16S rRNA and gyrB gene sequences, strain UDC329(T) was grouped with members of the genus Shewanella and appeared most closely related to Shewanella fodinae JC15(T) (97.9% 16S rRNA gene sequence similarity), Shewanella indica KJW27(T) (95.0%), Shewanella algae ATCC 51192(T) (94.8%), Shewanella haliotis DW01(T) (94.5%) and Shewanella chilikensis JC5(T) (93.9%). The level of DNA-DNA relatedness between strain UDC329(T) and S. fodinae JC15(T) was, however, only 27.4%. On the basis of phenotypic, genotypic and DNA-DNA relatedness data, strain UDC329(T) represents a novel species in the genus Shewanella, for which the name Shewanella dokdonensis sp. nov. is proposed. The type strain is UDC329(T) (=KCTC 22898(T)=DSM 23626(T)).