Shewanella dokdonensis sp. nov., isolated from seawater

Abstract

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 Gramstaining- 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 17:1ω8c (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 UDC329T 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).