Abstract

A Gram-staining-negative, motile, non-spore-forming and rod-shaped bacterial strain, 20-23RT, was isolated from intestine of bensasi goatfish, Upeneus bensasi, and its taxonomic position was investigated by using a polyphasic study. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain 20-23RT belonged to the genus Shewanella. Strain 20-23RT exhibited 16S rRNA gene sequence similarity values of 99.5, 99.2, and 97.5% to Shewanella algae ATCC 51192T, Shewanella haliotis DW01T, and Shewanella chilikensis JC5T, respectively. Strain 20-23RT exhibited 93.1-96.0% 16S rRNA gene sequence similarity to the other Shewanella species. It also exhibited 98.3-98.4% gyrB sequence similarity to the type strains of S. algae and S. haliotis. Strain 20-23RT contained simultaneously both menaquinones and ubiquinones; the predominant menaquinone was MK-7 and the predominant ubiquinones were Q-8 and Q-7. The fatty acid profiles of strain 20-23RT, S. algae KCTC 22552T and S. haliotis KCTC 12896T were similar; major components were iso-C15:0, C16:0, C16:1 ω7c and/or iso-C15:0 2-OH and C17:1 ω8c. The DNA G+C content of strain 20-23RT was 53.9 mol%. Differential phenotypic properties and genetic distinctiveness of strain 20-23RT, together with the phylogenetic distinctiveness, revealed that this strain is distinguishable from recognized Shewanella species. On the basis of the data presented, strain 20-23RT represents a novel species of the genus Shewanella, for which the name Shewanella upenei sp. nov. is proposed. The type strain is 20-23RT (=KCTC 22806T =CCUG 58400T).

• Keywords: Shewanella upenei; taxonomy; new species