Shewanella irciniae sp. nov., a novel member of the family Shewanellaceae, isolated from the marine sponge Ircinia dendroides in the Bay of Villefranche, Mediterranean Sea

Strain UST040317-058^T, comprising non-pigmented, rod-shaped, facultatively anaerobic, Gram-negative cells that are motile by means of single polar flagella, was isolated from the surface of a marine sponge (Ircinia dendroides) collected from the Mediterranean Sea. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a separate cluster with the recognized bacterium Shewanella algae IAM 14159^T, with which it showed a sequence similarity of 95.0%. The sequence similarity between strain UST040317-058^T and its other (six) closest relatives ranged from 91.6 to 93.8%. Strain UST040317-058^T showed oxidase, catalase and gelatinase activities. The typical respiratory quinones for shewanellas, menaquinone MK-7 and ubiquinones Q-7 and Q-8, were also detected. The predominant fatty acids in strain UST040317-058^T were i15:0, 16:0, 17:1ω8c and summed feature 3 (comprising i15:0 2-OH and/or 16:1ω7c), altogether representing 56.9% of the total. The DNA G + C content was 39.9 mol%. The strain could be differentiated from other Shewanella species by its inability to reduce nitrate or produce H₂S and by 10-22 additional phenotypic characteristics. On the basis of the phylogenetic and phenotypic data presented in this study, strain UST040317-058^T represents a novel species in the genus Shewanella, for which the name Shewanella irciniae sp. nov. is proposed. The type strain is UST040317-058^T (=JCM 13528^T = NRRL B-41466^T).