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 : 1omega8c and summed feature 3 (comprising i15 : 0 2-OH and/or 16 : 1omega7c), 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 H(2)S 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)).