Shewanella japonica sp. nov

EP Ivanova, T Sawabe, NM Gorshkova, VI Svetashev, VV Mikhailov, DV Nicolau and R Christen Pacific Institute of Bioorganic Chemistry of the Far-Eastern Branch of the Russian Academy of Sciences, 690022 Vladivostok, Pr. 100 Let Vladivostoku 159, Russia Two strains of agar-digesting bacteria, KMM 3299(T) and KMM 3300, respectively isolated from sea water and the mussel Protothaca jedoensis, have been characterized. Based on sequencing of the 16S rRNA gene, KMM 3299(T) showed the highest similarity (93--95%) to members of the genus Shewanella. The G+C contents of the DNAs of these strains were 43--44 mol%. The level of DNA homology between the two strains was conspecific (95%), indicating that they represent a distinct genospecies. These organisms were non-pigmented, Gram-negative, polarly flagellated, facultatively anaerobic, mesophilic, neutrophilic and able to degrade a wide range of high molecular mass polymers, including alginate, carrageenan, laminaran and agar. The novel organisms were susceptible to gentamycin, carbenicillin, lincomycin and oleandomycin. The predominant cellular fatty acids were i-15:0, 16:0, 16:1(n-7), 18:1(n-7). Eicosapentaenoic acid, 20:5(n-3), was detected in the two isolates at levels of 1--8%, depending on the temperature of cultivation. Phylogenetic evidence, together with phenotypic characteristics, showed that the two isolates studied constitute a novel species of the genus Shewanella. The name Shewanella japonica is proposed; the type strain is KMM 3299(T)(=LMG 19691(T)=CIP 106860(T)).