Shewanella saliphila sp nov., Shewanella ulleungensis sp nov and Shewanella litoralis sp nov., isolated from coastal seawater

Three Gram-negative, non-spore-forming, rod-shaped and motile bacterial strains, designated MMS16-UL250(T), MMS16-UL253(T) and MMS16-UL482(T), were isolated from coastal seawater and subjected to taxonomic characterization. All isolates grew at 4-30 degrees C (optimum, 25 degrees C), at pH 6-10 (pH 7) and in the presence of up to 8% NaCl (2.5-4.5%). The 16S rRNA gene sequence similarities between the three isolates and Shewanella algicola St-6T, the closest species, were 98.1-99.2%, and those among the isolates were 98.5-99.0%. In the phylogenetic tree, MMS16-UL250(T) formed a cluster with S. algicola St-6(T), but the DNA-DNA relatedness between the two strains was 28.8 +/- 1.5%, thus confirming their separation at species level. The other two strains formed separate phylogenetic lines respectively. The main quinones for all strains were Q-7, Q-8, MK-7 and MMK-7, which is typical for Shewanella. The major polar lipids of all strains were phosphatidylglycerol and phosphatidylethanolamine, and the common major fatty acid was a summed feature consisting of C-16:17c and/or C-16:16c while the proportions varied among the three strains. The DNA G+C contents of the strains also varied between 42.1 and 43.7mol%. Phenotypic properties distinguished each strain from S. algicola as well as from one another. Based on the polyphasic analysis, each strain is considered to represent a novel species of Shewanella, for which the names Shewanellasaliphila sp. nov. (type strain, MMS16-UL250(T)=KCTC 62131T=JCM 32304(T)), Shewanella ulleungensis sp. nov. (type strain, MMS16-UL253(T)=KCTC 62130(T)=JCM 32305(T)) and Shewanella litoralis sp. nov. (type strain, MMS16-UL482(T)=KCTC 62129(T)=JCM 32306(T)) are proposed.