Rhodovulum salis sp. nov. And Rhodovulum viride sp. nov., phototrophic Alphaproteobacteria isolated from marine habitats

Abstract

Two strains (JA746T and JA756T) having yellowish brown-to-green pigment were isolated from a solar saltern and a pink pond, respectively. While both strains were non-motile and shared the presence of bacteriochlorophyll-a, major cellular fatty acids (C18: 1ω7c, C16: 0, C18: 0), quinone (Q-10), polar lipids and hopanoids, they differed from each other in their carotenoid composition. The G+C content of genomic DNA of strains JA746T and 756Twas 62.4 and 63.3 mol%, respectively. The 16S rRNA gene-based EzTaxon-e BLAST search analysis of strains JA746T and 756T indicated highest sequence similarity with members of the genus Rhodovulum in the familyRhodobacteraceae of the class Alphaproteobacteria. Strain JA746T has high sequence similarities with Rhodovulum visakhapatnamense JA181T (97.3 %),Rhodovulum steppense A-20sT (97.3 %), Rhodovulum phaeolacus JA580T(97 %), Rhodovulum strictum MB-G2T (97 %) and other members of the genusRhodovulum ( < 97 %). Strain JA756T has high sequence similarities withRhodovulum visakhapatnamense JA181T (99.8 %), Rhodovulum sulfidophilumHansen W4T (99.1 %), Rhodovulum kholense JA297T (97.9 %) and other members of the genus Rhodovulum ( < 97 %). The sequence similarity between strains JA746T and JA756T was 97.5 %. However, these strains are not closely related to each other or to their phylogenetic neighbours since the DNA-DNA reassociation values were less than 56 %. The genomic information was also supported by phenotypic and chemotaxonomic results, leading us to classify strains JA746T (= NBRC 108898T = KCTC 15180T) and JA756T (= NBRC 109122T = KCTC 15223T) as the type strains of two novel species of the genus Rhodovulum, for which the names Rhodovulum salis sp. nov. andRhodovulum viride sp. nov. are proposed, respectively. © 2014 IUMS.