Roseomonas aestuarii sp. nov., a bacteriochlorophyll-a containing alphaproteobacterium isolated from an estuarine habitat of India

Two strains (JC17^T and JC19a) of orange pigmented bacteria were isolated from an estuarine sample. Cells of both the strains were Gram-negative coccobacilli, non-motile, non-spore forming and strictly aerobic. Chemo-organoheterotrophy was the growth mode for both strains and was possible on a wide range of organic compounds. Strains were non-hemolytic and contained low levels of BChl-a and carotenoids. The fatty acids (>1.0%) comprised C_18:1ω7c, C_16:1ω7c/iso-C_15:02OH, C_16:0, C_16:0 3-OH, C_18:12OH, C_16:1ω5c, and C_19:0 cycloω8c. The genomic DNA G+C content of strain JC17^T was 66.2 mol%. A phylogenetic tree based on 16 S rRNA gene sequence analysis showed that strains JC17^T and JC19a had the highest similarity to members of the genus Roseomonas and were closely related to Roseomonas cervicalis CIP104027^T (96.4%) and Roseomonas ludipueritiae CIP107418^T (96.3%) of the family Acetobacteraceae within the class Alphaproteobacteria. Strains JC17^T and JC19a shared 100% 16 S rRNA gene sequence similarity, were phenotypically (morphological, physiological, biochemical characters) identical and had closely related genomes (85% DDH). Based on polyphasic taxonomic data, strain JC17^T is classified as a novel species of the genus Roseomonas for which the name Roseomonas aestuarii sp. nov. is proposed. The type strain is JC17^T (=CCUG 57456^T =KCTC 22692^T =NBRC105654^T).