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

Two strains (JC17T 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 C18:1ω7c, C16:1ω7c/iso-C15:02OH, C16:0, C16:0 3-OH, C18:12OH, C16:1ω5c, and C19:0 cycloω8c. The genomic DNA G+C content of strain JC17T was 66.2 mol%. A phylogenetic tree based on 16 S rRNA gene sequence analysis showed that strains JC17T and JC19a had the highest similarity to members of the genus Roseomonas and were closely related to Roseomonas cervicalis CIP104027T (96.4%) and Roseomonas ludipueritiae CIP107418T (96.3%) of the family Acetobacteraceae within the class Alphaproteobacteria. Strains JC17T 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 JC17T is classified as a novel species of the genus Roseomonas for which the name Roseomonas aestuarii sp. nov. is proposed. The type strain is JC17T (=CCUG 57456T =KCTC 22692T =NBRC105654T).