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Abstract: 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 C18:1 ω7c, C16:1 ω7c/iso-C15:02OH, C16:0, C16:0 3-OH, C18:12OH, C16:1 ω5c, and C19:0 cycloω8c. The genomic DNA G+C content of strain JC17T was 66.2mol%. A phylogenetic tree based on 16S 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% 16S 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). [Copyright &y& Elsevier]

An anoxygenic, phototrophic gammaproteobacterium designated strain JA418(T) was isolated from a sediment sample collected from the Baitarani River, Orissa, India. The bacterium was a Gram-negative, motile rod with a single polar flagellum. Bacteriochlorophyll a and rhodopin were the major photosynthetic pigments. The organism grew best at slightly alkaline pH (8-8.5) and lacked chemotrophic growth. The major fatty acids were C(16 : 0), C(16 : 1)omega7c/C(16 : 1)omega6c and C(18 : 1)omega7c. A phylogenetic tree based on 16S rRNA gene sequence analysis showed that strain JA418(T) clusters with species of the genus Marichromatium belonging to the class Gammaproteobacteria. The highest 16S rRNA gene sequence similarities of strain JA418(T) were found with the type strains of Marichromatium gracile (95.9 %), Marichromatium indicum (95.6 %), Marichromatium purpuratum (95.5 %) and Marichromatium bheemlicum (95.6 %). The DNA base composition of strain JA418(T) was 71.4 mol% G+C (by HPLC). Based on the 16S rRNA gene sequence analysis and physiological and chemotaxonomic characteristics, strain JA418(T) is sufficiently different from other Marichromatium species to merit the description of a novel species, Marichromatium fluminis sp. nov., to accommodate it. The type strain is JA418(T) (=KCTC 5717(T) =NBRC 105221(T)).