Rhodobacter sediminicola sp. nov., isolated from a fresh water pond

Abstract

A phototrophic bacterium, designated as strain JA983T, was isolated from a freshwater pond in Gujarat, India. The strain was yellowish brown, catalase- and oxidase-positive, rod-to-oval shaped, Gram-stain-negative and motile. Growth was observed at 20–35 °C. NaCl was not required for optimum growth and up to 5 % was tolerated. Growth was observed at pH 6.0–8.0, with an optimum at pH 7.0. An unidentified glycolipid, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminolipids (AL1, AL2) and two unidentified lipids (L1 and L2) are the polar lipids of JA983T. Q10 is the only quinone. C18 : 1 ω7c/C18 : 1 ω6c is the major fatty acid. JA983T showed highest 16S rRNA gene sequence similarity with the type strains of Rhodobacter sphaeroides (98.99%), Rhodobacter megalophilus (98.99 %), Rhodobacter johrii (98.99 %) and other members of the genus Rhodobacter with less than 98.7 % similarity. In a 16S rRNA gene sequence-based phylogenetic tree, JA983T formed a different sub-clade with its nearest phylogenetic members of genus Rhodobacter . Phenotypic, chemotaxonomic, phylogenetic and genomic [average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) differences indicated that JA983T is significantly different from other species of the genus Rhodobacter and thus represents a novel species of the genus for which the name Rhodobacter sediminicola sp. nov. is proposed. The type strain is JA983T (=KCTC 15782T=NBRC 113843T).