Fodinicurvata sediminis gen. nov., sp nov and Fodinicurvata fenggangensis sp nov., poly-β-hydroxybutyrate-producing bacteria in the family Rhodospirillaceae

Two Gram-negatively stained, facultatively anaerobic, non-motile, vibrioid and rod-shaped, chemoheterotrophic bacterial strains, designated YIM D82(T) and YIM D812(T), were isolated from a salt mine in Yunnan, south-west China. DNA-DNA hybridization, genomic DNA G+C content and phylogenetic analyses based on 16S rRNA gene sequences divided the two isolates into two distinct genospecies that were also clearly differentiated by fatty acid profiles, carbon source utilization patterns, antibiotic susceptibility and biochemical characteristics. The two isolates grew in the presence of 1.5-20% NaCl, and optimally at 28 degrees C and pH 7.5. The genomic DNA G+C contents of strains YIM D82(T) and YIM D812(T) were 61.5 and 62.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains YIM D82(T) and YIM D812(T) were members of the family Rhodospirillaceae and showed 90.5-90.6 % and 90.1-90.2% similarities with their closest relatives, Rhodovibrio sodomensis and Rhodovibrio salinarum, respectively. Differential phenotypic and genotypic characteristics of the two isolates from recognized genera showed that the two strains should be classified as representing a new genus and two novel species for which the names Fodinicurvata sediminis gen. nov., sp. nov. (type strain YIM D82(T)=DSM 21159(T)=KCTC 22351(T)) and Fodinicurvata fenggangensis sp. nov. (type strain YIM D812(T)=CCTCC AA 208037(T)=DSM 21160(T)) are proposed.