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 D82T and YIM D812T, 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 °C and pH 7.5. The genomic DNA G+C contents of strains YIM D82T and YIM D812T were 61.5 and 62.3 mol%, respectively. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains YIM D82T and YIM D812T 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 D82T=DSM 21159T=KCTC 22351T) and Fodinicurvata fenggangensis sp. nov. (type strain YIM D812T=CCTCC AA 208037T=DSM 21160T) are proposed.