Oharaeibacter diazotrophicus gen. nov., sp. nov., a diazotrophic and facultatively methylotrophic bacterium, isolated from rice rhizosphere

A novel facultatively methanol-utilizing bacterial strain, SM30^T, was isolated from rice rhizosphere. Strain SM30^T was Gramstain-negative, aerobic, motile, short rods, and grew optimally at pH 7 and at 28 °C. It could tolerate 0 to 2%(w/v) NaCl. Based on 16S rRNA gene sequence comparisons, strain SM30^T was most closely related to Pleomorphomonas oryzae DSM 16300^T, with a low similarity of 94.17 %. One of the lanthanide metals, lanthanum, could enhance its growth slightly on methanol. Phylogenetic trees, based on the mxaF, xoxF and cpn60 genes of SM30^T showed its distinct phylogenetic position with respect to species with validly published names. Polymerase chain reaction (PCR) amplification of the nifH and growth on nitrogen-free medium indicated that strain SM30^T is a diazotroph. The major cellular fatty acids were summed feature 8 (containing _{18: 1}ω7c and _{18: 1}ω6c) and cyclo _{19: 0}ω8c. The major quinone was ubiquinone 10. The DNA G+C content was 74.6 mol%. Based on the genotypic and phenotypic characteristics, strain SM30^T represents a novel genus and species, for which the name Oharaeibacter diazotrophicus gen. nov., sp. nov. is proposed with the type strain SM30^T (=NBRC 111955^T =DSM 102969^T).