Methylobacillus arboreus sp. nov., and Methylobacillus gramineus sp. nov., novel non-pigmented obligately methylotrophic bacteria associated with plants

Two newly isolated obligate methanol-utilizing bacteria (strains IvaT and LapT) with the ribulose monophosphate pathway of C1 assimilation are described. The isolates are strictly aerobic, Gram negative, asporogenous, motile rods multiplying by binary fission, mesophilic and neutrophilic, synthesize indole-3-acetate. The prevailing cellular fatty acids are straight-chain saturated C16:0 and unsaturated C16:1 acids. The major ubiquinone is Q-8. The predominant phospholipids are phosphatidylethanolamine, phosphatidylglycerol and cardiolipin. Ammonia is assimilated by glutamate dehydrogenase. The DNA G+C contents of strains IvaT and LapT are 54.0 and 50.5 mol% (Tm), respectively.Based on 16S rRNA gene sequence analysis and DNA–DNA relatedness (38–45%) with type strains of the genus Methylobacillus, the novel isolates are classified as the new species of this genus and named Methylobacillus arboreus IvaT (VKM B-2590T, CCUG 59684T, DSM 23628T) and Methylobacillus gramineus LapT (VKM B-2591T, CCUG 59687T, DSM 23629T).The GenBank accession numbers for the 16S rRNA gene and mxaF gene sequences of the strains IvaT and LapT are GU937479, GU937478 and HM030736, HM030735, respectively.