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

摘要

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 C_16:0 and unsaturated C_16:1 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% (T_m), 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.