An aerobic facultatively methylotrophic bacterium was isolated from roots of Sonchus arvensis L. and designated strain OsotT The cells of this strain were Gram-stain-negative, asporogenous, motile short rods multiplying by binary fisson. They utilized methanol, methylamines and a variety of polycarbon compounds as the carbon and energy sources. Methanol was assimilated after sequential oxidation to formaldehyde and CO2 via the ribulose bisphosphate pathway. The organism grew optimally at 22-29 °C and pH 7.5-8.0. The dominant phospholipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol and diphosphatidylglycerol (cardiolipin). The major cellular fatty acids of strain OsotT cells grown in R2A medium were C18 : 1ω7c (49.0 %), C19 : 0ω8c cyclo (38.3 %) and C16 : 0 (8.4 %). The major ubiquinone was Q-10. The DNA G+C content of strain OsotT was 66.1 mol% (Tm). On the basis of 16S rRNA gene sequence analysis strain OsotT is phylogenetically related to the members of genus Ancylobacter (97.1-98.8 % sequence similarity). Based on 16S rRNA gene sequence analysis and DNA-DNA relatedness (27-29 %) with type strains of the genus Ancylobacter, the novel isolate is classified as a new species of this genus and named Ancylobacter sonchi sp. nov.; the type strain is OsotT (=VKM B-3145T=JCM 32039T).
Keywords: Ancylobacter sonchi sp. nov.; facultative methylotroph; phytosymbiont; ribulose bisphosphate pathway.