Ancylobacter lacus sp. nov. and Ancylobacter plantiphilus sp. nov., Novel Aerobic Facultative Methylotrophic Bacteria

Novel aerobic facultatively methylotrophic bacteria were isolated from the water of a freshwater lake (strain F30L(T)), soil sample of rhizosphere of white clover Trifolium repens L. (strain 1TC(T)), and rhizosphere of carrot Daucus carota L. (strain Dau2). The isolates were gram-negative, non-spore-forming, nonmotile, pleomorphic/rod-shaped cells, propagating by binary fission; they were facultative methylotrophs, using a broad range of polycarbon compounds, apart from methanol. Optimum growth occurred at 25-29 degrees C and pH 7.0-7.5, 0.5 vol % CH3OH, and 0.05 wt % NaCl. The strains employ the ribulose bisphosphate pathway for C-1 assimilation. The predominant phospholipids were phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, and diphosphatidylglycerol. In the whole-cell fatty acid pattern of strains, C-18:1 omega 7c, C-19: 0 omega 8c cyclo, C-16:0 and C-18:0 acids were predominant. The major ubiquinone was Q-10. According to the 16S rRNA gene sequencing, strain F30L(T) exhibited high similarity to Ancylobacter dichloromethanicus DM16(T) (97.8%), while strains 1TC(T) and Dau2 were closely related to A. oerskovii DSM 18746(T) (98.6%). The 16S rRNA gene sequence similarity between strains 1TC(T) and Dau2 was 99.4%. DNA-DNA hybridization of the strain F30L(T) with A. dichloromethanicus DM16(T) revealed only 22% homology; homology for strain 1TC(T) and A. oerskovii DSM 18746(T) was 27%, while DNA-DNA homology between strains 1TC(T) and Dau2 was 77%. Based on the data obtained, strain F30L(T) was identified as a new species within the genus Ancylobacter, Ancylobacter lacus sp. nov. (VKM B-3280(T) = DSM 106439(T)). Strains 1TC(T) and Dau2 (=BK\M B-3227 = CCUG71988) represent a novel species of the same genus, for which the name Ancylobacterplantiphilus sp. nov. is proposed, with the type strain 1TC(T) (=VKM B-3219(T) = DSM 106438(T)).