A single strain, designated BF49(T), was isolated from a biofilm of a tufa deposit from the Westerhofer rivulet, Lower Saxony, Germany. The G+C content of the genomic DNA of strain BF49(T) was 69 mol% and the predominant ubiquinone was Q-8. Major fatty acids were C-16:1 omega 7c/15 iso 2OH and C-16:0. Comparative 16S rRNA gene sequence analysis indicated that the isolate was placed within the genus Methylibium, class Betaproteobacteria, distantly related to the type strain Methylibium petroleiphilum LMG 22953(T) (97.4% similarity), Methylibium fulvum Gsoil 322(T)(96%), and Methylibium aquaticum IMCC1728(T)(95.7%). On the basis of phylogenetic and phenotypic distinctness we propose a novel species, Methylibium subsaxonicum sp. nov., with strain BF49(T) (DSM 19570(T), CIP 109700(T)) as the type strain.