A Gram-negative bacterium, designated strain LMG 22510T, was isolated from water of a pharmaceutical company steam generator. The cells had a ring-like and horseshoe-shaped morphology and possessed gliding motility. Phylogenetic analysis of the 16S rRNA gene sequence showed that the strain was a member of the Flexibacter group within the phylum 'Bacteroidetes'; its nearest neighbour was Spirosoma linguale (88.8 % sequence similarity). DNA base content, fatty acid composition and biochemical characteristics were determined. Genotypic and phenotypic data indicated that strain LMG 22510T could not be assigned to any recognized genus; therefore, a novel genus and species is proposed, Larkinella insperata gen. nov., sp. nov., with LMG 22510T (= NCIMB 14103T) as the type strain.