A cis-1,4-polyisoprene-degrading bacterium (strain Kb2(T)) was isolated from foul water taken from the inside of a deteriorated automobile tyre found on a farmer's field in Westfalia, Germany. The strain was aerobic, Gram-positive, exhibited orange smooth and rough colonies on complex nutrient agar, produced elementary branching hyphae that fragmented into rod/coccus-like elements and showed chemotaxonomic markers which were consistent with its classification within the genus Gordonia, i.e. the presence of meso-diaminopimelic acid, arabinose and galactose in whole-cell hydrolysates (cell-wall chemotype IV), N-glycolylmuramic acid in the peptidoglycan wall, a fatty-acid pattern composed of unbranched saturated and monounsaturated fatty acids plus tuberculostearic acid, mycolic acids comprising 56-60 carbon atoms and MK-9(H-2) as the only menaquinone. The 16S rDNA sequence of strain Kb2(T) was found to be most similar to the 16S rDNA sequences of the type strains of Gordonia alkanivorans (DSM 44369(T)) and Gordonia nitida (KCTC 0605BP(T)). However, DNA-DNA relatedness data showed that strain Kb2(T) (= DSM 44215(T) = NRRL B-24152(T)) could be distinguished from these two species and represented a new species within the genus Gordonia, for which the name Gordonia westfalica is proposed.