A Gram-positive, endospore-forming, xylanase-producing bacterium isolated from a rice field was studied taxonomically. The strain grows at 10-40 degrees C and in the presence of lysozyme or 5 % (w/v) NaCl. Chemotaxonomic analysis revealed that MK-7 was the predominant menaquinone of the isolated strain, while the major fatty acid was anteiso-C(15 : 0). Comparison of 16S rRNA gene sequences showed that strain BP-23(T) fell within the radiation of the cluster comprising Paenibacillus species. The highest 16S rRNA gene sequence similarities were found with Paenibacillus illinoisensis (97.4 %), Paenibacillus pabuli (97.1 %) and Paenibacillus amylolyticus (96.9 %). The DNA-DNA relatedness of strain BP-23(T) with respect to these three species was very low (32.7, 31.6 and 23.0 %, respectively). On the basis of phenotypic and genotypic data, strain BP-23(T) should be placed in the genus Paenibacillus and designated a novel species, for which the name Paenibacillus barcinonensis sp. nov. is proposed. The type strain is BP-23(T) (=CECT 7022(T)=DSM 15478(T)).