We determined the taxonomic status of six Bacillus species (Bacillus alginolyticus, Bacillus chondroitinus, Bacillus curdlanolyticus, Bacillus glucanolyticus, Bacillus kobensis, and Bacillus thiaminolyticus) by using the results of 16S rRNA gene sequence and cellular fatty acid composition analyses. Phylogenetic analysis clustered these species closely with the Paenibacillus species. Like the Paenibacillus species, the six Bacillus species contained anteiso-C15:0 fatty acid as a major cellular fatty acid. The use of a specific PCR primer designed for differentiating the genus Paenibacillus from other members of the Bacillaceae showed that the six Bacillus species had the same amplified 16S rRNA gene fragment as members of the genus Paenibacillus. Based on these observations and other taxonomic characteristics, the six Bacillus species were transferred to the genus Paenibacillus. In addition, we propose emendation of the genus Paenibacillus.