Triclosan is a polychlorinated hydroxy diphenylether that has been widely used as an antimicrobial compound. An enrichment using triclosan as a sole source of carbon and energy yielded a consortium of bacteria capable of growing on this compound. The dichloro ring was partially mineralized, resulting in the conversion of approximately 35% of the [(14)C]triclosan to [(14)C]CO(2). Use of molecular fingerprinting techniques and 16S rDNA cloning and sequencing aided in the identification and eventual isolation of an auxotrophic Sphingomonas-like organism, strain Rd1, which was able to partially mineralize triclosan when grown on complex media.