Cultures enriched by serial transfer through a mineral salts medium containing fluoranthene were used to establish a stable, 7-membered bacterial community from a sandy soil highly contaminated with coal-tar creosote. This community exhibited an ability to utilize fluoranthene as sole carbon source for growth as demonstrated by increases in protein concentration and changes in absorption spectra when grown on fluoranthene in liquid culture. Biotransformation of other polycyclic aromatic hydrocarbons (PAHs) were verified by demonstrating their disappearance from an artificial PAH mixture using capillary gas chromatography. When grown on fluoranthene as sole carbon source and subsequently exposed to fluoranthene plus 16 additional PAHs typical of those found in creosote, this community transformed all PAHs present in this defined mixture. Continued incubation resulted in extensive degradation of the remaining 4 compounds. (Copyright (c) 1989 American Society for Microbiology.)