metabolism of aromatic carbon compounds. I. Decomposition of phenolic compounds and aromatic hydrocarbons by phenol-adapted bacteria. J. Bacteriol. 87:910-919. 1964.-Bacteria from soil and related environments were selected or adapted to metabolize phenol, hydroxy phenols, nitrophenols, chlorophenols, methylphenols, alkylphenols, and arylphenols when cultured in mineral salts media with the specific substrate as the sole source of carbon. A phenol-adapted culture (substrate-induced enzyme synthesis proven) was challenged in respirometric tests with 104 related compounds; probable significant oxidative activity occurred with 65. Dihydric phenols were generally oxidized; trihydric phenols were not. Cresols and dimethylphenols were oxidized; adding a chloro group increased resistance. Benzoic and hydroxybenzoic acids were oxidized; sulfonated, methoxylated, nitro, and chlorobenzoic acids were not; m-toluic acid was utilized but not the o-and p-isomers. Benzaldehyde and p-hydroxybenzaldehyde were oxidized. In general, nitro-and chloro-substituted compounds and the benzenes were difficult to oxidize.