Anaerobic toluene oxidation by the sulfate-reducing bacterium, strain Tol2 (proposed name Desulfobacula toluolica) was specifically inhibited by benzyl alcohol when added at concentrations around 500 microM. Benzyl alcohol added at lower, non-inhibitory concentrations (around 5 microM) was not oxidized by active cells pregrown on toluene, indicating that the alcohol is not a free intermediate of toluene metabolism in the sulfate reducer. Conversion of p-xylene in toluene-metabolizing cells to p-methylbenzoate as dead-end product suggests that the sulfate reducer, like denitrifiers, initiates toluene oxidation at the methyl group.