An enrichment culture obtained from anaerobic granular sludge of a bench-scale anaerobic reactor degraded methanol at 65 degrees C via sulfate reduction and acetogenesis, Sulfate reduction was the dominant process (S2-/acetate = 2.5). No methane formation was observed. Approximately 30% of the methanol was converted by acetogenic bacteria to acetate, while the remainder was degraded by these bacteria to H-2 and CO2 in syntrophy with hydrogen-consuming sulfate-reducing bacteria. Pure cultures of sulfate-reducing and acetogenic bacteria were isolated and characterized.