抄録
Effects of sulfate load on substrates utilization for sulfidogens and methanogens were investigated in anaerobic sludge that had been acclimated with glucose under various sulfate loads (0 to 0.475mmol SO42-·l-1·d-1). Methanogenesis was decreased with increasing sulfate load and the methane production rate was decreased by 23% at 0.475mmol SO42-·l-1·d-1 compared with no sulfate load sludge. When sulfate reduction was inhibited by the addition of molybdate in sulfate load sludge, methane production rate was the same as that in no sulfate load sludge. At the same time, the utilization rates of propionate and acetate by sulfidogens were increased, but that of acetate, hydrogen and formate by methanogens were decreased with increasing sulfate load. The utilization rate of propionate by syntrophic hydrogen-producing acetogens also decreased. These results showed that sulfidogens competed for acetate with methanogens and for propionate with syntrophic hydrogen-producing acetogens in high sulfate load condition.
