Abstract
In order to investigate the decomposition of sedimented organic matter in sewers, screenings were used instead of sediments. Because screenings whose sizes were larger than 2mm contained high amount of organic matter usually accumulated in sewer pipes.
When the activity of sulfate reduction was present and sulfate concentration was high amount, approximately 40% of organic matter in the screenings was decomposed for 10 days, on the other hand, when sulfate reduction was inhibited by 20 mM of sodium molybdate only 10% of organic matter was decomposed for 10 days.
Acetic acid and propionic acid were producted during sulfate reduction. However, no fatty acids were detected when sulfate reduction was inhibited.
These results indicated that sulfate reducing bacteria play an important role not only in the production and decomposition of fatty acids but also in the decomposition of solid organic matter.
The authors suggest that the decomposition of fatty acids by sulfate reducing bacteria has accelerated the fermentative acid production resulting in the dehydrolation of organic matter.
