Abstract:
Degradation of propionate is a central issue for improving performance of an anaerobic digestion system, because propionate is an intermediate product, which is generally accumulated in anaerobic digesters. Many factors containing pH, temperature, volatile fatty acids, hydrogen partial pressure, and toxins would inhibit the biodegradation of propionate under anaerobic conditions. Propionate can be oxidized only if a syntrophic association is carried out by propionate-oxidizing bacteria and hydrogen-consumming bacteria. As propionate degraders, syntrophic propionate-oxidizing bacteria (SPOB) play an important role in anaerobic food chain and anaerobic global carbon cycles. However, these microorganisms are often difficult to be isolated and cultured as result of extremely fastidious metabolism type. To date, only ten species were identified as SPOB, which belonged to class Deltaproteobacteria or Firmicutes. Most identified SPOB degrade propionate through methylmalonyl coenzyme A pathway (MMC) pathway and genomic information indicated the catabolic pathways are controlled by ecological factors and/or global cellular conditions. Further investigation is needed on the response mechanism of SPOB to the environmental factors. To prevent anaerobic digestor from propionate accumulation, it is important to detect SPOB in time and forecast the accumulation of propionate with mathematical models.
Page(s):
843-850
DOI:
DOI not available
Published:
Journal: International Journal of Agriculture and Biology, Volume: 14, Issue: 5, Year: 2012