Removal of volatile fatty acids in anaerobic digestion of organic wastes can accelerate eventual decomposition of organic wastes to CO(2) and H(2)O using a recovery of electric energy by a microbial fuel cell. The fuel cell anode chamber was a 10 cm (I.D.) x 20 cm long cylindrical Plexiglass having an ion ceramic cylinder separator (I.D. 10 mm, O.D.12 mm, 0.3 mu m average pore size). The aluminum foil cathode (12 cm(2) surface area) was located inside the ceramic cylinder. Between the two cylinders, 1 liter of activated carbon particles was packed as anode electrode having a void fraction of 0.4. This fuel cell was connected to a 5 liter bioreactor (working volume 1.5 liter), and the bioreactor was run in batch mode by re-circulating a synthetic wastewater of 5 g/L glucose. Maximum TVFA (total volatile fatty acids) and SCOD (soluble chemical oxygen demand) removal rate were 3.79 g/L.day, 5.88 g/L.day, respectively. TVFA removal efficiency (92.7%) and SCOD removal efficiency (94.7%) under maximum current density operation were higher than the operation with maximum power density In acid fermentation, butyric acid concentration was highest because Clostridium butyricum was a dominant microbial communitiy in the inoculum. The microbial cells collected from the anode bio-film samples were affiliated with Bacillus cereus based on the nucleotide sequences of dominant DGGE (denaturing gradient gel electrophoresis) bands.