Tetrachloroethylene as electron acceptor for the anaerobic degradation of benzoate

Teltrachloroethylene (PCE) was biotransformed by reductive dehalgenation under anoxic conditions with benzoate as the electron donor. The experiments were carried out under batch culture conditions with biomass from an anoxic fixed bed reactor fed with benzoate and PCE. Inhibition of methanogenesis by bromoethane-sulfonic acid (BES) resulted in a complete inhibition of benzoate degradation. Benzoate, however, was decomposed in the presence of BES if PCE was added to the cultures. With 2.8 mmol/1 PCE, that was transformed to 1.4 mmol/1 cis-1,2-dichloroethylene (DCE) and 3.8 mmol/1 chloride, 2 mmol/1 benzoate were degraded to about 3.2 mmol/1 acetate. The elimination of benzoate was directly proportional to DCE accumulation, ranging between 1:0.5 and 1:1.