Degradation of a variety of halogenated aliphatic compounds by an anaerobic mixed culture

We investigated the biodegradation of tetrachloroethylene (perchloroethylene, PCE) and halogenated aliphatic compounds by using anaerobic mixed cultivation. The mixed culture degraded PCE at concentrations of up to 150 mg/l in 40 d via trichloroethylene (TCE) to cis-1,2-dichloroethylene (cDCE). Small amounts of vinyl chloride (VC) and CO2 were also detected. The same culture degraded various halogenated aliphatic compounds such as cDCE, VC, 1,2-dichloroethane (DE), 1,3-dichloropropene (DP), dichloromethane (DM), 1,1,2-trichloroethane (TE), and chloroform (CF). Acetate was the most effective electron donor for dechlorination, although formate, glucose and lactate were also effective, but to a lesser extent. The mixed culture degraded PCE in the temperature range 25 to 43 degrees C, with an optimum between 30 and 37 degrees C, and the pH range of 6.2 to 11.0.