Investigation of cell exudates active in carbon tetrachloride and chloroform degradation

Contamination of groundwater by chlorinated solvents such as carbon tetrachloride (CCl4) and chloroform (CHCl3) is a widespread problem. The cell exudates from the methanogen Methanosarcina thermophila are active in the degradation of CCl4 and CHCl3. This research was performed to characterize these exudates. Examination of the influence of pH indicated that activity was greater under alkaline conditions. Rapid CCl4 degradation occurred from 35–65°C, with first‐order degradation rate coefficients increasing as temperature increased. It was found that proteins were not responsible for CCl4 degradation. The active agents in the cell exudates were