Degradation of Trichloroethylene by Bacteria Isolated from Activated Sludge

Trichloroethylene (TCE) is one of the most serious chlorinated pollutants of some groundwater of many industrial countries so that a possibility of its microbial degradation is an aim of many research and engineer teams. Natural strain C. testosteroni RF2 and its derivative strain VM obtained by mutagenesis were tested for their capability to trichloroethylene (TCE) degradation. Both strains were able to grow on lactate and phenol in the presence of TCE at its concentrations of 0.8 to 50 mg/l and in the state of resting cells were able to degrade TCE for approx. 22 – 24 hours. TCE degradation by both strains led to more than 95 % release of inorganic chlorides, but VM culture produced a significantly higher quantity of trichloroacetic acid (3.4 mol %) than maternal strain RF2 (0.15 mol %). Using lactate and phenol as the growth and inductive substrates respectively, it was possible to carry out three consecutive stages of TCE degradation by the strain RF2 under growing conditions, with substantial regeneration of its transformation capacity.