Abstract
We have constructed a bacterial library consisting of toluene-degrading bacteria isolated from soil activated sludge, and TCE waste. The library had been subjected to large subunits of oxygenases responsible for the first oxidation of toluene. Chromosomal DNA extracts from three strains, A1071, B6122 and IB5, which had been suggested to have toluene dioxygenase (TDO) from the result of colony hybridization, showed positive signals with todC1, a large subunit of TDO of Pseudomonas putida F1, in dot hybridization analysis, and thereby, these strains were selected for the analyses of degradation kinetics of toluene and trichloroethylene (TCE). Results of degradation experiments using resting cells revealed the variety in TCE degradation ability among these strains; A1071 demonstrated degradation kinetics similar to the strain F1 while B6122 could not degrade TCE at all. The interaction between toluene and TCE was suggested to be competitive inhibition. Kinetic parameters on the competitive inhibition between toluene and TCE degradation were determined and compared among these strains.
