Degradation of PCB in different soils by inoculated Alcaligenes xylosoxidans

The degradation of PCB in soils by the biphenyl-utilising strain Alcaligenes xylosoxidans was studied in different soil types. In addition to the congener specificity, significant differences in the degradation of PCB by the strain in the different soil types were observed. Efficiency of degradation was generally better in sterilised soils, but the differences were not as significant as the differences observed between different soil types. These results indicate that the degradation of PCB is probably related not only to the capabilities of the strain employed and quality and amount of competitive species inhabiting the soils, but also to the soil sorption of the PCB congeners. Degradation is faster in the soils containing an intermediate amount of organic carbon with a high portion of total and aromatic carbon in humic acids.