Microbial dehalogenation of polychlorinated biphenyls in aerobic conditions.

From soils contaminated with polychlorinated biphenyls (PCBs) a strain of Alcaligenes sp. able to grow in a mineral medium with a commercial mixture of PCBs as carbon source was isolated. This strain consumed up to 200 ppm in seven days in laboratory conditions. After 24 h of incubation, some new congeners of PCBs could be recognized by mass spectrometry. Through the identification of these compounds it was possible to postulate examples of possible transformations by dechlorinations of penta- and tetra-chlorinated congeners into tri-chlorinated ones. The properties of the isolated strain are appropriate for bioremediation of contaminated areas and also for using in bioreactors in order to remove the xenobiotic chemical.