Anaerobic biodegradation of polychlorinated biphenyls by bacteria from Hudson River sediments

Anaerobic biodegradation of monochlorobiphenyls; a tetrachlorobiphenyl; Aroclor 1221, a polychlorinated biphenyl (PCB) mixture; and sediment PCBs was investigated by using mixed bacterial populations from Hudson River sediments obtained by PCB enrichment. When the bacteria were incubated with Aroclor 1221, the disappearance of congeners was in general inversely related to GC retention time and thus indirectly to the octanol/water partition coefficient. When incubated with 14C-labeled monochlorobiphenyls, 14CO2 was detected, but methane was not. Radioactivity was also found in the cell material and the aqueous fraction. 2,4,2',4'-Tetrachlorobiphenyl produced little evidence of biodegradation or reductive dechlorination. Inoculation of anaerobic sediments from the Hudson River with the mixed population produced a marked decrease in sediment PCBs, whereas uninoculated sediments were observed to have little change. This decrease was also related to the partition coefficient.