FIG. 2.

PCB dechlorination pathways of the predominant PCB congeners in Aroclor 1260. Parent congeners are shown in bold text. The pathways are shown with large arrows that indicate different phylotypes: black solid arrows, DEH10; open arrows, SF1; hatched arrows, SF2; gray solid arrows, both DEH10 and SF1. Small arrows indicate minor pathways. The predominant end products are boxed. Reactions in which there was at least a twofold increase in the number of dechlorinating phylotypes relative to the no-PCB control are indicated with asterisks.