Development of microbial granules for PCB dechlorination.
The effect of acclimating anaerobic granules from commercial bioreactors with different carbon/electron sources on their ability to reductively dechlorinate a tri- (2,3,4-CB) and heptachlorobiphenyl (2,2',3,3',4,5,6-CB) was studied. The anaerobic granules were first grown in upflow anaerobic sludge blanket (UASB) reactors fed with two different mixtures of carbon/electron sources, i.e., propionate/butyrate/methanol and formate/methanol. Differences in dechlorination patterns for 2,2',3,3',4,5,6-CB were observed in batch experiments inoculated with granules from these two sets of UASB reactors. The reductive dechlorination of 2,2',3,3',4,5,6-CB for propionate/butyrate/methanol acclimated granules proceeded via 2,2',3,3',4,5-CB for all 2,2',3,3',4,5-CB for all 2,2',3',4,5-CB + 2,2',3',4-CB for all 2,4-CB + 2,3-CB + 2,4'-CB and 2,2',3,3',5,6-CB for all 2,2',3,5,6-CB for all 2,2',3,5-CB for all 2',3,5-CB. The dechlorination pathway for formate/methanol acclimated granules followed: 2,2',3,3',4,5-CB + 2,2',3,3',5,6-CB for all 2,2',3,3',4-CB + 2,2',3,3',6-CB for all 2,2',3,3'-CB for all 2,2',3-CB for all 2,2'-CB. This research demonstrates a successful strategy for the development of biocatalysts to serve as the inoculum of partially decontaminated sites in order to provide microorganisms with specificities complementary to those of naturally occuring dechlorinators.
Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Gent, Belgium. Hendrik.Nollet@ugent.be
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D000693:Anaerobiosis; D001421:Bacteria, Anaerobic / Q000378:metabolism*; D001673:Biodegradation, Environmental; D018533:Biomass; D002713:Chlorine / Q000302:isolation & purification; D007700:Kinetics; D011078:Polychlorinated Biphenyls / Q000493:pharmacokinetics*; D018505:Waste Management / Q000379:methods
D002713:Chlorine; D011078:Polychlorinated Biphenyls