Aerobic Bioaugmentation to Decrease Polychlorinated Biphenyl (PCB) Emissions from Contaminated Sediments to Air

Environ Sci Technol. 2022 Oct 18;56(20):14338-14349. doi: 10.1021/acs.est.2c01043. Epub 2022 Sep 30.


We conducted experiments to determine whether bioaugmentation with aerobic, polychlorinated biphenyl (PCB)-degrading microorganisms can mitigate polychlorinated biphenyl (PCB) emissions from contaminated sediment to air. Paraburkholderia xenovorans strain LB400 was added to bioreactors containing PCB-contaminated site sediment. PCB mass in both the headspace and aqueous bioreactor compartments was measured using passive samplers over 35 days. Time-series measurements of all 209 PCB congeners revealed a 57% decrease in total PCB mass accumulated in the vapor phase of bioaugmented treatments relative to non-bioaugmented controls, on average. A comparative congener-specific analysis revealed preferential biodegradation of lower-chlorinated PCBs (LC-PCBs) by LB400. Release of the most abundant congener (PCB 4 [2,2'-dichlorobiphenyl]) decreased by over 90%. Simulations with a PCB reactive transport model closely aligned with experimental observations. We also evaluated the effect of the phytogenic biosurfactant, saponin, on PCB bioavailability and biodegradation by LB400. Time-series qPCR measurements of biphenyl dioxygenase (bphA) genes showed that saponin better maintained bphA abundance, compared to the saponin-free treatment. These findings indicate that an active population of bioaugmented, aerobic PCB-degrading microorganisms can effectively lower PCB emissions and may therefore contribute to minimizing PCB inhalation exposure in communities surrounding PCB-contaminated sites.

Keywords: Paraburkholderia xenovorans LB400; bioavailability; biodegradation; bioremediation; biosurfactants; contaminant fate and transport; passive sampling; polychlorinated biphenyls.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Biodegradation, Environmental
  • Dioxygenases*
  • Hydroxylamines
  • Polychlorinated Biphenyls* / metabolism


  • Hydroxylamines
  • N-benzoyl-N-phenylhydroxylamine
  • Polychlorinated Biphenyls
  • Dioxygenases