Paraburkholderia Xenovorans Strain LB400 Significantly Decreased Volatilization of Polychlorinated Biphenyls (PCBs) from Freshwater and Saline Sediments

Airborne PCB emissions from contaminated sediments pose a public health risk and are frequently cited as a concern for communities located near PCB-contaminated bodies of water. We assessed the potential to decrease the emissions of lower-chlorinated (LC)-PCBs (<3 chlorines) through bioaugmentation with aerobic PCB-degrading <i>Paraburkholderia xenovorans</i> strain LB400 in laboratory microcosms using historically PCB-contaminated sediments from a wastewater lagoon (Altavista, VA; AVL) and an estuary (New Bedford Harbor, MA; NBH). We compared the impact of nonshaken vs shaken conditions on airborne PCBs in LB400-bioaugmented AVL sediment (51% LC-PCBs) to better replicate field conditions. After 35 days, airborne LC-PCBs decreased by 54% in nonshaken bioaugmented AVL sediments, compared to a 60% decrease in shaken bioaugmented sediments. Bioaugmenting LB400 into unshaken NBH sediments (44% LC-PCBs) significantly decreased airborne LC-PCBs by 50% over 35 days. Biphenyl dioxygenase gene (<i>bphA</i>) abundance decreased by several orders of magnitude after 16 days in all experiments, demonstrating a potential decrease in treatment effectiveness over time. These novel findings demonstrate that LB400 effectively degrades LC-PCBs with varying profiles over a range of environmentally relevant mixing scenarios. Further treatment delivery development has the potential to protect nearby communities from PCB exposure, decrease health risks, and improve quality of life.