Enhanced Remediation of Pentachlorophenol (PCP)-Contaminated Groundwater by Bioaugmentation with Known PCP-Degrading Bacteria
2015
Joshi, Vaibhav V. | Prewitt, M Lynn | Ma, Din-Pow | Borazjani, Abdolhamid
The objective of this study was to test whether bioaugmentation with known pentachlorophenol (PCP)-degrading bacteria (Sphingobium chlorophenolicum and Burkholderia cepacia) could enhance remediation of PCP-contaminated groundwater. Groundwater PCP concentrations were determined by US Environmental Protection Agency (EPA) method 3510C and gas chromatography. Gene expression for PCP-degrading enzymes: pentachlorophenol 4-monooxygenase (pcpB; S. chlorophenolicum) and chlorophenol 4-monooxygenase (TftD; B. cepacia) was determined by real-time polymerase chain reaction (RT-PCR) using gene-specific primers. Bioaugmented treatments with S. chlorophenolicum and B. cepacia showed 32% and 49% decrease (p < .05) whereas un-bioaugmented (indigenous) treatment did not show significant decrease (p > .05) in average PCP concentration, respectively, over 72 days. Decreased PCP levels correlated strongly (r = −.82, p < .05) with increased PCP-tolerant bacteria in bioaugmented treatments, whereas no significant correlation was observed (r = −.22, p > .05) in un-bioaugmented treatment. In addition, a decrease in PCP levels also correlated significantly with an increase in gene expression of PCP-degrading enzymes, pcp B (r = −.77044) and Tft D (r = −.87905) (p < .05). PCP concentrations decreased and pcp B or Tft D expressions were higher in bioaugmented treatments with S. chlorophenolicum (50%, 7-fold) or B. cepacia (67%, 10.7-fold), respectively, than indigenous treatment. Therefore, bioaugmentation with known PCP-degrading bacteria enhanced remediation of PCP-contaminated groundwater than indigenous bacteria alone. Results of this study may provide a more efficient and environmentally friendly technique for on-site remediation of PCP-contaminated groundwater.
Show more [+] Less [-]AGROVOC Keywords
Bibliographic information
This bibliographic record has been provided by National Agricultural Library