Biodegradation of Diesel Hydrocarbon in Soil by Bioaugmentation of Pseudomonas aeruginosa: A Laboratory Scale Study

Abstract

Bioremediation is an option that offers the possibility to destroy or render harmless contaminants using natural biological activity. This study examined the capacity of an indigenous isolate of Pseudomonas aeruginosa to remediate the diesel contaminated soil. Five different sets of cement bioreactors containing 2.5 kg soil; Bioreactor A (control, uncontaminated soil), B (sterilized soil), C (contaminated soil without any addition), D (contaminated soil with the addition of nutrients), E (contaminated soil with the addition of nutrients and bacterial inoculum) were prepared. Different soil enzyme activities like dehydrogenase, catalases, lipase and FDA hydrolase along with physicochemical parameters were investigated during the bioremediation process. The results obtained revealed that bioaugmentation of P. aeruginosa in diesel contaminated soil proved to be a better approach. 66 % diesel degradation was observed during the incubation period of 30 days. The soil enzyme activity increases as the hydrocarbon concentration decreased over time during bioremediation period. The FTIR and gas chromatographic analysis also confirmed the degradation of long chain alkanes of diesel hydrocarbons during bioremediation.