Biodegradation of polycyclic aromatic hydrocarbons using indigenous soil microorganisms

Abstract

In Pakistan detoxification of polycyclic aromatic hydrocarbons (PAHs) contaminated sites require development of degradation system. Present research work is a laboratory scale study conducted to investigate the degradation of two polycyclic aromatic hydrocarbons i.e. anthracene and phenanthrene, which present a high pollution potential and health risk and have been used as a model for degradation studies on PAHs because of their relative toxicity. This study aimed to evaluate anthracene and phenanthrene degradation potential by pseudomonas sp.The organism was able to grow on media containing anthracene and phenanthrene. It was found that the biomass of the organisms decreased with the increase of PAH concentration in the cultures. Psudomonas bacteria showed more growth on anthracene as compared to phenanthrene, which also indicates that anthracene is less toxic to bacterial culture than phenanthrene. Analysis of degradation by Pseudomonas sp estimated by Gas chromatography revealed that with increase in concentration the degradation rate decreased. 350 mg/L of anthracene showed 57.02 % degradation, while 250 mg/L showed 82.344 %, for phenanthrene 250 mg/L showed 53.106 % degradation, while 100 mg/L showed 58.363 %. anthracene showed more degradation than phenanthrene. The maximum degradation was observed in first 3 to 4 days, which reduced with the passage of time due to lowered bacterial count.