Abstract:
Global efforts of forestation and reutilization of barren lands to mitigate climate change have increased in last decade. Brownfields are non-utilizable barren lands due to the presence or potential presence of hazardous substance, pollutant, or contaminant. In present study, brownfield of Chak Naurang, Punjab, Pakistan contaminated with petroleum hydrocarbon was analyzed in order to evaluate the possibility of bioremediation. Physicochemical analysis of composite soil sample demonstrated that contaminated soil was slightly alkaline clay-loam with TPH of 22.2 g/kg. The concentration of nitrogen, phosphorus and potassium was found to be quite low i.e. 644 mg/kg, 12.46 mg/kg and, 20 mg/kg, respectively. Electrical conductivity (E.C) i.e., 4.3 dS/m and 18% water content showed the deteriorated condition of affected soil. The crude oil degrading and biosurfactants producing microorganisms were isolated from the contaminated soil using soil enrichment technique. The isolated microorganisms were tested for biosurfactants production on the basis of qualitative and quantitative assays. Our results showed that efficient biosurfactants producing microorganisms belong to the genera of Pseudomonas, Bacillus, Paenibacillus, Achromobacter, Meyerozyma andAspergillus. Statistical analyses exhibited significant differences (p<0.05) amongst the biosurfactants production capabilities of the characterized strains. These findings revealed that contamination of petroleum hydrocarbons has adversely effected soil composition and agriculture properties. The affected soil harbors diverse microbial communities that can produce biosurfactants and use crude oil as sole carbon substrate. Moreover, nutrients amendments could be an effective strategy to stimulate bioremediation process and for improving soil productivity.
