Hydrocarbon degradation and metal remediation by hydrocarbon-utilising and metal-tolerant Klebsiella pneumoniae YSA-9 isolated from soil contaminated with petroleum

Petroleum contamination of our biosphere particularly soil and water is due to the release of petroleum products from petrochemical industries. The aim of the present study was to isolate hydrocarbon-utilising and metal-tolerant bacteria capable of hydrocarbon degradation and metal remediation. Petroleum contaminated soil from which the bacteria were isolated had a total hydrocarbon concentration of 3538 mg/kg and several metals. The soil was also observed for the total bacterial population which was observed as 2.23 x 10(6) CFU/g of soil. Among different strains, strain YSA-9 showed the highest potential for hydrocarbon-utilisation with an absorbance of 0.920. Strain YSA-9 also displayed high tolerance to Cr (VI) and Cu up to 900 mu g/ml to each metal. Strain YSA-9 was identified by 16S rRNA as Klebsiella pneumoniae. Strain YSA-9 showed a wide range of hydrocarbon degradation, degrading many hydrocarbons with the formation of new compounds and remedying higher amounts of metals. Klebsiella pneumoniae YSA-9 significantly removed Cr (VI) and Cu by biosorption at different pH, metal concentrations, temperature and the time of incubation. A wide range of hydrocarbon degradation and higher metal remediation by strain YSA-9 makes strain YSA-9 a super bio-inoculant for the remediation of polluted soils.