Lead-resistant bacteria isolated from oil wastewater sample for bioremediation of lead

Anthropogenic activities such as oil exploration have resulted in an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous bacterial communities have enhanced tolerance to heavy metals, we isolated and characterized culturable lead-resistant bacteria from an oil wastewater sample and determined whether they could reduce lead ions from the medium. The wastewater sample containing indigenous bacteria were taken out from a traditional oil field, Bojonegoro District, East Java, Indonesia, and bacteria were culturedHalomonascomplex (HMC) medium containing lead (II) chloride (PbCl2) with different concentrations. Bioaccumulation of lead by heavy-metals resistant bacteria was determined by using atomic absorption spectrophotometry (AAS). Our result found 21 bacterial strains that resist lead ions, of which one strain (RPb5-3) highly resisted to 10 mM. This bacterial strain also exhibited the highest accumulation of Pb, and it could grow at various temperatures, or more than their original environment. The bacterial strains could be used for bioremediation of lead toxicity, especially in oil pollutants.