Research on the Possibility of Reducing Lead Contamination in Soil Using Microorganisms
Abstract:
In Ulaanbaatar City's soil, the main polluters of the surface soil are Lead, Chromium, and other heavy metals from industrial and mining activities, electric power stations, sewage, and vehicle emissions. Organisms that live in environments polluted by heavy metals do the mechanisms of adaptation to survive. Some microorganisms are resistant to metal and can accumulate it in their cells or detoxify it by reacting with its metabolic products. The purpose of the work was to identify bacteria that can resist the action of lead salts and to determine some activity. In 18 city soil samples, Lead was found at 5.9-5132 mg/kg, and 3 points exceeded the maximum permissible level. The agar dilution method determined that resistant bacteria isolate to varying concentrations of heavy metals such as Lead, Zinc, Ferric, Copper, Chromium, and Cadmium. Lead-resistant bacteria were isolated on a medium with PbCl2. Four strains could resist nine mM of Lead, two mM of Zinc, two mM of Chromium, and one mM of Iron. In liquid media, our strain B.thuringiensis MN01 can reduce the lead concentration by up to 46 % within 1 month. Consortium bacteria have been determined in active laboratory conditions to reduce the concentration of 1 mM of Lead to 0 mM after 1 month.
