Isolation of urease-producing bacteria and removal effect on the Cd and Pb in filtrate

Abstract

Heavy metal pollution in farmland soil around mining and metallurgical industrial parks in China is serious, which seriously affects crop yields and quality and threatens national public health. As an economic and environmental remediation technology, bioremediation can both reduce the metal availability in soil and decrease the accumulation of heavy metals in plants by using microorganisms. We used urea agar plates to screen and isolate urease-producing bacteria from the rhizosphere soil of agricultural crops in Cd- and Pb-contaminated farmland, and investigated its growth characteristics, the removal effects on Cd and Pb in the solution were also studied. The results showed that three urease-producing bacteria, Bacillus megateriumC6, Bacillus aryabhattaiC14, Bacillus sp.C15 were identified by screening. They had higher ability to produce urease, which were up to 876.1U/mL, 815.4U/mL and 809.3 U/mL, respectively within 24h. By studying the influence of urease-producing bacteria on the concentration of Cd and Pb in the solution, it was found that urease-producing bacteria had certain removal effect on Cd and Pb, and the removal efficiency was 51.9% and 84.1% respectively after 14 days, indicating that the urease-producing bacteria had better removal effect on Pb.