Phosphate promotes uranium (VI) adsorption in Staphylococcus aureus LZ-01

Abstract

Staphylococcus aureus LZ-01 was isolated from the Yellow River upstream from Lanzhou which can resist and reduce chromium (VI) to chromium (III). In this study, strain LZ-01's uranium (VI) resistance and adsorption abilities were investigated. Our results showed that it can resist 2 mmol l-1 U(VI) and adsorb 96% of 2 mmol l-1 U(VI) after 6 h incubation. Transmission electron microscopy (TEM) images showed that precipitates were formed on the surface of the cells. Energy dispersive X-ray spectroscopy (EDX) analysis indicated that the precipitates contained uranium and phosphorus. The U(VI) adsorption rate of strain LZ-01 was promoted by 20 mmol l-1 phosphate. It adsorbed 45% of 2·5 mmol l-1 U(VI) in 30 min compared to 36% without phosphate (P < 0·05). Strain LZ-01 can resist heavy metals and survive in nuclear waste-contaminated environments. Strain LZ-01 might be a potential candidate for nuclear waste remediation with phosphate added. Significance and Impact of the Study: Staphylococcus aureus LZ-01 can resist 2 mmol l-1 U(VI). It could adsorb more than 90% of the 2 mmol l-1 U(VI) in 6 h. Uranium is precipitated with phosphorus on the surface of the cells. Phosphate promotes uranium adsorption in strain LZ-01, and its U(VI) adsorption capacity is related to its cell availability. These results indicate that the strain LZ-01 might be a potential candidate for remediation of nuclear waste when phosphate is added.