title: Biosorption and biomineralization of uranium(VI) by Saccharomyces cerevisiae-Crystal formation of chernikovite.
abstract: Biosorption of heavy metal elements including radionuclides by microorganisms is a promising and effective method for the remediation of the contaminated places. The responses of live Saccharomyces cerevisiae in the toxic uranium solutions during the biosorption process and the mechanism of uranium biomineralization by cells were investigated in the present study. A novel experimental phenomenon that uranium concentrations have negative correlation with pH values and positive correlation with phosphate concentrations in the supernatant was observed, indicating that hydrogen ions, phosphate ions and uranyl ions were involved in the chernikovite precipitation actively. During the biosorption process, live cells desorb deposited uranium within the equilibrium state of biosorption system was reached and the phosphorus concentration increased gradually in the supernatant. These metabolic detoxification behaviours could significantly alleviate uranium toxicity and protect the survival of the cells better in the environment. The results of microscopic and spectroscopic analysis demonstrated that the precipitate on the cell surface was a type of uranium-phosphate compound in the form of a scale-like substance, and S. cerevisiae could transform the uranium precipitate into crystalline state-tetragonal chernikovite [H2(UO2)2(PO4)2·8H2O].
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, No. 222, Tianshui South Road, Chengguan District, Lanzhou 730000, China. Electronic address: zhengxy15@lzu.edu.cn.
authors.forename: Xin-Yan
authors.initials: XY
authors.lastname: Zheng
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, No. 222, Tianshui South Road, Chengguan District, Lanzhou 730000, China. Electronic address: wangxiaoyu2014@lzu.edu.cn.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Wang
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, No. 222, Tianshui South Road, Chengguan District, Lanzhou 730000, China. Electronic address: shenyh15@lzu.edu.cn.
authors.forename: Yang-Hao
authors.initials: YH
authors.lastname: Shen
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, No. 222, Tianshui South Road, Chengguan District, Lanzhou 730000, China. Electronic address: luxia0939@163.com.
authors.forename: Xia
authors.initials: X
authors.lastname: Lu
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, No. 222, Tianshui South Road, Chengguan District, Lanzhou 730000, China. Electronic address: tswang@lzu.edu.cn.
authors.forename: Tie-Shan
authors.initials: TS
authors.lastname: Wang
mesh_terms: D000818:Animals; D011232:Chemical Precipitation; D003460:Crystallization; D010710:Phosphates / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D011848:Radioactive Pollutants / Q000378:metabolism / Q000493:pharmacokinetics; D011868:Radioisotopes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D014501:Uranium / Q000378:metabolism / Q000493:pharmacokinetics*; D017974:Uranium Compounds / Q000378:metabolism / Q000493:pharmacokinetics
chemical_list: D010710:Phosphates; D011848:Radioactive Pollutants; D011868:Radioisotopes; D017974:Uranium Compounds; D010758:Phosphorus; D014501:Uranium
keywords: Biomineralization; Biosorption; Chernikovite; Phosphorus; Saccharomyces cerevisiae; Uranium