title: Biomineralization of Pb(II) into Pb-hydroxyapatite induced by Bacillus cereus 12-2 isolated from Lead-Zinc mine tailings.
abstract: The remediation of Pb(II) through biomineralization is rergarded as a promising technique as well as an interesting phenomenon for transforming heavy metals from mobile species into very stable minerals in the environment. Studies are well needed for in-depth understanding the mechanism of Pb(II) immobilized by bacteria. In the present study, we investigated the uptake and biomineralization of Pb(II) using Bacillus cereus 12-2 isolated from lead-zinc mine tailings. The maximum Pb(II) uptake capacity of B. cereus 12-2 was 340 mg/g at pH 3.0. Zeta potential analyses and selective passivation experiments demonstrated that electrostatic attraction was the main force driving the uptake of Pb(II), while the carboxyl, amide and phosphate functional groups of the bacteria provided the binding sites for immobilizing Pb(II). XRD and TEM investigation revealed that the Pb(II) loaded on bacteria could be stepwise transformed into rod-shaped Ca2.5Pb7.5(OH)2(PO4)6 nanocrystal. Combined with protein denaturalization experiments, we proposed that the biomineralization of Pb(II) possibly consisted of two steps: (1) Rapid biosorption of Pb(II) on B. cereus 12-2 through the synergy of electrostatic attraction, ionic exchange and chelating activity of functional groups; (2) enzyme-mediated mineral transformation from amorphous precipitate to rod-shaped crystalline minerals happening gradually inside the bacteria.
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, PR China; Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou 350002, PR China.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, PR China; Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou 350002, PR China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Pan
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Lab of Biopesticide and Chemical Biology, Fujian Agriculture and Forestry University, Ministry of Education & Fujian-Taiwan Joint Center for Ecological Control of Crop Pests, Fuzhou 350002, PR China. Electronic address: guanxfafu@126.com.
authors.forename: Xiong
authors.initials: X
authors.lastname: Guan
authors.affiliation: Key Laboratory of Design and Assembly of Functional Nanostructures, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, PR China; School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China. Electronic address: zlin@scut.edu.cn.
authors.forename: Zhang
authors.initials: Z
authors.lastname: Lin
mesh_terms: D001409:Bacillus cereus / Q000737:chemistry* / Q000378:metabolism*; D017886:Durapatite / Q000737:chemistry / Q000378:metabolism; D007220:Industrial Waste; D007854:Lead / Q000737:chemistry / Q000378:metabolism; D008906:Mining; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism; D015032:Zinc
chemical_list: D007220:Industrial Waste; D007854:Lead; D017886:Durapatite; D015032:Zinc
keywords: Bacillus cereus; Biomineralization; Biosorption; Lead