title: Microbial reduction of uranium (VI) by Bacillus sp. dwc-2: A macroscopic and spectroscopic study.
abstract: The microbial reduction of U(VI) by Bacillus sp. dwc-2, isolated from soil in Southwest China, was explored using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES). Our studies indicated that approximately 16.0% of U(VI) at an initial concentration of 100mg/L uranium nitrate could be reduced by Bacillus sp. dwc-2 at pH8.2 under anaerobic conditions at room temperature. Additionally, natural organic matter (NOM) played an important role in enhancing the bioreduction of U(VI) by Bacillus sp. dwc-2. XPS results demonstrated that the uranium presented mixed valence states (U(VI) and U(IV)) after bioreduction, which was subsequently confirmed by XANES. Furthermore, the TEM and high resolution transmission electron microscopy (HRTEM) analysis suggested that the reduced uranium was bioaccumulated mainly within the cell and as a crystalline structure on the cell wall. These observations implied that the reduction of uranium may have a significant effect on its fate in the soil environment in which these bacterial strains occur.
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China; Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China. Electronic address: lixiaolongscu720@126.com.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China; Key Laboratory of Biological Resource and Ecological Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China.
authors.forename: Congcong
authors.initials: C
authors.lastname: Ding
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China. Electronic address: liaojiali@scu.edu.cn.
authors.forename: Jiali
authors.initials: J
authors.lastname: Liao
authors.affiliation: Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Du
authors.affiliation: Key Laboratory of Biological Resource and Ecological Environment of the Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610064, China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China.
authors.forename: Jijun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China.
authors.forename: Yuanyou
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Institute of Nuclear Physics and Chemistry, CAEP, Mianyang 621900, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tang
authors.affiliation: Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology, Sichuan University, Chengdu 610064, China. Electronic address: nliu720@scu.edu.cn.
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002681:China; D010084:Oxidation-Reduction; D014501:Uranium / Q000378:metabolism*
chemical_list: D014501:Uranium
keywords: Bacillus sp. dwc-2; Bioreduction; Nanoparticle; Uranium