Biomineralization of Uranium: A Simulated Experiment and Its Significance  

作　　者：MINMaozhong HuifangXU L.L.BARTON WANGJinping PENGXinjian H.WIATROWSKI 

机构地区：[1]DepartmentofEarthSciences,StateKey.LaboratoryofMineralDepositResearch,NanjingUniversityNanjing,Jiangsu210093,China [2]DepartmentofEarthandPlanetarySciences,UniversityofNewMexico,Albuquerque,NM87131-1116,USA [3]DepartmentofBiology,UniversityofNewMexico,Albuquerque,NM87131-1116,USA

出　　处：《Acta Geologica Sinica(English Edition)》2005年第1期134-138,共5页地质学报（英文版）

基　　金：the National Science Foundation.USA.(NSF Grant EAR 02-10820);the National Natural ScienceFoundation of China(NSFC Grant No.40173031);the International Cooperative Research Foundation of NSFC(Grant No.2002-40210104086); the Ph.D.Base Foundation of the Ministry of Education of China(Grant No.20020284036).

摘　　要：A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.A simulated experimental reduction of and the synthesis of uraninite by a sulfate-reducing bacteria, Desulfovibrio desulfuricans DSM 642, are first reported. The simulated physicochemical experimental conditions were: 35°C, pH=7.0-7.4, corresponding to the environments of formation of the sandstone-hosted interlayer oxidation-zone type uranium deposits in Xinjiang, NW China. Uraninite was formed on the surface of the host bacteria after a one-week's incubation. Therefore, sulfate-reducing bacteria, which existed extensively in Jurassic sandstone-producing environments, might have participated in the biomineralization of this uranium deposit. There is an important difference in the order- disorder of the crystalline structure between the uraninite produced by Desulfovibrio desulfuricans and naturally occurring uraninite. Long time and slow precipitation and growth of uraninite in the geological environment might have resulted in larger uraninite crystals, with uraninite nanocrystals arranged in order, whereas the experimentally produced uraninite is composed of unordered uraninite nanocrystals which, in contrast, result from the short time span of formation and rapid precipitation and growth of uraninite. The discovery has important implications for understanding genetic significance in mineralogy, and also indicates that in-situ bioremediation of U-contaminated environments and use of biotechnology in the treatment of radioactive liquid waste is being contemplated.

关 键 词：microbial biomineralization URANINITE sulfate-reducing bacteria sandstone-hosted uranium deposit simulated experiment 

分 类 号：P619.14[天文地球—矿床学]