The influence of initial pH on the chalcopyrite oxidation dissolution at 65 ℃ was investigated by bioleaching and cyclic voltammetiy experiments,and the oxidation products were investigated by XRD and Raman spectrosc...The influence of initial pH on the chalcopyrite oxidation dissolution at 65 ℃ was investigated by bioleaching and cyclic voltammetiy experiments,and the oxidation products were investigated by XRD and Raman spectroscopy.Bioleaching results show that chalcopyrite dissolution rate increases with the decrease of the initial pH in chemical leaching,while the influence of initial pH on bioleaching is on the contrary.The presence of Acidianus manzaensis does not promote chalcopyrite dissolution under initial pH1.0,which mainly results from serious inhibition of high acidity to the growth of Acidianus manzaensis.Electrochemical experiments results show that anodic oxidation currents of electrolyte with or without Acidianus manzaensis both increase with the increase of initial pH,and covellite and sulfur are detected on the electrode surface.The results confirm that chalcopyrite dissolution in chemical leaching is under the combined action of oxidation and non-oxidation of proton,with conversion of chalcopyrite to covellite and elemental sulfur.展开更多
The formation and evolution of secondary minerals during bioleaching of chalcopyrite by thermoacidophilic Archaea Acidianus manzaensis were analyzed by combining synchrotron radiation X-ray diffraction（SR-XRD） and S...The formation and evolution of secondary minerals during bioleaching of chalcopyrite by thermoacidophilic Archaea Acidianus manzaensis were analyzed by combining synchrotron radiation X-ray diffraction（SR-XRD） and S, Fe and Cu Kα X-ray absorption near edge structure（XANES） spectroscopy. Leaching experiment showed that 82.4% of Cu2＋ was dissolved by A. manzaensis after 10 d. The surface of chalcopyrite was corroded apparently and covered with leaching products. During bioleaching, the formation and evolution of secondary minerals were as follows： 1） little elemental sulfur, jarosite, bornite and chalcocite were found at days 2 and 4; and 2） bornite and chalcocite disappeared, covellite formed, and jarosite gradually became the main component at days 6 and 10. These results indicated that metal-deficiency sulfides chalcocite and bornite were first formed with a low redox potential value（360-461 m V）, and then gradually transformed to covellite with a high redox potential value（461-531 m V）.展开更多
Iron L-edge and sulfur K-edge X-ray absorption near edge structure（XANES） spectroscopy analysis of pyrite leached by extreme thermophilic Archaea strain Acidianus manzaensis（A.manzaensis） was carried out.Leaching ...Iron L-edge and sulfur K-edge X-ray absorption near edge structure（XANES） spectroscopy analysis of pyrite leached by extreme thermophilic Archaea strain Acidianus manzaensis（A.manzaensis） was carried out.Leaching experiments show that the oxidation of pyrite can be accelerated by A.manzaensis.Leaching results show that with the increase of leaching time,pH value in the leaching solution gradually decreases,redox potential increases rapidly from day 0 to day 3,and then increases slowly.The SEM results show that the pyrite surfaces are corroded gradually by A.manzaensis,and the XRD results show that the leaching residues contain new compositions of jarosite and elemental sulfur（S0）.The iron L-edge XANES spectroscopy analysis of pyrite during biooxidation indicates that pyrite is gradually converted to Fe（III）-containing species.The sulfur K-edge XANES spectroscopy analysis indicates that elemental sulfur is produced during bioleaching and maintains mass fractions of 3.2%-5.9%.Sodium thiosulfate was also detected from day 2 to day 4,indicating the existence of thiosulfate during biooxidation of pyrite.展开更多
以万座嗜酸两面菌(Acidianus manzaensis)为研究对象,探索并优化其膜蛋白提取方法,以优化后的方法提取该菌分别以单质硫(S0)和亚铁(Fe2+)为能源底物进行生长时的膜蛋白质,并进行聚丙烯酰胺凝胶电泳(SDS-PAGE)研究膜蛋白在两种能源底物...以万座嗜酸两面菌(Acidianus manzaensis)为研究对象,探索并优化其膜蛋白提取方法,以优化后的方法提取该菌分别以单质硫(S0)和亚铁(Fe2+)为能源底物进行生长时的膜蛋白质,并进行聚丙烯酰胺凝胶电泳(SDS-PAGE)研究膜蛋白在两种能源底物培养下的表达差异。首先通过80℃水浴60-70 min对A.manzaensis胞外黏附蛋白进行初步分离。其次比较了不同提取剂(Triton X-110,SDS和Triton X-114)对膜蛋白的提取效果,结果表明Triton X-114的提取效果较好,其最佳浓度为10%(w/v);比较了不同沉淀剂(三氯乙酸(TCA),丙酮,三氯乙酸/丙酮,甲醇和乙醇)对膜蛋白质沉淀的效果,结果表明TCA/丙酮的沉淀效果最不理想,会导致沉淀后低分子量蛋白发生缺失,而其他几种没有明显差别,综合比较选择较常用的丙酮作为膜蛋白提取的沉淀剂。最后基于优化后膜蛋白提取方法,分别对S0和Fe2+培养的A.manzaensis膜蛋白质进行提取及SDS-PAGE,结果发现分子量为35.6 k D和16.9 k D的蛋白只在A.manzaensis以S0生长时出现,表明这些蛋白质很可能在A.manzaensis硫氧化中发挥了重要作用;分子量为72 k D和26 k D的蛋白质在A.manzaensis以Fe2+生长时比其以S0生长时显著表达上调,表明此蛋白可能与A.manzaensis铁氧化相关。展开更多
Bioleaching of chalcopyrite with different crystal structures (α-phase,β-phase and γ-phase) by Acidianus manzaensis was comparatively studied by synchrotron radiation based X-ray diffraction (SR-XRD) and S K-edge X...Bioleaching of chalcopyrite with different crystal structures (α-phase,β-phase and γ-phase) by Acidianus manzaensis was comparatively studied by synchrotron radiation based X-ray diffraction (SR-XRD) and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. The α-phase,β-phase and γ-phase chalcopyrite was prepared by heating original chalcopyrite at 583, 773 and 848 K, respectively. Bioleaching results showed that [Cu^2+] in the leaching solution of α-phase,β-phase,γ-phase and original chalcopyrite after 10 days of bioleaching was 1.27, 1.86, 1.43 and 1.13 g/L, respectively, suggesting that β-phase had a better leaching kinetics than others. SR-XRD and XANES results indicated that jarosite and chalcopyrite were the main components in the leaching residues in all cases, and elemental sulfur formed in the early stage of bioleaching. While for β-phase and γ-phase chalcopyrite during bioleaching, bornite was produced in the initial stage of leaching, and turned into chalcocite on day 6.展开更多
The attachment and bioleaching experiments were conducted to evaluate the zinc recovery from Hualilan ore by thethermoacidophilic archaeon Acidianus copahuensis. Cells of this species pregrown on tetrathionate showed ...The attachment and bioleaching experiments were conducted to evaluate the zinc recovery from Hualilan ore by thethermoacidophilic archaeon Acidianus copahuensis. Cells of this species pregrown on tetrathionate showed higher capability ofattachment to the ore than cells pregrown on other energy sources and such attachment seemed to be mediated by the product ofextracellular polymeric substances. A. copahuensis achieved a successful bioleaching of the ore reaching 100% of zinc recoverywhen tetrathionate was added. Simultaneous addition of yeast extract and tetrathionate maintained the zinc extraction at higher rate.Zinc dissolution kinetics was controlled by chemical reaction in cultures with the external addition of tetrathionate but by thediffusion through a product layer of jarosite in the other cultures.展开更多
Chalcopyrite dissolution was evaluated by bioleaching and electrochemical experiments with thermophile A. manzaensis（Acidianus manzaensis） and mesophile L. ferriphilum（Leptospirillum ferriphium） cultures at 65 ℃ ...Chalcopyrite dissolution was evaluated by bioleaching and electrochemical experiments with thermophile A. manzaensis（Acidianus manzaensis） and mesophile L. ferriphilum（Leptospirillum ferriphium） cultures at 65 ℃ and 40 ℃, respectively. It was investigated that the bioleaching of chalcopyrite was stepwise. It was reduced to Cu2 S at a lower redox potential locating in the whole bioleaching process by A. manzaensis at high temperature while only at initial days of bioleaching by L. ferriphilum at a relative low temperature. No reduced product was detected when the redox potential was beyond a high level（e.g., 550 m V（vs SCE）） bioleached by L. ferriphilum. Chalcopyrite bioleaching efficiency was substantially improved bioleached by A. manaensis compared to that by L. ferriphilum, which was mainly attributed to the reduction reaction occurring during bioleaching. The reductive intermediate Cu2 S was more amenable to oxidation than chalcopyrite, causing enhanced copper extraction.展开更多
The effect of L-cysteine in different concentrations on the bioleaching of Ni-Cu sulfide was studied with an extremely thermophilic archaea,Acidianus manzaensis. It is found that adding certain amounts of L-cysteine t...The effect of L-cysteine in different concentrations on the bioleaching of Ni-Cu sulfide was studied with an extremely thermophilic archaea,Acidianus manzaensis. It is found that adding certain amounts of L-cysteine to the bioleaching system of Ni-Cu sulfide largely enhances the leaching rate. X-ray diffraction (XRD) patterns show the change of bioleached solid residues and the effect of L-cysteine on the surface charges of minerals. Zeta potential and IR spectra of mineral surface show that the interaction between L-cysteine and mineral leads to the formation of metal complex,which is propitious to the bioleaching of Ni-Cu sulfide by Acidianus manzaensis.展开更多
The thermostability of three sulfur oxygenase reductases （SORs） was investigated from thermoacidophilic achaea Acidianus tengchongensis （SORAT） and Sulfolobus tokodaii （SORsT） as well as the moderately thermophi...The thermostability of three sulfur oxygenase reductases （SORs） was investigated from thermoacidophilic achaea Acidianus tengchongensis （SORAT） and Sulfolobus tokodaii （SORsT） as well as the moderately thermophilic bacterium Acidithiobacillus sp. SM-1 （SORsB）. The optimal temperatures for catalyzing sulfur oxidation were 80 ℃ （SORAT）, 85 ℃ （SORsT）, and 70 ℃ （SORsB）, respectively. The half-lives of the three SORs at their optimal catalytic conditions were 100 min （SORAT）, 58 min （SORsT）, and 37 min （SORsB）. In order to reveal the structural basis of the thermostability of these SORs, three-dimensional structural models of them were generated by homology modeling using the previously reported high-resolution X-ray structure of SORAA （from Acidianus ambivalens） as a template. The results suggest that thermostability was dependent on： （a） high number of the charged amino acid glutamic acid and the flexible amino acid proline, （b） low number of the therraolabile amino acid glutamine, （c） increased number of ion pairs, （d） decreased ratio of hydrophobie accessible solvent surface area （ASA） to charged ASA, and （e） increased volumes of the cavity. The number of cavities and the number of hydrogen bonds did not signifieantly affect the thermostability of SORs, whereas the cavity volumes increased as the thermal stability increased.展开更多
基金Projects (50974140,51274257) supported by the National Natural Science Foundation of ChinaProject (JXXJBS11003) supported by the Doctor Initiating Foundation of Jiangxi University of Science and Technology,China
文摘The influence of initial pH on the chalcopyrite oxidation dissolution at 65 ℃ was investigated by bioleaching and cyclic voltammetiy experiments,and the oxidation products were investigated by XRD and Raman spectroscopy.Bioleaching results show that chalcopyrite dissolution rate increases with the decrease of the initial pH in chemical leaching,while the influence of initial pH on bioleaching is on the contrary.The presence of Acidianus manzaensis does not promote chalcopyrite dissolution under initial pH1.0,which mainly results from serious inhibition of high acidity to the growth of Acidianus manzaensis.Electrochemical experiments results show that anodic oxidation currents of electrolyte with or without Acidianus manzaensis both increase with the increase of initial pH,and covellite and sulfur are detected on the electrode surface.The results confirm that chalcopyrite dissolution in chemical leaching is under the combined action of oxidation and non-oxidation of proton,with conversion of chalcopyrite to covellite and elemental sulfur.
基金Project(U1232103)supported by the Joint Funds of National Natural Science Foundation of China and Large Scientific Facility Foundation of Chinese Academy of SciencesProject(51274257)supported by the National Natural Science Foundation of China+2 种基金Project(CX2014B092)supported by Hunan Provincial Innovation Foundation For Postgraduate,ChinaProject(VR-12419)supported by Beijing Synchrotron Radiation Facility Public User Program,ChinaProjects(13SRBL15U13024,13SRBL14B13023)supported by the Open Funds of Shanghai Synchrotron Radiation Facility,China
文摘The formation and evolution of secondary minerals during bioleaching of chalcopyrite by thermoacidophilic Archaea Acidianus manzaensis were analyzed by combining synchrotron radiation X-ray diffraction（SR-XRD） and S, Fe and Cu Kα X-ray absorption near edge structure（XANES） spectroscopy. Leaching experiment showed that 82.4% of Cu2＋ was dissolved by A. manzaensis after 10 d. The surface of chalcopyrite was corroded apparently and covered with leaching products. During bioleaching, the formation and evolution of secondary minerals were as follows： 1） little elemental sulfur, jarosite, bornite and chalcocite were found at days 2 and 4; and 2） bornite and chalcocite disappeared, covellite formed, and jarosite gradually became the main component at days 6 and 10. These results indicated that metal-deficiency sulfides chalcocite and bornite were first formed with a low redox potential value（360-461 m V）, and then gradually transformed to covellite with a high redox potential value（461-531 m V）.
基金Project(51274257)supported by the National Natural Science Foundation of ChinaProject(U1232103)supported by the Joint Funds of National Natural Science Foundation of China and Large Scientific Facility Foundation of Chinese Academy of Sciences+1 种基金Project(CX2014B092)supported by the Hunan Provincial Innovation Foundation For Postgraduate,ChinaProject(VR-12419)supported by Beijing Synchrotron Radiation Facility Public User Program,China
文摘Iron L-edge and sulfur K-edge X-ray absorption near edge structure（XANES） spectroscopy analysis of pyrite leached by extreme thermophilic Archaea strain Acidianus manzaensis（A.manzaensis） was carried out.Leaching experiments show that the oxidation of pyrite can be accelerated by A.manzaensis.Leaching results show that with the increase of leaching time,pH value in the leaching solution gradually decreases,redox potential increases rapidly from day 0 to day 3,and then increases slowly.The SEM results show that the pyrite surfaces are corroded gradually by A.manzaensis,and the XRD results show that the leaching residues contain new compositions of jarosite and elemental sulfur（S0）.The iron L-edge XANES spectroscopy analysis of pyrite during biooxidation indicates that pyrite is gradually converted to Fe（III）-containing species.The sulfur K-edge XANES spectroscopy analysis indicates that elemental sulfur is produced during bioleaching and maintains mass fractions of 3.2%-5.9%.Sodium thiosulfate was also detected from day 2 to day 4,indicating the existence of thiosulfate during biooxidation of pyrite.
文摘以万座嗜酸两面菌(Acidianus manzaensis)为研究对象,探索并优化其膜蛋白提取方法,以优化后的方法提取该菌分别以单质硫(S0)和亚铁(Fe2+)为能源底物进行生长时的膜蛋白质,并进行聚丙烯酰胺凝胶电泳(SDS-PAGE)研究膜蛋白在两种能源底物培养下的表达差异。首先通过80℃水浴60-70 min对A.manzaensis胞外黏附蛋白进行初步分离。其次比较了不同提取剂(Triton X-110,SDS和Triton X-114)对膜蛋白的提取效果,结果表明Triton X-114的提取效果较好,其最佳浓度为10%(w/v);比较了不同沉淀剂(三氯乙酸(TCA),丙酮,三氯乙酸/丙酮,甲醇和乙醇)对膜蛋白质沉淀的效果,结果表明TCA/丙酮的沉淀效果最不理想,会导致沉淀后低分子量蛋白发生缺失,而其他几种没有明显差别,综合比较选择较常用的丙酮作为膜蛋白提取的沉淀剂。最后基于优化后膜蛋白提取方法,分别对S0和Fe2+培养的A.manzaensis膜蛋白质进行提取及SDS-PAGE,结果发现分子量为35.6 k D和16.9 k D的蛋白只在A.manzaensis以S0生长时出现,表明这些蛋白质很可能在A.manzaensis硫氧化中发挥了重要作用;分子量为72 k D和26 k D的蛋白质在A.manzaensis以Fe2+生长时比其以S0生长时显著表达上调,表明此蛋白可能与A.manzaensis铁氧化相关。
基金Projects(51774342,51404104) supported by the National Natural Science Foundation of ChinaProject(2017A030313219) supported by the Natural Science Foundation of Guangdong Province,China+2 种基金Project(2015JJ3062) supported by Science Foundation for Youths of Hunan Province,ChinaProjects(2017-BEPC-PT-001052,2016-BEPC-PT-000887) supported by Beijing Synchrotron Radiation Facility Public User Program,ChinaProject(2016-SSRF-PT-004969) supported by the Open Funds of Shanghai Synchrotron Radiation Facility,China
文摘Bioleaching of chalcopyrite with different crystal structures (α-phase,β-phase and γ-phase) by Acidianus manzaensis was comparatively studied by synchrotron radiation based X-ray diffraction (SR-XRD) and S K-edge X-ray absorption near edge structure (XANES) spectroscopy. The α-phase,β-phase and γ-phase chalcopyrite was prepared by heating original chalcopyrite at 583, 773 and 848 K, respectively. Bioleaching results showed that [Cu^2+] in the leaching solution of α-phase,β-phase,γ-phase and original chalcopyrite after 10 days of bioleaching was 1.27, 1.86, 1.43 and 1.13 g/L, respectively, suggesting that β-phase had a better leaching kinetics than others. SR-XRD and XANES results indicated that jarosite and chalcopyrite were the main components in the leaching residues in all cases, and elemental sulfur formed in the early stage of bioleaching. While for β-phase and γ-phase chalcopyrite during bioleaching, bornite was produced in the initial stage of leaching, and turned into chalcocite on day 6.
基金support from ANPCy T (PICT 2012 0623 and PICT 2013 0630)
文摘The attachment and bioleaching experiments were conducted to evaluate the zinc recovery from Hualilan ore by thethermoacidophilic archaeon Acidianus copahuensis. Cells of this species pregrown on tetrathionate showed higher capability ofattachment to the ore than cells pregrown on other energy sources and such attachment seemed to be mediated by the product ofextracellular polymeric substances. A. copahuensis achieved a successful bioleaching of the ore reaching 100% of zinc recoverywhen tetrathionate was added. Simultaneous addition of yeast extract and tetrathionate maintained the zinc extraction at higher rate.Zinc dissolution kinetics was controlled by chemical reaction in cultures with the external addition of tetrathionate but by thediffusion through a product layer of jarosite in the other cultures.
基金Project(2010CB630903)supported by National Basic Research Program of ChinaProject(51374249)supported by the National Natural Science Foundation of China
文摘Chalcopyrite dissolution was evaluated by bioleaching and electrochemical experiments with thermophile A. manzaensis（Acidianus manzaensis） and mesophile L. ferriphilum（Leptospirillum ferriphium） cultures at 65 ℃ and 40 ℃, respectively. It was investigated that the bioleaching of chalcopyrite was stepwise. It was reduced to Cu2 S at a lower redox potential locating in the whole bioleaching process by A. manzaensis at high temperature while only at initial days of bioleaching by L. ferriphilum at a relative low temperature. No reduced product was detected when the redox potential was beyond a high level（e.g., 550 m V（vs SCE）） bioleached by L. ferriphilum. Chalcopyrite bioleaching efficiency was substantially improved bioleached by A. manaensis compared to that by L. ferriphilum, which was mainly attributed to the reduction reaction occurring during bioleaching. The reductive intermediate Cu2 S was more amenable to oxidation than chalcopyrite, causing enhanced copper extraction.
基金Projects(50621063, 30400010) supported by the National Natural Science Foundation of ChinaProject(2010CB630903) supported by the National Basic Research Program of China
文摘The effect of L-cysteine in different concentrations on the bioleaching of Ni-Cu sulfide was studied with an extremely thermophilic archaea,Acidianus manzaensis. It is found that adding certain amounts of L-cysteine to the bioleaching system of Ni-Cu sulfide largely enhances the leaching rate. X-ray diffraction (XRD) patterns show the change of bioleached solid residues and the effect of L-cysteine on the surface charges of minerals. Zeta potential and IR spectra of mineral surface show that the interaction between L-cysteine and mineral leads to the formation of metal complex,which is propitious to the bioleaching of Ni-Cu sulfide by Acidianus manzaensis.
基金Supported by the National Natural Science Foundation of China (31070042,30870039,30921065)partially by Open Funding Project of the National Key Laboratory of Biochemical Engineering,China (2010KF-2)
文摘The thermostability of three sulfur oxygenase reductases （SORs） was investigated from thermoacidophilic achaea Acidianus tengchongensis （SORAT） and Sulfolobus tokodaii （SORsT） as well as the moderately thermophilic bacterium Acidithiobacillus sp. SM-1 （SORsB）. The optimal temperatures for catalyzing sulfur oxidation were 80 ℃ （SORAT）, 85 ℃ （SORsT）, and 70 ℃ （SORsB）, respectively. The half-lives of the three SORs at their optimal catalytic conditions were 100 min （SORAT）, 58 min （SORsT）, and 37 min （SORsB）. In order to reveal the structural basis of the thermostability of these SORs, three-dimensional structural models of them were generated by homology modeling using the previously reported high-resolution X-ray structure of SORAA （from Acidianus ambivalens） as a template. The results suggest that thermostability was dependent on： （a） high number of the charged amino acid glutamic acid and the flexible amino acid proline, （b） low number of the therraolabile amino acid glutamine, （c） increased number of ion pairs, （d） decreased ratio of hydrophobie accessible solvent surface area （ASA） to charged ASA, and （e） increased volumes of the cavity. The number of cavities and the number of hydrogen bonds did not signifieantly affect the thermostability of SORs, whereas the cavity volumes increased as the thermal stability increased.
