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Qin R, Dai X, Xian Y, Zhou Y, Su C, Chen Z, Lu X, Ai C, Lu Y. Assessing the effect of sulfate on the anaerobic oxidation of methane coupled with Cr(VI) bioreduction by sludge characteristic and metagenomics analysis. J Environ Manage 2024; 349:119398. [PMID: 37897905 DOI: 10.1016/j.jenvman.2023.119398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 10/30/2023]
Abstract
Methane-driven hexavalent chromium (Cr(VI)) reduction in a microbial fuel cell (MFC) has attracted much attention. However, whether the presence of sulfate (SO42-) affects the reduction of Cr(VI) is still lacking in systematic studies. This study involved constructing a MFC-granular sludge (MFC-GS) coupling system with dissolved methane (CH4) was used as the electron donor to investigate the effect of SO42- on Cr(VI) bioreduction, sludge characteristic, and functional metabolic mechanisms. When the SO42- concentration was 10 mg/L, the average removal rate of Cr(VI) in the anaerobic stage decreased to the lowest value (22.25 ± 2.06%). Adding 10 mg/L SO42- obviously inhibited the electrochemical performance of the system. Increasing SO42- concentration weakened the fluorescence peaks of tryptophan and aromatic proteins in the extracellular polymeric substance of sludge. Under the influence of SO42-, Methanothrix_soehngenii decreased from 14.44% to 5.89%. The relative abundance of methane metabolic was down-regulated from 1.47% to 0.98%, while the sulfur metabolic was up-regulated from 0.09% to 0.21% when SO42- was added. These findings provided some reference for the treatment of wastewater containing Cr(VI) and SO42- complex pollutants in the MFC-GS coupling system.
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Affiliation(s)
- Ronghua Qin
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Xiaoyun Dai
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Yunchuan Xian
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Yijie Zhou
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Chengyuan Su
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China; College of Environment and Resources, Guangxi Normal University, 15 Yucai Road, Guilin, 541004, PR China.
| | - Zhengpeng Chen
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Xinya Lu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Chenbing Ai
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
| | - Yuxiang Lu
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, 15 Yucai Road, Guilin, 541004, PR China
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Amanze C, Zheng X, Anaman R, Wu X, Fosua BA, Xiao S, Xia M, Ai C, Yu R, Wu X, Shen L, Liu Y, Li J, Dolgor E, Zeng W. Effect of nickel (II) on the performance of anodic electroactive biofilms in bioelectrochemical systems. Water Res 2022; 222:118889. [PMID: 35907303 DOI: 10.1016/j.watres.2022.118889] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/19/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
The impact of nickel (Ni2+) on the performance of anodic electroactive biofilms (EABs) in the bioelectrochemical system (BES) was investigated in this study. Although it has been reported that Ni2+ influences microorganisms in a number of ways, it is unknown how its presence in the anode of a BES affects extracellular electron transfer (EET) of EABs, microbial viability, and the bacterial community. Results revealed that the addition of Ni2+ decreased power output from 673.24 ± 12.40 mW/m2 at 0 mg/L to 179.26 ± 9.05 mW/m2 at 80 mg/L. The metal and chemical oxygen demand removal efficiencies of the microbial fuel cells (MFCs) declined as Ni2+ concentration increased, which could be attributed to decreased microbial viability as revealed by SEM and CLSM. FTIR analysis revealed the involvement of various microbial biofilm functional groups, including hydroxyl, amides, methyl, amine, and carboxyl, in the uptake of Ni2+. The presence of Ni2+ on the anodic biofilms was confirmed by SEM-EDS and XPS analyses. CV demonstrated that the electron transfer performance of the anodic biofilms was negatively correlated with the various Ni2+ concentrations. EIS showed that the internal resistance of the MFCs increased with increasing Ni2+ concentration, resulting in a decrease in power output. High-throughput sequencing results revealed a decrease in Geobacter and an increase in Desulfovibrio in response to Ni2+ concentrations of 10, 20, 40, and 80 mg/L. Furthermore, the various Ni2+ concentrations decreased the expression of EET-related genes. The Ni2+-fed MFCs had a higher abundance of the nikR gene than the control group, which was important for Ni2+ resistance. This work advances our understanding of Ni2+ inhibition on EABs, as well as the concurrent removal of organic matter and Ni2+ from wastewater.
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Affiliation(s)
- Charles Amanze
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Xiaoya Zheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Richmond Anaman
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Xiaoyan Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Bridget Ataa Fosua
- School of Metallurgy and Environment, Central South University, Changsha 410083, China
| | - Shanshan Xiao
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Mingchen Xia
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Chenbing Ai
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
| | - Runlan Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China
| | - Xueling Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China
| | - Yuandong Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China
| | - Jiaokun Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China
| | - Erdenechimeg Dolgor
- Department of Chemical and Biological Engineering, School of Engineering and Applied Sciences, National University of Mongolia, 14200, Mongolia
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha 410083, China.
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3
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Amanze C, Zheng X, Man M, Yu Z, Ai C, Wu X, Xiao S, Xia M, Yu R, Wu X, Shen L, Liu Y, Li J, Dolgor E, Zeng W. Recovery of heavy metals from industrial wastewater using bioelectrochemical system inoculated with novel Castellaniella species. Environ Res 2022; 205:112467. [PMID: 34863983 DOI: 10.1016/j.envres.2021.112467] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/27/2021] [Accepted: 11/28/2021] [Indexed: 06/13/2023]
Abstract
Water pollution is a global issue that has drastically increased in recent years due to rapid industrial development. Different technologies have been designed for the removal of pollutants from wastewater. However, most of these techniques are expensive, generate new waste, and focus solely on metal removal instead of metal recovery. In this study, novel facultative exoelectrogenic strains designated Castellaniella sp. A5, Castellaniella sp. B3, and Castellaniella sp. A3 were isolated from a microbial fuel cell (MFC). These isolates were utilized as pure and mixed culture inoculums in a bioelectrochemical system (BES) to produce bioelectricity and treat simulated industrial wastewater. A single-chamber MFC inoculated with the mixed culture attained the highest electricity generation (i.e., 320 mW/m2 power density and 3.19 A/m2 current density), chemical oxygen demand removal efficiency (91.15 ± 0.05%), and coulombic efficiency (54.81 ± 4.18%). In addition, the BES containing biofilms of the mixed culture achieved the highest Cu, Cr, and Cd removal efficiencies of 99.89 ± 0.07%, 99.59 ± 0.53%, and 99.91 ± 0.04%, respectively. The Cr6+ and Cu2+ in the simulated industrial wastewater were recovered via microbial electrochemical reduction as Cr3+ and Cu0, respectively. However, Cd2+ precipitated as Cd (OH)2 or CdCO3 on the surface of the cathodes. These results suggest that a mixed culture inoculum of Castellaniella sp. A5, Castellaniella sp. B3, and Castellaniella sp. A3 has great potential as a biocatalyst in BES for heavy metals recovery from industrial wastewater.
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Affiliation(s)
- Charles Amanze
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Xiaoya Zheng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Meilian Man
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Zhaojing Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Chenbing Ai
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Xiaoyan Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Shanshan Xiao
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Mingchen Xia
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China
| | - Runlan Yu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China
| | - Xueling Wu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China
| | - Li Shen
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China
| | - Yuandong Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China
| | - Jiaokun Li
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China
| | - Erdenechimeg Dolgor
- Department of Chemical and Biological Engineering, School of Engineering and Applied Sciences, National University of Mongolia, 14200, Mongolia
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, China; Key Laboratory of Biometallurgy, Ministry of Education, Changsha, 410083, China.
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Ai C, Yan Z, Hou S, Huo Q, Chai L, Qiu G, Zeng W. Sequentially recover heavy metals from smelting wastewater using bioelectrochemical system coupled with thermoelectric generators. Ecotoxicol Environ Saf 2020; 205:111174. [PMID: 32853867 DOI: 10.1016/j.ecoenv.2020.111174] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 06/11/2023]
Abstract
Smelting wastewater is characterized with high concentration of toxic heavy metals and high acidity, which must be properly treated before discharge. Here, bioelectrochemical system (BES) coupled with thermoelectric generator (TEG) was first demonstrated to simultaneously treat organic wastewater and smelting wastewater by utilizing the simulated waste heat that was abundant in smelting factories. By modulating the input voltage generated from simulated waste heat via TEG to 0, 1.0 and 2.0 V, almost all the Cu2+, Cd2+ and Co2+ in smelting wastewater were sequentially recovered with a respective rate of 121.17, 158.20 and 193.87 mg L-1 d-1. Cu2+ was bioelectrochemically recovered as Cu0. While, Cd2+ and Co2+ were recovered by electrodeposition as Cd(OH)2, CdCO3 or Co(OH)2 on cathodic surface. High throughput sequencing analysis showed that the microbial community of anodic biofilm was greatly shifted after successive treatment by batch-mode. Desulfovibrio (17.00%), Megasphaera (11.81%), Geobacter (10.36%) and Propionibacterium (8.64%) were predominant genera in anodic biofilm enriched from activated sludge in BES before treatment. After successive treatment by batch-mode, Geobacter (34.76%), Microbacter (8.60%) and Desulfovibrio (5.33%) were shifted as the major genera. Economic analysis revealed that it was feasible to use TEG to substitute electrical grid energy to integrate with BES for wastewater treatment. In addition, literature review indicated that it was not uncommon for the coexistence of waste heat with typical pollutants (e.g. heavy metal ions and various biodegradation-resistant organic wastes) that could be treated by BES in different kinds of factories or geothermal sites. This study provides novel insights to expand the application potentials of BES by integrating with TEG to utilize widespread waste heat.
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Affiliation(s)
- Chenbing Ai
- Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection (Guangxi Normal University), Ministry of Education, China; College of Life Science, Guangxi Normal University, Guilin, 541004, China; School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, Hunan, China
| | - Zhang Yan
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China; College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou, Fujian Province, 350007, China
| | - Shanshan Hou
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Qiang Huo
- College of Environment and Resources, Guangxi Normal University, Guilin, 541004, China
| | - Liyuan Chai
- School of Metallurgy and Environment, Central South University, Changsha, 410083, Hunan, China; Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha, 410083, Hunan, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China; Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
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Yuan S, Yu Q, Wang S, Xu Y, Ge H, Wang J, Zhang S, Chen W, Li J, Song Q, GU W, Yan J, Li X, Wang J, Zhang H, Huang D, Wang B, Ai C, Zhao L, Song Y, Yu J. Individualized Adaptive Radiotherapy versus Standard Radiotherapy with Chemotherapy for Patients with Locally Advanced Non-Small Cell Lung Cancer: A Multicenter Randomized Phase III Clinical Trial CRTOG1601. Int J Radiat Oncol Biol Phys 2020. [DOI: 10.1016/j.ijrobp.2020.07.2286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Ai C, Yan Z, Zhou H, Hou S, Chai L, Qiu G, Zeng W. Metagenomic Insights into the Effects of Seasonal Temperature Variation on the Activities of Activated Sludge. Microorganisms 2019; 7:E713. [PMID: 31861224 PMCID: PMC6956059 DOI: 10.3390/microorganisms7120713] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/13/2019] [Accepted: 12/13/2019] [Indexed: 01/09/2023] Open
Abstract
It is well acknowledged that the activities of activated sludge (AS) are influenced by seasonal temperature variation. However, the underlying mechanisms remain largely unknown. Here, the activities of activated sludge under three simulated temperature variation trends were compared in lab-scale. The TN, HN3-H, and COD removal activities of activated sludge were improved as temperature elevated from 20 °C to 35 °C. While, the TN, HN3-H, COD and total phosphorus removal activities of activated sludge were inhibited as temperature declined from 20 °C to 5 °C. Both the extracellular polymer substances (EPS) composition (e.g., total amount, PS, PN and DNA) and sludge index of activated sludge were altered by simulated seasonal temperature variation. The variation of microbial community structures and the functional potentials of activated sludge were further explored by metagenomics. Proteobacteria, Actinobacteria, Acidobacteria and Bacteroidetes were the dominant phyla for each activated sludge sample under different temperatures. However, the predominant genera of activated sludge were significantly modulated by simulated temperature variation. The functional genes encoding enzymes for nitrogen metabolism in microorganisms were analyzed. The enzyme genes related to ammonification had the highest abundance despite the changing temperature, especially for gene encoding glutamine synthetase. With the temperature raising from 20 °C to 35 °C. The abundance of amoCAB genes encoding ammonia monooxygenase (EC:1.14.99.39) increased by 305.8%. Meanwhile, all the enzyme genes associate with denitrification were reduced. As the temperature declined from 20 °C to 5 °C, the abundance of enzyme genes related to nitrogen metabolism were raised except for carbamate kinase (EC:2.7.2.2), glutamate dehydrogenase (EC:1.4.1.3), glutamine synthetase (EC:6.3.1.2). Metagenomic data indicate that succession of the dominant genera in microbial community structure is, to some extent, beneficial to maintain the functional stability of activated sludge under the temperature variation within a certain temperature range. This study provides novel insights into the effects of seasonal temperature variation on the activities of activated sludge.
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Affiliation(s)
- Chenbing Ai
- School of Metallurgy and Environment, Central South University, Changsha 410083, China; (C.A.)
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Zhang Yan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
- College of Environmental Science and Engineering, Fujian Key Laboratory of Pollution Control & Resource Reuse, Fujian Normal University, Fuzhou 350007, China
| | - Han Zhou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Shanshan Hou
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Liyuan Chai
- School of Metallurgy and Environment, Central South University, Changsha 410083, China; (C.A.)
- Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution, Central South University, Changsha 410083, China
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China
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7
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McCarthy S, Ai C, Blum P. Enhancement of Metallosphaera sedula Bioleaching by Targeted Recombination and Adaptive Laboratory Evolution. Adv Appl Microbiol 2018; 104:135-165. [PMID: 30143251 DOI: 10.1016/bs.aambs.2018.03.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Thermophilic and lithoautotrophic archaea such as Metallosphaera sedula occupy acidic, metal-rich environments and are used in biomining processes. Biotechnological approaches could accelerate these processes and improve metal recovery by biomining organisms, but systems for genetic manipulation in these organisms are currently lacking. To gain a better understanding of the interplay between metal resistance, autotrophy, and lithotrophic metabolism, a genetic system was developed for M. sedula and used to evaluate parameters governing the efficiency of copper bioleaching. Additionally, adaptive laboratory evolution was used to select for naturally evolved M. sedula cell lines with desirable phenotypes for biomining, and these adapted cell lines were shown to have increased bioleaching capacity and efficiency. Genomic methods were used to analyze mutations that led to resistance in the experimentally evolved cell lines, while transcriptomics was used to examine changes in stress-inducible gene expression specific to the environmental conditions.
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Affiliation(s)
- Samuel McCarthy
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Chenbing Ai
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Paul Blum
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, United States.
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Ai C, Liang Y, Miao B, Chen M, Zeng W, Qiu G. Identification and Analysis of a Novel Gene Cluster Involves in Fe 2+ Oxidation in Acidithiobacillus ferrooxidans ATCC 23270, a Typical Biomining Acidophile. Curr Microbiol 2018; 75:818-826. [PMID: 29464360 DOI: 10.1007/s00284-018-1453-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/12/2018] [Indexed: 11/26/2022]
Abstract
Iron-oxidizing Acidithiobacillus spp. are applied worldwide in biomining industry to extract metals from sulfide minerals. They derive energy for survival through Fe2+ oxidation and generate Fe3+ for the dissolution of sulfide minerals. However, molecular mechanisms of their iron oxidation still remain elusive. A novel two-cytochrome-encoding gene cluster (named tce gene cluster) encoding a high-molecular-weight cytochrome c (AFE_1428) and a c4-type cytochrome c552 (AFE_1429) in A. ferrooxidans ATCC 23270 was first identified in this study. Bioinformatic analysis together with transcriptional study showed that AFE_1428 and AFE_1429 were the corresponding paralog of Cyc2 (AFE_3153) and Cyc1 (AFE_3152) which were encoded by the extensively studied rus operon and had been proven involving in ferrous iron oxidation. Both AFE_1428 and AFE_1429 contained signal peptide and the classic heme-binding motif(s) as their corresponding paralog. The modeled structure of AFE_1429 showed high resemblance to Cyc1. AFE_1428 and AFE_1429 were preferentially transcribed as their corresponding paralogs in the presence of ferrous iron as sole energy source as compared with sulfur. The tce gene cluster is highly conserved in the genomes of four phylogenetic-related A. ferrooxidans strains that were originally isolated from different sites separated with huge geographical distance, which further implies the importance of this gene cluster. Collectively, AFE_1428 and AFE_1429 involve in Fe2+ oxidation like their corresponding paralog by integrating with the metalloproteins encoded by rus operon. This study provides novel insights into the Fe2+ oxidation mechanism in Fe2+-oxidizing A. ferrooxidans ssp.
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Affiliation(s)
- Chenbing Ai
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Yuting Liang
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Bo Miao
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China
| | - Miao Chen
- CSIRO Process Science and Engineering, Clayton, VIC, Australia
| | - Weimin Zeng
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China.
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
- CSIRO Process Science and Engineering, Clayton, VIC, Australia.
| | - Guanzhou Qiu
- School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, Hunan, China.
- Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha, 410083, China.
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9
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Zhang Q, Ai C, Wang G, Liu X, Tian F, Zhao J, Zhang H, Chen Y, Chen W. Oral application of lactic acid bacteria following treatment with antibiotics inhibits allergic airway inflammation. J Appl Microbiol 2015; 119:809-17. [DOI: 10.1111/jam.12885] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Revised: 05/20/2015] [Accepted: 05/21/2015] [Indexed: 12/26/2022]
Affiliation(s)
- Q. Zhang
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - C. Ai
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - G. Wang
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - X. Liu
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - F. Tian
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - J. Zhao
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - H. Zhang
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - Y.Q. Chen
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
| | - W. Chen
- State Key Laboratory of Food Science and Technology; School of Food Science and Technology; Jiangnan University; Wuxi Jiangsu China
- Beijing Innovation Centre of Food Nutrition and Human Health; Beijing Technology & Business University; Beijing 100048 China
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Wang Y, Zhang X, Liu Q, Ai C, Mo H, Zeng J. Expression, Purification and Molecular Structure Modeling of Thioredoxin (Trx) and Thioredoxin Reductase (TrxR) from Acidithiobacillus ferrooxidans. Curr Microbiol 2009; 59:35-41. [DOI: 10.1007/s00284-009-9390-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2008] [Revised: 02/17/2009] [Accepted: 02/19/2009] [Indexed: 10/21/2022]
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11
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Zeng J, Zhang X, Wang Y, Ai C, Liu Q, Qiu G. Glu43 is an essential residue for coordinating the [Fe2S2] cluster of IscR from Acidithiobacillus ferrooxidans. FEBS Lett 2008; 582:3889-92. [PMID: 18955052 DOI: 10.1016/j.febslet.2008.09.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Revised: 09/29/2008] [Accepted: 09/29/2008] [Indexed: 11/28/2022]
Abstract
The iron-sulfur cluster regulator (IscR) was reported to be a repressor of the iscRSUA operon. In vitro transcription reactions revealed that the IscR had a repression effect on the iscR promoter. The IscR contains a [Fe2S2] cluster per each monomer, and three highly conserved cysteines were identified to ligate the [Fe2S2] cluster. It was proposed that a non-cysteine residue might be the fourth ligand for the [Fe2S2] cluster. In this study, using site-directed mutagenesis, Glu43 was found to be the fourth residue that coordinates the [Fe2S2] cluster of IscR.
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Affiliation(s)
- Jia Zeng
- Department of Bioengineering, School of Resources Processing and Bioengineering, Central South University, Changsha, Hunan 410083, PR China.
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12
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Wen X, Chen L, Ai C, Zhou Z, Jiang H. Variation in lipid composition of Chinese mitten-handed crab, Eriocheir sinensis during ovarian maturation. Comp Biochem Physiol B Biochem Mol Biol 2001; 130:95-104. [PMID: 11470448 DOI: 10.1016/s1096-4959(01)00411-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
This experiment was conducted to investigate the variation in lipid composition during the ovarian maturation of the crab Eriocheir sinensis. The Chinese mitten-handed crab broodstock was divided into six different maturation periods according to the size and color of ovary. Ovary, hepatopancreas, muscle, and hemolymph of broodstock in different maturation periods were analyzed for total lipid and fatty acids using gas chromatography, and lipid classes by thin-layer chromatography. The ovarian lipid concentration (expressed as percent wet ovarian weight) increased steadily from stage II (5.4%) to stage IV (19.1%), and decreased to the lowest levels after spawning (stage V, 6.6%). The hepatopancreatic lipid concentration (expressed as percent wet hepatopancreatic weight) increased with maturity of the ovaries, reached a maximum at stage III(2) (29.9%), and decreased during the subsequent period to spawning (16.7%). The muscular and hemolymph lipid concentration did not change markedly during the ovarian development. These results suggest the possible movement of hepatopancreatic lipids to the ovaries during the ovarian maturation. Both triacylglycerol and phosphatidylcholine were responsible for the increase in ovarian lipid concentration during sexual maturation. The fatty acids of total lipid, triacylglycerol, and phosphatidylcholine of the ovaries did not vary systematically during the ovarian maturation, but the ratio between n-3PUFA (polyunsaturated fatty acid) and n-6PUFA did change regularly with the ovarian lipid. These suggest that enough PUFA, especially n-3PUFA, should be supplied to the crab during ovarian maturation.
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Affiliation(s)
- X Wen
- Department of Biology, East China Normal University, 200062, Shanghai, PR China.
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13
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Abstract
Economists often estimate models with a log-transformed dependent variable. The results from the log-transformed model are often retransformed back to the unlogged scale. Other studies have shown how to obtain consistent estimates on the original scale but have not provided variance equations for those estimates. In this paper, we derive the variance for three estimates--the conditional mean of y, the slope of y, and the average slope of y--on the retransformed scale. We then illustrate our proposed procedures with skewed health expenditure data from a sample of Medicaid eligible patients with severe mental illness.
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Affiliation(s)
- C Ai
- University of Florida, USA
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Sarkar PS, Appukuttan B, Han J, Ito Y, Ai C, Tsai W, Chai Y, Stout JT, Reddy S. Heterozygous loss of Six5 in mice is sufficient to cause ocular cataracts. Nat Genet 2000; 25:110-4. [PMID: 10802668 DOI: 10.1038/75500] [Citation(s) in RCA: 150] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Myotonic dystrophy (DM) is an autosomal dominant disorder characterized by skeletal muscle wasting, myotonia, cardiac arrhythmia, hyperinsulinaemia, mental retardation and ocular cataracts. The genetic defect in DM is a CTG repeat expansion located in the 3' untranslated region of DMPK and 5' of a homeodomain-encoding gene, SIX5 (formerly DMAHP; refs 2-5). There are three mechanisms by which CTG expansion can result in DM. First, repeat expansion may alter the processing or transport of the mutant DMPK mRNA and consequently reduce DMPK levels. Second, CTG expansion may establish a region of heterochromatin 3' of the repeat sequence and decrease SIX5 transcription. Third, toxic effects of the repeat expansion may be intrinsic to the repeated elements at the level of DNA or RNA (refs 10,11). Previous studies have demonstrated that a dose-dependent loss of Dm15 (the mouse DMPK homologue) in mice produces a partial DM phenotype characterized by decreased development of skeletal muscle force and cardiac conduction disorders. To test the role of Six5 loss in DM, we have analysed a strain of mice in which Six5 was deleted. Our results demonstrate that the rate and severity of cataract formation is inversely related to Six5 dosage and is temporally progressive. Six5+/- and Six5-/- mice show increased steady-state levels of the Na+/K+-ATPase alpha-1 subunit and decreased Dm15 mRNA levels. Thus, altered ion homeostasis within the lens may contribute to cataract formation. As ocular cataracts are a characteristic feature of DM, these results demonstrate that decreased SIX5 transcription is important in the aetiology of DM. Our data support the hypothesis that DM is a contiguous gene syndrome associated with the partial loss of both DMPK and SIX5.
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Affiliation(s)
- P S Sarkar
- Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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Abstract
A Fizeau interferometer utilizes a multimode laser as a light source for testing thin transparent plate samples. As a result of multimode linear laser operation, interference fringes are obtained only when the optical path difference between two surfaces is equal to twice a multiple of the laser's effective cavity length. For three parallel surfaces, we can either adjust their separations or select a laser such that only two of the three surfaces meet the requirement of twice a multiple of the laser's effective cavity length.
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Abstract
Multiple reflections between two surfaces of a window introduce a fixed pattern error in optical measurements. One way to remove these spurious reflections is to use a reasonably large wedge so that the interference fringes formed by the two surfaces are too dense for the detector to resolve. However, this method does not work if the wedge angle is small, e.g., several arcseconds. By tilting both the window and the return mirror properly, it is possible to remove the effect of multiple reflections of a window. Theory and experimental results are presented.
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Abstract
We describe a modified three-flat method. In a Cartesian coordinate system, a flat can be expressed as the sum of even-odd, odd-even, even-even, and odd-odd functions. The even-odd and the odd-even functions of each flat are obtained first, and then the even-even function is calculated. All three functions are exact. The odd-odd function is difficult to obtain. In theory, this function can be solved by rotating the flat 90°, 45°, 22.5°, etc. The components of the Fourier series of this odd-odd function are derived and extracted from each rotation of the flat. A flat is approximated by the sum of the first three functions and the known components of the odd-odd function. In the experiments, the flats are oriented in six configurations by rotating the flats 180°, 90°, and 45° with respect to one another, and six measurements are performed. The exact profiles along every 45° diameter are obtained, and the profile in the area between two adjacent diameters of these diameters is also obtained with some approximation. The theoretical derivation, experiment results, and error analysis are presented.
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Abstract
Phase errors in a Fizeau phase-shifting interferometer caused by multiple-reflected beams from a retroreflective optics, such as a corner cube and a right-angle prism, are studied. Single- and double-pass configurations are presented, and their measurement results are compared. An attenuator is not needed in a double-pass configuration because light is reflected by the retroreflective optics twice and the reference surface once and hence the intensities match. It is more accurate to test a corner cube or a right-angle prism in a double-pass configuration than in a single-pass configuration. Simulations and experimental results are presented.
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Abstract
We describe a sensitive method for measuring the stress birefringence of an optical window that utilizes a phase-measuring Fizeau interferometer incorporating a variable retarder and a nonpolarizing beam splitter. When we test a material in an interferometer cavity, the wave front transmitted through the material is deviated by the surfaces, inhomogeneity, and birefringence of the material. Birefringence causes the transmitted wave front to have different optical path difference (OPD) profiles for the vertical and horizontal orientations of linear polarization. Subtracting these OPD profiles reveals the amount of phase difference between the fast and slow axes of the material. Hence, birefringence may be calculated. Phase-measurement techniques and a computer-controlled interferometer employing a variable liquid-crystal retarder provide a fully automated instrument for measuring stress birefringence. The theoretical derivation, discussion of the instrument, and experimental results are presented.
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Abstract
The alignment of a corner cube affects the measurement of its dihedral angle. For 5 deg of tilt, the error is up to 7%, depending on the orientation of the tilt. A vector model is devised to derive formulas that take misalignment into account for both solid and hollow corner cubes. When the wave-front tilt caused by the dihedral angle error is not much greater than that caused by the surface figure, because of vignetting for a tilting illumination, the surface figure of the cube facet makes varying contributions to the wave-front tilt for different incident angles. Simulations and experimental results are presented.
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Abstract
The phase errors caused by spurious reflection in Twyman-Green and Fizeau interferometers are studied. A practical algorithm effectively eliminating the error is presented. Two other algorithms are reviewed, and the results obtained using the three algorithms are compared.
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Abstract
If the nonlinearity of the motion of a piezoelectric transducer (PZT) can be described as a quadratic function, the integrated intensity of one frame in phase shift interferometry can be calculated using the Fresnel integral. For a PZT with smaller nonlinearity, the rms phase error is almost linearly proportional to the quadratic coefficient The effects of PZT nonlinearity on the three- and the four-bucket algorithms are compared.
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