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Sample records for acidophile acidithiobacillus ferrooxidans

  1. Growth of the acidophilic iron-sulfur bacterium Acidithiobacillus ferrooxidans under Mars-like geochemical conditions

    Science.gov (United States)

    Bauermeister, Anja; Rettberg, Petra; Flemming, Hans-Curt

    2014-08-01

    The question of life on Mars has been in focus of astrobiological research for several decades, and recent missions in orbit or on the surface of the planet are constantly expanding our knowledge on Martian geochemistry. For example, massive stratified deposits have been identified on Mars containing sulfate minerals and iron oxides, which suggest the existence of acidic aqueous conditions in the past, similar to acidic iron- and sulfur-rich environments on Earth. Acidophilic organisms thriving in such habitats could have been an integral part of a possibly widely extinct Martian ecosystem, but remains might possibly even exist today in protected subsurface niches. The chemolithoautotrophic strain Acidithiobacillus ferrooxidans was selected as a model organism to study the metabolic capacities of acidophilic iron-sulfur bacteria, especially regarding their ability to grow with in situ resources that could be expected on Mars. The experiments were not designed to accurately simulate Martian physical conditions (except when certain single parameters such as oxygen partial pressure were considered), but rather the geochemical environment that can be found on Mars. A. ferrooxidans could grow solely on the minerals contained in synthetic Mars regolith mixtures with no added nutrients, using either O2 as an external electron acceptor for iron oxidation, or H2 as an external electron donor for iron reduction, and thus might play important roles in the redox cycling of iron on Mars. Though the oxygen partial pressure of the Martian atmosphere at the surface was not sufficient for detectable iron oxidation and growth of A. ferrooxidans during short-term incubation (7 days), alternative chemical O2-generating processes in the subsurface might yield microhabitats enriched in oxygen, which principally are possible under such conditions. The bacteria might also contribute to the reductive dissolution of Fe3+-containing minerals like goethite and hematite, which are

  2. Characterization of Extreme Acidophile Bacteria (Acidithiobacillus ferrooxidans) Bioleaching Copper from Flexible PCB by ICP-AES

    OpenAIRE

    Weihua Gu; Jianfeng Bai; Jue Dai; Chenglong Zhang; Wenyi Yuan; Jingwei Wang; Pengcheng Wang; Xin Zhao

    2014-01-01

    In order to improve copper leaching efficiency from the flexible printed circuit board (PCB) by Acidithiobacillus ferrooxidans, it is necessary to quantitatively measure the bacteria bioleaching copper under extreme acidic condition from flexible PCB. The inductively coupled plasma-atomic emission spectroscopy (ICP-AES) is a very accurate way to analyze metals in solution; this paper investigated the optimal conditions for copper bioleaching by Acidithiobacillus ferrooxidans from flexible PCB...

  3. Purification and characterization of sulfide:quinone oxidoreductase from an acidophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Wakai, Satoshi; Tsujita, Mizuho; Kikumoto, Mei; Manchur, Mohammed A; Kanao, Tadayoshi; Kamimura, Kazuo

    2007-11-01

    Sulfide:quinone oxidoreductase (SQR) was purified from membrane of acidophilic chemolithotrophic bacterium Acidithiobacillus ferrooxidans NASF-1 cells grown on sulfur medium. It was composed of a single polypeptide with an apparent molecular mass of 47 kDa. The apparent K(m) values for sulfide and ubiquinone were 42 and 14 muM respectively. The apparent optimum pH for the SQR activity was about 7.0. A gene encoding a putative SQR of A. ferrooxidans NASF-1 was cloned and sequenced. The gene was expressed in Escherichia coli as a thioredoxin-fusion protein in inclusion bodies in an inactive form. A polyclonal antibody prepared against the recombinant protein reacted immunologically with the purified SQR. Western blotting analysis using the antibody revealed an increased level of SQR synthesis in sulfur-grown A. ferrooxidans NASF-1 cells, implying the involvement of SQR in elemental sulfur oxidation in sulfur-grown A. ferrooxidans NASF-1 cells. PMID:17986789

  4. Characterization of Extreme Acidophile Bacteria (Acidithiobacillus ferrooxidans Bioleaching Copper from Flexible PCB by ICP-AES

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    Weihua Gu

    2014-01-01

    Full Text Available In order to improve copper leaching efficiency from the flexible printed circuit board (PCB by Acidithiobacillus ferrooxidans, it is necessary to quantitatively measure the bacteria bioleaching copper under extreme acidic condition from flexible PCB. The inductively coupled plasma-atomic emission spectroscopy (ICP-AES is a very accurate way to analyze metals in solution; this paper investigated the optimal conditions for copper bioleaching by Acidithiobacillus ferrooxidans from flexible PCB through ICP-AES. The conditions included particle size of flexible PCB powder, quantity of flexible PCB powder, initial pH of culture medium, bacteria inoculation, bacteria activation time, and quantity of FeSO4·7H2O. Prior to ICP-AES measurement, culture solution was digested by aqua regia. The experimental results demonstrated that flexible PCB contained one main metal (copper; this was associated with the structure of flexible PCB. The optimization conditions were in 50 mL medium, flexible PCB 10 g/L, particle size of flexible PCB 0.42~0.84 mm, culture medium initial pH 2.5, bacteria inoculation 5%, bacteria activation time 5 d, and quantity of FeSO4·7H2O 30 g/L. Under the optimization condition, the leaching rate of copper was 90.10%, which was 42.4% higher than the blank group. For the ICP-AES determination, it reached a conclusion that the best corresponding wavelength (nm of copper will be 224.7 (nm.

  5. Genes and pathways for CO2 fixation in the obligate, chemolithoautotrophic acidophile, Acidithiobacillus ferrooxidans, Carbon fixation in A. ferrooxidans

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    Esparza Mario

    2010-08-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is chemolithoautotrophic γ-proteobacterium that thrives at extremely low pH (pH 1-2. Although a substantial amount of information is available regarding CO2 uptake and fixation in a variety of facultative autotrophs, less is known about the processes in obligate autotrophs, especially those living in extremely acidic conditions, prompting the present study. Results Four gene clusters (termed cbb1-4 in the A. ferrooxidans genome are predicted to encode enzymes and structural proteins involved in carbon assimilation via the Calvin-Benson-Bassham (CBB cycle including form I of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO, EC 4.1.1.39 and the CO2-concentrating carboxysomes. RT-PCR experiments demonstrated that each gene cluster is a single transcriptional unit and thus is an operon. Operon cbb1 is divergently transcribed from a gene, cbbR, encoding the LysR-type transcriptional regulator CbbR that has been shown in many organisms to regulate the expression of RubisCO genes. Sigma70-like -10 and -35 promoter boxes and potential CbbR-binding sites (T-N11-A/TNA-N7TNA were predicted in the upstream regions of the four operons. Electrophoretic mobility shift assays (EMSAs confirmed that purified CbbR is able to bind to the upstream regions of the cbb1, cbb2 and cbb3 operons, demonstrating that the predicted CbbR-binding sites are functional in vitro. However, CbbR failed to bind the upstream region of the cbb4 operon that contains cbbP, encoding phosphoribulokinase (EC 2.7.1.19. Thus, other factors not present in the assay may be required for binding or the region lacks a functional CbbR-binding site. The cbb3 operon contains genes predicted to encode anthranilate synthase components I and II, catalyzing the formation of anthranilate and pyruvate from chorismate. This suggests a novel regulatory connection between CO2 fixation and tryptophan biosynthesis. The presence of a form II Rubis

  6. A new iron-oxidizing/O2-reducing supercomplex spanning both inner and outer membranes, isolated from the extreme acidophile Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Castelle, Cindy; Guiral, Marianne; Malarte, Guillaume; Ledgham, Fouzia; Leroy, Gisèle; Brugna, Myriam; Giudici-Orticoni, Marie-Thérèse

    2008-09-19

    The iron respiratory chain of the acidophilic bacterium Acidithiobacillus ferrooxidans involves various metalloenzymes. Here we demonstrate that the oxygen reduction pathway from ferrous iron (named downhill pathway) is organized as a supercomplex constituted of proteins located in the outer and inner membranes as well as in the periplasm. For the first time, the outer membrane-bound cytochrome c Cyc2 was purified, and we showed that it is responsible for iron oxidation and determined that its redox potential is the highest measured to date for a cytochrome c. The organization of metalloproteins inside the supramolecular structure was specified by protein-protein interaction experiments. The isolated complex spanning the two membranes had iron oxidase as well as oxygen reductase activities, indicating functional electron transfer between the first iron electron acceptor, Cyc2, and the Cu(A) center of cytochrome c oxidase aa(3). This is the first characterization of a respirasome from an acidophilic bacterium. In Acidithiobacillus ferrooxidans,O(2) reduction from ferrous iron must be coupled to the energy-consuming reduction of NAD(+)(P) from ferrous iron (uphill pathway) required for CO(2) fixation and other anabolic processes. Besides the proteins involved in the O(2) reduction, there were additional proteins in the supercomplex, involved in uphill pathway (bc complex and cytochrome Cyc(42)), suggesting a possible physical link between these two pathways.

  7. Draft genome sequence of extremely acidophilic bacterium Acidithiobacillus ferrooxidans DLC-5 isolated from acid mine drainage in Northeast China

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    Peng Chen

    2015-12-01

    Full Text Available Acidithiobacillus ferrooxidans type strain DLC-5, isolated from Wudalianchi in Heihe of Heilongjiang Province, China. Here, we present the draft genome of strain DLC-5 which contains 4,232,149 bp in 2745 contigs with 57.628% GC content and includes 32,719 protein-coding genes and 64 tRNA-encoding genes. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. JNNH00000000.1.

  8. Insights into the Quorum Sensing Regulon of the Acidophilic Acidithiobacillus ferrooxidans Revealed by Transcriptomic in the Presence of an Acyl Homoserine Lactone Superagonist Analog

    Science.gov (United States)

    Mamani, Sigde; Moinier, Danielle; Denis, Yann; Soulère, Laurent; Queneau, Yves; Talla, Emmanuel; Bonnefoy, Violaine; Guiliani, Nicolas

    2016-01-01

    While a functional quorum sensing system has been identified in the acidophilic chemolithoautotrophic Acidithiobacillus ferrooxidans ATCC 23270T and shown to modulate cell adhesion to solid substrates, nothing is known about the genes it regulates. To address the question of how quorum sensing controls biofilm formation in A. ferrooxidansT, the transcriptome of this organism in conditions in which quorum sensing response is stimulated by a synthetic superagonist AHL (N-acyl homoserine lactones) analog has been studied. First, the effect on biofilm formation of a synthetic AHL tetrazolic analog, tetrazole 9c, known for its agonistic QS activity, was assessed by fluorescence and electron microscopy. A fast adherence of A. ferrooxidansT cells on sulfur coupons was observed. Then, tetrazole 9c was used in DNA microarray experiments that allowed the identification of genes regulated by quorum sensing signaling, and more particularly, those involved in early biofilm formation. Interestingly, afeI gene, encoding the AHL synthase, but not the A. ferrooxidans quorum sensing transcriptional regulator AfeR encoding gene, was shown to be regulated by quorum sensing. Data indicated that quorum sensing network represents at least 4.5% (141 genes) of the ATCC 23270T genome of which 42.5% (60 genes) are related to biofilm formation. Finally, AfeR was shown to bind specifically to the regulatory region of the afeI gene at the level of the palindromic sequence predicted to be the AfeR binding site. Our results give new insights on the response of A. ferrooxidans to quorum sensing and on biofilm biogenesis.

  9. Involvement of sulfide:quinone oxidoreductase in sulfur oxidation of an acidophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans NASF-1.

    Science.gov (United States)

    Wakai, Satoshi; Kikumoto, Mei; Kanao, Tadayoshi; Kamimura, Kazuo

    2004-12-01

    The effects of cyanide, azide, and 2-n-Heptyl-4-hydroxy-quinoline-N-oxide (HQNO) on the oxidation of ferrous ion or elemental sulfur with Acidithiobacillus ferrooxidans NASF-1 cells grown in iron- or sulfur-medium were examined. The iron oxidation of both iron- and sulfur-grown cells was strongly inhibited by cyanide and azide, but not by HQNO. Sulfur oxidation was relatively resistant to cyanide and azide, and inhibited by HQNO. Higher sulfide oxidation, ubiquinol dehydrogenase activity, and sulfide:quinone oxidoreductase (SQR) activity were observed in sulfur-grown cells more than in iron-grown cells. Sulfide oxidation in the presence of ubiquinone with the membrane fraction was inhibited by HQNO, but not by cyanide, azide, antimycin A, and myxothiazol. The transcription of three genes, encoding an aa(3)-type cytochrome c oxidase (coxB), a bd-type ubiquinol oxidase (cydA), and an sqr, were measured by real-time reverse transcription polymerase chain reaction. The transcriptional levels of coxB and cydA genes were similar in sulfur- and iron-grown cells, but that of sqr was 3-fold higher in sulfur-grown cells than in iron-grown cells. A model is proposed for the oxidation of reduced inorganic sulfur compounds in A. ferrooxidans NASF-1 cells. PMID:15618623

  10. Bioleaching of zinc from gold ores using Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Pakawadee Kaewkannetra; Francisco Jose Garcia-Garcia; Tze Yen Chiu

    2009-01-01

    that Acidithiobacillus ferrooxidans can successfully leach zinc by as much as 6 times compared with the control experiment (without Acidithiobacillus ferrooxidans ferrooxidans). The maximum efficiency (92.3%) for microbial leaching is obtained in

  11. The role of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in arsenic bioleaching from soil.

    Science.gov (United States)

    Ko, Myoung-Soo; Park, Hyun-Sung; Kim, Kyoung-Woong; Lee, Jong-Un

    2013-12-01

    Bioleaching of As from the soil in an abandoned Ag-Au mine was carried out using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. A. ferrooxidans is an iron oxidizer and A. thiooxidans is a sulfur oxidizer. These two microbes are acidophilic and chemoautotrophic microbes. Soil samples were collected from the Myoungbong and Songcheon mines. The main contaminant of the soil was As, with an average concentration of 4,624 mg/kg at Myoungbong and 5,590 mg/kg at Songcheon. A. ferrooxidans and A. thiooxidans generated lower pH conditions during their metabolism process. The bioleaching of As from soil has a higher removal efficiency than chemical leaching. A. ferrooxidans could remove 70 % of the As from the Myoungbong and Songcheon soils; however, A. thiooxidans extracted only 40 % of the As from the Myoungbong soil. This study shows that bioleaching is an effective process for As removal from soil.

  12. Gene Identification and Substrate Regulation Provide Insights into Sulfur Accumulation during Bioleaching with the Psychrotolerant Acidophile Acidithiobacillus ferrivorans

    OpenAIRE

    Liljeqvist, Maria; Rzhepishevska, Olena I.; Dopson, Mark

    2013-01-01

    The psychrotolerant acidophile Acidithiobacillus ferrivorans has been identified from cold environments and has been shown to use ferrous iron and inorganic sulfur compounds as its energy sources. A bioinformatic evaluation presented in this study suggested that Acidithiobacillus ferrivorans utilized a ferrous iron oxidation pathway similar to that of the related species Acidithiobacillus ferrooxidans. However, the inorganic sulfur oxidation pathway was less clear, since the Acidithiobacillus...

  13. Bioleaching of anilite by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    CHENG Hai-na; HU Yue-hua; GAO Jian; MA Heng

    2008-01-01

    In order to characterize the efficiency of copper bioleaching from anilite using pure cultures of Acidithiobacillus ferrooxidans in the absence and presence of ferrous sulphate,the experiments were carried out in shake flasks with or without 4 g/L ferrous sulphate (FeSO4·7H2O) at pH 2.0,150 r/min and 35 ℃.The tests show that Acidithiobacillus ferrooxidans is unable to attack anilite in iron-free 9K medium.Anilite is rapidly oxidized by bacterial leaching when ferrous sulphate is added.Chemical oxidation of anilite is slow compared with Acidithiobacillus ferrooxidans initiated solubilization in the presence of iron.The EDAX analysis of the surfaces of anilite confirms that sulfur coating layer is present as a reaction product on the surface of the bacterially leached mineral.

  14. Draft genome sequence of Acidithiobacillus ferrooxidans YQH-1

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    Lei Yan

    2015-12-01

    Full Text Available Acidithiobacillus ferrooxidans YQH-1 is a moderate acidophilic bacterium isolated from a river in a volcano of Northeast China. Here, we describe the draft genome of strain YQH-1, which was assembled into 123 contigs containing 3,111,222 bp with a G + C content of 58.63%. A large number of genes related to carbon dioxide fixation, dinitrogen fixation, pH tolerance, heavy metal detoxification, and oxidative stress defense were detected. The genome sequence can be accessed at DDBJ/EMBL/GenBank under the accession no. LJBT00000000.

  15. Visualization of capsular polysaccharide induction in Acidithiobacillus ferrooxidans

    NARCIS (Netherlands)

    Bellenberg, S.; Leon Morales, C.F.; Sand, W.; Vera, M.

    2012-01-01

    Extracellular Polymeric Substances (EPS) are of fundamental importance for attachment to metal sulfides, biofilm formation and leaching efficiency of Acidithiobacillus ferrooxidans. In this work we have visualized the capsular polysaccharides (CPS) of A. ferrooxidans ATCC 23270 using the fluorescent

  16. Biooxidación de sulfuros mediante cepas nativas de acidófilos compatibles con Acidithiobacillus ferrooxidans y thiooxidans, mina de oro El Zancudo, (Titiribí, Colombia Sulphide bioxidation using native Acidithiobacillus ferrooxidans and thiooxidans, related acidophile strains from "El Zancudo" gold mine (Titiribí, Colombia

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    Márquez G. Marco A.

    2005-12-01

    Full Text Available El propósito de esta investigación fue evaluar a escala de laboratorio la acción de microorganismos acidófilos nativos compatibles con las especies Acidithiobacillus ferrooxidans y thiooxidans, aislados de la mina El Zancudo, Titiribí (Antioquia sobre la oxidación de sulfuros donde predominan la pirita y arsenopirita, variando las concentraciones de sustrato (8% y 16%, y el tamaño de partícula (75 um y 106 xm. Los resultados de las mediciones diarias de pH y potencial redox realizadas por un tiempo de 25 días, demuestran que hubo una actividad de oxidación eficiente y se llegó a valores de pH de 1,4 y potencial redox de 600 mV, además de encontrarse en solución niveles altos de alrededor de 20 g/L de As y 60 g/L de Fe. Por los análisis de DRX, FTIR y SEM/EDX, se evidencia la presencia de productos propios de la oxidación bacteriana, como jarosita y arsenatos de hierro, además de una corrosión inicial y avanzada en los granos de pirita y arsenopirita, respectivamente. Palabras clave: quimiolitotrofos, biolixiviación, pirita, arsenopirita, mineralogía aplicada.This investigation was aimed at a laboratory evaluation of the action of native Acidithiobacillus ferrooxidans-and thiooxidans-related acidophile micro-organism (isolated from El Zancudo gold mine in Titiribí, Colombia on the oxidation of sulphides, mainly consisting of pyrite and arsenopyrite; sulphide concentration varied from 8% to 16% and particle size from 75 um to 106 um. pH and redox potential measurement revealed efficient oxidation for each culture over a 25-day period, reaching 1,4 pH and 600 mV redox potential. 20 g/L As and 60 g/L Fe levels were reached in solution. XRD, FTIR and SEM/EDX analysis revealed the presence of bacterial oxidation products such as jarosite and iron arsenates, as well as low and high corrosion in pyrites and arsenopyrites, respectively. Key words: chemolithotrophics, bioleaching, pyrite, arsenopyrite, applied mineralogy.

  17. Adhesion forces between cells of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans or Leptospirillum ferrooxidans and chalcopyrite.

    Science.gov (United States)

    Zhu, Jianyu; Li, Qian; Jiao, Weifeng; Jiang, Hao; Sand, Wolfgang; Xia, Jinlan; Liu, Xueduan; Qin, Wenqing; Qiu, Guanzhou; Hu, Yuehua; Chai, Liyuan

    2012-06-01

    The efficiency of copper leaching is improved by bacteria attached to chalcopyrite. Therefore, the study of the attachment mechanism to control leaching is important. The adhesion of three species of leaching microorganisms including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans to chalcopyrite was investigated by using atomic force microscopy (AFM). The forces were measured with tip-immobilized cells approached to and retracted from the mineral. The results show that both the surface charge and the hydrophobicity of bacteria cells influence the adhesion force. Furthermore, the adhesion force decreased in case the extracellular polymeric substances (EPS) had been removed. In addition, the data indicate that the amount of attached cells increased with increasing adhesion force.

  18. Arsenic Precipitation in the Bioleaching of Realgar Using Acidithiobacillus ferrooxidans

    OpenAIRE

    Peng Chen; Lei Yan; Qiang Wang; Hongyu Li

    2013-01-01

    The current study investigates the characteristics of arsenic precipitation during the bioleaching of realgar. The bioleaching performance of Acidithiobacillus ferrooxidans BY-3 (A. ferrooxidans) was investigated through scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectrophotometry. SEM and XRD analyses revealed that the arsenic-adapted strain of A. ferrooxidans was more hydrophobic and showed high...

  19. Arsenic Precipitation in the Bioleaching of Realgar Using Acidithiobacillus ferrooxidans

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    Peng Chen

    2013-01-01

    Full Text Available The current study investigates the characteristics of arsenic precipitation during the bioleaching of realgar. The bioleaching performance of Acidithiobacillus ferrooxidans BY-3 (A. ferrooxidans was investigated through scanning electron microscopy (SEM, transmission electron microscopy (TEM, X-ray diffraction (XRD, and Fourier transform infrared (FT-IR spectrophotometry. SEM and XRD analyses revealed that the arsenic-adapted strain of A. ferrooxidans was more hydrophobic and showed higher attachment efficiency to realgar compared with the wild strain. The arsenic precipitation using A. ferrooxidans resulted in the precipitation of an arsenic-rich compound on the surface of the bacterial cell, as shown in the TEM images. The FT-IR spectra suggested that the −OH and −NH groups were closely involved in the biosorption process. The observations above strongly suggest that the cell surface of A. ferrooxidans plays a role in the induction of arsenic tolerance during the bioleaching of realgar.

  20. The small heat shock proteins from Acidithiobacillus ferrooxidans: gene expression, phylogenetic analysis, and structural modeling

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    Ribeiro Daniela A

    2011-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is an acidophilic, chemolithoautotrophic bacterium that has been successfully used in metal bioleaching. In this study, an analysis of the A. ferrooxidans ATCC 23270 genome revealed the presence of three sHSP genes, Afe_1009, Afe_1437 and Afe_2172, that encode proteins from the HSP20 family, a class of intracellular multimers that is especially important in extremophile microorganisms. Results The expression of the sHSP genes was investigated in A. ferrooxidans cells submitted to a heat shock at 40°C for 15, 30 and 60 minutes. After 60 minutes, the gene on locus Afe_1437 was about 20-fold more highly expressed than the gene on locus Afe_2172. Bioinformatic and phylogenetic analyses showed that the sHSPs from A. ferrooxidans are possible non-paralogous proteins, and are regulated by the σ32 factor, a common transcription factor of heat shock proteins. Structural studies using homology molecular modeling indicated that the proteins encoded by Afe_1009 and Afe_1437 have a conserved α-crystallin domain and share similar structural features with the sHSP from Methanococcus jannaschii, suggesting that their biological assembly involves 24 molecules and resembles a hollow spherical shell. Conclusion We conclude that the sHSPs encoded by the Afe_1437 and Afe_1009 genes are more likely to act as molecular chaperones in the A. ferrooxidans heat shock response. In addition, the three sHSPs from A. ferrooxidans are not recent paralogs, and the Afe_1437 and Afe_1009 genes could be inherited horizontally by A. ferrooxidans.

  1. Transcriptional and functional studies of Acidithiobacillus ferrooxidans genes related to survival in the presence of copper.

    Science.gov (United States)

    Navarro, Claudio A; Orellana, Luis H; Mauriaca, Cecilia; Jerez, Carlos A

    2009-10-01

    The acidophilic Acidithiobacillus ferrooxidans can resist exceptionally high copper (Cu) concentrations. This property is important for its use in biomining processes, where Cu and other metal levels range usually between 15 and 100 mM. To learn about the mechanisms that allow A. ferrooxidans cells to survive in this environment, a bioinformatic search of its genome showed the presence of at least 10 genes that are possibly related to Cu homeostasis. Among them are three genes coding for putative ATPases related to the transport of Cu (A. ferrooxidans copA1 [copA1(Af)], copA2(Af), and copB(Af)), three genes related to a system of the resistance nodulation cell division family involved in the extraction of Cu from the cell (cusA(Af), cusB(Af), and cusC(Af)), and two genes coding for periplasmic chaperones for this metal (cusF(Af) and copC(Af)). The expression of most of these open reading frames was studied by real-time reverse transcriptase PCR using A. ferrooxidans cells adapted for growth in the presence of high concentrations of Cu. The putative A. ferrooxidans Cu resistance determinants were found to be upregulated when this bacterium was exposed to Cu in the range of 5 to 25 mM. These A. ferrooxidans genes conferred to Escherichia coli a greater Cu resistance than wild-type cells, supporting their functionality. The results reported here and previously published data strongly suggest that the high resistance of the extremophilic A. ferrooxidans to Cu may be due to part or all of the following key elements: (i) a wide repertoire of Cu resistance determinants, (ii) the duplication of some of these Cu resistance determinants, (iii) the existence of novel Cu chaperones, and (iv) a polyP-based Cu resistance system.

  2. Bioleaching of metals from printed wire boards by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans and their mixture.

    Science.gov (United States)

    Wang, Jingwei; Bai, Jianfeng; Xu, Jinqiu; Liang, Bo

    2009-12-30

    Bioleaching processes were used to mobilize metals from printed wire boards (PWBs). The bacteria Acidithiobacillus ferrooxidans (A. ferrooxidans) and Acidithiobacillus thiooxidans (A. thiooxidans) isolated from an acidic mine drainage were grown and acclimated in presence of PWBs and then used as bioleaching bacteria to solubilize metals from PWBs. The experimental results demonstrate that all the percentages of copper, lead, zinc solubilized into the leaching solution from actual PWBs basically increased with decrease of sieve fraction of sample and decrease of PWBs concentration. The concentration of PWBs should be controlled under the range from 7.8 to 19.5 g l(-1). Under 7.8 g l(-1) of the concentration of PWBs, the percentages of copper solubilized are 99.0%, 74.9%, 99.9% at 0.5-1.0mm of sieve fraction at 9 d of leaching time by the pure culture of A. ferrooxidans, the pure culture of A. thiooxidans, and mixed culture of A. ferrooxidans and A. thiooxidans, respectively, while the percentages of copper, lead and zinc solubilized are all more than 88.9% at thiooxidans were able to grow in the presence of PWBs and the pure culture of A. ferrooxidans, and the mixed culture of A. ferrooxidans and A. thiooxidans can not only efficiently bioleach the main metal copper but also bioleach other minor metals such as lead, zinc as well.

  3. Reduction of vanadium(V) with Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Bredberg, Katarina; Karlsson, Hans T; Holst, Olle

    2004-03-01

    Biotechnological leaching has been proposed as a suitable method for extraction of vanadium from spent catalysts and oil ash. In the biological leaching process, the vanadium(V) can be reduced to vanadium(IV), which is a less toxic and more soluble form of the vanadium. The present investigation showed that Acidithiobacillus ferrooxidans efficiently reduced vanadium(V) in the form of vanadium pentaoxide, to vanadyl(IV) ions, and tolerated high concentrations of vanadium(IV) and vanadium(V). A. ferrooxidans was compared with Acidithiobacillus thiooxidans, which has previously been utilized for vanadium leaching and reduction. Vanadium pentaoxide and sodium vanadate were used as model compounds. The results of this study indicate possibilities to develop an economical and technically feasible process for biotechnological vanadium recovery.

  4. Dynamic corrosion of copper-nickel sulfide by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    TONG Lin-lin; JIANG Mao-fa; YANG Hong-ying; YU Juan; FAN You-jing; ZHANG Yao

    2009-01-01

    The dynamic corrosion process of bio-oxidation of copper-nickel sulfide from Karatungk in northern Xinjiang Province of China was studied. The polished wafer of the copper-nickel sulphide was used to carry on a series of oxidation corrosion experiment by Acidithiobacillus ferrooxidans. The changes of superficial corrosion appearance and the mineral dynamic corrosion process were discovered by microscope observation. Then, the galvanic cell model was established, and the bio-oxidation activation order of typical copper-nickel sulphide minerals was ascertained as pyrrhotite>pentlandite>chalocopyrite.

  5. Bioleaching of Covellite By Using Pure and Mixed Culture of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus%铜蓝精矿的生物浸出

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    程海娜; 胡岳华; 马恒

    2007-01-01

    采用两种嗜酸硫杆菌(嗜酸氧化亚铁硫杆菌和喜温硫杆菌)对铜蓝进行生物浸出,实验在有或没有4 g/L硫酸亚铁pH2.0、150转/分、35℃的三角瓶中进行.实验结果表明:用两种菌混合浸出的铜几乎等于嗜酸氧化亚铁硫杆菌单独浸出的铜;另外,亚铁的加入能提高铜的浸出.%Covellite oxidation was evaluated with two acidophilic thiobacilli that are important in bioleaching processes.The experiments were carried out in shake flasks in the absence and presence of 4 g/L Fe2+ (as ferrous sulphate) at pH 2.0, 150 rpm and 35 ℃. The tests showed that the copper extraction by the Acidithiobacillus ferrooxidans culture was nearly the same as that by the mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus caldus. On the other hand, additional iron clearly improved Cu leaching.

  6. Stochastic simulation of growth curves of Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    YANG Yu; PENG Hong; QIU Guan-zhou; LIU Jian-she; HU Yue-hua

    2006-01-01

    To reveal the low growth rate of Acidithiobacillus ferrooxidans, a stochastic growth model was proposed to analyze growth curves of these bacteria in a batch culture. An algorithm was applied to simulate the bacteria population during lag and exponential phase. The results show that the model moderately fits the experimental data.Further, the mean growth constant (K) of growth curves is obtained by fitting the logarithm of the simulating population data versus the generation numbers with the different initial population number (N0) and initial mean activity of population (A0). When N0 is 300 and 700 respectively, the discrepancy of K value is only 0.91%, however, A0 is 0.34 and 0.38 respectively, the discrepancy of K value is 19.53%. It suggests that the effect of A0 on the lag phase exceeds N0, though both parameters could shorten the lag phase by increasing their values.

  7. Sulfur activation-related extracellular proteins of Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cheng-gui; ZHANG Rui-yong; XIA Jin-lan; ZHANG Qian; NIE Zhen-yuan

    2008-01-01

    The fractions of the extracellular proteins of Acidithiobacillus ferrooxidans grown on two different energy substrates,elemental sulfur and ferrous sulfate,were selectively prepared with hot water treatment and distinctly shown by two-dimensional gel electrophoresis.Some protein spots with apparently higher abundance in sulfur energy substrate than in ferrous sulfate energy substrate were identified by using MALDI-TOF/TOF.Based on peptide mass fingerprints and bioinformatical analysis,the extracellular proteins were classified according to their functions as conjugal transfer protein,pilin,vacJ lipoprotein,polysaccharide deacetylase family protein,Ser/Thr protein phosphatase family protein and hypothetical proteins.Several extracellular proteins were found abundant in thiol groups and with CXXC functional motif,these proteins may be directly involved in the sulfur activation by use of their thiol group (Pr-SH) to bond the elemental sulfur.

  8. Bioleaching of sphalerite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans cultured in 9K medium modified with pyrrhotite

    Institute of Scientific and Technical Information of China (English)

    CHEN Song; QIU Guan-zhou; QIN Wen-qing; LAN Zhuo-yue

    2008-01-01

    Elective culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in 9K medium modified with pyrrhotite was studied. Bioleaching of flotation concentrate of sphalerite by the selected bacteria was carried out. The results show that the microorganisms cultured by pyrrhotite are a mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, of which the capability to oxidize ferrous to ferric irons is enhanced by the high mass ratio of Fe to S in pyrrhotite. Three pyrrhotite samples were separated into various parts with corresponding S/Fe ratios by magnetic separation and were used to culture the elective bacteria as the substrate. The association of the cultures could provide a more rapid and complete oxidation of sphalerite than that of bacteria cultivated by conventional methods.

  9. Acidithiobacillus ferrooxidans metabolism: from genome sequence to industrial applications

    Directory of Open Access Journals (Sweden)

    Blake Robert

    2008-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is a major participant in consortia of microorganisms used for the industrial recovery of copper (bioleaching or biomining. It is a chemolithoautrophic, γ-proteobacterium using energy from the oxidation of iron- and sulfur-containing minerals for growth. It thrives at extremely low pH (pH 1–2 and fixes both carbon and nitrogen from the atmosphere. It solubilizes copper and other metals from rocks and plays an important role in nutrient and metal biogeochemical cycling in acid environments. The lack of a well-developed system for genetic manipulation has prevented thorough exploration of its physiology. Also, confusion has been caused by prior metabolic models constructed based upon the examination of multiple, and sometimes distantly related, strains of the microorganism. Results The genome of the type strain A. ferrooxidans ATCC 23270 was sequenced and annotated to identify general features and provide a framework for in silico metabolic reconstruction. Earlier models of iron and sulfur oxidation, biofilm formation, quorum sensing, inorganic ion uptake, and amino acid metabolism are confirmed and extended. Initial models are presented for central carbon metabolism, anaerobic metabolism (including sulfur reduction, hydrogen metabolism and nitrogen fixation, stress responses, DNA repair, and metal and toxic compound fluxes. Conclusion Bioinformatics analysis provides a valuable platform for gene discovery and functional prediction that helps explain the activity of A. ferrooxidans in industrial bioleaching and its role as a primary producer in acidic environments. An analysis of the genome of the type strain provides a coherent view of its gene content and metabolic potential.

  10. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper.

    Science.gov (United States)

    Zheng, Xuecheng; Li, Dongwei

    2016-01-01

    This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 10(8) cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A. ferrooxidans, and organic acids could chelate or precipitate harmful heavy metals to reduce their damage on A. ferrooxidans and promote its growth. Organic acids could also damage the mineral lattice to increase the leaching effect. PMID:26942203

  11. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper

    Directory of Open Access Journals (Sweden)

    Xuecheng Zheng

    2016-01-01

    Full Text Available This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 108 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A. ferrooxidans, and organic acids could chelate or precipitate harmful heavy metals to reduce their damage on A. ferrooxidans and promote its growth. Organic acids could also damage the mineral lattice to increase the leaching effect.

  12. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper

    OpenAIRE

    Xuecheng Zheng; Dongwei Li

    2016-01-01

    This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 108 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in th...

  13. Insights into the iron and sulfur energetic metabolism of Acidithiobacillus ferrooxidans by microarray transcriptome profiling

    Energy Technology Data Exchange (ETDEWEB)

    R. Quatrini; C. Appia-Ayme; Y. Denis; J. Ratouchniak; F. Veloso; J. Valdes; C. Lefimil; S. Silver; F. Roberto; O. Orellana; F. Denizot; E. Jedlicki; D. Holmes; V. Bonnefoy

    2006-09-01

    Acidithiobacillus ferrooxidans is a well known acidophilic, chemolithoautotrophic, Gram negative, bacterium involved in bioleaching and acid mine drainage. In aerobic conditions, it gains energy mainly from the oxidation of ferrous iron and/or reduced sulfur compounds present in ores. After initial oxidation of the substrate, electrons from ferrous iron or sulfur enter respiratory chains and are transported through several redox proteins to oxygen. However, the oxidation of ferrous iron and reduced sulfur compounds has also to provide electrons for the reduction of NAD(P) that is subsequently required for many metabolic processes including CO2 fixation. To help to unravel the enzymatic pathways and the electron transfer chains involved in these processes, a genome-wide microarray transcript profiling analysis was carried out. Oligonucleotides corresponding to approximately 3000 genes of the A. ferrooxidans type strain ATCC23270 were spotted onto glass-slides and hybridized with cDNA retrotranscribed from RNA extracted from ferrous iron and sulfur grown cells. The genes which are preferentially transcribed in ferrous iron conditions and those preferentially transcribed in sulfur conditions were analyzed. The expression of a substantial number of these genes has been validated by real-time PCR, Northern blot hybridization and/or immunodetection analysis. Our results support and extend certain models of iron and sulfur oxidation and highlight previous observations regarding the possible presence of alternate electron pathways. Our findings also suggest ways in which iron and sulfur oxidation may be co-ordinately regulated. An accompanying paper (Appia-Ayme et al.) describes results pertaining to other metabolic functions.

  14. Bioleaching of two different types of chalcopyrite by Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Dong, Ying-bo; Lin, Hai; Fu, Kai-bin; Xu, Xiao-fang; Zhou, Shan-shan

    2013-02-01

    Two different types of chalcopyrite (pyritic chalcopyrite and porphyry chalcopyrite) were bioleached with Acidithiobacillus ferrooxidans ATF6. The bioleaching of the pyritic chalcopyrite and porphyry chalcopyrite is quite different. The copper extraction reaches 46.96% for the pyritic chalcopyrite after 48-d leaching, but it is only 14.50% for the porphyry chalcopyrite. Proper amounts of initial ferrous ions can improve the efficiency of copper extraction for the two different types of chalcopyrite. The optimum dosage of ferrous ions for the pyritic chalcopyrite and porphyry chalcopyrite is different. The adsorption of ATF6 on the pyritic chalcopyrite and porphyry chalcopyrite was also studied in this paper. It is found that ATF6 is selectively adsorbed by the two different types of chalcopyrite; the higher adsorption onto the pyritic chalcopyrite than the porphyry chalcopyrite leads to the higher copper dissolution rate of the pyritic chalcopyrite. In addition, the zeta-potential of chalcopyrite before and after bioleaching further confirms that ATF6 is more easily adsorbed onto the pyritic chalcopyrite.

  15. Metabolomic study of Chilean biomining bacteria Acidithiobacillus ferrooxidans strain Wenelen and Acidithiobacillus thiooxidans strain Licanantay.

    Science.gov (United States)

    Martínez, Patricio; Gálvez, Sebastián; Ohtsuka, Norimasa; Budinich, Marko; Cortés, María Paz; Serpell, Cristián; Nakahigashi, Kenji; Hirayama, Akiyoshi; Tomita, Masaru; Soga, Tomoyoshi; Martínez, Servet; Maass, Alejandro; Parada, Pilar

    2013-02-01

    In this study, we present the first metabolic profiles for two bioleaching bacteria using capillary electrophoresis coupled with mass spectrometry. The bacteria, Acidithiobacillus ferrooxidans strain Wenelen (DSM 16786) and Acidithiobacillus thiooxidans strain Licanantay (DSM 17318), were sampled at different growth phases and on different substrates: the former was grown with iron and sulfur, and the latter with sulfur and chalcopyrite. Metabolic profiles were scored from planktonic and sessile states. Spermidine was detected in intra- and extracellular samples for both strains, suggesting it has an important role in biofilm formation in the presence of solid substrate. The canonical pathway for spermidine synthesis seems absent as its upstream precursor, putrescine, was not present in samples. Glutathione, a catalytic activator of elemental sulfur, was identified as one of the most abundant metabolites in the intracellular space in A. thiooxidans strain Licanantay, confirming its participation in the sulfur oxidation pathway. Amino acid profiles varied according to the growth conditions and bioleaching species. Glutamic and aspartic acid were highly abundant in intra- and extracellular extracts. Both are constituents of the extracellular matrix, and have a probable role in cell detoxification. This novel metabolomic information validates previous knowledge from in silico metabolic reconstructions based on genomic sequences, and reveals important biomining functions such as biofilm formation, energy management and stress responses. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11306-012-0443-3) contains supplementary material, which is available to authorized users.

  16. Bioinformatic Prediction of Gene Functions Regulated by Quorum Sensing in the Bioleaching Bacterium Acidithiobacillus ferrooxidans

    OpenAIRE

    Alvaro Banderas; Nicolas Guiliani

    2013-01-01

    The biomining bacterium Acidithiobacillus ferrooxidans oxidizes sulfide ores and promotes metal solubilization. The efficiency of this process depends on the attachment of cells to surfaces, a process regulated by quorum sensing (QS) cell-to-cell signalling in many Gram-negative bacteria. At. ferrooxidans has a functional QS system and the presence of AHLs enhances its attachment to pyrite. However, direct targets of the QS transcription factor AfeR remain unknown. In this study, a bioinforma...

  17. Sulfur metabolism in the extreme acidophile Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Stefanie eMangold

    2011-02-01

    Full Text Available Given the challenges to life at low pH, an analysis of inorganic sulfur compound oxidation was initiated in the chemolithoautotrophic extremophile Acidithiobacillus caldus. A. caldus is able to metabolize elemental sulfur and a broad range of inorganic sulfur compounds. It has been implicated in the production of environmentally damaging acidic solutions as well as participating in industrial bioleaching operations where it forms part of microbial consortia used for the recovery of metal ions. Based upon the recently published A. caldus type strain genome sequence, a bioinformatic reconstruction of elemental sulfur and inorganic sulfur compound metabolism predicted genes included: sulfide quinone reductase (sqr, tetrathionate hydrolase (tth, two sox gene clusters potentially involved in thiosulfate oxidation (soxABXYZ, sulfur oxygenase reductase (sor, and various electron transport components. RNA transcript profiles by semi-quantitative reverse transcription PCR suggested up-regulation of sox genes in the presence of tetrathionate. Extensive gel based proteomic comparisons of total soluble and membrane enriched protein fractions during growth on elemental sulfur and tetrathionate identified differential protein levels from the two Sox clusters as well as several chaperone and stress proteins up-regulated in the presence of elemental sulfur. Proteomics results also suggested the involvement of heterodisulfide reductase (HdrABC in A. caldus inorganic sulfur compound metabolism. A putative new function of Hdr in acidophiles is discussed. Additional proteomic analysis evaluated protein expression differences between cells grown attached to solid, elemental sulfur versus planktonic cells. This study has provided insights into sulfur metabolism of this acidophilic chemolithotroph and gene expression during attachment to solid elemental sulfur.

  18. Comparison Analysis of Coal Biodesulfurization and Coal’s Pyrite Bioleaching with Acidithiobacillus ferrooxidans

    OpenAIRE

    Fen-Fen Hong; Huan He; Jin-Yan Liu; Xiu-Xiang Tao; Lei Zheng; Yi-Dong Zhao

    2013-01-01

    Acidithiobacillus ferrooxidans (A. ferrooxidans) was applied in coal biodesulfurization and coal’s pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal’s pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal’s pyrite bioleaching rate was 72.0%. SEM micrographs...

  19. Molecular characterization of Acidithiobacillus ferrooxidans and A. thiooxidans strains isolated from mine wastes in Brazil.

    Science.gov (United States)

    Paulino, L C; Bergamo, R F; Garcia, O; de Mello, M P; Manfio, G P; Ottoboni, L M

    2001-10-01

    Nineteen strains of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, including 12 strains isolated from coal, copper, gold and uranium mines in Brazil, strains isolated from similar sources in other countries and the type strains of the two species were characterized together with the type strain of A. caldus by using a combination of molecular systematic methods, namely ribotyping, BOX- and ERIC-PCR and DNA-DNA hybridization assays. Data derived from the molecular fingerprinting analyses showed that the tested strains encompassed a high degree of genetic variability. Two of the Brazilian A. ferrooxidans organisms (strains SSP and PCE) isolated from acid coal mine waste and uranium mine effluent, respectively, and A. thiooxidans strain DAMS, isolated from uranium mine effluent, were the most genetically divergent organisms. The DNA-DNA hybridization data did not support the allocation of Acidithiobacillus strain SSP to the A. ferrooxidans genomic species, as it shared only just over 40% DNA relatedness with the type strain of the species. Acidithiobacillus strain SSP was not clearly related to A. ferrooxidans in the 16S rDNA tree.

  20. Bioleaching of chalcopyrite concentrate using Leptospirillum ferriphilum, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in a continuous bubble column reactor.

    Science.gov (United States)

    Xia, Lexian; Yin, Chu; Dai, Songlin; Qiu, Guanzhou; Chen, Xinhua; Liu, Jianshe

    2010-03-01

    To estimate the bioleaching performance of chalcopyrite for various hydraulic residence times (HRTs), laboratory-scale bioleaching of chalcopyrite concentrate was carried out in a continuous bubble column reactor with three different HRTs of 120, 80 and 40 h, respectively. An extraction rate and ratio of 0.578 g Cu l(-1) h(-1) and 39.7%, respectively, were achieved for an HRT of 80 h at a solids concentration of 10% (w/v). Lower bioleaching performances than this were obtained for a longer HRT of 120 h and a shorter HRT of 40 h. In addition, there was obvious competition between Leptospirillum ferriphilum and Acidithiobacillus ferrooxidans to oxidize ferrous iron, causing large compositional differences between the microbial communities obtained for the different HRTs. Leptospirillum ferriphilum and Acidithiobacillus thiooxidans were found to be the dominant microbes for the longer HRT (120 h). Acidithiobacillus ferrooxidans became the dominant species when the HRT was decreased. The proportion of Acidithiobacillus thiooxidans was comparatively constant in the microbial community throughout the three process stages.

  1. Purification and biochemical characterization of the F1-ATPase from Acidithiobacillus ferrooxidans NASF-1 and analysis of the atp operon.

    Science.gov (United States)

    Wakai, Satoshi; Ohmori, Asami; Kanao, Tadayoshi; Sugio, Tsuyoshi; Kamimura, Kazuo

    2005-10-01

    ATPase was purified 51-fold from a chemoautotrophic, obligately acidophilic iron-oxidizing bacterium, Acidithiobacillus ferrooxidans NASF-1. The purified ATPase showed the typical subunit pattern of the F1-ATPase on a polyacrylamide gel containing sodium dodecyl sulfate, with 5 subunits of apparent molecular masses of 55, 50, 33, 20, and 18 kDa. The enzyme hydrolyzed ATP, GTP, and ITP, but neither UTP nor ADP. The K(m) value for ATP was 1.8 mM. ATPase activity was optimum at pH 8.5 at 45 degrees C, and was activated by sulfite. Azide strongly inhibited the enzyme activity, whereas the enzyme was relatively resistant to vanadate, nitrate, and N,N'-dicyclohexylcarbodiimide. The genes encoding the subunits for the F1F(O)-ATPase from A. ferrooxidans NASF-1 were cloned as three overlapping fragments by PCR cloning and sequenced. The molecular masses of the alpha, beta, gamma, delta, and epsilon subunits of the F1 portion were deduced from the amino acid sequences to be 55.5, 50.5, 33.1, 19.2, and 15.1 kDa, respectively. PMID:16244438

  2. Copper Ions Stimulate Polyphosphate Degradation and Phosphate Efflux in Acidithiobacillus ferrooxidans

    OpenAIRE

    Alvarez, Sergio; Jerez, Carlos A.

    2004-01-01

    For some bacteria and algae, it has been proposed that inorganic polyphosphates and transport of metal-phosphate complexes could participate in heavy metal tolerance. To test for this possibility in Acidithiobacillus ferrooxidans, a microorganism with a high level of resistance to heavy metals, the polyphosphate levels were determined when the bacterium was grown in or shifted to the presence of a high copper concentration (100 mM). Under these conditions, cells showed a rapid decrease in pol...

  3. Reduction of arsenic content in a complex galena concentrate by Acidithiobacillus ferrooxidans

    OpenAIRE

    López Alejandro; Pereyra Benito; Esperón Margarita; Makita Mario; Orrantia Erasmo

    2004-01-01

    Abstract Background Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxidans. There are a few studies about the benefit of metals of low value through bioleaching. ...

  4. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    OpenAIRE

    Ellen Cristine Giese; Patrícia Morgado Vaz

    2015-01-01

    Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The...

  5. Development and evaluation of whole-genome oligonucleotide array for Acidithiobacillus ferrooxidans ATCC 23270

    Institute of Scientific and Technical Information of China (English)

    LI Qian; SHEN Li; LUO Hai-lang; YIN Hua-qun; LIAO Li-qin; QIU Guan-zhou; LIU Xue-duan

    2008-01-01

    To effectively monitor the characteristic of Acidithiobacillus ferrooxidans ATCC 23270 at the whole-genomic level,a whole-genome 50-mer-based oligonucleotide microarray was developed based on the 3 217 ORFs of A.ferrooxidans ATCC 23270 genome.Based on artificial oligonucleotide probes,the results showed that the optimal hybridization temperature was 45 ℃.Specificity tests with the purified PCR amplifications of 5 genes (Sulfide-quinone reductase,Cytochrome C,Iron oxidase,Mercuric resistance protein,Nitrogenase iron protein) of A.ferrooxidans ATCC 23270 indicated that the probes on the arrays appeared to be specific to their corresponding target genes.Based on the WGA hybridization to global transcriptional difference of A.ferrooxidans ATCC 23270 strains cultured with Fe(Ⅱ) and S(0),the developed 50-mer WGA could be used for global transcriptome analysis of A.ferrooxidans ATCC 23270.The detection limit was estimated to be approximately 5 ng with the genomic DNA,and at 100 ng of the DNA concentration,all of the signals reached the saturation.In addition,strong linear relationships were observed between hybridization signal intensity and the target DNA concentrations (r2=0.977 and 0.992).The results indicated that this technology had potential as a specific,sensitive and quantitative tool for detection and identification of the strain A.ferrooxidans ATCC 23270 at the whole-genome level.

  6. Improved dewatering of CEPT sludge by biogenic flocculant from Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Wong, Jonathan W C; Murugesan, Kumarasamy; Yu, Shuk Man; Kurade, Mayur B; Selvam, Ammaiyappan

    2016-01-01

    Bioleaching using an iron-oxidizing bacterium, Acidithiobacillus ferrooxidans, and its biogenic flocculants was evaluated to improve the dewaterability of chemically enhanced primary treatment (CEPT) sewage sludge. CEPT sludge in flasks was inoculated with A. ferrooxidans culture, medium-free cells and the cell-free culture filtrate with and without the energy substance Fe(2+), and periodically the sludge samples were analysed for the dewaterability. This investigation proves that bioleaching effectively improved the sludge dewaterability as evidenced from drastic reduction in capillary suction time (≤20 seconds) and specific resistance to filtration (≥90%); however, it requires an adaptability period of 1-2 days. On the other hand, the biogenic flocculant produced by A. ferrooxidans greatly decreased the time-to-filtration and facilitated the dewaterability within 4 h. Results indicate that rapid dewatering of CEPT sludge by biogenic flocculants provides an opportunity to replace the synthetic organic polymer for dewatering. PMID:26901727

  7. Global transcriptional responses of Acidithiobacillus ferrooxidans Wenelen under different sulfide minerals.

    Science.gov (United States)

    Latorre, Mauricio; Ehrenfeld, Nicole; Cortés, María Paz; Travisany, Dante; Budinich, Marko; Aravena, Andrés; González, Mauricio; Bobadilla-Fazzini, Roberto A; Parada, Pilar; Maass, Alejandro

    2016-01-01

    In order to provide new information about the adaptation of Acidithiobacillus ferrooxidans during the bioleaching process, the current analysis presents the first report of the global transcriptional response of the native copper mine strain Wenelen (DSM 16786) oxidized under different sulfide minerals. Microarrays were used to measure the response of At. ferrooxidans Wenelen to shifts from iron supplemented liquid cultures (reference state) to the addition of solid substrates enriched in pyrite or chalcopyrite. Genes encoding for energy metabolism showed a similar transcriptional profile for the two sulfide minerals. Interestingly, four operons related to sulfur metabolism were over-expressed during growth on a reduced sulfur source. Genes associated with metal tolerance (RND and ATPases type P) were up-regulated in the presence of pyrite or chalcopyrite. These results suggest that At. ferrooxidans Wenelen presents an efficient transcriptional system developed to respond to environmental conditions, namely the ability to withstand high copper concentrations. PMID:26476161

  8. Visualisation of the interaction between Acidithiobacillus ferrooxidans and oil shale by atomic force microscopy

    Directory of Open Access Journals (Sweden)

    Milić Jelena S.

    2012-01-01

    Full Text Available This study visually documents the mechanical contact and interaction between the bacterial cells of two biogeocenotically different strains of Acidithiobacillus ferrooxidans (At. ferrooxidans and oil shale containing pyrite. Atomic force microscopy (AFM imaging was used to visualise initial interaction between the microorganisms and the surface minerals of an oil shale and to evaluate bacterial effects in the first hours of the bioleaching process. Acidithiobacillus ferrooxidans was attached to the shale surface already after 2 h, and after 48 h, numerous cells covered the surface with a biofilm. After 5 day incubation with At. ferrooxidans, AFM imaging revealed ellipsoid etched pits that represent footprints left by detached cells. Combining AFM surface imaging and leaching analysis following bacterial colonisation of oil shale layers demonstrates that an initial attachment to the surface is necessary for the leaching and that later on, once a sufficient concentration of Fe2+ ions in the solution is achieved, cells detach to become free cells, and leaching occurs primarily by the Fe3+. This experiment confirmed that microorganisms isolated from sites in which a particular substrate is found will demonstrate stronger binding to that substrate.

  9. Insights into the relation between adhesion force and chalcopyrite-bioleaching by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Zhu, Jianyu; Wang, Qianfen; Zhou, Shuang; Li, Qian; Gan, Min; Jiang, Hao; Qin, Wenqing; Liu, Xueduan; Hu, Yuehua; Qiu, Guanzhou

    2015-02-01

    This paper presents a study on the relation between bacterial adhesion force and bioleaching rate of chalcopyrite, which sheds light on the influence of interfacial interaction on bioleaching behavior. In our research, Acidithiobacillus ferrooxidans (A. ferrooxidans) were adapted to grow with FeSO4 · 7H2O, element sulfur or chalcopyrite. Then, surface properties of Acidithiobacillus ferrooxidans and chalcopyrite were analyzed by contact angle, zeta potential and Fourier transform infrared spectroscopy (FTIR). Adhesion force between bacteria and chalcopyrite was measured by atomic force microscopy (AFM). Attachment and bioleaching behaviors were also monitored. The results showed that A. ferrooxidans adapted with chalcopyrite exhibited the strongest adhesion force to chalcopyrite and the highest bioleaching rate. Culture adapted with sulfur bacteria took second place and FeSO4 · 7H2O-adapted bacteria were the lowest. Bioleaching rate and bacterial attachment capacity were positively related to bacterial adhesion force, which is affected by the nature of energy source. According to this work, the attachment of bacteria to chalcopyrite surface is one of the most important aspects that influence the bioleaching process of chalcopyrite. PMID:25511439

  10. Bioflotation of sulfide minerals with Acidithiobacillus ferrooxidans in relation to copper activation and surface oxidation.

    Science.gov (United States)

    Pecina-Treviño, E T; Ramos-Escobedo, G T; Gallegos-Acevedo, P M; López-Saucedo, F J; Orrantia-Borunda, E

    2012-08-24

    Surface oxidation of sulfides and copper (Cu) activation are 2 of the main processes that determine the efficiency of flotation. The present study was developed with the intention to ascertain the role of the phenomena in the biomodification of sulfides by Acidithiobacillus ferrooxidans culture (cells and growth media) and their impact in bioflotation. Surface characteristics of chalcopyrite, sphalerite, and pyrrhotite, alone and in mixtures, after interaction with A. ferrooxidans were evaluated. Chalcopyrite floatability was increased substantially by biomodification, while bacteria depressed pyrrhotite floatability, favoring separation. The results showed that elemental sulfur concentration increased because of the oxidation generated by bacterial cells, the effect is intensified by the Fe(III) left in the culture and by galvanic contact. Acidithiobacillus ferrooxidans culture affects the Cu activation of sphalerite. The implications of elemental sulfur concentration and Cu activation of sphalerite are key factors that must be considered for the future development of sulfide bioflotation processes, since the depressive effect of cells could be counteracted by elemental sulfur generation.

  11. Engineering the iron-oxidizing chemolithoautotroph Acidithiobacillus ferrooxidans for biochemical production.

    Science.gov (United States)

    Kernan, Timothy; Majumdar, Sudipta; Li, Xiaozheng; Guan, Jingyang; West, Alan C; Banta, Scott

    2016-01-01

    There is growing interest in developing non-photosynthetic routes for the conversion of CO2 to fuels and chemicals. One underexplored approach is the transfer of energy to the metabolism of genetically modified chemolithoautotrophic bacteria. Acidithiobacillus ferrooxidans is an obligate chemolithoautotroph that derives its metabolic energy from the oxidation of iron or sulfur at low pH. Two heterologous biosynthetic pathways have been expressed in A. ferrooxidans to produce either isobutyric acid or heptadecane from CO2 and the oxidation of Fe(2+). A sevenfold improvement in productivity of isobutyric acid was obtained through improved media formulations in batch cultures. Steady-state efficiencies were lower in continuous cultures, likely due to ferric inhibition. If coupled to solar panels, the photon-to-fuel efficiency of this proof-of-principle process approaches estimates for agriculture-derived biofuels. These efforts lay the foundation for the utilization of this organism in the exploitation of electrical energy for biochemical synthesis. PMID:26174759

  12. Engineering the iron-oxidizing chemolithoautotroph Acidithiobacillus ferrooxidans for biochemical production.

    Science.gov (United States)

    Kernan, Timothy; Majumdar, Sudipta; Li, Xiaozheng; Guan, Jingyang; West, Alan C; Banta, Scott

    2016-01-01

    There is growing interest in developing non-photosynthetic routes for the conversion of CO2 to fuels and chemicals. One underexplored approach is the transfer of energy to the metabolism of genetically modified chemolithoautotrophic bacteria. Acidithiobacillus ferrooxidans is an obligate chemolithoautotroph that derives its metabolic energy from the oxidation of iron or sulfur at low pH. Two heterologous biosynthetic pathways have been expressed in A. ferrooxidans to produce either isobutyric acid or heptadecane from CO2 and the oxidation of Fe(2+). A sevenfold improvement in productivity of isobutyric acid was obtained through improved media formulations in batch cultures. Steady-state efficiencies were lower in continuous cultures, likely due to ferric inhibition. If coupled to solar panels, the photon-to-fuel efficiency of this proof-of-principle process approaches estimates for agriculture-derived biofuels. These efforts lay the foundation for the utilization of this organism in the exploitation of electrical energy for biochemical synthesis.

  13. Bioleaching of Primary Nickel Ore Using Acidithiobacillus ferrooxidans LR Cells Immobilized in Glass Beads

    Directory of Open Access Journals (Sweden)

    Ellen Cristine Giese

    2015-06-01

    Full Text Available Sulphide minerals are one of the most important sources of value metals. For several years, a large number of hydrometallurgical and biotechnological processes have been developed to leach low-grade sulphide ores and the conditions are well established. However, the management of microorganisms in the bioleaching process is not easy to handle. In this paper, the use of immobilized cells of Acidithiobacillus ferrooxidans LR in glass beads in bioleaching of primary nickel ore was evaluated. The column experiments inoculated with immobilized cells of A. ferrooxidans LR showed the same efficiency than the conventional method using free cells and is promising for application on a larger scale as it ensuring integrity and activity of biomining microorganisms and reduce process costs. DOI: http://dx.doi.org/10.17807/orbital.v7i2.698 

  14. Formation of jarosite during Fe{sup 2+} oxidation by Acidithiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Daoud, J.; Karamanev, D. [University of Western Ontario, London, ON (Canada). Dept. of Chemical & Biochemical Engineering

    2006-07-15

    Jarosite precipitation is a very important phenomenon that is observed in many bacterial cultures. In many applications involving Acidithiobacillus ferrooxidans, like coal desulphurization and bioleaching, it is crucial to minimize jarosite formation in order to increase efficiency. The formation of jarosite during the oxidation of ferrous iron by free suspended cells of A. ferrooxidans was studied. The process was studied as a function of time, pH and temperature. The main parameter affecting the jarosite formation was pH. Several experiments yielded results showing oxidation rates as high as 0.181-0.194 g/L h, with low jarosite precipitation of 0.0125-0.0209 g at conditions of pH 1.6-1.7 with an operating temperature of 35{sup o} C.

  15. Bio-oxidation of galena particles by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Lei Jiang; Huaiyang Zhou; Xiaotong Peng; Zhonghao Ding

    2008-01-01

    This paper deals with the bio-oxidation of galena particles (-80 meshes) usingAcidithiobacillusferrooxidans and compares it with Fe3+ oxidation. Experimental results show that, at least, 0.00197 mol galena was leached from 100mL pulp (density of 3.8%) with 39 days' bio-oxidation, as compared to 0.00329 mol galena by Fe3+ with 9 days' oxidation. Because Fe3+ was constantly consumed, leaching by F3+e almost stopped after 9 days. Large amounts of lead sulfate were detected in both bio-oxidation and Fe3+ oxidation of galena. A. ferrooxidans followed a unique growth pattern during the bio-oxidation of galena. In the initial 15 days, the bacteria attached themselves to the galena surface with the formation of erosion pits similar in shape and length to those of the bacteria, and there were hardly any bacteria suspended in the solution. After 15 days, suspended bacteria increased. It is thus suggested that A. ferrooxidans may directly oxidize galena.

  16. Use of Walnut Shell Powder to Inhibit Expression of Fe(2+)-Oxidizing Genes of Acidithiobacillus Ferrooxidans.

    Science.gov (United States)

    Li, Yuhui; Liu, Yehao; Tan, Huifang; Zhang, Yifeng; Yue, Mei

    2016-01-01

    Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe(2+) or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe(2+) oxidization and H⁺ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s). Third, the expression of Fe(2+)-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s) in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe(2+) oxidation and H⁺ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe(2+)-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD. PMID:27144574

  17. Use of Walnut Shell Powder to Inhibit Expression of Fe2+-Oxidizing Genes of Acidithiobacillus Ferrooxidans

    Science.gov (United States)

    Li, Yuhui; Liu, Yehao; Tan, Huifang; Zhang, Yifeng; Yue, Mei

    2016-01-01

    Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe2+ oxidization and H+ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s). Third, the expression of Fe2+-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s) in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe2+ oxidation and H+ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe2+-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD. PMID:27144574

  18. Use of Walnut Shell Powder to Inhibit Expression of Fe2+-Oxidizing Genes of Acidithiobacillus Ferrooxidans

    Directory of Open Access Journals (Sweden)

    Yuhui Li

    2016-04-01

    Full Text Available Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD. This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe2+ oxidization and H+ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s. Third, the expression of Fe2+-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe2+ oxidation and H+ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe2+-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD.

  19. Expression, purification and molecular modeling of iron-containing superoxide dismutase from Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    LIU Yuan-dong; GAO Jian; QIU Guan-zhou; LIU Xue-duan; ZHANG Cheng-gui; OUYANG Xu-dong; JIANG Ying; ZENG Jia

    2008-01-01

    The superoxide dismutase(SOD) from Acidithiobacillus ferrooxidans may play an important role in its tolerance to the extremely toxic and oxidative environment of bioleaching.This gene was cloned and then successfully expressed in Escherichia coli.The expressed protein was finally purified by one-step affinity chromatography to homogeneity and observed to be dimer according to SDS-PAGE and MALDI-TOF-MS.The metal content determination and optical spectra results of the recombinant protein confirmed that the protein was an iron-containing superoxide dismutase.Molecular modeling for the protein revealed that the iron atom was ligated by His26,His75,Asp158 and His162.

  20. Ferrous Sulphate Oxidation Using Acidithiobacillus Ferrooxidans Cells Immobilized in Ceramic Beads

    OpenAIRE

    Junfeng, Y.; Guoliang, L.; Wei, C.

    2007-01-01

    The immobilization of Acidithiobacillus ferrooxidans cells on ceramic beads as carrier is described. The effects of ferrous ion concentration and dilution on the kinetics of ferrous ion oxidation in a packed-bed bioreactor were studied. In a medium containing 13.91 g of ferrous ion per litre, the fastest oxidation rate was 4.21 g L–1 at a dilution rate of 0.8 h–1. The corresponding conversion was X = 70 %. At ferrous ion mass concentrations greater than = 8.34 g L–1 and dilution rates greate...

  1. Draft genome sequence of the extremely acidophilic biomining bacterium Acidithiobacillus thiooxidans ATCC 19377 provides insights into the evolution of the Acidithiobacillus genus.

    Science.gov (United States)

    Valdes, Jorge; Ossandon, Francisco; Quatrini, Raquel; Dopson, Mark; Holmes, David S

    2011-12-01

    Acidithiobacillus thiooxidans is a mesophilic, extremely acidophilic, chemolithoautotrophic gammaproteobacterium that derives energy from the oxidation of sulfur and inorganic sulfur compounds. Here we present the draft genome sequence of A. thiooxidans ATCC 19377, which has allowed the identification of genes for survival and colonization of extremely acidic environments.

  2. Draft Genome Sequence of the Extremely Acidophilic Biomining Bacterium Acidithiobacillus thiooxidans ATCC 19377 Provides Insights into the Evolution of the Acidithiobacillus Genus

    OpenAIRE

    Valdes, Jorge; Ossandon, Francisco; Quatrini, Raquel; Dopson, Mark; Holmes, David S

    2011-01-01

    Acidithiobacillus thiooxidans is a mesophilic, extremely acidophilic, chemolithoautotrophic gammaproteobacterium that derives energy from the oxidation of sulfur and inorganic sulfur compounds. Here we present the draft genome sequence of A. thiooxidans ATCC 19377, which has allowed the identification of genes for survival and colonization of extremely acidic environments.

  3. Mutagenic breeding of silver-resistant Acidithiobacillus ferrooxidans and exploration of resistant mechanism

    Institute of Scientific and Technical Information of China (English)

    WU Xue-ling; QIU Guan-zhou; GAO Jian; DING Jian-nan; KANG Jian; LIU Xin-xing

    2007-01-01

    The silver-resistant Acidithiobacillus ferrooxidans were isolated from 22 acid mine drainage (AMD) samples collected from Dexing Copper Mine and Chengmen Mountain Mine, Jiangxi Province, China. Isolate DX16 is obtained from the sample taken from Dexing Copper Mine and still carries out ferrous ion oxidation when incubated in 9K medium containing silver nitrate (240 mg/L). While isolate H1, a less resistant strain taken from Yin Mountain Mine, has a tolerate level of only 60 mg/L. Based on 16S ribosomal DNA sequencing, both bacterial 16SrDNA sequences are 100% similar to Acidithiobacillus ferrooxidans ATCC 23270. Through ultraviolet irradiation induced mutations, isolate mDX16 that is obtained from DX16 carries out ferrous ion oxidation when incubated in 9K medium containing higher concentration of silver nitrate (250 mg/L). When silver-resistant gene (SilC) analysis is carried out on the two isolates, it is seen that this gene was absent in both.

  4. Inter- and intraspecific genomic variability of the 16S-23S intergenic spacer regions (ISR) in representatives of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Ni, Yong-Qing; Yang, Yuan; Bao, Jing-Ting; He, Kai-Yu; Li, Hong-Yu

    2007-05-01

    The complete sequences of 32 intergenic spacer regions (ISR) from Acidithiobacillus strains, including 29 field strains isolated from coal, copper, molybdenum mine wastes or sediment of different geoclimatic regions in China, reference strain ATCC19859 and the type strains of the two species were determined. These data, together with other sequences available in the GenBank database, were used to carry out the first detailed assessment of the inter- and intraspecific genomic variability of the ISR sequences and to infer phylogenetic relationships within the genus. The total length of the 16S-23S rRNA intergenic spacer regions of the Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans strains ranged from 451 to 490 bp, and from 434 to 456 bp, respectively. The degree of intrageneric ISR sequence similarity was higher than the degree of intergeneric similarity, and the overall similarity values of the ISRs varied from 60.49% to 84.71% between representatives of different species of the genus Acidithiobacillus. Sequences from the spacer of the A. thiooxidans and A. ferrooxidans strains ranged from 86.71% to 99.56% and 92.36% to 100% similarity, respectively. All Acidithiobacillus strains were separated into three phylogenetic major clusters and seven phylogenetic groups. ISR may be a potential target for the development of in situ hybridization probe aimed at accurately detecting acidithiobacilli in the various acidic environments.

  5. Comparison Analysis of Coal Biodesulfurization and Coal’s Pyrite Bioleaching with Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Fen-Fen Hong

    2013-01-01

    Full Text Available Acidithiobacillus ferrooxidans (A. ferrooxidans was applied in coal biodesulfurization and coal’s pyrite bioleaching. The result showed that A. ferrooxidans had significantly promoted the biodesulfurization of coal and bioleaching of coal’s pyrite. After 16 days of processing, the total sulfur removal rate of coal was 50.6%, and among them the removal of pyritic sulfur was up to 69.9%. On the contrary, after 12 days of processing, the coal’s pyrite bioleaching rate was 72.0%. SEM micrographs showed that the major pyrite forms in coal were massive and veinlets. It seems that the bacteria took priority to remove the massive pyrite. The sulfur relative contents analysis from XANES showed that the elemental sulfur (28.32% and jarosite (18.99% were accumulated in the biotreated residual coal. However, XRD and XANES spectra of residual pyrite indicated that the sulfur components were mainly composed of pyrite (49.34% and elemental sulfur (50.72% but no other sulfur contents were detected. Based on the present results, we speculated that the pyrite forms in coal might affect sulfur biooxidation process.

  6. Zinc bioleaching from an iron concentrate using Acidithiobacillus ferrooxidans strain from Hercules Mine of Coahuila, Mexico

    Science.gov (United States)

    Núñez-Ramírez, Diola Marina; Solís-Soto, Aquiles; López-Miranda, Javier; Pereyra-Alférez, Benito; Rutiaga-Quiñónes, Miriam; Medina-Torres, Luis; Medrano-Roldán, Hiram

    2011-10-01

    The iron concentrate from Hercules Mine of Coahuila, Mexico, which mainly contained pyrite and pyrrhotite, was treated by the bioleaching process using native strain Acidithiobacillus ferrooxidans ( A. ferrooxidans) to determine the ability of these bacteria on the leaching of zinc. The native bacteria were isolated from the iron concentrate of the mine. The bioleaching experiments were carried out in shake flasks to analyze the effects of pH values, pulp density, and the ferrous sulfate concentration on the bioleaching process. The results obtained by microbial kinetic analyses for the evaluation of some aspects of zinc leaching show that the native bacteria A. ferrooxidans, which is enriched with a 9K Silverman medium under the optimum conditions of pH 2.0, 20 g/L pulp density, and 40 g/L FeSO4, increases the zinc extraction considerably observed by monitoring during15 d, i.e., the zinc concentration has a decrease of about 95% in the iron concentrate.

  7. Bioinformatic Prediction of Gene Functions Regulated by Quorum Sensing in the Bioleaching Bacterium Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Alvaro Banderas

    2013-08-01

    Full Text Available The biomining bacterium Acidithiobacillus ferrooxidans oxidizes sulfide ores and promotes metal solubilization. The efficiency of this process depends on the attachment of cells to surfaces, a process regulated by quorum sensing (QS cell-to-cell signalling in many Gram-negative bacteria. At. ferrooxidans has a functional QS system and the presence of AHLs enhances its attachment to pyrite. However, direct targets of the QS transcription factor AfeR remain unknown. In this study, a bioinformatic approach was used to infer possible AfeR direct targets based on the particular palindromic features of the AfeR binding site. A set of Hidden Markov Models designed to maintain palindromic regions and vary non-palindromic regions was used to screen for putative binding sites. By annotating the context of each predicted binding site (PBS, we classified them according to their positional coherence relative to other putative genomic structures such as start codons, RNA polymerase promoter elements and intergenic regions. We further used the Multiple EM for Motif Elicitation algorithm (MEME to further filter out low homology PBSs. In summary, 75 target-genes were identified, 34 of which have a higher confidence level. Among the identified genes, we found afeR itself, zwf, genes encoding glycosyltransferase activities, metallo-beta lactamases, and active transport-related proteins. Glycosyltransferases and Zwf (Glucose 6-phosphate-1-dehydrogenase might be directly involved in polysaccharide biosynthesis and attachment to minerals by At. ferrooxidans cells during the bioleaching process.

  8. Ex-situ bioremediation of U(VI from contaminated mine water using Acidithiobacillus ferrooxidans strains

    Directory of Open Access Journals (Sweden)

    Maria eRomero-Gonzalez

    2016-05-01

    Full Text Available The ex-situ bioremoval of U(VI from contaminated water using Acidithiobacillus ferrooxidans strain 8455 and 13538 was studied under a range of pH and uranium concentrations. The effect of pH on the growth of bacteria was evaluated across the range 1.5 – 4.5 pH units. The respiration rate of At. ferrooxidans at different U(VI concentrations was quantified as a measure of the rate of metabolic activity over time using an oxygen electrode. The biosorption process was quantified using a uranyl nitrate solution, U-spiked growth media and U-contaminated mine water. The results showed that both strains of At. ferrooxidans are able to remove U(VI from solution at pH 2.5 – 4.5, exhibiting a buffering capacity at pH 3.5. The respiration rate of the micro-organism was affected at U(VI concentration of 30 mg L-1. The kinetics of the sorption fitted a pseudo-first order equation, and depended on the concentration of U(VI. The KD obtained from the biosorption experiments indicated that strain 8455 is more efficient for the removal of U(VI. A bioreactor designed to treat a solution of 100 mg U(VI L-1 removed at least 50% of the U(VI in water. The study demonstrated that At. ferrooxidans can be used for the ex-situ bioremediation of U(VI contaminated mine water.

  9. Amenability of low-grade uranium towards column bioleaching by acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    R and D studies were carried out at NML using Acidithiobacillus ferrooxidans (Ac.Tf) in column for the bio-recovery of uranium from the low-grade uranium ore containing 0.024% U3O8 of Turamdih mines, Singhbhum. A recovery of 55.48% uranium was obtained in bio-leaching as against ∼ 44.9% in sterile control in 30 days at 1.7 pH in a column containing 2.5kg ore of particle size mainly in the range 5-1mm. In the large scale column, leaching with 80kg ore of particle size ∼ 0.5cm, uranium bio-recovery was found to be 69.8% in comparison to a recovery of 55% in control set at 1.7 pH in 50 days. The uranium recoveries followed indirect leaching mechanism. (author)

  10. Study of Acidithiobacillus ferrooxidans and enzymatic bio-Fenton process-mediated corrosion of copper-nickel alloy.

    Science.gov (United States)

    Jadhav, U; Hocheng, H

    2016-10-01

    This study presents the corrosion behavior of the copper-nickel (Cu-Ni) alloy in the presence of Acidithiobacillus ferrooxidans (A. ferrooxidans) and glucose oxidase (GOx) enzyme. In both the cases ferric ions played an important role in weight loss and thereby to carry out the corrosion of the Cu-Ni alloy. A corrosion rate of 0.6 (±0.008), 2.11 (±0.05), 3.69 (±0.26), 0.7 (±0.006) and 0.08 (±0.002) mm/year was obtained in 72 h using 9K medium with ferrous sulfate, A. ferrooxidans culture supernatant, A. ferrooxidans cells, GOx enzyme and hydrogen peroxide (H2O2) solution respectively. The scanning electron microscopy (SEM) micrographs showed that a variable extent of corrosion was caused by 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells. An arithmetic average surface roughness (Ra) of 174.78 nm was observed for the control work-piece using optical profilometer. The change in Ra was observed with the treatment of the Cu-Ni alloy using various systems. The Ra for 9K medium with ferrous sulfate, GOx and A. ferrooxidans cells was 374.54, 607.32 and 799.48 nm, respectively, after 24 h. These results suggest that A. ferrooxidans cells were responsible for more corrosion of the Cu-Ni alloy than other systems used. PMID:26930447

  11. Immobilization of Acidithiobacillus ferrooxidans on Cotton Gauze for the Bioleaching of Waste Printed Circuit Boards.

    Science.gov (United States)

    Nie, Hongyan; Zhu, Nengwu; Cao, Yanlan; Xu, Zhiguo; Wu, Pingxiao

    2015-10-01

    The bioleaching parameters of metal concentrates from waste printed circuit boards by Acidithiobacillus ferrooxidans immobilized on cotton gauze in a two-step reactor were investigated in this study. The results indicated that an average ferrous iron oxidation rate of 0.54 g/(L·h) and a ferrous iron oxidation ratio of 96.90 % were obtained after 12 h at aeration rate of 1 L/min in bio-oxidation reactor. After 96 h, the highest leaching efficiency of copper reached 91.68 % under the conditions of the content of the metal powder 12 g/L, the retention time 6 h, and the aeration rate 1 L/min. The bioleaching efficiency of copper could be above 91.12 % under repeated continuous batch operation. Meanwhile, 95.32 % of zinc, 90.32 % of magnesium, 86.31 % of aluminum, and 59.07 % of nickel were extracted after 96 h. All the findings suggested that the recovery of metal concentrates from waste printed circuit boards via immobilization of A. ferrooxidans on cotton gauze was feasible. PMID:26239442

  12. Column bioleaching copper and its kinetics of waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Chen, Shu; Yang, Yuankun; Liu, Congqiang; Dong, Faqin; Liu, Bijun

    2015-12-01

    Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28d, the copper recovery reached at 94.8% from the starting materials contained 24.8% copper. Additionally, the concentration of Fe(3+) concentration varied significantly during bioleaching, which inevitably will influence the Cu oxidation, thus bioleaching process. Thus the variation in Fe(3+) concentration should be taken into consideration in the conventional kinetic models of bioleaching process. Experimental results show that the rate of copper dissolution is controlled by external diffusion rather than internal one because of the iron hydrolysis and formation of jarosite precipitates at the surface of the material. The kinetics of column bioleaching WPCBs remains unchanged because the size and morphology of precipitates are unaffected by maintaining the pH of solution at 2.25 level. In bioleaching process, the formation of jarosite precipitate can be prevented by adding dilute sulfuric acid and maintaining an acidic condition of the leaching medium. In such way, the Fe(2)(+)-Fe(3+) cycle process can kept going and create a favorable condition for Cu bioleaching. Our experimental results show that column Cu bioleaching from WPCBs by A. ferrooxidans is promising.

  13. Column bioleaching copper and its kinetics of waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Chen, Shu; Yang, Yuankun; Liu, Congqiang; Dong, Faqin; Liu, Bijun

    2015-12-01

    Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28d, the copper recovery reached at 94.8% from the starting materials contained 24.8% copper. Additionally, the concentration of Fe(3+) concentration varied significantly during bioleaching, which inevitably will influence the Cu oxidation, thus bioleaching process. Thus the variation in Fe(3+) concentration should be taken into consideration in the conventional kinetic models of bioleaching process. Experimental results show that the rate of copper dissolution is controlled by external diffusion rather than internal one because of the iron hydrolysis and formation of jarosite precipitates at the surface of the material. The kinetics of column bioleaching WPCBs remains unchanged because the size and morphology of precipitates are unaffected by maintaining the pH of solution at 2.25 level. In bioleaching process, the formation of jarosite precipitate can be prevented by adding dilute sulfuric acid and maintaining an acidic condition of the leaching medium. In such way, the Fe(2)(+)-Fe(3+) cycle process can kept going and create a favorable condition for Cu bioleaching. Our experimental results show that column Cu bioleaching from WPCBs by A. ferrooxidans is promising. PMID:26196406

  14. Metabolic reconstruction of sulfur assimilation in the extremophile Acidithiobacillus ferrooxidans based on genome analysis

    Directory of Open Access Journals (Sweden)

    Jedlicki Eugenia

    2003-12-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is a gamma-proteobacterium that lives at pH2 and obtains energy by the oxidation of sulfur and iron. It is used in the biomining industry for the recovery of metals and is one of the causative agents of acid mine drainage. Effective tools for the study of its genetics and physiology are not in widespread use and, despite considerable effort, an understanding of its unusual physiology remains at a rudimentary level. Nearly complete genome sequences of A. ferrooxidans are available from two public sources and we have exploited this information to reconstruct aspects of its sulfur metabolism. Results Two candidate mechanisms for sulfate uptake from the environment were detected but both belong to large paralogous families of membrane transporters and their identification remains tentative. Prospective genes, pathways and regulatory mechanisms were identified that are likely to be involved in the assimilation of sulfate into cysteine and in the formation of Fe-S centers. Genes and regulatory networks were also uncovered that may link sulfur assimilation with nitrogen fixation, hydrogen utilization and sulfur reduction. Potential pathways were identified for sulfation of extracellular metabolites that may possibly be involved in cellular attachment to pyrite, sulfur and other solid substrates. Conclusions A bioinformatic analysis of the genome sequence of A. ferrooxidans has revealed candidate genes, metabolic process and control mechanisms potentially involved in aspects of sulfur metabolism. Metabolic modeling provides an important preliminary step in understanding the unusual physiology of this extremophile especially given the severe difficulties involved in its genetic manipulation and biochemical analysis.

  15. Molecular characterization ofAcidithiobacillus ferrooxidans strains isolated from different environments by three PCR-based methods

    Institute of Scientific and Technical Information of China (English)

    吴学玲; 刘莉莉; 张真真; 刘新星; 邓凡凡

    2015-01-01

    PCR-based DNA fingerprinting, REP-PCR (repetitive element PCR), RAPD (randomly amplified polymorphic DNA) and 16S rDNA sequence analyses were used to characterize 23Acidithiobacillus ferrooxidansstrains isolated from different environments. (GTG)5 and BOXA1R primer were selected for REP-PCR. Twenty arbitrary primers were used for RAPD to acquire DNA profiles fromA. ferrooxidans. Both RAPD and REP-PCR produce complex banding patterns and show good discriminatory ability in differentiating closely related strains ofA. ferrooxidans. The strains are clustered into 4 or 5 major groups and reveal genomic diversity using (GTG)5-PCR, BOX-PCR and RAPD analysis. Phylogenetic tree based on 16S rDNA sequences of 23 strains and related strains shows that they are clustered into two distinct groups. Twelve strains are highly related to a newAcidithiobacillus namedAcidithiobacillus ferrivorans. The results indicate that PCR-based methods are effective in revealing genetic diversity among A. ferrooxidans.

  16. Synthesis of argentojarosite with simulated bioleaching solutions produced by Acidithiobacillus ferrooxidans.

    Science.gov (United States)

    Mukherjee, Chiranjit; Jones, F Sandy; Bigham, Jerry M; Tuovinen, Olli H

    2016-09-01

    Argentojarosite (AgFe3(SO4)2(OH)6) is formed as a secondary phase in Ag-catalyzed bioleaching of chalcopyrite (CuFeS2), but to date very little is known about the paragenesis or characteristics of this silver-containing compound. The purpose of this study was to synthesize argentojarosite via biological oxidation of 120mM ferrous sulfate by Acidithiobacillus ferrooxidans. Because of its toxicity to A. ferrooxidans, Ag(+) (as AgNO3) was added to spent culture media (pH2) after complete oxidation of ferrous sulfate. Schwertmannite (ideally Fe8O8(OH)6(SO4)) was precipitated during the iron oxidation phase, and subsequent Ag(+) addition resulted in the formation of argentojarosite. Contact time (8h, 5d, and 14d) and Ag(+) concentration (0, 5, 20, and 40mM) were used as variables in these experiments. Synthesis of argentojarosite, schwertmannite and other mineral phases was confirmed through X-ray diffraction analysis. Additional analyses of solid-phase oxidation products included elemental composition, color and specific surface area. The sample synthesized in the presence of 40mM Ag(+) and with 14d contact time yielded an X-ray diffraction pattern of well crystallized argentojarosite, and its elemental composition closely matched the calculated Ag, Fe, and S contents of ideal argentojarosite. The color and surface area of the remaining samples were influenced by the presence of residual schwertmannite. This phase remained stable over the time course of 14d when no Ag(+) was present in the system. When equilibrations were extended to 42d, partial conversion of reference schwertmannite to goethite was noted in the absence of Ag. In the presence of 20mM or 40mM Ag over the same time course, some formation of argentojarosite was also noted. In this case, schwertmannite was the only source of Fe and SO4 for argentojarosite formation. PMID:27207050

  17. The environmental context of Acidithiobacillus ferrooxidans and its potential role as an ecosystem engineer in sulphidic mine waste

    Energy Technology Data Exchange (ETDEWEB)

    Ebenaa, Gustav

    2001-06-01

    Microorganisms are the causative agent of the environmental problems since they catalyse the weathering of the (sulphidic) waste. The chemical oxidation alone is not fast enough to create any severe environmental problems. Acidithiobacillus ferrooxidans is thought to be a key organism in weathering of sulphide minerals. A. ferrooxidans is affected by several more or less abiotic factors. The influence of temperature, pH and nutrient deficiency as potentially limiting factors for the activity of A. ferrooxidans has been investigated. It seems that temperature has less influence on its activity, but rather reflects the origin of the bacterial isolate. An alkaline pH seems enough to hinder growth and activity. The nutrients do not seem to be a limiting factor in the studied environment. The possible regulation of the activity of A. ferrooxidans is therefore a way to, at least partly, mitigate the environmental impact from mine waste. Waste from the mining industry is the largest waste problem in Sweden. With amounts over 600 million tonnes one could easily imagine the tremendous cost involved in the abatement. The MiMi-programme, with researchers from several relevant fields, has as its aim to evaluate present and to find alternative techniques to mitigate the environmental impact from mine waste. The understanding of A. ferrooxidans and its role as an ecosystem engineer is essential both in evaluating present techniques and even more so in finding alternative abatement techniques for sulphidic mine waste.

  18. Biosorption of inorganic and organic arsenic from aqueous solution by Acidithiobacillus ferrooxidans BY-3

    International Nuclear Information System (INIS)

    The traditional techniques for removing low concentration arsenic are unsuitable. The biosorption characteristics of arsenite (iAsIII) and monomethyl arsonate (MMAV) from aqueous solution by Acidithiobacillus ferrooxidans BY-3 (At. f BY-3) were investigated as a function of pH, contact time, initial arsenic concentration, biomass dosage and temperature in this study. Results indicated that Langmuir isotherm model fitted better than Freundlich model to the equilibrium data. Analysis of kinetic data showed that the biosorption processes of both iAsIII and MMAV involved pseudo-second-order kinetics. The thermodynamic parameters such as ΔGo, ΔHo and ΔSo of the biosorption process showed that the adsorption of iAsIII and MMAV onto At. f BY-3 was feasible, spontaneous and endothermic under the examined conditions. The competitive biosorption of iAsIII and MMAV in binary mixture system was evaluated, and the results indicated that At. f BY-3 favored MMAV biosorption. Fourier-transform infrared spectroscopy (FT-IR) showed -OH and -NH groups were involved in the biosorption process.

  19. Full structure building and docking of NifS from extremophile Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    LIU Yuan-dong; QIU Guan-zhou; WANG Hai-dong; JIANG Ying; ZHANG Cheng-gui; XIA Le-xia

    2008-01-01

    The gene iscS-2 from extremophile Acidithiobacillus ferrooxidans may play a crucial role in nitrogenase maturation. To investigate the protein encoded by this gene, a reliable integral three-dimensional molecular structure was built. The obtained structure was further used to search binding sites, carry out the flexible docking with cofactor pyridoxal 5′-phosphate(PLP) and substrate cysteine, and identify its key residues. The docking results of PLP reveal that the residues of Lys203, His100, Thr73, Ser200, His202, Asp177 and Gln180 have large interaction energies and/or hydrogen bonds fixation with PLP. The docking results of cysteine show that the amino group in cysteine is very near His100, Lys203 and PLP, and the interaction energies for cysteine with them are very big. These identified residues are in line with the experimental facts of NifS from other sources. Moreover, the four residues of Asn152, Val179, Ala102 and Met148 in the PLP docking and the two residues of Lys208 and Ala102 in the cysteine docking also have large interaction energies, which are fitly conserved in NifS from all kinds of sources but have not been identified before. According to these results, this gene encodes NifS protein, and the substrate cysteine can be effectively recruited into the active site. Furthermore, all of the above detected key residues are directly responsible for the binding and/or catalysis of PLP and cysteine.

  20. Homology modeling and evolutionary trace analysis of superoxide dismutase from extremophile Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The gene sod in Acidithiobacillus ferrooxidans may play a crucial role in its tolerance to the extremely acidic, toxic and oxidative environment of bioleaching. For insight into the anti-toxic mechanism of the bacteria, a three-dimensional (3D) molecular structure of the protein encoded by this gene was built by homology modeling techniques, refined by molecular dynamics simulations, assessed by PROFILE-3D and PROSTAT programs and its key residues were further detected by evolutionary trace analysis. Through these procedures, some trace residues were identified and spatially clustered. Among them, the residues of Asn38, Gly103 and Glu161 are randomly scattered throughout the mapped structure; interestingly, the other residues are all distinctly clustered in a subgroup near Fe atom. From these results, this gene can be confirmed at 3D level to encode the Fe-depending superoxide dismutase and subsequently play an anti-toxic role. Furthermore, the detected key residues around Fe binding site can be conjectured to be directly responsible for Fe binding and catalytic function.

  1. Laboratory chalcopyrite oxidation by Acidithiobacillus ferrooxidans: Oxygen and sulfur isotope fractionation

    Science.gov (United States)

    Thurston, R.S.; Mandernack, K.W.; Shanks, Wayne C., III

    2010-01-01

    Laboratory experiments were conducted to simulate chalcopyrite oxidation under anaerobic and aerobic conditions in the absence or presence of the bacterium Acidithiobacillus ferrooxidans. Experiments were carried out with 3 different oxygen isotope values of water (??18OH2O) so that approach to equilibrium or steady-state isotope fractionation for different starting conditions could be evaluated. The contribution of dissolved O2 and water-derived oxygen to dissolved sulfate formed by chalcopyrite oxidation was unambiguously resolved during the aerobic experiments. Aerobic oxidation of chalcopyrite showed 93 ?? 1% incorporation of water oxygen into the resulting sulfate during the biological experiments. Anaerobic experiments showed similar percentages of water oxygen incorporation into sulfate, but were more variable. The experiments also allowed determination of sulfate-water oxygen isotope fractionation, ??18OSO4-H2O, of ~ 3.8??? for the anaerobic experiments. Aerobic oxidation produced apparent ??SO4-H2O values (6.4???) higher than the anaerobic experiments, possibly due to additional incorporation of dissolved O2 into sulfate. ??34SSO4 values are ~ 4??? lower than the parent sulfide mineral during anaerobic oxidation of chalcopyrite, with no significant difference between abiotic and biological processes. For the aerobic experiments, a small depletion in ??34SSO4 of ~- 1.5 ?? 0.2??? was observed for the biological experiments. Fewer solids precipitated during oxidation under aerobic conditions than under anaerobic conditions, which may account for the observed differences in sulfur isotope fractionation under these contrasting conditions. ?? 2009 Elsevier B.V.

  2. Bio-decomposition of rock phosphate containing pyrites by Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    CHI Ru-an; XIAO Chun-qiao; HUANG Xiao-hui; WANG Cun-wen; WU Yuan-xin

    2007-01-01

    Leaching soluble phosphorus from rock phosphate containing pyrites by Acidithiobacillus ferrooxidans (A. f) is feasible,and the reaction mechanism is as follows. Pyrites are oxidized by A. f. to produce H2SO4 and FeSO4; the rock phosphate is decomposed by H2SO4, forming soluble phosphorus compounds; and Fe2+ from FeSO4 is oxidized to Fe3+, providing energy for the growth of A. f.. In this process, as H2SO4 is produced in the reaction, an acidic condition in the culture medium is formed, which benefits the growth of A. f. and aids both continuous oxidation of pyrites and leaching of soluble phosphorus from rock phosphate.The fraction of phosphorous leached can reach the largest in the presence of 1.0 g/L Fe3+, 200 mg/L Mg2+ and 400 mg/L NH4+. The optimal technological parameters on the fraction of phosphorous leached are as follows: the volume fraction of inocula of A. f, the

  3. Diversity and Ecophysiology of New Isolates of Extremely Acidophilic CS2-Converting Acidithiobacillus Strains

    Science.gov (United States)

    Smeulders, Marjan J.; Pol, Arjan; Zandvoort, Marcel H.; Jetten, Mike S. M.

    2013-01-01

    Biofiltration of industrial carbon disulfide (CS2)-contaminated waste air streams results in the acidification of biofilters and therefore reduced performance, high water use, and increased costs. To address these issues, we isolated 16 extremely acidophilic CS2-converting Acidithiobacillus thiooxidans strains that tolerated up to 6% (vol/vol) sulfuric acid. The ecophysiological properties of five selected strains (2Bp, Sts 4-3, S1p, G8, and BBW1) were compared. These five strains had pH optima between 1 (2Bp) and 2 (S1p). Their affinities for CS2 ranged between 80 (G8) and 130 (2Bp) μM. Strains S1p, G8, and BBW1 had more hydrophobic cell surfaces and produced less extracellular polymeric substance than did strains 2Bp and Sts 4-3. All five strains converted about 80% of the S added as CS2 to S0 when CS2 was supplied in excess. The rate of S0 consumption varied between 7 (Sts 4-3) and 63 (S1p) nmol O2 min−1 ml culture−1. Low S0 consumption rates correlated partly with low levels of cell attachment to externally produced S0 globules. During chemostat growth, the relative amount of CS2 hydrolase in the cell increased with decreasing growth rates. This resulted in more S0 accumulation during CS2 overloads at low growth rates. Intermittent interruptions of the CS2 supply affected all five strains. Strains S1p, G8, and BBW1 recovered from 24 h of starvation within 4 h, and strains 2Bp and Sts 4-3 recovered within 24 h after CS2 was resupplied. We recommend the use of mixtures of Acidithiobacillus strains in industrial biofilters. PMID:23995926

  4. Differentiation of Acidithiobacillus ferrooxidans and A. thiooxidans strains based on 16S-23S rDNA spacer polymorphism analysis.

    Science.gov (United States)

    Bergamo, Rogério F; Novo, Maria Teresa M; Veríssimo, Ricardo V; Paulino, Luciana C; Stoppe, Nancy C; Sato, Maria Inês Z; Manfio, Gilson P; Prado, Paulo Inácio; Garcia, Oswaldo; Ottoboni, Laura M M

    2004-09-01

    Restriction fragment length polymorphism (RFLP) and sequence analyses of the PCR-amplified 16S-23S rDNA intergenic spacer (ITS) were used for differentiating Acidithiobacillus thiooxidans strains from other related acidithiobacilli, including A. ferrooxidans and A. caldus. RFLP fingerprints obtained with AluI, DdeI, HaeIII, HinfI and MspI enabled the differentiation of all Acidithiobacillus reference strains into species groups. The A. thiooxidans strains investigated (metal mine isolates) yielded identical RFLP patterns to the A. thiooxidans type strain (ATCC 19377(T)), except for strain DAMS, which had a distinct pattern for all enzymes tested. Fourteen A. ferrooxidans mine strains were assigned to 3 RFLP groups, the majority of which were grouped with A. ferrooxidans ATCC 23270(T). The spacer region of one representative strain from each of the RFLP groups obtained was subjected to sequence analysis, in addition to eleven additional A. thiooxidans strains isolated from sediment and water samples, and A. caldus DSM 8584(T). The tRNA(IIe) and tRNA(Ala) genes, present in all strains analyzed, showed high sequence similarity. Phylogenetic analysis of the ITS sequences differentiated all three Acidithiobacillus species. Inter- and infraspecific genetic variations detected were mainly due to the size and sequence polymorphism of the ITS3 region. Mantel tests showed no significant correlation between ITS sequence similarity and the geographical origin of strains. The results showed that the 16S-23S rDNA spacer region is a useful target for the development of molecular-based methods aimed at the detection, rapid differentiation and identification of acidithiobacilli.

  5. Fate of extracellular polymeric substances of anaerobically digested sewage sludge during pre-dewatering conditioning with Acidithiobacillus ferrooxidans culture.

    Science.gov (United States)

    Murugesan, Kumarasamy; Ravindran, Balasubramani; Selvam, Ammaiyappan; Kurade, Mayur B; Yu, Shuk-Man; Wong, Jonathan W C

    2016-10-01

    This study investigated the fate of extracellular polymeric substances (EPS) of anaerobically digested saline sewage sludge during its preconditioning. Sludge was conditioned with Acidithiobacillus ferrooxidans (AF) culture for 24h in the presence and absence of Fe(2+) as an energy substrate. pH decreased from 7.24 to 3.12 during sludge conditioning process. The capillary suction time (CST) of conditioned sludge significantly decreased to 94% as compared with control within 4h of conditioning with or without Fe(2+), indicating a significant (P<0.001) improvement in sludge dewaterability. A noticeable decrease in extractable EPS was observed in conditioned sludge. The EPS contents showed a significant negative correlation with dewaterability of sludge (P<0.05). The results suggest that bioacidification treatment using A. ferrooxidans effectively improved sludge dewaterability through modification of sludge EPS. PMID:27040507

  6. Selection and evaluation of reference genes for improved interrogation of microbial transcriptomes: case study with the extremophile Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Holmes David S

    2009-06-01

    Full Text Available Abstract Background Normalization is a prerequisite for accurate real time PCR (qPCR expression analysis and for the validation of microarray profiling data in microbial systems. The choice and use of reference genes that are stably expressed across samples, experimental conditions and designs is a key consideration for the accurate interpretation of gene expression data. Results Here, we evaluate a carefully selected set of reference genes derived from previous microarray-based transcriptional profiling experiments performed on Acidithiobacillus ferrooxidans and identify a set of genes with minimal variability under five different experimental conditions that are frequently used in Acidithiobacilli research. Suitability of these and other previously reported reference genes to monitor the expression of four selected target genes from A. ferrooxidans grown with different energy sources was investigated. Utilization of reference genes map, rpoC, alaS and era results in improved interpretation of gene expression profiles in A. ferrooxidans. Conclusion This investigation provides a validated set of reference genes for studying A. ferrooxidans gene expression under typical biological conditions and an initial point of departure for exploring new experimental setups in this microorganism and eventually in other closely related Acidithiobacilli. The information could also be of value for future transcriptomic experiments in other bacterial systems.

  7. Homology modeling and docking studies of IscS from extremophile Acidithiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The gene iscS-3 from Acidithiobacillus ferrooxidans may play a central role in the delivery of sulfur to a variety of metabolic pathways in this organism. For insight into the sulfur metabolic mechanism of the bacteria, an integral three-dimensional (3D) molecular structure of the protein encoded by this gene was built by homology modeling techniques, refined by molecular dynamics simulations, assessed by PROFILE-3D and PROSTAT programs and further used to search bind sites, carry out flexible docking with cofactor pyridoxal 5'-phosphate(PLP) and substrate cysteine and hereby detect its key residues. Through these procedures, the detail conformations of PLP-IscS(P-I) and cysteine-PLP-IscS(C-P-I) complexes were obtained. In P-I complex, the residues of Lys208, His106, Thr78, Ser205, His207, Asp182 and Gln185 have large interaction energies and/or hydrogen bonds fixation with PLP. In C-P-I complex, the amino group in cysteine is very near His106, Lys208 and PLP, the interaction energies for cysteine with them are very high. The above results are well consistent with those experimental facts of the homologues from other sources. Interestingly, the four residues of Glu105, Glu79, Ser203 and His180 in P-I docking and the residue of Lys213 in C-P-I docking also have great interaction energies, which are fitly conservation in IscSs from all kinds of sources but have not been identified before. From these results, this gene can be confirmed at 3D level to encode the iron-sulfur cluster assembly protein lscS and subsequently play a sulfur traffic role. Furthermore, the substrate cysteine can be presumed to be effectively recruited into the active site. Finally, the above detected key residues can be conjectured to be directly responsible for the bind and/or catalysis of PLP and cysteine.

  8. Occurrence of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in uranium mine-Caldas uranium mining and extraction plant, Brazil (CUMEP)

    International Nuclear Information System (INIS)

    The sulfated minerals present in mining areas may cause serious environmental problems due to the action of chemolithotrophic bacteria from genus Acithiobacillus, represented mainly by Acithiobacillus ferrooxidans and Acithiobacillus thiooxidans. These microorganisms are able to oxidize mineral sulfates, elementary sulfur and ferrous ion (A. ferrooxidans), as well are capable of mobilizing radionuclide as uranium to the environment. In this context, this study aimed at investigating the occurrence and the fluctuation of A. ferrooxidans and A. thiooxidans populations within the mine effluents, tailing dam and waste rocks of the Caldas Uranium Mining arid Extraction Plant (CUMEP) in Minas Gerais State - Brazil. Samples from 16 sites were evenly taken monthly in the CUMEP, during 28 months. The oxi-reduction potential, pH and temperature values were determined at the Radioecology Laboratory. The Most Probable Number technique was applied using a series of five tubes for selective counting of A. ferrooxidans and A. thiooxidans. Each sample was submitted to serial dilutions using Tween 80 and sterilized water (pH=2.0) and subsequently transferred into assay tubes containing T and K with ferrous ion and also elementary sulfur, as energy source, for detection of A. ferrooxidans and A. thiooxidans, respectively. Populations of A. ferrooxidans and A. thiooxidans presented seasonal quantitative fluctuations at the different studied sites. A. ferrooxidans showed higher or equal frequency to that observed for A. thiooxidans; as consequence, they were considered the predominant bacteria in this environment. In the majority of the sites, the highest values for the frequency and counting of A. ferrooxidans and A. thiooxidans were observed during the rainy period (October to March). The relative seasonal behavior when several variables are evaluated simultaneously indicated that, due to the high values of oxi-reduction potential, the low values of pH, the detection of the highest

  9. Genome Sequence of the Acidophilic Ferrous Iron-Oxidizing Isolate Acidithrix ferrooxidans Strain Py-F3, the Proposed Type Strain of the Novel Actinobacterial Genus Acidithrix

    Science.gov (United States)

    Eisen, Sebastian; Poehlein, Anja; Johnson, D. Barrie; Daniel, Rolf; Schlömann, Michael

    2015-01-01

    Extremely acidophilic iron-oxidizing Gram-positive bacteria comprise species within the phyla Firmicutes and Actinobacteria. Here, we report the 4.02-Mb draft genome of Acidithrix ferrooxidans Py-F3, which was isolated from a stream draining an abandoned copper mine and proposed as the type species of a new genus of Actinobacteria. PMID:25931603

  10. Estudo da oxidação dos sulfetos sintéticos molibdenita (MoS2) e covelita (CuS) por Acidithiobacillus ferrooxidans via respirometria celular Oxidation study of the synthetic sulfides molybdenite (MoS2) and covellite (CuS) by Acidithiobacillus ferrooxidans using respirometric experiments

    OpenAIRE

    Wilmo E. Francisco Junior; Denise Bevilaqua; Oswaldo Garcia Júnior

    2009-01-01

    This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry...

  11. Reduction of arsenic content in a complex galena concentrate by Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    López Alejandro

    2004-10-01

    Full Text Available Abstract Background Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxidans. There are a few studies about the benefit of metals of low value through bioleaching. From all of these, there are almost no studies dealing with complex minerals containing arsenopyrite (FeAsS. Reduction and/or elimination of arsenic in these ores increase their value and allows the exploitation of a vast variety of minerals that today are being underexploited. Results Arsenopyrite was totally oxidized. The sum of arsenic remaining in solution and removed by sampling represents from 22 to 33% in weight (yield of the original content in the mineral. The rest of the biooxidized arsenic form amorphous compounds that precipitate. Galena (PbS was totally oxidized too, anglesite (PbSO4 formed is virtually insoluble and remains in the solids. The influence of seven factors in a batch process was studied. The maximum rate of arsenic dissolution in the concentrate was found using the following levels of factors: small surface area of particle exposure, low pulp density, injecting air and adding 9 K medium to the system. It was also found that ferric chloride and carbon dioxide decreased the arsenic dissolution rate. Bioleaching kinetic data of arsenic solubilization were used to estimate the dilution rate for a continuous culture. Calculated dilution rates were relatively small (0.088–0.103 day-1. Conclusion Proper conditions of solubilization of arsenic during bioleaching are key features to improve the percentage (22 to 33% in weight of arsenic removal. Further studies are needed to determine other factors that influence specifically the

  12. Biooxidación de concentrados de arsenopirita por Acidithiobacillus ferrooxidans en erlenmeyer agitados

    Directory of Open Access Journals (Sweden)

    Juan David Ospina

    2012-03-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Título en ingles: Biooxidation of arsenopyrite concentrates by Acidithiobacillus ferrooxidans in shake flasks Resumen Se evaluó el proceso de biooxidación de concentrados de arsenopirita por A. ferrooxidans ATCC 23270, previa adaptación de los microorganismos al mineral y dos tamaños de partícula, pasante malla Tyler 200 (~75μm y 325 (~45μm. También, se determinó el grado de concentración del mineral mediante DRX y MOLPP/LR, bajo norma ASTM D 2799 de 2009. Los microorganismos fueron adaptados mediante disminución gradual, en etapas sucesivas, de sulfato ferroso y posterior aumento en el contenido de arsenopirita. Finalmente, se llevó a cabo el proceso de biooxidación del mineral sin adición de Fe2+. Después de treinta días de proceso, la disolución de arsénico para la malla Tyler 200 fue de 7550 mgL-1 (18,7% y para la malla Tyler 325 fue de 2850 mgL-1 (7,1%. Por otra parte, la curva de crecimiento bacteriano mostró que entre los días 6 y 21 de proceso la población bacteriana promedio fue de 1,70x108 cel.mL‐1 y de 8,00x107 cel.mL‐1 para las mallas Tyler 200 y 325, respectivamente. Por lo tanto, el tamaño de partícula jugó un papel fundamental en la cinética de adaptación de

  13. Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

    Institute of Scientific and Technical Information of China (English)

    Run-lan Yu; Jing Liu; Jian-xi Tan; Wei-min Zeng; Li-juan Shi; Guo-hua Gu; Wen-qing Qin; Guan-zhou Qiu

    2014-01-01

    The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular poly-saccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleach-ing. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

  14. Effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans during chalcopyrite bioleaching

    Science.gov (United States)

    Yu, Run-lan; Liu, Jing; Tan, Jian-xi; Zeng, Wei-min; Shi, Li-juan; Gu, Guo-hua; Qin, Wen-qing; Qiu, Guan-zhou

    2014-04-01

    The pH value plays an important role in the bioleaching of sulphide minerals. The effect of pH values on the extracellular polysaccharide secreted by Acidithiobacillus ferrooxidans was investigated in different phases of bacterial growth during chalcopyrite bioleaching. It is found that extracellular polysaccharide secretion from the cells attached to chalcopyrite is more efficiently than that of the free cells in the bioleaching solution. Three factors, pH values, the concentration of soluble metal ions, and the bacterial growth and metabolism, affect extracellular polysaccharide secretion in the free cells, and are related to the bacterial growth phase. Extracellular polysaccharide secretion from the attached cells is mainly dependent on the pH value of the bacterial culture.

  15. Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part I: Flask experiments

    Energy Technology Data Exchange (ETDEWEB)

    S.M. Mousavi; S. Yaghmaei; F. Salimi; A. Jafari [Sharif University of Technology, Tehran (Iran). Department of Chemical and Petroleum Engineering

    2006-12-15

    Biological oxidation of ferrous sulfate by Acidithiobacillus ferrooxidans has proved to be a significant step in the bioleaching of sulfide minerals and the treatment of acid mine drainage. The same bioreaction also has beneficial applications in the desulphurization of coal and removal of hydrogen sulfide from gaseous effluents. In this research, the effects of some process variables such as pH, temperature, elemental sulfur, amount of initial ferrous and magnesium ions on oxidation of ferrous sulfate by a native A. ferrooxidans, which was isolated from a chalcopyrite concentrate, were investigated. All experiments carried out in shake flasks at 33{sup o}C that was obtained as optimum temperature for the specific bacterial growth rate. The optimum range of pH for the maximum growth of the cells and effective biooxidation of ferrous sulfate varied from 2 to 2.3. The maximum biooxidation rate was achieved 1.2 g/L h in a culture initially containing 20.2 g/L Fe{sup 2+}. Mg{sup 2+} from 20 mg/L to 120 mg/L did not have any effect on the efficiency of the process, while the presence of elemental sulfur had negative effect on the biooxidation. 16 refs., 8 figs.

  16. Comparative Genomics of the Extreme Acidophile Acidithiobacillus thiooxidans Reveals Intraspecific Divergence and Niche Adaptation

    OpenAIRE

    Zhang, Xian; Feng, Xue; Tao, Jiemeng; Ma, Liyuan; Xiao, Yunhua; Liang, Yili; Liu, Xueduan; Yin, Huaqun

    2016-01-01

    Acidithiobacillus thiooxidans known for its ubiquity in diverse acidic and sulfur-bearing environments worldwide was used as the research subject in this study. To explore the genomic fluidity and intraspecific diversity of Acidithiobacillus thiooxidans (A. thiooxidans) species, comparative genomics based on nine draft genomes was performed. Phylogenomic scrutiny provided first insights into the multiple groupings of these strains, suggesting that genetic diversity might be potentially correl...

  17. Increases of ferrous iron oxidation activity and arsenic stressed cell growth by overexpression of Cyc2 in Acidithiobacillus ferrooxidans ATCC19859.

    Science.gov (United States)

    Liu, Wei; Lin, Jianqun; Pang, Xin; Mi, Shuang; Cui, Shuang; Lin, Jianqiang

    2013-01-01

    Acidithiobacillus ferrooxidans plays an important role in bioleaching in reproducing the mineral oxidant of ferric iron (Fe(3+) ) by oxidization of ferrous iron (Fe(2+) ). The high-molecular-weight c-type cytochrome Cyc2 that is located in the external membrane is postulated as the first electron carrier in the Fe(2+) oxidation respiratory pathway of A. ferrooxidans. To increase ferrous iron oxidation activity, a recombinant plasmid pTCYC2 containing cyc2 gene under the control of Ptac promoter was constructed and transferred into A. ferrooxidans ATCC19859. The transcriptional level of cyc2 gene was increased by 2.63-fold and Cyc2 protein expression was observed in the recombinant strain compared with the control. The ferrous iron oxidation activity and the arsenic stressed cell growth of the recombinant strain were also elevated.

  18. Impact of bioavailable Pb2+ on Fe2+ oxidation in the presence of a mixed culture of Acidithiobacillus ferrooxidans

    Science.gov (United States)

    Wang, H.; Yang, X.; Gong, L.; Jiang, Z.

    2009-12-01

    Numerous investigations were conducted on the effects of a variety of metals, including As, Cu, Zn, Cr on the growth of Acidithiobacillus ferrooxidans (an iron oxidizer and indigenous to acidic environment) and Fe2+ oxidation. However, less work was reported concerning the Pb2+ effect due to its quick precipitation as anglesite in SO42--rich solutions. The reported inhibiting concentrations of Pb2+ varied greatly on the oxidizing rate of ferrous in the presence of A. ferrooxidans, and the reasons remain unclear. Comparative studies were conducted between chemical and microbial oxidation of ferrous by a mixed culture of A. ferrooxidans in the presence of different concentration of Pb2+. Eh, pH and Fe2+ concentration were monitored periodically and the final precipitates were analyzed by X-ray diffraction (XRD), scanning electronic microscopy (SEM), and SEM-EDAX (Energy-dispersive X-ray spectroscopy). To check the impact of bioavailable Pb2+ on Fe2+ oxidation, initial precipitation was removed before the microbial inoculation. Our data showed that Pb2+ will exert a remarkable inhibition on microbial oxidation of ferrous when initial Pb2+ concentration reached as high as 5 g/L. However, the bioavailable Pb2+ in this case should be much lower than 5 g/L in the solution due to the precipitation of anglesite (The absolute concentration was under analysis). The threshold of Pb2+ concentrations to inhibit the microbial oxidation varies among the previous studies. This might result from the different microbial strains used or the mistaking of initial concentration as the substantial concentration of bioavailable Pb2+ after precipitation as anglesite. In contrast, Pb2+ does not show any obvious influence on chemical oxidation of ferrous. XRD spectrum of the final precipitates showed that anglesite was the only solid phase detected in chemical systems, while pure jarosite was found in the microbial systems. No lead was detected in jarosite by SEM-EDAX, inferring that Pb was

  19. Attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum cultured under varying conditions to pyrite, chalcopyrite, low-grade ore and quartz in a packed column reactor.

    Science.gov (United States)

    Africa, Cindy-Jade; van Hille, Robert P; Harrison, Susan T L

    2013-02-01

    The attachment of Acidithiobacillus ferrooxidans and Leptospirillum ferriphilum spp. grown on ferrous medium or adapted to a pyrite mineral concentrate to four mineral substrata, namely, chalcopyrite and pyrite concentrates, a low-grade chalcopyrite ore (0.5 wt%) and quartzite, was investigated. The quartzite represented a typical gangue mineral and served as a control. The attachment studies were carried out in a novel particle-coated column reactor. The saturated reactor containing glass beads, which were coated with fine mineral concentrates, provided a quantifiable surface area of mineral concentrate and maintained good fluid flow. A. ferrooxidans and Leptospirillum spp. had similar attachment characteristics. Enhanced attachment efficiency occurred with bacteria grown on sulphide minerals relative to those grown on ferrous sulphate in an ore-free environment. Selective attachment to sulphide minerals relative to gangue materials occurred, with mineral adapted cultures attaching to the minerals more efficiently than ferrous grown cultures. Mineral-adapted cultures showed highest levels of attachment to pyrite (74% and 79% attachment for A. ferrooxidans and L. ferriphilum, respectively). This was followed by attachment of mineral-adapted cultures to chalcopyrite (63% and 58% for A. ferrooxidans and L. ferriphilum, respectively). A. ferrooxidans and L. ferriphilum exhibited lower levels of attachment to low-grade ore and quartz relative to the sulphide minerals. PMID:22410741

  20. Estudo da oxidação dos sulfetos sintéticos molibdenita (MoS2 e covelita (CuS por Acidithiobacillus ferrooxidans via respirometria celular Oxidation study of the synthetic sulfides molybdenite (MoS2 and covellite (CuS by Acidithiobacillus ferrooxidans using respirometric experiments

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    Wilmo E. Francisco Junior

    2009-01-01

    Full Text Available This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry-bacterial attack, what is influenced by its electronic structures. Besides, experiments conducted in the presence of Fe3+ did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations.

  1. Effects of pyrite bioleaching solution of Acidithiobacillus ferrooxidans on viability, differentiation and mineralization potentials of rat osteoblasts.

    Science.gov (United States)

    Zhou, Jian; Chen, Ke-Ming; Zhi, De-Juan; Xie, Qin-Jian; Xian, Cory J; Li, Hong-Yu

    2015-12-01

    Iron pyrite, an important component of traditional Chinese medicine, has a poor solubility, bioavailability, and patient compliance due to a high dose required and associated side effects, all of which have limited its clinical applications and experimental studies on its action mechanisms in improving fracture healing. This study investigated Acidithiobacillus ferrooxidans (A.f)-bioleaching of two kinds of pyrites and examined bioactivities of the derived solutions in viability and osteogenic differentiation in rat calvarial osteoblasts. A.f bioleaching improved element contents (Fe, Mn, Zn, Cu, and Se) in the derived solutions and the solutions concentration-dependently affected osteoblast viability and differentiation. While the solutions had no effects at low concentrations and inhibited the osteoblast alkaline phosphatase (ALP) activity at high concentrations, they improved ALP activity at their optimal concentrations. The improved osteoblast differentiation and osteogenic function at optimal concentrations were also revealed by levels of ALP cytochemical staining, calcium deposition, numbers and areas of mineralized nodules formed, mRNA and protein expression levels of osteogenesis-related genes (osteocalcin, Bmp-2, Runx-2, and IGF-1), and Runx-2 nuclear translocation. Data from this study will be useful in offering new strategies for improving pyrite bioavailability and providing a mechanistic explanation for the beneficial effects of pyrite in improving bone healing. PMID:26283321

  2. Adaptación de una cepa compatible con Acidithiobacillus ferrooxidans sobre concentrados de calcopirita (CuFeS2, esfalerita (ZnS y galena (PbS

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    E Mejía

    2011-08-01

    Full Text Available Adaptation of a strain Acidithiobacillus ferrooxidans compatible on concentrates of chalcopyrite (CuFeS2, sphalerite (ZnS and galena (PbSRESUMENEn este estudio se evaluó la adaptación de una cepa compatible con Acidithiobacillus ferrooxidans a altas densidades de pulpa de calcopirita, esfalerita y galena, con dos distribuciones de tamaño de partícula, -200 y -325 serie Tyler de tamices. Los microorganismos fueron adaptados por la disminución gradual de la fuente principal de energía, sulfato ferroso, y el aumento en el contenido de mineral, para finalmente realizar un subcultivo sin la adición de fuente de energía externa. La realización de subcultivos en serie resultó ser una estrategia eficaz para la adaptación a altas densidades de pulpa de esfalerita, calcopirita y galena indicando que el protocolo empleado es adecuado. Los resultados muestran que la cepa compatible con Acidithiobacillus ferrooxidans es más resistente a altas concentraciones de esfalerita, seguido por calcopirita y finalmente por galena. El tamaño de partícula juega un papel fundamental en la adaptación de los microorganismos al mineral. Palabras clave: esfalerita, calcopirita, galena, adaptación, Acidithiobacillus ferrooxidans, biolixiviación. ABSTRACTIn this study the adaptation of Acidithiobacillus ferrooxidans-like to high concentrations of chalcopyrite, sphalerite and galena were evaluated with two mineral-particle sizes: 200 and 325 Tyler mesh. The strain was adapted using two simultaneous processes. The first one consisted in a gradual decreasing of the main energy source, ferrous sulphate. The second one consisted in a gradual increasing of the mineral content. Finally, a test was made without ferrous sulphate. The serial subculturing was found to be an efficient strategy to adapt Acidithiobacillus ferrooxidans-like to higher concentrations of chalcopyrite, sphalerite and galena. This indicates that a suitable protocol was employed. The results

  3. Evaluación de oxidación bacteriana de sulfuros con Acidithiobacillus ferrooxidans mediante pruebas de FTIR y difracción de rayos X Evaluating Acidithiobacillus ferrooxidans bacterial oxidation of sulphur compounds using FTIR and X-ray diffraction assays

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    Ruiz Orlando

    2003-06-01

    Full Text Available Una cepa bacteriana nativa con capacidad de oxidar hierro ferroso y compuestos del azufre fue aislada a partir de efluentes y material de la mina de oro La Maruja, en el municipio de Marmato (Caldas, la cual fue identificada bioquímicamente como Acidithiobacillus ferrooxidans. Esta cepa fue evaluada en su capacidad de oxidar concentra­dos de sulfuros metálicos a dos diferentes concentraciones de pulpa y dos tamaños de partícula. Después de 15 días de biooxidación de los sulfuros se observó que, efectivamente, la bacteria mostró acción catalizadora sobre el proce­so de disolución del mineral. Palabras clave: biooxidación; biolixiviación; A. ferrooxidans; sulfuros metálicosA native bacterial strain capable of oxidising ferrous iron and sulphur compounds was isolated from effluent and material from the La Maruja gold mine in the municipality of Marmato (Caldas; this was biochemically identified as being Acidithiobacillus ferrooxidans. This strain's ability to oxidise metallic sulphide concentrates having two differ-ent pulp proportions and two particle sizes was evaluated. Sulphide bio-oxidation was observed after 15 days showing this strain's catalytic action on the mineral break-down process. Key words: bio-oxidation; bio-leaching; A. ferrooxidans; sulphides

  4. Synchrotron radiation based STXM analysis and micro-XRF mapping of differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on Fe(2+) and S(0).

    Science.gov (United States)

    Xia, Jin-Lan; Liu, Hong-Chang; Nie, Zhen-Yuan; Peng, An-An; Zhen, Xiang-Jun; Yang, Yun; Zhang, Xiu-Li

    2013-09-01

    The differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on substrates Fe(2+) and S(0) was investigated by using synchrotron radiation based scanning transmission X-ray microscopy (STXM) imaging and microbeam X-ray fluorescence (μ-XRF) mapping. The extracellular thiol groups (SH) were first alkylated by iodoacetic acid forming Protein-SCH2COOH and then the P-SCH2COOH was marked by calcium ions forming P-SCH2COOCa. The STXM imaging and μ-XRF mapping of SH were based on analysis of SCH2COO-bonded Ca(2+). The results indicated that the thiol group content of A. ferrooxidans grown on S(0) is 3.88 times to that on Fe(2+). Combined with selective labeling of SH by Ca(2+), the STXM imaging and μ-XRF mapping provided an in situ and rapid analysis of differential expression of extracellular thiol groups. PMID:23850802

  5. Synchrotron radiation based STXM analysis and micro-XRF mapping of differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on Fe(2+) and S(0).

    Science.gov (United States)

    Xia, Jin-Lan; Liu, Hong-Chang; Nie, Zhen-Yuan; Peng, An-An; Zhen, Xiang-Jun; Yang, Yun; Zhang, Xiu-Li

    2013-09-01

    The differential expression of extracellular thiol groups by Acidithiobacillus ferrooxidans grown on substrates Fe(2+) and S(0) was investigated by using synchrotron radiation based scanning transmission X-ray microscopy (STXM) imaging and microbeam X-ray fluorescence (μ-XRF) mapping. The extracellular thiol groups (SH) were first alkylated by iodoacetic acid forming Protein-SCH2COOH and then the P-SCH2COOH was marked by calcium ions forming P-SCH2COOCa. The STXM imaging and μ-XRF mapping of SH were based on analysis of SCH2COO-bonded Ca(2+). The results indicated that the thiol group content of A. ferrooxidans grown on S(0) is 3.88 times to that on Fe(2+). Combined with selective labeling of SH by Ca(2+), the STXM imaging and μ-XRF mapping provided an in situ and rapid analysis of differential expression of extracellular thiol groups.

  6. Oxidation of dibenzothiophene as a model substrate for the removal of organic sulphur from fossil fuels by iron(III ions generated from pyrite by Acidithiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    VLADIMIR P. BESKOSKI

    2007-06-01

    Full Text Available Within this paper a new idea for the removal of organically bonded sulphur from fossil fuels is discussed. Dibenzothiophene (DBT was used as a model compound of organicmolecules containing sulphur. This form of (biodesulphurization was performed by an indirect mechanism in which iron(III ions generated from pyrite by Acidithiobacillus ferrooxidans performed the abiotic oxidation. The obtained reaction products, dibenzothiopene sulfoxide and dibenzothiophene sulfone, are more soluble in water than the basic substrate and the obtained results confirmed the basic hypothesis and give the posibility of continuing the experiments related to application of this (biodesulphurization process.

  7. Characterization of a novel thiosulfate dehydrogenase from a marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    Science.gov (United States)

    Sharmin, Sultana; Yoshino, Eriko; Kanao, Tadayoshi; Kamimura, Kazuo

    2016-01-01

    A marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH, was isolated to develop a bioleaching process for NaCl-containing sulfide minerals. Because the sulfur moiety of sulfide minerals is metabolized to sulfate via thiosulfate as an intermediate, we purified and characterized the thiosulfate dehydrogenase (TSD) from strain SH. The enzyme had an apparent molecular mass of 44 kDa and was purified 71-fold from the solubilized membrane fraction. Tetrathionate was the product of the TSD-oxidized thiosulfate and ferricyanide or ubiquinone was the electron acceptor. Maximum enzyme activity was observed at pH 4.0, 40 °C, and 200 mM NaCl. To our knowledge, this is the first report of NaCl-stimulated TSD activity. TSD was structurally different from the previously reported thiosulfate-oxidizing enzymes. In addition, TSD activity was strongly inhibited by 2-heptyl-4-hydroxy-quinoline N-oxide, suggesting that the TSD is a novel thiosulfate:quinone reductase.

  8. Characterization of a novel thiosulfate dehydrogenase from a marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    Science.gov (United States)

    Sharmin, Sultana; Yoshino, Eriko; Kanao, Tadayoshi; Kamimura, Kazuo

    2016-01-01

    A marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH, was isolated to develop a bioleaching process for NaCl-containing sulfide minerals. Because the sulfur moiety of sulfide minerals is metabolized to sulfate via thiosulfate as an intermediate, we purified and characterized the thiosulfate dehydrogenase (TSD) from strain SH. The enzyme had an apparent molecular mass of 44 kDa and was purified 71-fold from the solubilized membrane fraction. Tetrathionate was the product of the TSD-oxidized thiosulfate and ferricyanide or ubiquinone was the electron acceptor. Maximum enzyme activity was observed at pH 4.0, 40 °C, and 200 mM NaCl. To our knowledge, this is the first report of NaCl-stimulated TSD activity. TSD was structurally different from the previously reported thiosulfate-oxidizing enzymes. In addition, TSD activity was strongly inhibited by 2-heptyl-4-hydroxy-quinoline N-oxide, suggesting that the TSD is a novel thiosulfate:quinone reductase. PMID:26393925

  9. Comparative Genomics of the Extreme Acidophile Acidithiobacillus thiooxidans Reveals Intraspecific Divergence and Niche Adaptation.

    Science.gov (United States)

    Zhang, Xian; Feng, Xue; Tao, Jiemeng; Ma, Liyuan; Xiao, Yunhua; Liang, Yili; Liu, Xueduan; Yin, Huaqun

    2016-01-01

    Acidithiobacillus thiooxidans known for its ubiquity in diverse acidic and sulfur-bearing environments worldwide was used as the research subject in this study. To explore the genomic fluidity and intraspecific diversity of Acidithiobacillus thiooxidans (A. thiooxidans) species, comparative genomics based on nine draft genomes was performed. Phylogenomic scrutiny provided first insights into the multiple groupings of these strains, suggesting that genetic diversity might be potentially correlated with their geographic distribution as well as geochemical conditions. While these strains shared a large number of common genes, they displayed differences in gene content. Functional assignment indicated that the core genome was essential for microbial basic activities such as energy acquisition and uptake of nutrients, whereas the accessory genome was thought to be involved in niche adaptation. Comprehensive analysis of their predicted central metabolism revealed that few differences were observed among these strains. Further analyses showed evidences of relevance between environmental conditions and genomic diversification. Furthermore, a diverse pool of mobile genetic elements including insertion sequences and genomic islands in all A. thiooxidans strains probably demonstrated the frequent genetic flow (such as lateral gene transfer) in the extremely acidic environments. From another perspective, these elements might endow A. thiooxidans species with capacities to withstand the chemical constraints of their natural habitats. Taken together, our findings bring some valuable data to better understand the genomic diversity and econiche adaptation within A. thiooxidans strains.

  10. Comparative Genomics of the Extreme Acidophile Acidithiobacillus thiooxidans Reveals Intraspecific Divergence and Niche Adaptation

    Directory of Open Access Journals (Sweden)

    Xian Zhang

    2016-08-01

    Full Text Available Acidithiobacillus thiooxidans known for its ubiquity in diverse acidic and sulfur-bearing environments worldwide was used as the research subject in this study. To explore the genomic fluidity and intraspecific diversity of Acidithiobacillus thiooxidans (A. thiooxidans species, comparative genomics based on nine draft genomes was performed. Phylogenomic scrutiny provided first insights into the multiple groupings of these strains, suggesting that genetic diversity might be potentially correlated with their geographic distribution as well as geochemical conditions. While these strains shared a large number of common genes, they displayed differences in gene content. Functional assignment indicated that the core genome was essential for microbial basic activities such as energy acquisition and uptake of nutrients, whereas the accessory genome was thought to be involved in niche adaptation. Comprehensive analysis of their predicted central metabolism revealed that few differences were observed among these strains. Further analyses showed evidences of relevance between environmental conditions and genomic diversification. Furthermore, a diverse pool of mobile genetic elements including insertion sequences and genomic islands in all A. thiooxidans strains probably demonstrated the frequent genetic flow (such as lateral gene transfer in the extremely acidic environments. From another perspective, these elements might endow A. thiooxidans species with capacities to withstand the chemical constraints of their natural habitats. Taken together, our findings bring some valuable data to better understand the genomic diversity and econiche adaptation within A. thiooxidans strains.

  11. Acidithiobacillus ferriphilus sp. nov., a facultatively anaerobic iron- and sulfur-metabolizing extreme acidophile.

    Science.gov (United States)

    Falagán, Carmen; Johnson, D Barrie

    2016-01-01

    The genus Acidithiobacillus includes three species that conserve energy from the oxidation of ferrous iron, as well as reduced sulfur, to support their growth. Previous work, based on multi-locus sequence analysis, identified a fourth group of iron- and sulfur-oxidizing acidithiobacilli as a potential distinct species. Eleven strains of 'Group IV' acidithiobacilli, isolated from different global locations, have been studied. These were all shown to be obligate chemolithotrophs, growing aerobically by coupling the oxidation of ferrous iron or reduced sulfur (but not hydrogen) to molecular oxygen, or anaerobically by the oxidation of reduced sulfur coupled to ferric iron reduction. All strains were mesophilic, although some were also psychrotolerant. Strain variation was also noted in terms of tolerance to extremely low pH and to elevated concentrations of transition metals. One strain was noted to display far greater tolerance to chloride than reported for other iron-oxidizing acidithiobacilli. All of the strains were able to catalyse the oxidative dissolution of pyrite and, on the basis of some of the combined traits of some of the strains examined, it is proposed that these may have niche roles in commercial mineral bioprocessing operations, such as for low temperature bioleaching of polysulfide ores in brackish waters. The name Acidithiobacillus ferriphilus sp. nov. is proposed to accommodate the strains described, with the type strain being M20T ( = DSM 100412T = JCM 30830T). PMID:26498321

  12. Comparación del potencial oxidativo de Acidithiobacillus ferrooxidans, en un proceso de biodesulfurización de carbón

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    Maria Prada Fonseca

    2016-05-01

    Full Text Available This study aimed comparing the oxidative activity of two strains of Acidithiobacillus ferrooxidans in a desulphurization process, using a sub-bituminous coal with a high sulfur content (2.30% total sulfur: 1.06% as pyritic, 1.10% as organic and 0.14% from sulfates from “La Guacamaya” mine, located in Puerto Libertador - Cordoba, Colombia. Several assays were performed in Erlenmeyer flasks, the total iron concentration used in solution were 200 mg/L and 1200 mg/L respectively, using ferrous sulfate. The process was monitored by periodically measuring the main physicochemical factors involved (pH, Eh, cell population and iron in solution. According to the results obtained, the highest efficiency of the process was achieved by working with microorganisms compatible with Acidithiobacillus ferrooxidans and initial concentration of 1200 mg/l of ferrous sulfate, which had higher pyrite oxidation rates (Py oxidized up to 68% and the best experimental conditions in the leaching medium (pH: 1,47; Eh: 625 mV; 6.3×108 cells/mL, in comparison with the axenic culture on the same conditions (Py oxidized: 52%; pH: 1,63; Eh: 580 mV; 5.1×108cells/mL, after 12 days of experimentation.

  13. Investigation of energy gene expressions and community structures of free and attached acidophilic bacteria in chalcopyrite bioleaching.

    Science.gov (United States)

    Zhu, Jianyu; Jiao, Weifeng; Li, Qian; Liu, Xueduan; Qin, Wenqing; Qiu, Guanzhou; Hu, Yuehua; Chai, Liyuan

    2012-12-01

    In order to better understand the bioleaching mechanism, expression of genes involved in energy conservation and community structure of free and attached acidophilic bacteria in chalcopyrite bioleaching were investigated. Using quantitative real-time PCR, we studied the expression of genes involved in energy conservation in free and attached Acidithiobacillus ferrooxidans during bioleaching of chalcopyrite. Sulfur oxidation genes of attached A. ferrooxidans were up-regulated while ferrous iron oxidation genes were down-regulated compared with free A. ferrooxidans in the solution. The up-regulation may be induced by elemental sulfur on the mineral surface. This conclusion was supported by the results of HPLC analysis. Sulfur-oxidizing Acidithiobacillus thiooxidans and ferrous-oxidizing Leptospirillum ferrooxidans were the members of the mixed culture in chalcopyrite bioleaching. Study of the community structure of free and attached bacteria showed that A. thiooxidans dominated the attached bacteria while L. ferrooxidans dominated the free bacteria. With respect to available energy sources during bioleaching of chalcopyrite, sulfur-oxidizers tend to be on the mineral surfaces whereas ferrous iron-oxidizers tend to be suspended in the aqueous phase. Taken together, these results indicate that the main role of attached acidophilic bacteria was to oxidize elemental sulfur and dissolution of chalcopyrite involved chiefly an indirect bioleaching mechanism.

  14. Comparative proteomic analysis of sulfur-oxidizing Acidithiobacillus ferrooxidans CCM 4253 cultures having lost the ability to couple anaerobic elemental sulfur oxidation with ferric iron reduction.

    Science.gov (United States)

    Kucera, Jiri; Sedo, Ondrej; Potesil, David; Janiczek, Oldrich; Zdrahal, Zbynek; Mandl, Martin

    2016-09-01

    In extremely acidic environments, ferric iron can be a thermodynamically favorable electron acceptor during elemental sulfur oxidation by some Acidithiobacillus spp. under anoxic conditions. Quantitative 2D-PAGE proteomic analysis of a resting cell suspension of a sulfur-grown Acidithiobacillus ferrooxidans CCM 4253 subculture that had lost its iron-reducing activity revealed 147 protein spots that were downregulated relative to an iron-reducing resting cell suspension of the antecedent sulfur-oxidizing culture and 111 that were upregulated. Tandem mass spectrometric analysis of strongly downregulated spots identified several physiologically important proteins that apparently play roles in ferrous iron oxidation, including the outer membrane cytochrome Cyc2 and rusticyanin. Other strongly repressed proteins were associated with sulfur metabolism, including heterodisulfide reductase, thiosulfate:quinone oxidoreductase and sulfide:quinone reductase. Transcript-level analyses revealed additional downregulation of other respiratory genes. Components of the iron-oxidizing system thus apparently play central roles in anaerobic sulfur oxidation coupled with ferric iron reduction in the studied microbial strain. PMID:27394989

  15. Oxidation study of the synthetic sulfides molybdenite (MoS{sub 2}) and covellite (CuS) by acidithiobacillus ferrooxidants using respirometric experiments; Estudo da oxidacao dos sulfetos sinteticos molibdenita (MoS2) e covelita (CuS) por Acidithiobacillus ferrooxidans via respirometria celular

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Junior, Wilmo E. [Universidade Federal de Rondonia (UFRO), Porto Velho, RO (Brazil). Dept. de Quimica; Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica], e-mail: wilmojr@bol.com.br; Bevilaqua, Denise; Garcia Junior, Oswaldo [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica

    2009-07-01

    This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry-bacterial attack, what is influenced by its electronic structures. Besides, experiments conducted in the presence of Fe{sup 3+} did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations. (author)

  16. Reserch Progresses in Ferrous Oxidation System of Acidithiobacillus ferrooxidans%氧化亚铁硫杆菌亚铁氧化系统的研究进展

    Institute of Scientific and Technical Information of China (English)

    欧阳建平; 陈新华

    2009-01-01

    氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)为无机化能自养菌,革兰氏阴性,能在极端酸性环境中生长.由于在生物冶金中的应用及特殊的生理学效应,该菌受到研究者的广泛关注.A.ferrooxidans能氧化亚铁、元素硫及还原态硫化物获得电子,并通过一系列电子载体将电子传递给氧生成水,同时释放能量供生命活动需要.目前对A.ferrooxidans电子传递系统的研究主要集中于亚铁氧化电子传递系统,已发现多种与亚铁氧化电子传递相关电子载体和操纵子,如电子载体铜蓝蛋白(Rustocyanin,Rus)、细胞色素C(Cytochrome C,Cyc)、细胞色素C氧化酶(Cytochrome Coxidase,Cox)、亚铁氧化酶(Iro)、细胞色素bc1复合物(cytochrome bc1 complex,bc1)等,以及rus操纵子和pet操纵子.综述了近年来有关A.ferrooxidans 亚铁氧化电子传递链相关蛋白载体,rus和pet操纵子结构与功能及表达调控等方面的研究进展.

  17. Comparison and evaluation of immobilization methods for preparing bacterial probes using acidophilic bioleaching bacteria Acidithiobacillus thiooxidans for AFM studies.

    Science.gov (United States)

    Diao, Mengxue; Taran, Elena; Mahler, Stephen M; Nguyen, Anh V

    2014-07-01

    We evaluated different strategies for constructing bacterial probes for atomic force microscopy studies of bioleaching Acidithiobacillus thiooxidans interacting with pyrite mineral surfaces. Of three available techniques, the bacterial colloidal probe technique is the most reliable and provides a versatile platform for quantifying true interactive forces between bioleaching microorganisms and mineral surfaces.

  18. Synthesis and properties of ternary (K, NH4, H3O)-jarosites precipitated from Acidithiobacillus ferrooxidans cultures in simulated bioleaching solutions

    International Nuclear Information System (INIS)

    The purpose of this study was to synthesize a series of solid solution jarosites by biological oxidation of ferrous iron at pH 2.2–4.4 and ambient temperature in media containing mixtures of K+ (0, 1, 4, 6, 12, 31 mM) and NH4+ (6.1, 80, 160, 320 mM). The starting material was a liquid medium for Acidithiobacillus ferrooxidans comprised of 120 mM FeSO4 solution and mineral salts at pH 2.2. Following inoculation with A. ferrooxidans, the cultures were incubated in shake flasks at 22 °C. As bacteria oxidized ferrous iron, ferric iron hydrolyzed and precipitated as jarosite-group minerals (AFe3(SO4)2(OH)6) and/or schwertmannite (idealized formula Fe8O8(OH)6(SO4)·nH2O). The precipitates were characterized by X-ray diffraction (XRD), elemental analysis, and Munsell color. Schwertmannite was the dominant mineral product at low combinations of K+ (≤ 4 mM) and NH4+ (≤ 80 mM) in the media. At higher single or combined concentrations, yellowish jarosite phases were produced, and Munsell hue provided a sensitive means of detecting minor schwertmannite in the oxidation products. Although the hydrated ionic radii of K+ and NH4+ are similar, K+ greatly facilitated the formation of a jarosite phase compared to NH4+. Unit cell and cell volume calculations from refinements of the powder XRD patterns indicated that the jarosite phases produced were mostly ternary (K, NH4, H3O)-solid solutions that were also deficient in structural Fe, especially at low NH4 contents. Thus, ferric iron precipitation from the simulated bioleaching systems yielded solid solutions of jarosite with chemical compositions that were dependent on the relative concentrations of K+ and NH4+ in the synthesis media. No phase separations involving discrete, end-member K-jarosite or NH4-jarosite were detected in the un-aged precipitates. - Highlights: • Fe(III) precipitates formed in A. ferrooxidans culture solutions were characterized. • The monovalent cation concentrations and ratios were varied to

  19. Development of Fluorenscent Quantitative Real-time PCR Method for Detection of Acidithiobacillus ferrooxidans%嗜酸氧化亚铁硫杆菌实时荧光定量PCR检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    唐连飞; 肖家勇; 朱中武; 孟芳; 欧阳振宇; 陈盼; 白雪; 禹思宇

    2010-01-01

    [目的] 建立一种检测进出境环保用微生物菌剂中嗜酸氧化亚铁硫杆菌(acidithiobacillus ferrooxidans,A.ferrooxidans)的实时荧光定量PCR方法.[方法] 用9K培养基培养 A.ferrooxidans标准菌株A.ferrooxidans ATCC23270,并提取基因组DNA作模板;根据GenBank中嗜酸氧化亚铁硫杆菌的16S基因序列设计合成引物和探针,用含有101 bp扩增目标产物的pGEM()-T Easy载体质粒为阳性对照.构建标准曲线,建立荧光定量PCR检测方法,并进行方法 学的评估.[结果] 成功建立了嗜酸氧化亚铁硫杆菌的荧光定量PCR检测方法,该方法对嗜酸硫杆菌属中嗜酸氧化硫硫杆菌(Acidithiobacillus thiooxidans,A.thiooxidans)和嗜酸喜温硫杆菌(Acidithiobacillus caldus,A.caldus)无交叉反应;最少可检测到100个阳性质粒,说明有很好的敏感性;试验内变异系数为0.32%,具有很好的重复性.[结论] 建立的嗜酸氧化亚铁硫杆菌的TaqMan探针荧光定量PCR检测方法特异性和灵敏度高、重复性好,可作为嗜酸氧化亚铁硫杆菌高通量的快速检测方法.

  20. The Study Kinetic for Growth of Acidithiobacillus ferrooxidans%嗜酸氧化亚铁硫杆菌生长动力学

    Institute of Scientific and Technical Information of China (English)

    柳建设; 张艳华; 李邦梅; 谢学辉

    2006-01-01

    在确定二价铁离子为A.f生长过程中惟一限制性底物条件下,通过考察初始亚铁离子浓度、初始pH值两种影响亚铁离子氧化代谢的主要因素来研究细菌的生长特性,得到以限制性底物亚铁离子浓度为表征的细菌生长曲线.利用基于Monod方程建立的细菌生长动力学方程模型,采用Matlab软件中的Gauiss-Newton算法确定了在不同条件下细菌生长动力学参数,包括最大比生长速率μm、Monod常数K及Ro,推导出了不同条件下A.f对数期以底物Fe(Ⅱ)浓度为表征的生长动力学方程.%In order to explain kinetic behaviors of microorganisms in varied experiment conditions, growth kinetic model of Acidithiobacillus ferrooxidans (A. f) was deduced based on Monod model. The kinetic parameters (Monod constant K, max specific growth rate μm, and Ro) of this model in different initial experiment condition were obtained by Gauss-Newton algorithm. The growth law in specific initial experiment condition and variable kinetic parameters were found. According to the growth behavior law studied under different initial experiment condition, the curves describing substrates (ferrous ion concentration) law and the growth velocity equations corresponding to the different initial experiment condition were obtained.

  1. Synthesis and properties of ternary (K, NH{sub 4}, H{sub 3}O)-jarosites precipitated from Acidithiobacillus ferrooxidans cultures in simulated bioleaching solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sandy Jones, F.; Bigham, Jerry M. [School of Environment and Natural Resources, Ohio State University, 2021 Coffey Road, Columbus, OH 43210 (United States); Gramp, Jonathan P. [Department of Microbiology, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210 (United States); Tuovinen, Olli H., E-mail: tuovinen.1@osu.edu [Department of Microbiology, Ohio State University, 484 West 12th Avenue, Columbus, OH 43210 (United States)

    2014-11-01

    The purpose of this study was to synthesize a series of solid solution jarosites by biological oxidation of ferrous iron at pH 2.2–4.4 and ambient temperature in media containing mixtures of K{sup +} (0, 1, 4, 6, 12, 31 mM) and NH{sub 4}{sup +} (6.1, 80, 160, 320 mM). The starting material was a liquid medium for Acidithiobacillus ferrooxidans comprised of 120 mM FeSO{sub 4} solution and mineral salts at pH 2.2. Following inoculation with A. ferrooxidans, the cultures were incubated in shake flasks at 22 °C. As bacteria oxidized ferrous iron, ferric iron hydrolyzed and precipitated as jarosite-group minerals (AFe{sub 3}(SO{sub 4}){sub 2}(OH){sub 6}) and/or schwertmannite (idealized formula Fe{sub 8}O{sub 8}(OH){sub 6}(SO{sub 4})·nH{sub 2}O). The precipitates were characterized by X-ray diffraction (XRD), elemental analysis, and Munsell color. Schwertmannite was the dominant mineral product at low combinations of K{sup +} (≤ 4 mM) and NH{sub 4}{sup +} (≤ 80 mM) in the media. At higher single or combined concentrations, yellowish jarosite phases were produced, and Munsell hue provided a sensitive means of detecting minor schwertmannite in the oxidation products. Although the hydrated ionic radii of K{sup +} and NH{sub 4}{sup +} are similar, K{sup +} greatly facilitated the formation of a jarosite phase compared to NH{sub 4}{sup +}. Unit cell and cell volume calculations from refinements of the powder XRD patterns indicated that the jarosite phases produced were mostly ternary (K, NH{sub 4}, H{sub 3}O)-solid solutions that were also deficient in structural Fe, especially at low NH{sub 4} contents. Thus, ferric iron precipitation from the simulated bioleaching systems yielded solid solutions of jarosite with chemical compositions that were dependent on the relative concentrations of K{sup +} and NH{sub 4}{sup +} in the synthesis media. No phase separations involving discrete, end-member K-jarosite or NH{sub 4}-jarosite were detected in the un-aged precipitates

  2. Isolation of a New Broad-Host-Range IncQ-Like Plasmid, pTC-F14, from the Acidophilic Bacterium Acidithiobacillus caldus and Analysis of the Plasmid Replicon

    OpenAIRE

    Gardner, Murray N.; Deane, Shelly M.; Rawlings, Douglas E

    2001-01-01

    A moderately thermophilic (45 to 50°C), highly acidophilic (pH 1.5 to 2.5), chemolithotrophic Acidithiobacillus caldus strain, f, was isolated from a biooxidation process used to treat nickel ore. Trans-alternating field electrophoresis analysis of total DNA from the A. caldus cells revealed two plasmids of approximately 14 and 45 kb. The 14-kb plasmid, designated pTC-F14, was cloned and shown by replacement of the cloning vector with a kanamycin resistance gene to be capable of autonomous re...

  3. Monitoring Acidophilic Microbes with Real-Time Polymerase Chain Reaction (PCR) Assays

    Energy Technology Data Exchange (ETDEWEB)

    Frank F. Roberto

    2008-08-01

    Many techniques that are used to characterize and monitor microbial populations associated with sulfide mineral bioleaching require the cultivation of the organisms on solid or liquid media. Chemolithotrophic species, such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, or thermophilic chemolithotrophs, such as Acidianus brierleyi and Sulfolobus solfataricus can grow quite slowly, requiring weeks to complete efforts to identify and quantify these microbes associated with bioleach samples. Real-time PCR (polymerase chain reaction) assays in which DNA targets are amplified in the presence of fluorescent oligonucleotide primers, allowing the monitoring and quantification of the amplification reactions as they progress, provide a means of rapidly detecting the presence of microbial species of interest, and their relative abundance in a sample. This presentation will describe the design and use of such assays to monitor acidophilic microbes in the environment and in bioleaching operations. These assays provide results within 2-3 hours, and can detect less than 100 individual microbial cells.

  4. 氧化亚铁硫杆菌固定化技术及其应用%Immobilized Technology of Acidithiobacillus Ferrooxidans and Its Application

    Institute of Scientific and Technical Information of China (English)

    廖泽君; 史文革

    2015-01-01

    Acidithiobacillus ferrooxidans is an important bacteria for ore-leaching. Cell immobi-lized technology can limit the bacteria within a particular region, increase the density of bacteria, effectively increase the oxidability on Fe2+ and low-valent sulfur,improve the stability and me-chanical intensity,simplify the conditions of production,and ultimately improve the economic benefits of industrial production. Materials used by this technique include the organic materials,inorganic materials and artificial synthetic materials. Immobilized methods involved include adsorption method, embedding cross methods, cross-linking methods,new immobilization methods,et al. The immobilized technology has a good application prospect in the field of bioleaching and bio-desulfurization,development of which establishes the foundation for realizing its industri-alization.%氧化亚铁硫杆菌是一种重要的浸矿细菌,细胞固定化技术能将该菌限定在特定的区域内,增加细菌密度,有效提高其对Fe2+及低价态硫的氧化能力,且能提高细菌的稳定性和机械强度,并简化浸矿生产条件,最终提高工业生产的经济效益。该技术运用的材料包括有机材料、无机材料和人工合成材料;涉及到的固定化方法包括吸附法、包埋法、交联法、新固定化法等。固定化氧化亚铁硫杆菌技术在生物浸矿和生物脱硫领域具有良好的应用前景,该技术的发展为其实现产业化奠定了基础。

  5. Different isotope and chemical patterns of pyrite oxidation related to lag and exponential growth phases of Acidithiobacillus ferrooxidans reveal a microbial growth strategy

    Science.gov (United States)

    Brunner, Benjamin; Yu, Jae-Young; Mielke, Randall E.; MacAskill, John A.; Madzunkov, Stojan; McGenity, Terry J.; Coleman, Max

    2008-06-01

    The solution chemistry during the initial (slow increase of dissolved iron and sulfate) and main stage (rapid increase of dissolved iron and sulfate) of pyrite leaching by Acidithiobacillus ferrooxidans (Af) at a starting pH of 2.05 shows significant differences. During the initial stage, ferrous iron (Fe2+) is the dominant iron species in solution and the molar ratio of produced sulfate (SO42-) and total iron (Fetot) is 1.1, thus does not reflect the stoichiometry of pyrite (FeS2). During the main stage, ferric iron (Fe3+) is the dominant iron species in solution and the SO42-:Fetot ratio is with 1.9, close to the stoichiometry of FeS2. Another difference between initial and main stage is an initial trend to slightly higher pH values followed by a drop during the main stage to pH 1.84. These observations raise the question if there are different modes of bioleaching of pyrite, and if there are, what those modes imply in terms of leaching mechanisms. Different oxygen and sulfur isotope trends of sulfate during the initial and main stages of pyrite oxidation confirm that there are two pyrite bioleaching modes. The biochemical reactions during initial stage are best explained by the net reaction FeS2 + 3O2 ⇒ Fe2+ + SO42- + SO2(g). The degassing of sulfur dioxide (SO2) acts as sink for sulfur depleted in 34S compared to pyrite, and is the cause of the SO42-:Fetot ratio of 1.1 and the near constant pH. During the exponential phase, pyrite sulfur is almost quantitatively converted to sulfate, according to the net reaction FeS2 + 15/4O2 + 1/2H2O ⇒ Fe3+ + 2SO42- + H+. We hypothesize that the transition between the modes of bioleaching of pyrite is due to the impact of the accumulation of ferrous iron, which induces changes in the metabolic activity of Af and may act as an inhibitor for the oxidation of sulfur species. This transition defines a fundamental change in the growth strategy of Af. A mode, where bacteria gain energy by oxidation of elemental sulfur to

  6. Quantifying adhesion of acidophilic bioleaching bacteria to silica and pyrite by atomic force microscopy with a bacterial probe.

    Science.gov (United States)

    Diao, Mengxue; Taran, Elena; Mahler, Stephen; Nguyen, Tuan A H; Nguyen, Anh V

    2014-03-01

    The adhesion of acidophilic bacteria to mineral surfaces is an important phenomenon in bioleaching processes. In this study, functionalized colloidal probes covered by bioleaching bacterial cells (Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans) were developed and used to sense specific adhesion forces to a silica surface and a pyrite surface in various solutions. Experimentally, recorded retraction curves of A. thiooxidans revealed sawtooth features that were in good agreement with the wormlike chain model, while that of L. ferrooxidans exhibited stair-step separation. The magnitudes of adhesion forces and snap-off distances were strongly influenced by the ionic strength and pH. Macroscopic surface properties including hydrophobicity and surface potential for bacterial cells and substrata were measured by a sessile drop method and microelectrophoresis. The ATR-FTIR spectra indicated the presence of different types of biopolymers on two strains of bacteria.

  7. The Effect of Specific Conditions on Cu, Ni, Zn and Al Recovery from PCBS Waste Using Acidophilic Bacterial Strains

    Directory of Open Access Journals (Sweden)

    Mrážiková A.

    2016-03-01

    Full Text Available The objective of this work was to evaluate the influence of static, stirring and shaking conditions on copper, zinc, nickel and aluminium dissolution from printed circuit boards (PCBs using the mixed acidophilic bacterial culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The results revealed that static conditions were the most effective in zinc and aluminium dissolution. Zinc was removed almost completely under static conditions, whereas maximum of nickel dissolution was reached under the stirring conditions. The highest copper recovery (36% was reached under stirring conditions. The shaking conditions appeared to be the least suitable. The relative importance of these systems for the bioleaching of copper and nickel decreased in the order: stirring, static conditions, shaking.

  8. Heavy metal resistance strategies of acidophilic bacteria and their acquisition: importance for biomining and bioremediation.

    Science.gov (United States)

    Navarro, Claudio A; von Bernath, Diego; Jerez, Carlos A

    2013-01-01

    Microbial solubilizing of metals in acid environments is successfully used in industrial bioleaching of ores or biomining to extract metals such as copper, gold, uranium and others. This is done mainly by acidophilic and other microorganisms that mobilize metals and generate acid mine drainage or AMD, causing serious environmental problems. However, bioremediation or removal of the toxic metals from contaminated soils can be achieved by using the specific properties of the acidophilic microorganisms interacting with these elements. These bacteria resist high levels of metals by using a few "canonical" systems such as active efflux or trapping of the metal ions by metal chaperones. Nonetheless, gene duplications, the presence of genomic islands, the existence of additional mechanisms such as passive instruments for pH and cation homeostasis in acidophiles and an inorganic polyphosphate-driven metal resistance mechanism have also been proposed. Horizontal gene transfer in environmental microorganisms present in natural ecosystems is considered to be an important mechanism in their adaptive evolution. This process is carried out by different mobile genetic elements, including genomic islands (GI), which increase the adaptability and versatility of the microorganism. This mini-review also describes the possible role of GIs in metal resistance of some environmental microorganisms of importance in biomining and bioremediation of metal polluted environments such as Thiomonas arsenitoxydans, a moderate acidophilic microorganism, Acidithiobacillus caldus and Acidithiobacillus ferrooxidans strains ATCC 23270 and ATCC 53993, all extreme acidophiles able to tolerate exceptionally high levels of heavy metals. Some of these bacteria contain variable numbers of GIs, most of which code for high numbers of genes related to metal resistance. In some cases there is an apparent correlation between the number of metal resistance genes and the metal tolerance of each of these

  9. Isolation of a strain of Acidithiobacillus caldus and its role in bioleaching of chalcopyrite

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Q.G.; Bo, F.; Bo, Z.H.; Xi, L.; Jian, G.; Fei, L.F.; Hua, C.X. [Central South University of Technology, Changsha (China)

    2007-09-15

    A moderately thermophilic and acidophilic sulfur-oxidizing bacterium named S-2, was isolated from coal heap drainage. The bacterium was motile, Gramnegative, rod-shaped, measured 0.4 to 0.6 by 1 to 2 gm, and grew optimally at 42-45{sup o}C and an initial pH of 2.5. The strain S-2 grew autotrophically by using elemental sulfur, sodium thiosulfate and potassium tetrathionate as energy sources. The strain did not use organic matter and inorganic minerals including ferrous sulfate, pyrite and chalcopyrite as energy sources. The morphological, biochemical, physiological characterization and analysis based on 16S rRNA gene sequence indicated that the strain S2 is most closely related to Acidithiobacillus caldus (> 99% similarity in gene sequence). The combination of the strain S-2 with Leptospirillum ferriphilum or Acidithiobacillus ferrooxidans in chalcopyrite bioleaching improved the copper-leaching efficiency. Scanning electron microscope (SEM) analysis revealed that the chalcopyrite surface in a mixed culture of Leptospirillum ferriphilum and Acidithiobacillus caldus was heavily etched. The energy dispersive X-ray (EDX) analysis indicated that Acidithiobacillus caldus has the potential role to enhance the recovery of copper from chalcopyrite by oxidizing the sulfur formed during the bioleaching progress.

  10. Difference in Acclimation of Acidithiobacillus ferrooxidans by Various Substrates and Its Effect on Coal Desulfurization Efficiency%不同底物驯化氧化亚铁硫杆菌的差异及对煤炭生物脱硫效率的影响

    Institute of Scientific and Technical Information of China (English)

    张德伟; 周立祥; 杨新萍; 王世梅

    2011-01-01

    In this study, Acidithiobacillus ferrooxidans LX5 was cultured in 9K medium with pyrite and ferrous sulfate as the substrates.Results showed that the number of A. ferrooxidans LX5 acclimated by pyrite for 20 d was 3.0 × 107cell/mL in the liquid, and the oxidation activity to pyrite was stronger. A. ferrooxidans LX5 cultured for 48 h was 1.0 × 108 cell/mL in medium with FeSO4.Extracellular polymeric substance(EPS) produced from A. ferrooxidans LX5 acclimated by pyrite was 2 395 μg/( 1010 cells) three times as much as that cultured with FeSO4. A high-sulfur coal desulfurization experiment were carried out with A. ferrooxidans LX5 domesticated respectively in medium with ferrous sulfate and pyrite. The results showed that the coal desulfurization rate was up to 72.4% after bioleaching for 13 d by A. ferrooxidans LX5 acclimated by pyrite, at the same time, the desulfurization rate was only 47.2% with A. ferrooxidans LX5 cultured with ferrous sulfate and reached 65.8% in 20 d. Therefore, the desulfurization efficiency can be improved of coal and shorten the desulfurization time when A. ferrooxidans LX5 acclimated with pyrite as the substrate.%分别以FeS2和FeSO4为底物培养驯化嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)LX5,结果发现以FeS2为底物驯化A.ferrooxidans LX5,在培养20 d时,培养液中LX5的菌体数量达3.0×107个/mL,对FeS2中亚铁及还原性硫的氧化能力均较强.A.ferrooxidans LX5在以FeSO4为底物的培养液中生长,培养48 h溶液中Fe2+全部氧化成Fe3+,菌体数量达到1.0×108个/mL.以FeS2为底物驯化培养A.ferrooxidans LX5产生的胞外多聚物的量(以DOC计)达到2 395μg/(1010cells),是同等条件下经FeSO4培养后产生EPS量的3倍.分别将经过FeS2和FeSO4驯化培养的A.firrooxidans LX5菌液作接种物,进行高硫煤生物浸出脱硫实验,结果表明,生物浸出脱硫13 d,接种FeS2驯化的A.ferrooxidans LX5处理,脱硫率达72.4%,而接种FeSO4培养的A.ferrooxidans

  11. Ardrea characterisation of acidophilic micro-organisms isolated from gold mines in Marmato, Colombia

    Directory of Open Access Journals (Sweden)

    Edna Judith Márquez F.

    2008-02-01

    Full Text Available Mineral bio-oxidation improves the extraction of valuable metals and also decreases the impact caused by mining waste; however, the interactions between the micro-organisms so involved are little known. Double-layer solid culture media techniques and amplified ribosomal DNA restriction enzyme analysis (Ardrea, using Eco72I, Eco24I, XcmI and BsaAI enzymes, were used for characterising four micro-organisms isolated from gold mines located in Marmato, Colombia. This work was aimed at better understanding of native acidophilic micro-organisms’ microbial interactions in mixed cultures. Iron and sulphur oxidising isolates revealed similar restriction patterns to those previously reported for Acidithiobacillus ferrooxidans; however, one of them exhibited different colony morphology compared to previously reported morphology. The iron non-oxidising isolate presented a restriction pattern agreeing with theoretical analysis of Acidithiobacillus thiooxidans database sequences. ARDREA proved to be a viable technique for differentiating between At. ferrooxidans and At. thiooxidans; in turn, it enabled checking isolates’ identity with their physiological traits and colony morphology.

  12. Adaptation of a mixed culture of acidophiles for a tank biooxidation of refractory gold concentrates containing a high concentration of arsenic.

    Science.gov (United States)

    Hong, Jeongsik; Silva, Rene A; Park, Jeonghyun; Lee, Eunseong; Park, Jayhyun; Kim, Hyunjung

    2016-05-01

    We adapted a mixed culture of acidophiles to high arsenic concentrations to confirm the possibility of achieving more than 70% biooxidation of refractory gold concentrates containing high arsenic (As) concentration. The biooxidation process was applied to refractory gold concentrates containing approximately 139.67 g/kg of total As in a stirred tank reactor using an adapted mixed culture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. The percentage of the biooxidation process was analyzed based on the total As removal efficiency. The As removal was monitored by inductively coupled plasma (ICP) analysis, conducted every 24 h. The results obtained with the adapted culture were compared with the percentage of biooxidation obtained with a non-adapted mixed culture of A. ferrooxidans and A. thiooxidans, and with their respective pure cultures. The percentages of biooxidation obtained during 358 h of reaction were 72.20%, 38.20%, 27.70%, and 11.45% for adapted culture, non-adapted culture, and pure cultures of A. thiooxidans and A. ferrooxidans, respectively. The adapted culture showed a peak maximum percentage of biooxidation of 77% at 120 h of reaction, confirming that it is possible to obtain biooxidation percentages over 70% in gold concentrates containing high As concentrations.

  13. Molecular genetics of Thiobacillus ferrooxidans.

    OpenAIRE

    Rawlings, D E; Kusano, T

    1994-01-01

    Thiobacillus ferrooxidans is a gram-negative, highly acidophilic (pH 1.5 to 2.0), autotrophic bacterium that obtains its energy through the oxidation of ferrous iron or reduced inorganic sulfur compounds. It is usually dominant in the mixed bacterial populations that are used industrially for the extraction of metals such as copper and uranium from their ores. More recently, these bacterial consortia have been used for the biooxidation of refractory gold-bearing arsenopyrite ores prior to the...

  14. Effects of inhibitors and NaCl on the oxidation of reduced inorganic sulfur compounds by a marine acidophilic, sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    Science.gov (United States)

    Kamimura, Kazuo; Higashino, Emi; Kanao, Tadayoshi; Sugio, Tsuyoshi

    2005-02-01

    The effect of NaCl and the pathways of the oxidation of reduced inorganic sulfur compounds were studied using resting cells and cell-free extracts of Acidithiobacillus thiooxidans strain SH. This isolate specifically requires NaCl for growth. The oxidation of sulfur and sulfite by resting cells was strongly inhibited by 2-heptyl-4-hydroxyquinoline-N-oxide. Carbonylcyanide m-chlorophenyl-hydrazone and monensin were also relatively strong inhibitors. Thiosulfate-oxidizing activity was not inhibited by these uncouplers. Valinomycin did not inhibit the oxidation of sulfur compounds. NaCl stimulated the sulfur- and sulfite-oxidizing activities in resting cells but not in cell-free extracts. The tetrathionate-oxidizing activity in resting cells was slightly stimulated by NaCl, whereas it did not influence the thiosulfate-oxidizing activity. Sulfide oxidation was biphasic, suggesting the formation of intermediate sulfur. The initial phase of sulfide oxidation was not affected by NaCl, whereas the subsequent oxidation of sulfur in the second phase was Na+-dependent. A model is proposed for the role of NaCl in the metabolism of reduced sulfur compounds in A. thiooxidans strain SH.

  15. Production of glycolic acid by chemolithotrophic iron- and sulfur-oxidizing bacteria and its role in delineating and sustaining acidophilic sulfide mineral-oxidizing consortia.

    Science.gov (United States)

    Nancucheo, Ivan; Johnson, D Barrie

    2010-01-01

    Glycolic acid was detected as an exudate in actively growing cultures of three chemolithotrophic acidophiles that are important in biomining operations, Leptospirillum ferriphilum, Acidithiobacillus (At.) ferrooxidans, and At. caldus. Although similar concentrations of glycolic acid were found in all cases, the concentrations corresponded to ca. 24% of the total dissolved organic carbon (DOC) in cultures of L. ferriphilum but only ca. 5% of the total DOC in cultures of the two Acidithiobacillus spp. Rapid acidification (to pH 1.0) of the culture medium of At. caldus resulted in a large increase in the level of DOC, although the concentration of glycolic acid did not change in proportion. The archaeon Ferroplasma acidiphilum grew in the cell-free spent medium of At. caldus; glycolic acid was not metabolized, although other unidentified compounds in the DOC pool were metabolized. Glycolic acid exhibited levels of toxicity with 21 strains of acidophiles screened similar to those of acetic acid. The most sensitive species were chemolithotrophs (L. ferriphilum and At. ferrivorans), while the most tolerant species were chemoorganotrophs (Acidocella, Acidobacterium, and Ferroplasma species), and the ability to metabolize glycolic acid appeared to be restricted (among acidophiles) to Firmicutes (chiefly Sulfobacillus spp.). Results of this study help explain why Sulfobacillus spp. rather than other acidophiles are the main organic carbon-degrading bacteria in continuously fed stirred tanks used to bioprocess sulfide mineral concentrates and also why temporary cessation of pH control in these systems, resulting in rapid acidification, often results in a plume of the archaeon Ferroplasma.

  16. 生物浸铀中影响嗜酸氧化亚铁硫杆菌活性的氟毒物活性形态%Really active form of fluorine toxicity affecting Acidithiobacillus ferrooxidans activity in bioleaching uranium

    Institute of Scientific and Technical Information of China (English)

    彭志俊; 余润兰; 邱冠周; 覃文庆; 顾帼华; 王清良; 李乾; 刘学端

    2013-01-01

    In order to determine the mechanism of bacterial tolerance to fluorine,Acidithiobacillus ferrooxidans ATCC 23270 was domesticated and studied under the conditions of different fluorine concentrations and pH values with or without treatment by Proteinase K.The bacterial activities were observed through measuring the changes of solution potentials by platinum electrode with Ag/AgCl reference electrode and the intracellular fluorine was determined by fluorine ion-selective electrode.The results indicated that the tolerance ofAcidithiobacitlusferrooxidans ATCC 23270 to fluorine could be obviously improved by domestication,HF was the effective form of fluorine to affect the bacterial activity,and pH increase or concentration change of ions of strong complex ability with fluorine ions in solution could result in false appearance of high fluorine-resistant strain.Some proteins located in cell wall or cell membrane were intimately relative with the bacterial fluorine tolerance.%为了确定浸矿菌耐氟的机制,在氟化物存在的条件下,驯化铀矿浸出菌嗜酸氧化亚铁硫杆菌ATCC23270,研究溶液中含不同氟浓度、不同pH值时铀矿浸出菌的活性变化,以及有无蛋白酶K处理时铀矿浸出菌细胞内氟浓度的变化情况.采用铂电极和Ag/AgCl参比电极测量氧化还原电位,以作为细菌不同活性的参照指标,采用氟离子选择性电极测定细胞内的氟浓度.结果表明,真正影响铀矿浸出菌活性的是HF,溶液pH值增加以及溶液中与氟有较强络合能力的离子浓度的变化,也会引起耐氟菌假象的出现.浸矿菌的耐氟能力可能与细胞壁和细胞膜上的一些蛋白密切相关.

  17. Characterization of bacteria acidophilic in samples of water coming into a region that suffers influence of uranium mine in Caldas (MG)

    International Nuclear Information System (INIS)

    The fundamental condition for the bioleaching of the uranium ore is the presence of metallic sulfide such as pyrite associated with the ore, which is found in the ore and in the waste at the Unidade de Tratamento de Minerio (UTM) of Pocos de Caldas, State of Minas Gerais, Brazil. The present study aims to determine the chemical and microbiological characteristics in effluents of uranium mining from the UTM and in Antas dam, which receives treated effluents from the UTM. Water samples were collected Pit Mine (CM), located within the UTM facilities and from site 41 (Antas dam) in July and October 2008. We verified low pH values in water samples from CM (3.7) in comparison to the ones found at site 41 (6.65). There was a higher medium density value of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and heterotrophic acidophilic bacteria in water samples at site CM compared to the values recorded from samples at site 41. Medium values of Fe2+, uranium and zinc in samples from the site CM were higher than at site 41. The concentration of fluoride (68.5 mL-l) and manganese (2.34 mL-1) in water samples from site 41 were above the limits fixed for water bodies in Resolution CONAMA 357. The relative seasonal variation of some variables observed at site CM (low pH values, high densities of Acidithiobacillus sp. and heterotrophic acidophilic bacteria) shows that this site is one of the main sites of occurrence of acid mine drainage and action of bioleaching bacteria at UTM. (author)

  18. Characterization of bacteria acidophilic in samples of water coming into a region that suffers influence of uranium mine in Caldas (MG)

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Michelle B.; Ferrari, Carla R.; Roque, Claudio V.; Ronqui, Leilane B.; Nascimento, Marcos R.L. do; Rodgher, Suzelei; Azevedo, Heliana [Laboratorio de Pocos de Caldas (LAPOC-CNEN/MG), MG (Brazil)], e-mail: michelle_borato@hotmail.com, e-mail: carlarolimferrari@yahoo.com.br, e-mail: cvroque@cnen.gov.br, e-mail: leilanebio@yahoo.com.br, e-mail: pmarcos@cnen.gov.br, e-mail: surodgher@uol.com.br, e-mail: hgomes@cnen.gov.br

    2009-07-01

    The fundamental condition for the bioleaching of the uranium ore is the presence of metallic sulfide such as pyrite associated with the ore, which is found in the ore and in the waste at the Unidade de Tratamento de Minerio (UTM) of Pocos de Caldas, State of Minas Gerais, Brazil. The present study aims to determine the chemical and microbiological characteristics in effluents of uranium mining from the UTM and in Antas dam, which receives treated effluents from the UTM. Water samples were collected Pit Mine (CM), located within the UTM facilities and from site 41 (Antas dam) in July and October 2008. We verified low pH values in water samples from CM (3.7) in comparison to the ones found at site 41 (6.65). There was a higher medium density value of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and heterotrophic acidophilic bacteria in water samples at site CM compared to the values recorded from samples at site 41. Medium values of Fe{sup 2+}, uranium and zinc in samples from the site CM were higher than at site 41. The concentration of fluoride (68.5 mL{sup -l}) and manganese (2.34 mL{sup -1}) in water samples from site 41 were above the limits fixed for water bodies in Resolution CONAMA 357. The relative seasonal variation of some variables observed at site CM (low pH values, high densities of Acidithiobacillus sp. and heterotrophic acidophilic bacteria) shows that this site is one of the main sites of occurrence of acid mine drainage and action of bioleaching bacteria at UTM. (author)

  19. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus "Ferrovum".

    Directory of Open Access Journals (Sweden)

    Sophie R Ullrich

    Full Text Available Members of the genus "Ferrovum" are ubiquitously distributed in acid mine drainage (AMD waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain "Ferrovum myxofaciens" P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus "Ferrovum" is extremely scarce.In order to access the wider genetic pool of the genus "Ferrovum" we sequenced the genome of a "Ferrovum"-containing mixed culture and successfully assembled the almost complete genome sequence of the novel "Ferrovum" strain JA12.The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct "Ferrovum" species. "Ferrovum" strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that "Ferrovum" strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively.The potential utilisation of urea by "Ferrovum" strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs "Ferrovum" strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin and Acidithiobacillus ferrivorans (iron oxidase indicates the existence of a modified pathway in "Ferrovum" strain JA12

  20. 嗜酸性氧化亚铁硫杆菌休止细胞保存时间及循环利用对施氏矿物生物合成的影响%Effects of storage time and recycling of resting Acidithiobacillus ferrooxidans cells on biogenic schwertmannite formation

    Institute of Scientific and Technical Information of China (English)

    柏双友; 梁剑茹; 廖岳华; 周立祥

    2011-01-01

    利用嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.ferrooxidans)休止细胞促进FeSO4形成的施氏矿物具有纯度高比表面积大的特点,对去除水环境中有毒重(类)金属有重要作用.为提供施氏矿物规模化生产优化参数,本研究通过摇瓶试验探讨了休止细胞保存时间对其活力的影响,以及休止细胞再次循环利用对施氏矿物生物合成中Fe2+氧化率和矿物产量的影响.结果表明,新鲜制备的A.ferrooxidans菌休止细胞可在48 h内将144 mmol·L-1 Fe2+(250 mL体系)全部氧化成Fe3+,在高浓度SO24-存在下约有41.99%的Fe3+被转化成棕红色施氏矿物沉淀,矿物产量达到1.34 g.当休止细胞在4℃保存达45 d时,Fe2+氧化率与新鲜细胞相比下降5.61%,施氏矿物产量降低35.07%.二次利用的循环A.ferrooxidans菌氧化Fe2+的能力大幅下降,其氧化性能只占新鲜休止细胞的1/7,这主要是由菌体本身氧化活性下降和矿物吸附包裹部分A.ferrooxidans菌导致菌体数量下降两个原因所致.可见,新制备的A.ferrooxidans菌休止细胞应现制现用,在4℃、pH=2.5的酸水中保存时间不宜超过30 d,A.ferrooxidans菌休止细胞可循环利用于施氏矿物的生物合成,但其效能仅为新鲜休止细胞的15%左右.%Schwertmannite biosynthesized by resting Acidithiobacillus ferrooxidans (A. ferrooxidans) with FeSO4 has high purity and specific surface area. It can play an important role in the removal of toxic heavy metals or metalloids in water environments. To provide the optimum parameters for industrial scale production of schwertmannite, the effects of storage time of resting A. ferrooxidans cells and reuse of the recycling cells on the strain growth andits ability to facilitate Fe2 + oxidation and mineral formation were investigated in batch experiments. The results indicated that the fresh resting A.ferrooxidans cells harvested within 30 d could completely oxidize 144 mmol·L- 1 Fe2

  1. Microbial leaching of marmatite by Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; QIU Guan-zhou; QIN Wen-qing; ZHANG Yan-sheng

    2006-01-01

    The bioleaching of marmatite in shaken flasks was studied. After leaching for 29 days, the leaching ratio of zinc was 91%.Three kinds of bacteria, mixture-based bacteria, 9K-based bacteria and sulfur-based bacteria were used in marmatite leaching, of which the mixture-based bacteria have the best leaching result while the sulfur-based bacteria have the worst. By analyzing the leaching residue using SEM and EDXA, the marmatite leaching mechanism was discussed.

  2. Modeling of uranium bioleaching by Acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Highlights: ► A mathematical model for the mesophilic bioleaching of uraninite is introduced. ► New rate expressions are used for the iron precipitation and uranium leaching rates. ► Good fits of the model are obtained, while the values of the parameters are within the range expected. ► The model can be applied to other bioleaching processes under the same conditions. - Abstract: In this paper, a mathematical model for the mesophilic bioleaching of uraninite is developed. The case of constant temperature, pH, and initial ore concentration is considered. The model is validated by comparing the calculated and measured values of uranium extraction, ferric and ferrous iron in solution, and cell concentration. Good fits of the model were obtained, while the values of the parameters were within the range expected. New rate expressions were used for the iron precipitation and uranium leaching rates. The rates of chemical leaching and ferric precipitation are related to the ratio of ferric to ferrous in solution. The fitted parameters can be considered applicable only to this study. In contrast, the model equation is general and can be applied to bioleaching under the same conditions.

  3. Physiology and Genetics of Acidithiobacillus species : Applications for Biomining

    OpenAIRE

    Rzhepishevska, Olena

    2008-01-01

    Bacteria from the genus Acidithiobacillus are often associated with biominingand acid mine drainage. Biomining utilises acidophilic, sulphur and ironoxidising microorganisms for recovery of metals from sulphidic low grade oresand concentrates. Acid mine drainage results in acidification and contaminationwith metals of soil and water emanating from the dissolution of metal sulphidesfrom deposits and mine waste storage. Acidophilic microorganisms play acentral role in these processes by catalys...

  4. PROGRESS OF THE STUDIES ON GENE TRANSFER SYSTEM OF THIOBACILLUS FERROOXIDANS%氧化亚铁硫杆菌基因转移系统研究进展

    Institute of Scientific and Technical Information of China (English)

    林建群; 彭基斌; 颜望明

    2001-01-01

    Thiobacillus ferrooxidans is a extremely acidophilic and obligately chemlithotrophic bacterium. It is the most important work for gene engineering of T.ferrooxidans to develop an efficient gene transfer systems. This paper summarized the genetics background of T.ferrooxidans, the process of establishing such a kind of gene transfer system, and its application in constructing arsenic resistance genetically engineered bacteria. Ref 22

  5. Evidence of cell surface iron speciation of acidophilic iron-oxidizing microorganisms in indirect bioleaching process.

    Science.gov (United States)

    Nie, Zhen-yuan; Liu, Hong-chang; Xia, Jin-lan; Yang, Yi; Zhen, Xiang-jun; Zhang, Li-Juan; Qiu, Guan-zhou

    2016-02-01

    While indirect model has been widely accepted in bioleaching, but the evidence of cell surface iron speciation has not been reported. In the present work the iron speciation on the cell surfaces of four typically acidophilic iron-oxidizing microorganism (mesophilic Acidithiobacillus ferrooxidans ATCC 23270, moderately thermophilic Leptospirillum ferriphilum YSK and Sulfobacillus thermosulfidooxidans St, and extremely thermophilic Acidianus manzaensis YN25) grown on different energy substrates (chalcopyrite, pyrite, ferrous sulfate and elemental sulfur (S(0))) were studied in situ firstly by using synchrotron-based micro- X-ray fluorescence analysis and X-ray absorption near-edge structure spectroscopy. Results showed that the cells grown on iron-containing substrates had apparently higher surface iron content than the cells grown on S(0). Both ferrous iron and ferric iron were detected on the cell surface of all tested AIOMs, and the Fe(II)/Fe(III) ratios of the same microorganism were affected by different energy substrates. The iron distribution and bonding state of single cell of A. manzaensis were then studied in situ by scanning transmission soft X-ray microscopy based on dual-energy contrast analysis and stack analysis. Results showed that the iron species distributed evenly on the cell surface and bonded with amino, carboxyl and hydroxyl groups. PMID:26645388

  6. Genome Analysis of the Biotechnologically Relevant Acidophilic Iron Oxidising Strain JA12 Indicates Phylogenetic and Metabolic Diversity within the Novel Genus “Ferrovum”

    Science.gov (United States)

    Ullrich, Sophie R.; Poehlein, Anja; Tischler, Judith S.; González, Carolina; Ossandon, Francisco J.; Daniel, Rolf; Holmes, David S.; Schlömann, Michael; Mühling, Martin

    2016-01-01

    Background Members of the genus “Ferrovum” are ubiquitously distributed in acid mine drainage (AMD) waters which are characterised by their high metal and sulfate loads. So far isolation and microbiological characterisation have only been successful for the designated type strain “Ferrovum myxofaciens” P3G. Thus, knowledge about physiological characteristics and the phylogeny of the genus “Ferrovum” is extremely scarce. Objective In order to access the wider genetic pool of the genus “Ferrovum” we sequenced the genome of a “Ferrovum”-containing mixed culture and successfully assembled the almost complete genome sequence of the novel “Ferrovum” strain JA12. Phylogeny and Lifestyle The genome-based phylogenetic analysis indicates that strain JA12 and the type strain represent two distinct “Ferrovum” species. “Ferrovum” strain JA12 is characterised by an unusually small genome in comparison to the type strain and other iron oxidising bacteria. The prediction of nutrient assimilation pathways suggests that “Ferrovum” strain JA12 maintains a chemolithoautotrophic lifestyle utilising carbon dioxide and bicarbonate, ammonium and urea, sulfate, phosphate and ferrous iron as carbon, nitrogen, sulfur, phosphorous and energy sources, respectively. Unique Metabolic Features The potential utilisation of urea by “Ferrovum” strain JA12 is moreover remarkable since it may furthermore represent a strategy among extreme acidophiles to cope with the acidic environment. Unlike other acidophilic chemolithoautotrophs “Ferrovum” strain JA12 exhibits a complete tricarboxylic acid cycle, a metabolic feature shared with the closer related neutrophilic iron oxidisers among the Betaproteobacteria including Sideroxydans lithotrophicus and Thiobacillus denitrificans. Furthermore, the absence of characteristic redox proteins involved in iron oxidation in the well-studied acidophiles Acidithiobacillus ferrooxidans (rusticyanin) and Acidithiobacillus

  7. Biological effect of Acidithiobacillus thiooxidans on some potentially toxic elements during alteration of SON 68 nuclear glass

    Science.gov (United States)

    Bachelet, M.; Crovisier, J. L.; Stille, P.; Vuilleumier, S.; Geoffroy, V.

    2009-04-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH, with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 m french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25degC. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, trace and ultra-trace elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 m under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials are found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium as tracer, showed that the progressive formation of a biofilm on the surface of glass has a protective effect against its alteration. Uranium and rare earth elements (REE) are efficiently trapped in the biogenic compartment of the system (exopolysaccharides + bacterial cells). Besides, the ratio

  8. Bioleaching of low grade uranium ore containing pyrite using A. ferrooxidans and A. thiooxidans

    International Nuclear Information System (INIS)

    A process of uranium extraction from ore containing 3.1 % pyrite by bacterial leaching was investigated in shaken flasks during 90 days. The highest uranium recovery amounting to 85.1 % was obtained using binary mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans that was exceeding results obtained by traditional acid leaching technique up to 27 %. High uranium recovery was founded to be due to the high degree of pyrite dissolution that can be readily achieved by bacterial leaching (up to 98.0 %). (author)

  9. Community dynamics of attached and free cells and the effects of attached cells on chalcopyrite bioleaching by Acidithiobacillus sp.

    Science.gov (United States)

    Yang, Hailin; Feng, Shoushuai; Xin, Yu; Wang, Wu

    2014-02-01

    The community dynamics of attached and free cells of Acidithiobacillus sp. were investigated and compared during chalcopyrite bioleaching process. In the mixed strains system, Acidithiobacillus ferrooxidans was the dominant species at the early stage while Acidithiobacillus thiooxidans owned competitive advantage from the middle stage to the end of bioprocess. Meanwhile, compared to A. ferrooxidans, more significant effects of attached cells on free biomass with A. thiooxidans were shown in either the pure or mixed strains systems. Moreover, the effects of attached cells on key chemical parameters were also studied in different adsorption-deficient systems. Consistently, the greatest reduction of key chemical ion was shown with A. thiooxidans and the loss of bioleaching efficiency was high to 50.5%. These results all demonstrated the bioleaching function of attached cells was more efficient than the free cells, especially with A. thiooxidans. These notable results would help us to further understand the chalcopyrite bioleaching.

  10. Biodegradation of the french reference nuclear glass SON 68 by Acidithiobacillus thiooxidans : protective effect of the biofilm,U and REE retention

    Science.gov (United States)

    Bachelet, M.; Crovisier, J.; Stille, P.; Boutin, R.; Vuilleumier, S.; Geoffroy, V.

    2008-12-01

    Although underground nuclear waste repositories are not expected to be favourable places for microbial activity, one should not exclude localized action of extremophilic bacteria on some materials involved in the storage concept. Among endogenous or accidentally introduced acidophiles, some are susceptible to lead to a locally drastic decreased in pH with potential consequences on materials corrosion. Experiments were performed with Acidithiobacillus thiooxidans on 100-125 μm french reference nuclear glass SON68 grains in a mineral medium under static conditions during 60 days at 25°C. Growth medium was periodically renewed and analyzed by ICP-AES and ICP-MS spectrometry for both major, traces and ultra-traces elements. Biofilm formation was evidenced by confocal laser microscopy, staining DNA with ethidium bromide and exopolysaccharides with calcofluor white. Biofilm thickness around material grains exceeded 20 μm under the chosen experimental conditions. It can be noticed that while numerous studies on biofilm formation upon interaction between Acidithiobacillus ferrooxidans and materials can be found in the literature, evidence for biofilm formation is still scarce for the case of the acidophilic bacterium A. thiooxidans. Presence of biofilm is a key parameter for material alteration at the solid/solution interface in biotic systems. Indeed, various constitutive elements of materials trapped in the polyanionic polymer of biofilm may also influence the alteration process. In particular, biofilm may reduce the alteration rate of materials by forming a protective barrier at their surface (Aouad et al., 2008). In this study, glass alteration rates, determined using strontium, molybdenum and caesium as tracers, showed that the biofilm has a protective effect against glass alteration. U and REE are efficiently trapped in the biogenic compartment of the system (exopolysaccharides (EPS) + bacterial cells). Biofilm analysis are in progress to determine whether these

  11. Bioleaching of low-grade uranium ore using Acidithiobacillus ferrooxidans

    OpenAIRE

    Pal, S; Pradhan, D.; T Das; Sukla, L. B.; Chaudhury, G. Roy

    2010-01-01

    Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda. The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external ...

  12. Bioleaching of low-grade uranium ore using Acidithiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    Bioleaching of uranium was carried out with Turamdih ore sample procured from Uranium Corporation of India Limited, Jaduguda. The bacterial strain that was used in the leaching experiments was isolated from the Jaduguda mine water sample. Efficiency of bioleaching was studied by varying parameters like pulp density and initial ferrous concentration as source of energy. It is observed that the efficiency of bioleaching was 49% at 10% pulp density (w/v) and initial pH 2.0. Addition of external has no effect on efficiency of bioleaching showing domination of direct leaching mechanism over indirect. (author)

  13. Leaching of selected heavy metals from electronic waste in the presence of the At. ferrooxidans bacteria

    OpenAIRE

    J. Willner

    2012-01-01

    Purpose: This paper presents the experimental work carried out to evaluate the leaching efficiency of zinc, nickel and lead from printed circuit boards (PCBs) using biological leaching with different quantities of acidophilic bacteria as inoculum.Design/methodology/approach: Bioleaching was conducted using periodic method in Erlenmneyer flasks, with pure cultures of At. ferrooxidans. Some conditional parameters: oxidation-reduction potential, pH were taken into account.Findings: The results d...

  14. Acidithiobacillus caldus Sulfur Oxidation Model Based on Transcriptome Analysis between the Wild Type and Sulfur Oxygenase Reductase Defective Mutant

    OpenAIRE

    Linxu Chen; Yilin Ren; Jianqun Lin; Xiangmei Liu; Xin Pang; Jianqiang Lin

    2012-01-01

    BACKGROUND: Acidithiobacillus caldus (A. caldus) is widely used in bio-leaching. It gains energy and electrons from oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs) for carbon dioxide fixation and growth. Genomic analyses suggest that its sulfur oxidation system involves a truncated sulfur oxidation (Sox) system (omitting SoxCD), non-Sox sulfur oxidation system similar to the sulfur oxidation in A. ferrooxidans, and sulfur oxygenase reductase (SOR). The complexity ...

  15. Recovery of Nickel and Cobalt from Laterite Tailings by Reductive Dissolution under Aerobic Conditions Using Acidithiobacillus Species.

    Science.gov (United States)

    Marrero, J; Coto, O; Goldmann, S; Graupner, T; Schippers, A

    2015-06-01

    Biomining of sulfidic ores has been applied for almost five decades. However, the bioprocessing of oxide ores such as laterites lags commercially behind. Recently, the Ferredox process was proposed to treat limonitic laterite ores by means of anaerobic reductive dissolution (AnRD), which was found to be more effective than aerobic bioleaching by fungi and other bacteria. We show here that the ferric iron reduction mediated by Acidithiobacillus thiooxidans can be applied to an aerobic reductive dissolution (AeRD) of nickel laterite tailings. AeRD using a consortium of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans extracted similar amounts of nickel (53-57%) and cobalt (55-60%) in only 7 days as AnRD using Acidithiobacillus ferrooxidans. The economic and environmental advantages of AeRD for processing of laterite tailings comprise no requirement for an anoxic atmosphere, 1.8-fold less acid consumption than for AnRD, as well as nickel and cobalt recovered in a ferrous-based pregnant leach solution (PLS), facilitating the subsequent metal recovery. In addition, an aerobic acid regeneration stage is proposed. Therefore, AeRD process development can be considered as environmentally friendly for treating laterites with low operational costs and as an attractive alternative to AnRD.

  16. Oxidation study of the synthetic sulfides molybdenite (MoS2) and covellite (CuS) by acidithiobacillus ferrooxidants using respirometric experiments

    International Nuclear Information System (INIS)

    This paper analyses the oxidation of covellite and molybdenite by Acidithiobacillus ferrooxidans strain LR using respirometric experiments. The results showed that both sulfides were oxidized by A. ferrooxidans, however, the covellite oxidation was much higher than molybdenite. Regarding the kinetic oxidation, the findings revealed that just molybdenite oxidation followed the classical Michaelis-Menten kinetic. It is probably associated with the pathway which these sulfides react to chemistry-bacterial attack, what is influenced by its electronic structures. Besides, experiments conducted in the presence of Fe3+ did not indicate alterations in molybdenite oxidation. Thus, ferric ions seem not to be essential to the sulfide oxidations. (author)

  17. Use of an acidophilic yeast strain to enable the growth of leaching bacteria on solid media.

    Science.gov (United States)

    Ngom, Baba; Liang, Yili; Liu, Yi; Yin, Huaqun; Liu, Xueduan

    2015-03-01

    In this study, a Candida digboiensis strain was isolated from a heap leaching plant in Zambia and used in double-layer agar plate to efficiently isolate and purify leaching bacteria. Unlike Acidiphilium sp., the yeast strain was tetrathionate tolerant and could metabolize a great range of organic compounds including organic acids. These properties allowed the yeast strain to enable and fasten the growth of iron and sulfur oxidizers on double-layer agar plate. The isolates were identified as Acidithiobacillus ferrooxidans FOX1, Leptospirillun ferriphilum BN, and Acidithiobacillus thiooxidans ZMB. These three leaching bacteria were inhibited by organic acids such as acetic and propionic acids; however, their activities were enhanced by Candida digboiensis NB under dissolved organic matter stress.

  18. Bioleaching of chromium from tannery sludge by indigenous Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Wang, Yuan-Shan; Pan, Zhi-Yan; Lang, Jian-Min; Xu, Jian-Miao; Zheng, Yu-Guo

    2007-08-17

    Chromium in tannery sludge will cause serious environmental problems and is toxic to organisms. The acidophilic sulfur-oxidizing Acidithiobacillus thiooxidans can leach heavy metals form urban and industrial wastes. This study examined the ability of an indigenous sulfur-oxidizing A. thiooxidans to leach chromium from tannery sludge. The results showed that the pH of sludge mixture inoculated with the indigenous A. thiooxidans decreased to around 2.0 after 4 days. After 6 days incubation in shaking flasks at 30 degrees C and 160 rpm, up to 99% of chromium was solubilized from tannery sludge. When treated in a 2-l bubble column bioreactor for 5 days at 30 degrees C and aeration of 0.5 vvm, 99.7% of chromium was leached from tannery sludge. The results demonstrated that chromium in tannery sludge can be efficiently leached by the indigenous A. thiooxidans.

  19. Dynamic of active microorganisms inhabiting a bioleaching industrial heap of low‐grade copper sulfide ore monitored by real‐time PCR and oligonucleotide prokaryotic acidophile microarray

    OpenAIRE

    Remonsellez, Francisco; Galleguillos, Felipe; Moreno‐Paz, Mercedes; Parro, Víctor; Acosta, Mauricio; Demergasso, Cecilia

    2009-01-01

    Summary The bioleaching of metal sulfide has developed into a very important industrial process and understanding the microbial dynamic is key to advancing commercial bioleaching operations. Here we report the first quantitative description of the dynamic of active communities in an industrial bioleaching heap. Acidithiobacillus ferrooxidans was the most abundant during the first part of the leaching cycle, while the abundance of Leptospirillum ferriphilum and Ferroplasma acidiphilum increase...

  20. Bioleaching of metals from steel slag by Acidithiobacillus thiooxidans culture supernatant.

    Science.gov (United States)

    Hocheng, Hong; Su, Cheer; Jadhav, Umesh U

    2014-12-01

    The generation of 300–500 kg of slag per ton of the steel produced is a formidable amount of solid waste available for treatment. They usually contain considerable quantities of valuable metals. In this sense, they may become either important secondary resource if processed in eco-friendly manner for secured supply of contained metals or potential pollutants, if not treated properly. It is possible to recover metals from steel slag by applying bioleaching process. Electric arc furnace (EAF) slag sample was used for bioleaching of metals. In the present study, before bioleaching experiment water washing of an EAF slag was carried out. This reduced slag pH from 11.2 to 8.3. Culture supernatants of Acidithiobacillus thiooxidans (At. thiooxidans), Acidithiobacillus ferrooxidans (At. ferrooxidans), and Aspergillus niger (A. niger) were used for metal solubilization. At. thiooxidans culture supernatant containing 0.016 M sulfuric acid was found most effective for bioleaching of metals from an EAF slag. Maximum metal extraction was found for Mg (28%), while it was least for Mo (0.1%) in six days. Repeated bioleaching cycles increased metal recovery from 28% to 75%, from 14% to 60% and from 11% to 27%, for Mg, Zn and Cu respectively.

  1. 采用SELDI蛋白质芯片技术研究氧化亚铁硫杆菌对磷酸盐缺失的反应%Research on The Proteome Response of Acidithiobacillus ferrooxidans to Phosphate Starvation by SELDI-Protein Chip Technologies

    Institute of Scientific and Technical Information of China (English)

    贺治国; 钟慧; 李庆华; 顾帼华; 胡岳华; 李桂源

    2008-01-01

    A cidithiobacillus ferrooxidans is a chemolithotrophic microorganism capable of using ferrous ions and sulphides as energy sources. This microorganism has an important role in the bioleaching of minerals. During this process, the bacteria are normally subjected to several stressing conditions, such as temperature changes, lack of nutrients or pH changes, which may affect the efficiency of the bacterial action. SELDI is a recent technology that allows for high-throughput proteomics studies. The Protein Chip SELDI technology was used to generate comparative protein profiles of A c idithiobacillus ferrooxidans grown under phosphate starvation or normal condition additionally adding Fe2+ as energy resource. There were 13 significantly differential expressed protein's peaks found by using SELDI Protein Chip technologies, which made a solid foundation for further isolation these low molecular proteins by adopting technologies such as HPLC etc.%氧化亚铁硫杆菌(At.f)是能够利用Fe2+和硫化矿来获取能量的一种化能自养菌.这种细菌在金属硫化矿的生物浸出中起着重要的作用.在硫化矿的生物浸出过程中,浸矿细菌通常会遇到多种胁迫条件,如温度的变化、营养成分的缺失和pH值的变化等,这些因素会影响到细菌的活性.因此对在胁迫条件下这类细菌的应急反应生理机制的研究具有重要的意义.SELDI蛋白质芯片技术是近年一种高通量的蛋白质组学研究技术.测定了以Fe2+为能源正常条件培养的At.f和磷酸盐缺失培养At.f的生长情况,绘制了相应的生长曲线;采用NP20蛋白质芯片,对At.f总蛋白的蛋白质芯片上样量进行了优化.在此基础上,采用IMAC-Cu、SAX2、WCX2三种特异性SELDI蛋白质芯片技术,获取了磷酸盐缺失培养At.f与正常条件培养的At.f的比较蛋白质图谱,采用软件对比较蛋白质图谱进行分析,发现了磷酸盐缺失培养At.f的13个明显差异表达的蛋白质分子,为

  2. Thiobacillus ferrooxidans detection using immunoelectron microscopy.

    Science.gov (United States)

    Coto, O; Fernández, A I; León, T; Rodríguez, D

    1992-11-01

    A specific, fast and very sensitive immunoelectron microscopy method was developed to morphologically and serologically distinguish different cultures of iron oxidizers. Bacteria isolated from the acidic waters of "Matahambre" and "Mina Delita" mines (Cuba) were characterized. An antiserum specific to Thiobacillus ferrooxidans did not react with other bacteria also present in the acidic waters of mine drainage. Our results suggest the occurrence of some strains of Thiobacillus ferrooxidans, Thiobacillus thiooxidans and Leptospirillum ferrooxidans in these waters.

  3. Improved chalcopyrite bioleaching by Acidithiobacillus sp. via direct step-wise regulation of microbial community structure.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    A direct step-wise regulation strategy of microbial community structure was developed for improving chalcopyrite bioleaching by Acidithiobacillus sp. Specially, the initial microbial proportion between Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was controlled at 3:1 with additional 2 g/L Fe(2+) for faster initiating iron metabolism. A. thiooxidans biomass was fed via a step-wise strategy (8-12th d) with the microbial proportion 1:1 for balancing community structure and promoting sulfur metabolism in the stationary phase. A. thiooxidans proportion was further improved via another step-wise feeding strategy (14-18th d) with the microbial proportion 1:2 for enhancing sulfur metabolism and weakening jarosite passivation in the later phase. With the community structure-shift control strategy, biochemical reaction was directly regulated for creating a better balance in different phases. Moreover, the final copper ion was increased from 57.1 to 93.2 mg/L, with the productivity 2.33 mg/(Ld). The novel strategy may be valuable in optimization of similar bioleaching process.

  4. Improved chalcopyrite bioleaching by Acidithiobacillus sp. via direct step-wise regulation of microbial community structure.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    A direct step-wise regulation strategy of microbial community structure was developed for improving chalcopyrite bioleaching by Acidithiobacillus sp. Specially, the initial microbial proportion between Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was controlled at 3:1 with additional 2 g/L Fe(2+) for faster initiating iron metabolism. A. thiooxidans biomass was fed via a step-wise strategy (8-12th d) with the microbial proportion 1:1 for balancing community structure and promoting sulfur metabolism in the stationary phase. A. thiooxidans proportion was further improved via another step-wise feeding strategy (14-18th d) with the microbial proportion 1:2 for enhancing sulfur metabolism and weakening jarosite passivation in the later phase. With the community structure-shift control strategy, biochemical reaction was directly regulated for creating a better balance in different phases. Moreover, the final copper ion was increased from 57.1 to 93.2 mg/L, with the productivity 2.33 mg/(Ld). The novel strategy may be valuable in optimization of similar bioleaching process. PMID:26011694

  5. Photoelectrochemical response of natural limonite and its effect on the growth of Acidithiobacillus ferrooxidans%天然褐铁矿的光电化学响应及对嗜酸性氧化亚铁硫杆菌生长的影响

    Institute of Scientific and Technical Information of China (English)

    颜云花; 李艳; 鲁安怀; 王鑫; 丁竑瑞; 曾翠平; 王长秋

    2009-01-01

    The effect of natural limonite on the growth of Acidithiabacillus ferrooxidans was studied through control experiments. The main phases of the natural limonite sample used in the experiments were identified as the mixture of goethite and hematite by X-ray diffraction analysis (XRD). UV-vis diffuse reflectance spectra and time-current curve under different irradiation conditions indicate that natural limonite has a good photoelectrochemical response. Dual-chambered system reactions were carried out with an "H"-type device. The results of three sets of control experiments show that A. f. grows better when external electrons are supplied by the photocatalysis of semiconductor minerals. Within 96 h, the cell density increases by 12 times. The variation of Fe~(2+) concentration is consistent with the growth curve of A. f. in control experiments, which reveals that natural limonite indirectly improves the growth of A. f. The mechanism can be interpreted as follows: Natural limonite can produce photo-generated electron-hole pairs under the visible light. The photo-generated hole is captured by the electron donor of ascorbic acid, while the separated photo-generated electrons transfer into cathode chamber to reduce Fe~(3+) to Fe~(2+) . The process achieves the electrochemical regeneration of Fe~(2+), which provides adequate electron energy for the growth of A.f.%通过对比实验研究了天然褐铁矿对嗜酸性氧化亚铁硫杆菌(A.f.)生长的影响.利用X射线衍射分析(XRD)确定实验中所用天然褐铁矿样品的主要物相为针铁矿和赤铁矿,紫外-可见漫反射光谱(UV-Vis DRS)和不同光照条件下的时间电流曲线表明天然褐铁矿在可见光下具有良好的光电化学响应.采用"H"型装置进行双室体系反应,设置了3组对比实验,结果显示A.f.在有光催化电子传入情况下生长较好,在96 h内细胞浓度增加了12倍,3组实验中Fe2+浓度的变化规律与A.f.的生长趋势相对应.由此揭示了

  6. [Inhibition of Low Molecular Organic Acids on the Activity of Acidithiobacillus Species and Its Effect on the Removal of Heavy Metals from Contaminated Soil].

    Science.gov (United States)

    Song, Yong-wei; Wang, He-rul; Cao, Yan-xiao; Li, Fei; Cui, Chun-hong; Zhou, Li

    2016-05-15

    Application of organic fertilizer can reduce the solubility and bioavailability of heavy metals in contaminated soil, but in the flooded anaerobic environment, organic fertilizer will be decomposed to produce a large number of low molecular organic acids, which can inhibit the biological activity of Acidithiobacillus species. Batch cultures studies showed that the monocarboxylic organic acids including formic acid, acetic acid, propionic acid, and butyric acid exhibited a marked toxicity to Acidithiobacillus species, as indicated by that 90% of inhibitory rate for Fe2 and So oxidation in 72 h were achieved at extremely low concentrations of 41.2 mg · L⁻¹, 78.3 mg · L⁻¹, 43.2 mg · L⁻¹, 123.4 mg · L⁻¹ and 81.9 mg 230. 4 mg · L⁻¹, 170.1 mg · L⁻¹, 123.4 mg · L⁻¹ respectively. Of these organic acids, formic acid was the most toxic one as indicated by that Fe2 and So oxidation was almost entirely inhibited at a low concentration. In addition, it was found that Acidithiobacillus ferrooxidans was more sensitive to low molecular organic acids than Acidithiobacillus thiooxidans. What's more, there was little effect on biological acidification process of heavy metal contaminated soil when organic acids were added at initial stage (Oh), but it was completely inhibited when these acids were added after 12 h of conventional biological acidification, thus decreasing the efficiency of heavy metals dissolution from soil.

  7. Leaching of selected heavy metals from electronic waste in the presence of the At. ferrooxidans bacteria

    Directory of Open Access Journals (Sweden)

    J. Willner

    2012-12-01

    Full Text Available Purpose: This paper presents the experimental work carried out to evaluate the leaching efficiency of zinc, nickel and lead from printed circuit boards (PCBs using biological leaching with different quantities of acidophilic bacteria as inoculum.Design/methodology/approach: Bioleaching was conducted using periodic method in Erlenmneyer flasks, with pure cultures of At. ferrooxidans. Some conditional parameters: oxidation-reduction potential, pH were taken into account.Findings: The results demonstrate that a greater quantity of inoculum conduces the extraction of metals from the solid into solution only in the initial stage of the bioleaching. 57% and 51% of the available Zn and Ni were leached from PCBs in the presence of At. ferrooxidans bacteria. No Pb was detected in the leachate during bioleaching.Research limitations/implications: Further research is needed to determine the influence of various conditions and parameters on activity of microorganisms and efficiency of metals bioleaching from waste materials.Practical implications: Presented study is a continuation of research conducted on the possibility of metals recovery from waste by biological methods.Originality/value: The paper could be an interesting source of information for researchers who apply bioleaching methods.

  8. Acidithiobacillus thiooxidans secretome containing a newly described lipoprotein Licanantase enhances chalcopyrite bioleaching rate.

    Science.gov (United States)

    Bobadilla Fazzini, Roberto A; Levican, Gloria; Parada, Pilar

    2011-02-01

    The nature of the mineral-bacteria interphase where electron and mass transfer processes occur is a key element of the bioleaching processes of sulfide minerals. This interphase is composed of proteins, metabolites, and other compounds embedded in extracellular polymeric substances mainly consisting of sugars and lipids (Gehrke et al., Appl Environ Microbiol 64(7):2743-2747, 1998). On this respect, despite Acidithiobacilli-a ubiquitous bacterial genera in bioleaching processes (Rawlings, Microb Cell Fact 4(1):13, 2005)-has long been recognized as secreting bacteria (Jones and Starkey, J Bacteriol 82:788-789, 1961; Schaeffer and Umbreit, J Bacteriol 85:492-493, 1963), few studies have been carried out in order to clarify the nature and the role of the secreted protein component: the secretome. This work characterizes for the first time the sulfur (meta)secretome of Acidithiobacillus thiooxidans strain DSM 17318 in pure and mixed cultures with Acidithiobacillus ferrooxidans DSM 16786, identifying the major component of these secreted fractions as a single lipoprotein named here as Licanantase. Bioleaching assays with the addition of Licanantase-enriched concentrated secretome fractions show that this newly found lipoprotein as an active protein additive exerts an increasing effect on chalcopyrite bioleaching rate.

  9. Hydrogen sulfide removal from air by Acidithiobacillus thiooxidans in a trickle bed reactor.

    Science.gov (United States)

    Ramirez, M; Gómez, J M; Cantero, D; Páca, J; Halecký, M; Kozliak, E I; Sobotka, M

    2009-09-01

    A strain of Acidithiobacillus thiooxidans immobilized in polyurethane foam was utilized for H(2)S removal in a bench-scale trickle-bed reactor, testing the limits of acidity and SO(4) (2-) accumulation. The use of this acidophilic strain resulted in remarkable stability in the performance of the system. The reactor maintained a >98-99 % H(2)S removal efficiency for c of up to 66 ppmv and empty bed residence time 98 % H(2)S was achieved under steady-state conditions, over the pH range of 0.44-7.30. Despite the accumulation of acidity and SO(4) (2-) (up to 97 g/L), the system operated without inhibition.

  10. Liquid-nitrogen cryopreservation of three kinds of autotrophicbioleaching bacteria

    Institute of Scientific and Technical Information of China (English)

    WU Xue-ling; XIN Xiao-hong; JIANG Ying; LIANG Ren-xing; YUAN Peng; FANG Cheng-xiang

    2008-01-01

    Three kinds of autotrophic bioleaching bacteria strains,including mesophilic and acidophilic ferrous ion-oxidizing bacteria Acidithiobacillus ferrooxidans (A.ferrooxidans),mesophilic and acidophilic sulfur-oxidizing bacteria Acidithiobacillus thiooxidans (A.thiooxidans),and moderately thermophilic sulfur-oxidizing bacteria Acidianus brierleyi,were cryopreserved in liquid nitrogen and their ferrous ion- or sulfur-oxidizing activities were investigated and compared with the original ones.The results revealed that ferrous ion/sulfur oxidation activities of the strains were almost equal before and after cryopreservation.Glycerin was used as cryoprotective agent.In conclusion,liquid-nitrogen cryopreservation is a simple and effective method for autotrophic bioleaching microorganisms.

  11. Sulfur Oxygenase Reductase (Sor) in the Moderately Thermoacidophilic Leaching Bacteria: Studies in Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus

    Science.gov (United States)

    Janosch, Claudia; Remonsellez, Francisco; Sand, Wolfgang; Vera, Mario

    2015-01-01

    The sulfur oxygenase reductase (Sor) catalyzes the oxygen dependent disproportionation of elemental sulfur, producing sulfite, thiosulfate and sulfide. Being considered an “archaeal like” enzyme, it is also encoded in the genomes of some acidophilic leaching bacteria such as Acidithiobacillus caldus, Acidithiobacillus thiooxidans, Acidithiobacillus ferrivorans and Sulfobacillus thermosulfidooxidans, among others. We measured Sor activity in crude extracts from Sb. thermosulfidooxidans DSM 9293T. The optimum temperature for its oxygenase activity was achieved at 75 °C, confirming the “thermophilic” nature of this enzyme. Additionally, a search for genes probably involved in sulfur metabolism in the genome sequence of Sb. thermosulfidooxidans DSM 9293T was done. Interestingly, no sox genes were found. Two sor genes, a complete heterodisulfidereductase (hdr) gene cluster, three tetrathionate hydrolase (tth) genes, three sulfide quinonereductase (sqr), as well as the doxD component of a thiosulfate quinonereductase (tqo) were found. Seven At. caldus strains were tested for Sor activity, which was not detected in any of them. We provide evidence that an earlier reported Sor activity from At. caldus S1 and S2 strains most likely was due to the presence of a Sulfobacillus contaminant. PMID:27682113

  12. Sulfur Oxygenase Reductase (Sor in the Moderately Thermoacidophilic Leaching Bacteria: Studies in Sulfobacillus thermosulfidooxidans and Acidithiobacillus caldus

    Directory of Open Access Journals (Sweden)

    Claudia Janosch

    2015-10-01

    Full Text Available The sulfur oxygenase reductase (Sor catalyzes the oxygen dependent disproportionation of elemental sulfur, producing sulfite, thiosulfate and sulfide. Being considered an “archaeal like” enzyme, it is also encoded in the genomes of some acidophilic leaching bacteria such as Acidithiobacillus caldus, Acidithiobacillus thiooxidans, Acidithiobacillus ferrivorans and Sulfobacillus thermosulfidooxidans, among others. We measured Sor activity in crude extracts from Sb. thermosulfidooxidans DSM 9293T. The optimum temperature for its oxygenase activity was achieved at 75 °C, confirming the “thermophilic” nature of this enzyme. Additionally, a search for genes probably involved in sulfur metabolism in the genome sequence of Sb. thermosulfidooxidans DSM 9293T was done. Interestingly, no sox genes were found. Two sor genes, a complete heterodisulfidereductase (hdr gene cluster, three tetrathionate hydrolase (tth genes, three sulfide quinonereductase (sqr, as well as the doxD component of a thiosulfate quinonereductase (tqo were found. Seven At. caldus strains were tested for Sor activity, which was not detected in any of them. We provide evidence that an earlier reported Sor activity from At. caldus S1 and S2 strains most likely was due to the presence of a Sulfobacillus contaminant.

  13. Bioflotation of pyrite with Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Shaoxian Song; Yimin Zhang; Shouci Lu

    2004-01-01

    Bioflotation of pyrite with bacteria Thiobacillus ferrooxidans in the presence or absence of potassium ethyl xanthate was studied on a pure pyrite through microflotation and electrophoretic light scattering measurements. The experimental results showed that in the absence of xanthate, pyrite flotation is slightly enhanced by Thiobacillus ferrooxidans. However, with xanthate as a collector, pyrite flotation is strongly depressed after being exposed to the bacteria. The longer is the time when the pyrite is exposed to the bacteria, the stronger the depression is. The mechanism of the depression might be due to the formation of the biofilms of Thiobacillus ferrooxidans on pyrite surfaces, preventing the adsorption of xanthate on pyrite surfaces in the form of dixanthogen or xanthate ions.

  14. Stoichiometric modeling of oxidation of reduced inorganic sulfur compounds (Riscs) in Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Bobadilla Fazzini, Roberto A; Cortés, Maria Paz; Padilla, Leandro; Maturana, Daniel; Budinich, Marko; Maass, Alejandro; Parada, Pilar

    2013-08-01

    The prokaryotic oxidation of reduced inorganic sulfur compounds (RISCs) is a topic of utmost importance from a biogeochemical and industrial perspective. Despite sulfur oxidizing bacterial activity is largely known, no quantitative approaches to biological RISCs oxidation have been made, gathering all the complex abiotic and enzymatic stoichiometry involved. Even though in the case of neutrophilic bacteria such as Paracoccus and Beggiatoa species the RISCs oxidation systems are well described, there is a lack of knowledge for acidophilic microorganisms. Here, we present the first experimentally validated stoichiometric model able to assess RISCs oxidation quantitatively in Acidithiobacillus thiooxidans (strain DSM 17318), the archetype of the sulfur oxidizing acidophilic chemolithoautotrophs. This model was built based on literature and genomic analysis, considering a widespread mix of formerly proposed RISCs oxidation models combined and evaluated experimentally. Thiosulfate partial oxidation by the Sox system (SoxABXYZ) was placed as central step of sulfur oxidation model, along with abiotic reactions. This model was coupled with a detailed stoichiometry of biomass production, providing accurate bacterial growth predictions. In silico deletion/inactivation highlights the role of sulfur dioxygenase as the main catalyzer and a moderate function of tetrathionate hydrolase in elemental sulfur catabolism, demonstrating that this model constitutes an advanced instrument for the optimization of At. thiooxidans biomass production with potential use in biohydrometallurgical and environmental applications.

  15. Geochemical diversity in S processes mediated by culture-adapted and environmental-enrichments of Acidithiobacillus spp.

    Science.gov (United States)

    Bernier, Luc; Warren, Lesley A.

    2007-12-01

    Coupled S speciation and acid generation resulting from S processing associated with five different microbial treatments, all primarily Acidithiobacillus spp. (i.e. autotrophic S-oxidizers) were evaluated in batch laboratory experiments. Microbial treatments included two culture-adapted strains, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, their consortia and two environmental enrichments from a mine tailings lake that were determined to be >95% Acidithiobacillus spp., by whole-cell fluorescent hybridization. Using batch experiments simulating acidic mine waters with no carbon amendments, acid generation, and S speciation associated with the oxidation of three S substrates (thiosulfate, tetrathionate, and elemental S) were evaluated. Aseptic controls showed no observable pH decrease over the experimental time course (1 month) for all three S compounds examined. In contrast, pH decreased in all microbial treatments from starting pH values of 4 to 2 or less for all three S substrates. Results show a non-linear relationship between the pH dynamics of the batch cultures and their corresponding sulfate concentrations, and indicate how known microbial S processing pathways have opposite impacts, ultimately on pH dynamics. Associated geochemical modeling indicated negligible abiogenic processes contributing to the observed results, indicating strong microbial control of acid generation extending over pH ranges from 4 to less than 2. However, the observed acid generation rates and associated S speciation were both microbial treatment and substrate-specific. Results reveal a number of novel insights regarding microbial catalysis of S oxidation: (1) metabolic diversity in S processing, as evidenced by the observed geochemical signatures in S chemical speciation and rates of acid generation amongst phylogenetically similar organisms (to the genus level); (2) consortial impacts differ from those of individual strain members; (3) environmental enrichments

  16. The effect of the introduction of exogenous strain Acidithiobacillus thiooxidans A01 on functional gene expression, structure and function of indigenous consortium during pyrite bioleaching.

    Science.gov (United States)

    Liu, Yi; Yin, Huaqun; Zeng, Weimin; Liang, Yili; Liu, Yao; Baba, Ngom; Qiu, Guanzhou; Shen, Li; Fu, Xian; Liu, Xueduan

    2011-09-01

    Acidithiobacillus thiooxidans A01 was added to a consortium of bioleaching bacteria including Acidithiobacilluscaldus, Leptospirillumferriphilum, Acidithiobacillus ferrooxidans, Sulfobacillus thermosulfidooxidans, Acidiphilium spp., and Ferroplasma thermophilum cultured in modified 9 K medium containing 0.5% (w/v) pyrite, and 10.7% increase of bioleaching rate was observed. Changes in community structure and gene expression were monitored with real-time PCR and functional gene arrays (FGAs). Real-time PCR showed that addition of At. thiooxidans caused increased numbers of all consortium members except At. caldus, and At. caldus, L. ferriphilum, and F. thermophilum remained dominant in this community. FGAs results showed that after addition of At. thiooxidans, most genes involved in iron, sulfur, carbon, and nitrogen metabolisms, metal resistance, electron transport, and extracellular polymeric substances of L. ferriphilum, F. thermophilum, and Acidiphilium spp., were up-regulated while most of these genes were down-regulated at 70-78 h in At. caldus and up-regulated in At. ferrooxidans, then down-regulated at 82-86 h.

  17. Purification and some properties of ubiquinol oxidase from obligately chemolithotrophic iron-oxidizing bacterium, Thiobacillus ferrooxidans NASF-1.

    Science.gov (United States)

    Kamimura, K; Fujii, S; Sugio, T

    2001-01-01

    Ubiquinol-oxidizing activity was detected in an acidophilic chemolithotrophic iron-oxidizing bacterium, T. ferrooxidans. The ubiquinol oxidase was purified 79-fold from plasma membranes of T. ferrooxidans NASF-1 cells. The purified oxidase is composed of two polypeptides with apparent molecular masses of 32,600 and 50,100 Da, as measured by gel electrophoresis in the presence of sodium dodecyl sulfate. The absorption spectrum of the reduced enzyme at room temperature showed big peaks at 530 and 563, and a small broad peak at 635 nm, indicating the involvement of cytochromes b and d. Characteristic peaks of cytochromes a and c were not observed in the spectrum at around 600 and 550 nm, respectively. This enzyme combined with CO, and its CO-reduced minus reduced difference spectrum showed peaks at 409 nm and 563 nm and a trough at 431 nm. These results indicated that the oxidase contained cytochrome b, but the involvement of cytochrome d was not clear. The enzyme catalyzed the oxidations of ubiquinol-2 and reduced N,N,N',N'-tetramethyl-p-phenylenediamine dihydrochloride. The ubiquinol oxidase activity was activated by the addition of albumin and lecithin to the reaction mixture and inhibited by the respiratory inhibitors KCN, HQNO, NaN3, and antimycin A1, although the enzyme was relatively resistant to KCN, and the divalent cation, Zn2+, compared with ubiquinol oxidases of E. coli. PMID:11272847

  18. Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

    Science.gov (United States)

    Sand, Wolfgang; Gehrke, Tilman

    2006-01-01

    Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

  19. Mechanism of arsenic tolerance and bioremoval of arsenic by Acidithiobacilus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Chandra Prabha M N

    2011-08-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 This paper reports the studies on mechanism of arsenic tolerance and bioremoval of arsenic ions (arsenite or arsenate by Acidithiobacillus ferrooxidans. Exposure of cells to arsenic ions resulted in increased cell surface hydrophobicity, decreased electrophoretic mobility and stronger adsorption affinity towards arsenopyrite. The mechanism of tolerance to arsenic ions were specific and could be attributed to the changes in specific protein expression in the outer membrane and cytosolic membrane fractions. Biosorption studies showed decrease in solution arsenic concentration only with ferrous–grown cells indicating that presence of ferric ions in the EPS was necessary for binding or entrapment of arsenic ions in the EPS. Bacterial EPS of ferrous–grown wild cells were able to uptake arsenate ions due to the strong affinity of ferric ions towards arsenate ions. Neither cells nor the ferric ions were capable of precipitating or oxidizing arsenite ions directly. Both arsenate ions and arsenite ions were co–precipitated with ferric ions formed during the growth of the bacteria.  

  20. [Inhibition of Low Molecular Organic Acids on the Activity of Acidithiobacillus Species and Its Effect on the Removal of Heavy Metals from Contaminated Soil].

    Science.gov (United States)

    Song, Yong-wei; Wang, He-rul; Cao, Yan-xiao; Li, Fei; Cui, Chun-hong; Zhou, Li

    2016-05-15

    Application of organic fertilizer can reduce the solubility and bioavailability of heavy metals in contaminated soil, but in the flooded anaerobic environment, organic fertilizer will be decomposed to produce a large number of low molecular organic acids, which can inhibit the biological activity of Acidithiobacillus species. Batch cultures studies showed that the monocarboxylic organic acids including formic acid, acetic acid, propionic acid, and butyric acid exhibited a marked toxicity to Acidithiobacillus species, as indicated by that 90% of inhibitory rate for Fe2 and So oxidation in 72 h were achieved at extremely low concentrations of 41.2 mg · L⁻¹, 78.3 mg · L⁻¹, 43.2 mg · L⁻¹, 123.4 mg · L⁻¹ and 81.9 mg 230. 4 mg · L⁻¹, 170.1 mg · L⁻¹, 123.4 mg · L⁻¹ respectively. Of these organic acids, formic acid was the most toxic one as indicated by that Fe2 and So oxidation was almost entirely inhibited at a low concentration. In addition, it was found that Acidithiobacillus ferrooxidans was more sensitive to low molecular organic acids than Acidithiobacillus thiooxidans. What's more, there was little effect on biological acidification process of heavy metal contaminated soil when organic acids were added at initial stage (Oh), but it was completely inhibited when these acids were added after 12 h of conventional biological acidification, thus decreasing the efficiency of heavy metals dissolution from soil. PMID:27506054

  1. Bioleaching of metals from electronic scrap by moderately thermophilic acidophilic bacteria

    NARCIS (Netherlands)

    Ilyas, Sadia; Anwar, Munir A.; Niazi, Shahida B.; Ghauri, M. Afzal

    2007-01-01

    The present work was aimed at studying the bioleachability of metals from electronic scrap by the selected moderately thermophilic strains of acidophilic chemolithotrophic and acidophilic heterotrophic bacteria. These included Sulfobacillus thermosulfidooxidans and an unidentified acidophilic hetero

  2. Biosynthesis of bifunctional iron oxyhydrosulfate by Acidithiobacillus ferroxidans and their application to coagulation and adsorption.

    Science.gov (United States)

    Gan, Min; Song, Zibo; Jie, Shiqi; Zhu, Jianyu; Zhu, Yaowu; Liu, Xinxing

    2016-02-01

    Coagulation and adsorption are important environmental technologies, which were widely applied in water treatment. In this study, a type of villous iron oxyhydrosulfate with low crystallinity, high content iron, sulfate and hydroxyl was synthesized by Acidithiobacillus ferrooxidans, which possessed coagulation and heavy metal adsorption ability simultaneously. The results showed that the Cu(II) adsorption capacity increased within a small range over the pH range of 3.0-5.0 but increased evidently over the range of 6.0-8.0. The maximal Cu(II) adsorption capacity of sample Af and Gf reached 50.97 and 46.08mg/g respectively. The optimum pH for Cr(VI) adsorption was 6.0, and the maximal adsorption capacity reached 51.32 and 59.57mg/g. The Langmuir isotherm can better describe the adsorption behavior of Cr(VI). Coagulation performance of the iron oxyhydrosulfate (Sh) has been significantly enhanced by polysilicic acid (PSA), which was mainly determined by PSA/Sh ratio, pH and coagulant dosage. Coagulation efficiency maintained approximately at 98% when the PSA/Sh ratio ranged from 0.4/0.1 to 1.0/0.1. Polysilicic acid worked efficiently in wide pH range extending, from 2 to 3.5. Coagulation performance improved significantly with the increasing of the coagulant dosage at lower dosage range, while, at higher dosage range, the improvement was not evident even with more coagulant addition.

  3. THE DEPRESSION OF PYRITE FLOTATION BY THIOBACILLUS FERROOXIDANS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The experimental studies on the microbial flotation of a pure pyrite sample using Thiobacillus ferrooxidans was conducted in the laboratory. The results indicate that Thiobacillus ferrooaidans has strong depression effect on the flotation of pyrite. Thiobacillus f errooxidans can adsorb on the surface of pyrite in a very short time (a few min. ), changing the surface from hydrophobic into hydrophilic and making the pyrite particles to lose their floatability. Therefore, Thiobacillus ferrooxidans is an effective microbial depressant of pyrite. It has also been pointed out that the depression of pyrite by Thiobacillus ferrooxidans is caused by the adsorption of the microbial colloids, but not by the oxidation effect.

  4. A new genome of Acidithiobacillus thiooxidans provides insights into adaptation to a bioleaching environment.

    Science.gov (United States)

    Travisany, Dante; Cortés, María Paz; Latorre, Mauricio; Di Genova, Alex; Budinich, Marko; Bobadilla-Fazzini, Roberto A; Parada, Pilar; González, Mauricio; Maass, Alejandro

    2014-11-01

    Acidithiobacillus thiooxidans is a sulfur oxidizing acidophilic bacterium found in many sulfur-rich environments. It is particularly interesting due to its role in bioleaching of sulphide minerals. In this work, we report the genome sequence of At. thiooxidans Licanantay, the first strain from a copper mine to be sequenced and currently used in bioleaching industrial processes. Through comparative genomic analysis with two other At. thiooxidans non-metal mining strains (ATCC 19377 and A01) we determined that these strains share a large core genome of 2109 coding sequences and a high average nucleotide identity over 98%. Nevertheless, the presence of 841 strain-specific genes (absent in other At. thiooxidans strains) suggests a particular adaptation of Licanantay to its specific biomining environment. Among this group, we highlight genes encoding for proteins involved in heavy metal tolerance, mineral cell attachment and cysteine biosynthesis. Several of these genes were located near genetic motility genes (e.g. transposases and integrases) in genomic regions of over 10 kbp absent in the other strains, suggesting the presence of genomic islands in the Licanantay genome probably produced by horizontal gene transfer in mining environments.

  5. Fractionation behavior of heavy metals in soil during bioleaching with Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Naresh Kumar, R; Nagendran, R

    2009-09-30

    The effects of bioleaching on the fractionation of soil heavy metals were investigated in this study. Bioleaching of heavy metals from contaminated soil was carried out in shake flask experiments. Acidophilic sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from soil was used for bioleaching. Bioleaching resulted in removal of heavy metals at higher levels. Variations in the binding forms of heavy metals before, during and after bioleaching were evaluated. It was noticed that bioleaching affected the binding forms of all the heavy metals present in the soil. The major contaminant chromium bound mainly to the fractions of soil which are not very reactive (organic and residual fractions) also showed good removal efficiency. Bioleaching influenced the fractionation of metals in soil after treatment and most of the remnant heavy metals were bound either to residual fraction or to other not easily mobile fractions of soil. The results of this study indicated that the bioleaching process can be useful for efficient removal of heavy metals from soil. Further, the soil with remnant metals can be disposed off safely.

  6. A new strain Acidithiobacillus albertensis BY-05 for bioleaching of metal sulfides ores

    Institute of Scientific and Technical Information of China (English)

    XIA Jin-lan; PENG An-an; HE Huan; YANG Yu; LIU Xue-duan; QIU Guan-zhou

    2007-01-01

    An acidophilic, rod-shaped Gram-negative sulfur oxidizing strain BY-05 was isolated from an acid mine drainage of copper ore in Baiyin area, Gansu Province, China. Ultrastructural studies show that the isolate has a tuft of polar flagella and possesses sulfur granules with clear membrane adhering to the cell innermembrane. Physiological study shows that this isolate grows autotrophically and aerobically by oxidizing S0 and reduced inorganic sulfur compounds (S2O2-3,S2O2-4,S2- and ZnS) with the optimum growth at pH 3.5-4.0 and at the temperature range of 25-30 ℃. The 16S rRNA gene sequence (DQ 423683) of strain BY-05 has 100% sequence similarity to that of Acidithiobacillus albertensis (DSM 14366). So it is identified and named as A. albertensis BY-05. Bioleaching experiments with this new strain show that it can play an important role in recovery of metals from chalcopyrite and sphalerite.

  7. Ferrous ion oxidation by Thiobacillus ferrooxidans immobilized on activated carbon

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ji-kui; QIN Wen-qing; NIU Yin-jian; LI Hua-xia

    2006-01-01

    The immobilization of Thiobacillus ferrooxidans on the activated carbon particles as support matrix was investigated. Cycling batch operation results in the complete oxidation of ferrous iron in 8 d when the modified 9 K medium is set to flow through the mini-bioreactor at a rate of 0.104 L/h at 25 ℃. The oxidation rate of ferrous iron with immobilized T. ferrooxidans is 9.38 g/(L·h). The results show that the immobilization of T. ferrooxidans on activated carbon can improve the rate of oxidation of ferrous iron. The SEM images show that a build-up of cells of T. ferrooxidans and iron precipitates is formed on the surface of activated carbon particles.

  8. Bioleaching of Copper Sulfide Ore by Acidithiobacillus Ferrooxidans and Acidithiobacillus Thiooxidans%中温嗜酸硫杆菌浸出低品位硫化铜矿

    Institute of Scientific and Technical Information of China (English)

    张雁生; 覃文庆; 王军; 任浏祎; 何名飞

    2007-01-01

    研究了中温嗜酸硫杆菌的生长条件,对黄铜矿进行了细菌浸出试验研究.研究表明,中温嗜酸硫杆菌最适宜的生长条件为:pH值为2,温度为30±1℃,此条件下细菌浓度为2.24×107个/mL.接种量、矿浆浓度对黄铜矿中铜的浸出率有显著的影响,随着接种量的增加,铜的浸出率提高.在相同浸出时间内,矿浆浓度5%左右时,黄铜矿中铜的浸出率最高.低品位硫化铜矿柱浸试验结果表明:细菌浸出75 d,铜的浸出率为45%.

  9. Single and cooperative bioleaching of sphalerite by two kinds of bacteria——Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    XIA Le-xian; LIU Jian-she; XIAO Li; ZENG Jia; LI Ban-mei; GENG Mei-mei; QIU Guan-zhou

    2008-01-01

    A cooperative bioleaching (Acidithiobacillus ferriooxidans and Acidithiobacillus thiooxidans) and single bioleaching (Acidithiobacillus ferriooxidans or Acidithiobacillus thiooxidans) of sphalerite were investigated by X-ray diffractometry, energy dispersive spectrography and scanning electron microscopy. The experimental results show that the leaching rate of zinc in the mixed culture is higher than that in pure culture and the sterile control. In these processes, two kinds of bacteria perform different functions and play a cooperative role during leaching of sphalerite. The bioleaching action carried out by Acidithiobacillus ferriooxidans (A. ferriooxidans) is not directly performed through Fe2+ but Fe3+, and its role is to oxidize Fe2+ to Fe 3+ and maintain a high redox potential. Moreover, the addition of an appropriate concentration of ferric iron to the leaching systems is beneficial to zinc dissolution. In the leaching systems without Acidithiobacillus thiooxidans (A. thiooxidans), elemental sulfur layers are formed on mineral surface during the dissolution of zinc and block continuous leaching. Acidithiobacillus thiooxidans, however, eliminate the passivation and cause the bioleaching process to continue in the leaching systems. At the same time, protons from the bacterial oxidization of the elemental sulfur layers also accelerate the leaching of zinc.

  10. Growth kinetics of Thiobacillus ferrooxidans in bioelectrochemical cell

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 王淀佐; 邱冠周; 胡岳华

    2004-01-01

    Thiobacillus ferrooxidans might be the most important bacteria used in biometallurgy. The foundation way of its growth process is oxidizing ferrous in order to obtain energy needed for metabolism, but the variation of ferrous concentration and mixed potential of the culture media would have crucial effect on the bacteria growth.Based on the characteristics of Thiobacillus ferrooxidans growth and redox potential of ferric and ferrous, an electrochemical cell was designed conventionally to study growth rule and the relationship between redox potential and bacteria growth was built up, and some growth kinetics of Thiobacillus ferrooxidans were elucidated. It demonstrates that the variation of open potential of electrochemical cell △E shows the growth tendency of Thiobacillus ferrooxidans, at the initial growth stage, the value of △E increases slowly, when at logistic growth stage, it increases drastically, and the growth rate of bacteria is linear with the oxidation rate of ferrous. The bacteria growth kinetics model is proposed using Monod and Michealis-Menten equation, and the kinetics parameters are got. The consistence of the measured and the calculated results proves that it is proper to use the proposed kinetics model and the electrochemical cell method to describe the growth rule of Thiobacillus ferrooxidans.

  11. A versatile and efficient markerless gene disruption system for Acidithiobacillus thiooxidans: application for characterizing a copper tolerance related multicopper oxidase gene.

    Science.gov (United States)

    Wen, Qing; Liu, Xiangmei; Wang, Huiyan; Lin, Jianqun

    2014-11-01

    The acidophilic bioleaching bacteria can usually survive in high concentrations of copper ions because of their special living environment. However, little is known about the copper homeostatic mechanisms of Acidithiobacillus thiooxidans, an important member of bioleaching bacteria. Here, a putative multicopper oxidase gene (cueO) was detected from the draft genome of A. thiooxidans ATCC 19377. The transcriptional level of cueO in response to 10 mM CuSO₄was upregulated 25.01 ± 2.59 folds. The response of P(cueO) to copper was also detected and might be stimulated by a putative CueR protein. Then, by using the counter-selectable marker lacZ and enhancing the expression of endonuclease I-SceI with tac promoter, a modified markerless gene disruption system was developed and the cueO gene disruption mutant (ΔcueO) of A. thiooxidans was successfully constructed with a markedly improved second homologous recombination frequency of 0.28 ± 0.048. The ΔcueO mutant was more sensitive to external copper and nearly completely lost the phenoloxidase activity; however, the activity could be restored after complementing the cueO gene. All results suggest the close relation of cueO gene to copper tolerance in A. thiooxidans. In addition, the developed efficient markerless gene knockout method can also be introduced into other Acidithiobacillus strains.

  12. Acidophilic algae isolated from mine-impacted environments and their roles in sustaining heterotrophic acidophiles

    Directory of Open Access Journals (Sweden)

    David Barrie Johnson

    2012-09-01

    Full Text Available Two acidophilic algae, identified as strains of Chlorella protothecoides var. acidicola and Euglena mutabilis, were isolated in pure culture from abandoned copper mines in Spain and Wales and grown in pH- and temperature-controlled bioreactors. The Chlorella isolate grew optimally at pH 2.5 and 30 ˚C, with a corresponding culture doubling time of 9 hours. The isolates displayed similar tolerance (10-50 mM to four transition metals tested. Growth of the algae in liquid media was paralleled with increasing concentrations of dissolved organic carbon (DOC. Glycolic acid was identified as a significant component (12- 14% of total DOC. Protracted incubation resulted in concentrations of glycolic acid declining in both cases, and glycolic acid added to a culture of Chlorella incubated in the dark was taken up by the alga (~100% within three days. Two monosaccharides were identified in cell-free liquors of each algal isolate: fructose and glucose (Chlorella, and mannitol and glucose (Euglena. These were rapidly metabolised by acidophilic heterotrophic bacteria (Acidiphilium and Acidobacterium spp. though only fructose was utilised by the more fastidious heterotroph Acidocella aromatica. The significance of algae in promoting the growth of iron- (and sulfate- reducing heterotrophic acidophiles that are important in remediating mine-impacted waters is discussed.

  13. Biosorption of Cu by Thiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Manriquez, A. [Departamento de Ingenieria Quimica y Metalurgia, Universidad de Sonora, Hermosillo (Mexico); Magana, P.I. [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico); Lopez, V. [Departamento de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico); Guzman, R. [Department of Chemical and Environmental Engineering, University of Arizona, Tucson (United States)

    1998-02-01

    Current technologies for removal and recovery of both toxic and industrial interest metals usually produce wastes with high concentrations of those substances. They are an important source of environmental pollution, specially when they contain heavy metals. This is one of the most important environmental problems, and of the most difficult to solve. So far, there have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, several variables that affect the capacity for copper biosorption by T. ferrooxidans have been studied. Particularly, the effect of pH, chemical pretreatment, biomass concentration and temperature have been considered. Results indicate that a capacity as high as 119 mg of Cu/g of dry biomass can be obtained at a temperature of 25 C. (orig.) With 6 figs., 1 tab., 13 refs.

  14. Complete genome sequence of Acidimicrobium ferrooxidans type strain (ICPT)

    Energy Technology Data Exchange (ETDEWEB)

    Clum, Alicia; Nolan, Matt; Lang, Elke; Glavina Del Rio, Tijana; Tice, Hope; Copeland, Alex; Cheng, Jan-Fang; Lucas, Susan; Chen, Feng; Bruce, David; Goodwin, Lynne; Pitluck, Sam; Ivanova, Natalia; Mavrommatis, Konstantinos; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Goker, Markus; Spring, Stefan; Land, Miriam; Hauser, Loren; Chang, Yun-Juan; Jefferies, Cynthia C.; Chain, Patrick; Bristow, James; Eisen, Jonathan A.; Markowitz, Victor; Hugenholtz, Philip; Kyrpides, Nikos C.; Klenk, Hans-Peter; Lapidus, Alla

    2009-05-20

    Acidimicrobium ferrooxidans (Clark and Norris 1996) is the sole and type species of the genus, which until recently was the only genus within the actinobacterial family Acidimicrobiaceae and in the order Acidomicrobiales. Rapid oxidation of iron pyrite during autotrophic growth in the absence of an enhanced CO2 concentration is characteristic for A. ferrooxidans. Here we describe the features of this organism, together with the complete genome sequence, and annotation. This is the first complete genome sequence of the order Acidomicrobiales, and the 2,158,157 bp long single replicon genome with its 2038 protein coding and 54 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  15. Pyrite Surface after Thiobacillus ferrooxidans Leaching at 30℃

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In order to investigate the effect of Thiobacillus ferrooxidans on the oxidation of pyrite, two parallel experiments, which employed H2SO4 solutions and acidic solutions inoculated with Thiobacillus ferrooxidans, were designed and carried out at 30℃. The initial pH of the two solutions was adjusted to 2.5 by dropwise addition of concentrated sulphuric acid. The surfaces of pyrite before exposure to leaching solutions and after exposure to the H2SO4 solutions and acidic solutions inoculated with Thiobacillus ferrooxidans were observed by scanning electron microscopy (SEM). There were a variety of erosion patterns by Thiobacillusferrooxidans on the bio-leached pyrite surfaces. A conclusion can be drawn that the oxidation of pyrite might have been caused by erosion of the surfaces.Attachment of the bacteria to pyrite surfaces resulted in erosion pits, leading to the oxidation of pyrite.It is possible that the direct mechanism plays the most important role in the oxidation of pyrite. The changes in iron ion concentrations of both the experimental solutions with time suggest that Thiobacillus ferrooxidans can enhance greatly the oxidation of pyrite.

  16. System-level understanding of the potential acid-tolerance components of Acidithiobacillus thiooxidans ZJJN-3 under extreme acid stress.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    In previous study, two extremely acidophilic strains Acidithiobacillus thiooxidans ZJJN-3 (collection site: bioleaching leachate) and ZJJN-5 (collection site: bioleaching wastewater) were isolated from a typical industrial bio-heap in China. Here, we unraveled the potential acid-tolerance components of ZJJN-3 by comparing the physiological differences with ZJJN-5 under different acid stresses. The parameters used for comparison included intracellular pH (pHin), capsule morphology, fatty acid composition of cell membrane, transcription of key molecular chaperones, H(+)-ATPase activities and NAD(+)/NADH ratio. It was indicated that the acid-tolerance of A. thiooxidans ZJJN-3 was systematically regulated. Capsule first thickened and then shed off along with increased acid stress. Cell membrane maintained the intracellular stability by up-regulating the proportion of unsaturated fatty acid and cyclopropane fatty acids. Meanwhile, the transcription of key repair molecular chaperones (GrpE-DnaK-DnaJ) was up-regulated by 2.2-3.5 folds for ensuring the proper folding of peptide. Moreover, low pHin promoted ZJJN-3 to biosynthesize more H(+)-ATPase for pumping H(+) out of cells. Furthermore, the NAD(+)/NADH ratio increased due to the decreased H(+) concentration. Based on the above physiological analysis, the potential acid-tolerance components of A. thiooxidans ZJJN-3 were first proposed and it would be useful for better understanding how these extremophiles responded to the high acid stress.

  17. System-level understanding of the potential acid-tolerance components of Acidithiobacillus thiooxidans ZJJN-3 under extreme acid stress.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    In previous study, two extremely acidophilic strains Acidithiobacillus thiooxidans ZJJN-3 (collection site: bioleaching leachate) and ZJJN-5 (collection site: bioleaching wastewater) were isolated from a typical industrial bio-heap in China. Here, we unraveled the potential acid-tolerance components of ZJJN-3 by comparing the physiological differences with ZJJN-5 under different acid stresses. The parameters used for comparison included intracellular pH (pHin), capsule morphology, fatty acid composition of cell membrane, transcription of key molecular chaperones, H(+)-ATPase activities and NAD(+)/NADH ratio. It was indicated that the acid-tolerance of A. thiooxidans ZJJN-3 was systematically regulated. Capsule first thickened and then shed off along with increased acid stress. Cell membrane maintained the intracellular stability by up-regulating the proportion of unsaturated fatty acid and cyclopropane fatty acids. Meanwhile, the transcription of key repair molecular chaperones (GrpE-DnaK-DnaJ) was up-regulated by 2.2-3.5 folds for ensuring the proper folding of peptide. Moreover, low pHin promoted ZJJN-3 to biosynthesize more H(+)-ATPase for pumping H(+) out of cells. Furthermore, the NAD(+)/NADH ratio increased due to the decreased H(+) concentration. Based on the above physiological analysis, the potential acid-tolerance components of A. thiooxidans ZJJN-3 were first proposed and it would be useful for better understanding how these extremophiles responded to the high acid stress. PMID:26264736

  18. Isolation of thiobacillus ferrooxidans and thiobacillus thiooxidans from West Kalimantan and North Sumatera Uranium ore specimens

    International Nuclear Information System (INIS)

    Isolation of thiobacillus ferrooxidans (T. ferrooxidans) and thiobacillus thiooxidans (T. thiooxidans) from West Kalimantan and North Sumatera U ore specimens have been carried out. T. thiooxidans have the ability to oxidize sulfur to sulfate, and T. ferrooxidans oxidizes ferro iron to ferric iron. Silverman medium (9 K medium) was used as growth medium for T. ferrooxidans. Starkey medium was used as growth medium for T. thiooxidans. For fungi contamination test the medium of malt extract agar was used. Meat pepton was used for the heterotrophic microorganisms contamination test. Results of the experiment showed that isolates of T. ferrooxidans have been obtained from 3 West Kalimantan U ore specimens from 2 North Sumatera U ore specimens. T. thiooxidans have been isolated from 2 West Kalimantan U ore specimens, but none has been isolated from North Sumatera U ore specimens. T. ferrooxidans isolated from West Kalimantan and North Sumatera have been tested in different growth conditions to determine the rate of growth. (author)

  19. Genomics and Metagenomics of Extreme Acidophiles in Biomining Environments

    Science.gov (United States)

    Holmes, D. S.

    2015-12-01

    Over 160 draft or complete genomes of extreme acidophiles (pH metagenomic studies of such environments. This provides a rich source of latent data that can be exploited for understanding the biology of biomining environments and for advancing biotechnological applications. Genomic and metagenomic data are already yielding valuable insights into cellular processes, including carbon and nitrogen management, heavy metal and acid resistance, iron and sulfur oxido-reduction, linking biogeochemical processes to organismal physiology. The data also allow the construction of useful models of the ecophysiology of biomining environments and provide insight into the gene and genome evolution of extreme acidophiles. Additionally, since most of these acidophiles are also chemoautolithotrophs that use minerals as energy sources or electron sinks, their genomes can be plundered for clues about the evolution of cellular metabolism and bioenergetic pathways during the Archaean abiotic/biotic transition on early Earth. Acknowledgements: Fondecyt 1130683.

  20. Spatial and Temporal Analysis of the Microbial Community in the Tailings of a Pb-Zn Mine Generating Acidic Drainage ▿ †

    Science.gov (United States)

    Huang, Li-Nan; Zhou, Wen-Hua; Hallberg, Kevin B.; Wan, Cai-Yun; Li, Jie; Shu, Wen-Sheng

    2011-01-01

    Analysis of spatial and temporal variations in the microbial community in the abandoned tailings impoundment of a Pb-Zn mine revealed distinct microbial populations associated with the different oxidation stages of the tailings. Although Acidithiobacillus ferrooxidans and Leptospirillum spp. were consistently present in the acidic tailings, acidophilic archaea, mostly Ferroplasma acidiphilum, were predominant in the oxidized zones and the oxidation front, indicating their importance to generation of acid mine drainage. PMID:21705549

  1. Detection of Thiobacillus ferrooxidans in acid mine environments by indirect fluorescent antibody staining.

    Science.gov (United States)

    Apel, W A; Dugan, P R; Filppi, J A; Rheins, M S

    1976-07-01

    An indirect fluorescent antibody (FA) staining technique was developed for the rapid detection of Thiobacillus ferrooxidans. The specificity of the FA stain for T. ferrooxidans was demonstrated with both laboratory and environmental samples. Coal refuse examined by scanning electron microscopy exhibited a rough, porous surface, which was characteristically covered by water-soluble crystals. Significant numbers of T. ferrooxidans were detected in the refuse pores. A positive correlation between numbers of T. ferrooxidans and acid production in coal refuse in the laboratory was demonstrated with the FA technique. PMID:61736

  2. Bacterial leaching of a sulfide ore by Thiobacillus ferrooxidans and Thiobacillus thiooxidans: I. Shake flask studies.

    Science.gov (United States)

    Lizama, H M; Suzuki, I

    1988-06-20

    Bacterial leaching of a sulfide ore containing pyrite, chalcopyrite, and sphalerite was studied in shake flask experiments using Thiobacillus ferrooxidans and Thiobacillus thiooxidans strains isolated from mine sites. The Fe(2+)grown T. ferrooxidans isolates solubilized sphalerite preferentially over chalcopyrite leaching 7-10% Cu, 68-76% Zn, and 10-22% Fe from the ore in 18 days. The sulfur grown T. thiooxidans isolates leached Zn much more slowly and very little Fe, with a Cu-Zn extraction ratio twice the value obtained with T. ferrooxidans. The ore adapted T. ferrooxidans started solubilizing Cu and Zn without a lag period. The ore-adapted T. thiooxidans extracted Cu as well as T. ferrooxidans, but the extraction of Zn or Fe was still much slower in the low-phosphate medium, while in the high-phosphate medium it approached the value obtained with T. ferrooxidans. A high Cu-Zn extraction ratio of 0.34 was obtained with T. thiooxidans in the low phosphate medium. In the mixed-culture experiments with T. ferrooxidans and T. thiooxidans, the culture behaved as T. thiooxidans in the low-phosphate medium with a higher Cu-Zn extraction ratio and as T. ferrooxidans in the high-phosphate medium with a lower Cu-Zn extraction ratio. It is concluded that T. ferrooxidans and T. thiooxidans solubilize sulfide minerals by different mechanisms.

  3. Complete genome sequence of Acidimicrobium ferrooxidans type strain (ICPT)

    Energy Technology Data Exchange (ETDEWEB)

    Clum, Alicia [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Lang, Elke [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Glavina Del Rio, Tijana [U.S. Department of Energy, Joint Genome Institute; Tice, Hope [U.S. Department of Energy, Joint Genome Institute; Copeland, A [U.S. Department of Energy, Joint Genome Institute; Cheng, Jan-Fang [U.S. Department of Energy, Joint Genome Institute; Lucas, Susan [U.S. Department of Energy, Joint Genome Institute; Chen, Feng [U.S. Department of Energy, Joint Genome Institute; Bruce, David [U.S. Department of Energy, Joint Genome Institute; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Pitluck, Sam [U.S. Department of Energy, Joint Genome Institute; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Mavromatis, K [U.S. Department of Energy, Joint Genome Institute; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Pati, Amrita [U.S. Department of Energy, Joint Genome Institute; Chen, Amy [U.S. Department of Energy, Joint Genome Institute; Palaniappan, Krishna [U.S. Department of Energy, Joint Genome Institute; Goker, Markus [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Spring, Stefan [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Land, Miriam L [ORNL; Hauser, Loren John [ORNL; Chang, Yun-Juan [ORNL; Jeffries, Cynthia [Oak Ridge National Laboratory (ORNL); Chain, Patrick S. G. [Lawrence Livermore National Laboratory (LLNL); Bristow, James [U.S. Department of Energy, Joint Genome Institute; Eisen, Jonathan [U.S. Department of Energy, Joint Genome Institute; Markowitz, Victor [U.S. Department of Energy, Joint Genome Institute; Hugenholtz, Philip [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Klenk, Hans-Peter [DSMZ - German Collection of Microorganisms and Cell Cultures GmbH, Braunschweig, Germany; Lapidus, Alla L. [U.S. Department of Energy, Joint Genome Institute

    2009-01-01

    Acidimicrobium ferrooxidans (Clark and Norris 1996) is the sole and type species of the ge-nus, which until recently was the only genus within the actinobacterial family Acidimicrobia-ceae and in the order Acidomicrobiales. Rapid oxidation of iron pyrite during autotrophic growth in the absence of an enhanced CO2 concentration is characteristic for A. ferrooxidans. Here we describe the features of this organism, together with the complete genome se-quence, and annotation. This is the first complete genome sequence of the order Acidomi-crobiales, and the 2,158,157 bp long single replicon genome with its 2038 protein coding and 54 RNA genes is part of the Genomic Encyclopedia of Bacteria and Archaea project.

  4. Leaching of Pyrites of Various Reactivities by Thiobacillus ferrooxidans

    OpenAIRE

    Baldi, Franco; Clark, Thomas; Pollack, S. S.; Olson, Gregory J.

    1992-01-01

    Wide variations were found in the rate of chemical and microbiological leaching of iron from pyritic materials from various sources. Thiobacillus ferrooxidans accelerated leaching of iron from all of the pyritic materials tested in shake flask suspensions at loadings of 0.4% (wt/vol) pulp density. The most chemically reactive pyrites exhibited the fastest bioleaching rates. However, at 2.0% pulp density, a delay in onset of bioleaching occurred with two of the pyrites derived from coal source...

  5. PCR-mediated detection of acidophilic, bioleaching-associated bacteria.

    OpenAIRE

    De Wulf-Durand, P; Bryant, L J; Sly, L I

    1997-01-01

    The detection of acidophilic microorganisms from mining environments by culture methods is time consuming and unreliable. Several PCR approaches were developed to amplify small-subunit rRNA sequences from the DNA of six bacterial phylotypes associated with acidic mining environments, permitting the detection of the target DNA at concentrations as low as 10 fg.

  6. Bacterial CS2 hydrolases from Acidithiobacillus thiooxidans strains are homologous to the archaeal catenane CS2 hydrolase.

    Science.gov (United States)

    Smeulders, Marjan J; Pol, Arjan; Venselaar, Hanka; Barends, Thomas R M; Hermans, John; Jetten, Mike S M; Op den Camp, Huub J M

    2013-09-01

    Carbon disulfide (CS(2)) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS(2) is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO(2)) and hydrogen sulfide (H2S), a property used in industrial biofiltration of CS(2)-polluted airstreams. We report on the mechanism of bacterial CS(2) conversion in the extremely acidophilic A. thiooxidans strains S1p and G8. The bacterial CS(2) hydrolases were highly abundant. They were purified and found to be homologous to the only other described (archaeal) CS(2) hydrolase from Acidianus strain A1-3, which forms a catenane of two interlocked rings. The enzymes cluster in a group of β-carbonic anhydrase (β-CA) homologues that may comprise a subclass of CS(2) hydrolases within the β-CA family. Unlike CAs, the CS(2) hydrolases did not hydrate CO(2) but converted CS(2) and COS with H(2)O to H(2)S and CO(2). The CS(2) hydrolases of A. thiooxidans strains G8, 2Bp, Sts 4-3, and BBW1, like the CS(2) hydrolase of Acidianus strain A1-3, exist as both octamers and hexadecamers in solution. The CS(2) hydrolase of A. thiooxidans strain S1p forms only octamers. Structure models of the A. thiooxidans CS(2) hydrolases based on the structure of Acidianus strain A1-3 CS(2) hydrolase suggest that the A. thiooxidans strain G8 CS(2) hydrolase may also form a catenane. In the A. thiooxidans strain S1p enzyme, two insertions (positions 26 and 27 [PD] and positions 56 to 61 [TPAGGG]) and a nine-amino-acid-longer C-terminal tail may prevent catenane formation.

  7. Oxidation of inorganic sulfur compounds in acidophilic prokaryotes

    Energy Technology Data Exchange (ETDEWEB)

    Rohwerder, T.; Sand, W. [Universitaet Duisburg-Essen, Biofilm Centre, Aquatic Biotechnology, Duisburg (Germany)

    2007-07-15

    The oxidation of reduced inorganic sulfur compounds to sulfuric acid is of great importance for biohydrometallurgical technologies as well as the formation of acidic (below pH 3) and often heavy metal-contaminated environments. The use of elemental sulfur as an electron donor is the predominant energy-yielding process in acidic natural sulfur-rich biotopes but also at mining sites containing sulfidic ores. Contrary to its significant role in the global sulfur cycle and its biotechnological importance, the microbial fundamentals of acidophilic sulfur oxidation are only incompletely understood. Besides giving an overview of sulfur-oxidizing acidophiles, this review describes the so far known enzymatic reactions related to elemental sulfur oxidation in acidophilic bacteria and archaea. Although generally similar reactions are employed in both prokaryotic groups, the stoichiometry of the key enzymes is different. Bacteria oxidize elemental sulfur by a sulfur dioxygenase to sulfite whereas in archaea, a sulfur oxygenase reductase is used forming equal amounts of sulfide and sulfite. In both cases, the activation mechanism of elemental sulfur is not known but highly reactive linear sulfur forms are assumed to be the actual substrate. Inhibition as well as promotion of these biochemical steps is highly relevant in bioleaching operations. An efficient oxidation can prevent the formation of passivating sulfur layers. In other cases, a specific inhibition of sulfur biooxidation may be beneficial for reducing cooling and neutralization costs. In conclusion, the demand for a better knowledge of the biochemistry of sulfur-oxidizing acidophiles is underlined. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  8. Specific dot-immunobinding assay for detection and enumeration of Thiobacillus ferrooxidans

    International Nuclear Information System (INIS)

    A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in 125I-labeled protein A or 125I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. Since a minimum of 103 cells per dot could be detected, the method offers the possibility of simultaneous processing of numerous samples in a short time to monitor the levels of T. ferrooxidans in bioleaching operations

  9. Inhibition of Low Molecular Organic Acids on the Activity of Acidithiobacillus Species and Its Effect on the Removal of Heavy Metals from Contaminated Soil%低分子有机酸对硫杆菌活性的抑制作用及对土壤重金属脱除的影响

    Institute of Scientific and Technical Information of China (English)

    宋永伟; 王鹤茹; 曹艳晓; 李飞; 崔春红; 周立祥

    2016-01-01

    Application of organic fertilizer can reduce the solubility and bioavailability of heavy metals in contaminated soil, but in the flooded anaerobic environment, organic fertilizer will be decomposed to produce a large number of low molecular organic acids, which can inhibit the biological activity of Acidithiobacillus species. Batch cultures studies showed that the monocarboxylic organic acids including formic acid, acetic acid, propionic acid, and butyric acid exhibited a marked toxicity to Acidithiobacillus species, as indicated by that 90% of inhibitory rate for Fe2 + and S0 oxidation in 72 h were achieved at extremely low concentrations of 41. 2 mg.L - 1 , 78. 3 mg.L - 1 , 43. 2 mg.L - 1 , 123. 4 mg.L - 1 and 81. 9 mg.L - 1 , 230. 4 mg.L - 1 , 170. 1 mg.L - 1 , 123. 4 mg.L - 1 , respectively. Of these organic acids, formic acid was the most toxic one as indicated by that Fe2 + and S0 oxidation was almost entirely inhibited at a low concentration. In addition, it was found that Acidithiobacillus ferrooxidans was more sensitive to low molecular organic acids than Acidithiobacillus thiooxidans. What,s more, there was little effect on biological acidification process of heavy metal contaminated soil when organic acids were added at initial stage (0h), but it was completely inhibited when these acids were added after 12 h of conventional biological acidification, thus decreasing the efficiency of heavy metals dissolution from soil.%施用有机肥能够降低污染土壤重金属溶解性和生物可利用性,但在淹水厌氧等环境中,有机肥会分解产生大量低分子有机酸,会抑制嗜酸性硫杆菌的生物活性.通过摇瓶实验研究了低分子有机酸对硫杆菌的毒害抑制效果和不同硫杆菌对各类有机酸的耐受水平.结果表明,纯体系培养下,A. ferrooxidans 和 A. thiooxidans 活性抑制率在72 h 内达到90%以上,所需甲、乙、丙、丁酸最低浓度分别为41.2、78.3、43.2、123.4 mg.L -1和81.9、230.4

  10. Electrochemical behavior of chalcopyrite in presence of Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    LI Hong-xu; QIU Guan-zhou; HU Yue-hua; CANG Da-qiang; WANG Dian-zuo

    2006-01-01

    The chalcopyrite anode dissolution behavior in the presence or absence of bacteria in 9 K media using bacteria modified powder microelectrode at 30 ℃ was studied. It is found that during the anode dissolution, many intermediate transient reactions occur accompanying with the production of chalcocite and covellite at potential between -0.075 V and -0.025 V (vs SCE). At low scanning potential between -0.1 and -0.250 V, the iron ion is released in ferrous form, but at the relative high potential up to 0.7 V, it is the ferric one. The presence of Thiobacillus ferrooxidans makes peak current increase and the initial peak potential negatively move, hinting the decomposed oxidation reaction easily occurred and especially the iron ion released and ferrous oxidation reaction enhanced. The characteristic at potential between -0.75 and -0.5 V demonstrates the Thiobacillus ferrooxidans also contributes to the element sulfur formed on the oxidation surface and removed during anode process. The added ferric in the cell could enhance the dissolution reaction, while the increased acid under pH=2 might slightly hamper the process. The anode dissolution kinetics studies show that the presence of bacteria could decease corrosion potential from 0.238 V to 0.184 V and increase the corrosion current density from 1.632 14×10-8 A/cm2 to 2.374 11×10-7A/cm2.

  11. Comparative study on effects of Tween-80 and sodium isobutyl-xanthate on growth and sulfur-oxidizing activities of Acidithiobacillus albertensis BY-05

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cheng-gui; XIA Jin-lan; ZHANG Rui-yong; PENG An-an; NIE Zhen-yuan; QIU Guan-zhou

    2008-01-01

    Effects of two typical surfactants, Tween-80 and sodium isobutyl-xanthate (NaIBX), with different concentrations on the growth and sulfur-oxidizing activities of a new strain Acidithiobacillus albertensis BY-05, an acidophilic sulfur-oxidizing bacterium, were investigated. The results indicate that both surfactants can enhance the growth and sulfur-oxidizing activities of A. albertensis BY-05 only at some special concentrations, e.g., 10-4-10-8 g/L for NaIBX and lower than 10-8 g/L for Tween-80, but were inhibited and even harmful at higher concentrations. Both surfactants can not be metabolized by A. albertensis BY-05. The contact between the bacteria and the sulfur particles may be dependent upon both the extracellular substance and the surfactants, both of which provide the amphiphilic environment improving the attachment for bacteria to the sulfur particles surface. These data could be significant for enlarging the applications of both A. albertensis BY-05 and some typical surfactants for industrial bioleaching of sulfides minerals.

  12. Genome Sequence of the Acidophilic Bacterium Acidocella sp. Strain MX-AZ02

    DEFF Research Database (Denmark)

    Servín-Garcidueñas, Luis E.; Garrett, Roger A.; Amils, Ricardo;

    2013-01-01

    Here, we report the draft genome sequence of Acidocella sp. strain MX-AZ02, an acidophilic and heterotrophic alphaproteobacterium isolated from a geothermal lake in western Mexico.......Here, we report the draft genome sequence of Acidocella sp. strain MX-AZ02, an acidophilic and heterotrophic alphaproteobacterium isolated from a geothermal lake in western Mexico....

  13. Genome Sequence of the Moderately Acidophilic Sulfate-Reducing Firmicute Desulfosporosinus acididurans (Strain M1T)

    Science.gov (United States)

    Petzsch, Patrick; Poehlein, Anja; Johnson, D. Barrie; Daniel, Rolf; Schlömann, Michael

    2015-01-01

    Microbial dissimilatory sulfate reduction is commonplace in many anaerobic environments, though few acidophilic bacteria are known to mediate this process. We report the 4.64-Mb draft genome of the type strain of the moderate acidophile Desulfosporosinus acididurans, which was isolated from acidic sediment in a river draining the Soufrière volcano, Montserrat. PMID:26251501

  14. Cloning and expression of the Thiobacillus ferrooxidans glutamine synthetase gene in Escherichia coli

    International Nuclear Information System (INIS)

    The glutamine synthetase (GS) gene glnA of Thiobacillus ferrooxidans was cloned on recombinant plasmid pMEB100 which enabled Escherichia coli glnA deletion mutants to utilize (NH4)2SO4 as the sole source of nitrogen. High levels of GS-specific activity were obtained in the E. coli glnA deletion mutants containing the T. ferrooxidans GS gene. The cloned T. ferrooxidans DNA fragment containing the glnA gene activated histidase activity in an E. coli glnA glnL glnG deletion mutant containing the Klebsiella aerogenes hut operon. Plasmid pMEB100 also enabled the E. coli glnA glnL glnG deletion mutant to utilize arginine or low levels of glutamine as the sole source of nitrogen. There was no detectable DNA homology between the T. ferrooxidans glnA gene and the E. coli glnA gene

  15. An Immunological Strategy To Monitor In Situ the Phosphate Starvation State in Thiobacillus ferrooxidans

    OpenAIRE

    Varela, Patricia; Levicán, Gloria; Rivera, Francisco; Jerez, Carlos A.

    1998-01-01

    Thiobacillus ferrooxidans is one of the chemolithoautotrophic bacteria important in industrial biomining operations. During the process of ore bioleaching, the microorganisms are subjected to several stressing conditions, including the lack of some essential nutrients, which can affect the rates and yields of bioleaching. When T. ferrooxidans is starved for phosphate, the cells respond by inducing the synthesis of several proteins, some of which are outer membrane proteins of high molecular w...

  16. Specific Dot-Immunobinding Assay for Detection and Enumeration of Thiobacillus ferrooxidans

    OpenAIRE

    Arredondo, Renato; Jerez, Carlos A.

    1989-01-01

    A specific and very sensitive dot-immunobinding assay for the detection and enumeration of the bioleaching microorganism Thiobacillus ferrooxidans was developed. Nitrocellulose spotted with samples was incubated with polyclonal antisera against whole T. ferrooxidans cells and then in 125I-labeled protein A or 125I-labeled goat antirabbit immunoglobulin G; incubation was followed by autoradiography. Since a minimum of 103 cells per dot could be detected, the method offers the possibility of si...

  17. Biosorption of Zn(II) by Thiobacillus ferrooxidans

    Energy Technology Data Exchange (ETDEWEB)

    Celaya, R.J.; Noriega, J.A.; Yeomans, J.H.; Ruiz-Manriquez, A. [Dept. de Ingenieria Quimica y Metalurgia, Universidad de Sonora, Hermosillo (Mexico); Ortega, L.J. [Dept. de Biotecnologia y Bioingenieria, Centro de Investigacion y Estudios Avanzados (Mexico)

    2000-06-01

    There have been a number of studies considering the possibility of removing and recovering heavy metals from diluted solutions. These are due, principally, because of the commercial value of some metals as well as in the environmental impact caused by them. The traditional methods for removing have several disadvantages when metals are present in concentrations lower than 100 mg/l. Biosorption, which uses biological materials as adsorbents, has been considered as an alternative method. In this work, variables like pH and biomass chemical pretreatment have been studied for its effect on the capacity for zinc biosorption by Thiobacillus ferrooxidans. Also, studies to determinate the time for zinc adsorption were carried out. Results indicate that a capacity as high as 82.61 mg of Zn(II)/g of dry biomass can be obtained at a temperature of 25 C and that the biosorption process occurs in a time of 30 min. (orig.)

  18. Enrichment of mesophilic acidophiles from the Underground Copper Mine Bor

    Directory of Open Access Journals (Sweden)

    Conić Vesna T.

    2009-01-01

    Full Text Available In this work, autotrophic growth of mesophilic acidophiles from the Underground Copper Mine Bor was performed. Two selected solution samples collected from the 'Tilva Roš' ore body were prepared in a 9K nutrient medium (Silverman and Lundgren, 1959. The first sample TR k-16 was obtained during the hole drilling of the ore body, and the second TR k-31 from the drainage channel. Two samples of 9K media (Silverman and Lundgren, 1959 were inoculated with two selected solution samples from the underground mine Tilva Roš. Inoculated culture media were incubated without prior autoclaving in the period of 6 days at a temperature of 28 ?C with purging air through the system with enough oxygen and carbon dioxide. Oxidation rate of ferrous ions in the first 3 days of incubation was 14.8 and 10.7 wt.% Fe2+/day, the next 3 days 17.3 and 13.6 and for the total period of 6 days 98.3 and 74.8 wt.% for the first and second sample, respectively, i.e. 100 wt.% with initial percentage of ferrous ion in each medium. After centrifugation of enriched samples of culture media at 3000 rpm for 5 min, a plenty of mesophilic acidophiles were determined by microscopic method. According to Karavaiko [6], in the processes of incubition for 9K nutrient solution cells number reach a value of 108 cells/cm3.

  19. Electricity generation from tetrathionate in microbial fuel cells by acidophiles

    Energy Technology Data Exchange (ETDEWEB)

    Sulonen, Mira L.K., E-mail: mira.sulonen@tut.fi; Kokko, Marika E.; Lakaniemi, Aino-Maija; Puhakka, Jaakko A.

    2015-03-02

    Highlights: • Electricity can be generated from tetrathionate in MFCs at pH below 2.5. • Tetrathionate disproportionated to sulfate and elemental sulfur. • Biohydrometallurgical process waters contained electrochemically active bacteria. • Acidithiobacillus spp. and Ferroplasma spp. were identified from the MFCs. - Abstract: Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m{sup −2} and 13.9 mW m{sup −2} and 433 mA m{sup −2} and 17.6 mW m{sup −2}, respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2–2.5.

  20. Electricity generation from tetrathionate in microbial fuel cells by acidophiles

    International Nuclear Information System (INIS)

    Highlights: • Electricity can be generated from tetrathionate in MFCs at pH below 2.5. • Tetrathionate disproportionated to sulfate and elemental sulfur. • Biohydrometallurgical process waters contained electrochemically active bacteria. • Acidithiobacillus spp. and Ferroplasma spp. were identified from the MFCs. - Abstract: Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m−2 and 13.9 mW m−2 and 433 mA m−2 and 17.6 mW m−2, respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2–2.5

  1. Bioleaching of heavy metals from sewage sludge using Acidithiobacillus thiooxidans

    Science.gov (United States)

    Wen, Ye-Ming; Lin, Hong-Yan; Wang, Qing-Ping; Chen, Zu-Liang

    2010-11-01

    Acidithiobacillus thiooxidans was isolated from sewage sludge using the incubation in the Waksman liquor medium and the inoculation in Waksman solid plate. It was found that the optimum conditions of the bioleaching included solid concentration 2%, sulfur concentration 5 gṡL-1 and cell concentration 10%. The removal efficiency of Cr, Cu, Pb and Zh in sewage sludge, which was obtained from waste treatment plant, Jinshan, Fuzhou, was 43.65%, 96.24%, 41.61% and 96.50% in the period of 4˜10 days under the optimum conditions, respectively. After processing using the proposed techniques, the heavy metals in sewage sludge did meet the requirement the standards of nation.

  2. Rate Equations and Kinetic Parameters of the Reactions Involved in Pyrite Oxidation by Thiobacillus ferrooxidans.

    Science.gov (United States)

    Lizama, H M; Suzuki, I

    1989-11-01

    Rate equations and kinetic parameters were obtained for various reactions involved in the bacterial oxidation of pyrite. The rate constants were 3.5 muM Fe per min per FeS(2) percent pulp density for the spontaneous pyrite dissolution, 10 muM Fe per min per mM Fe for the indirect leaching with Fe, 90 muM O(2) per min per mg of wet cells per ml for the Thiobacillus ferrooxidans oxidation of washed pyrite, and 250 muM O(2) per min per mg of wet cells per ml for the T. ferrooxidans oxidation of unwashed pyrite. The K(m) values for pyrite concentration were similar and were 1.9, 2.5, and 2.75% pulp density for indirect leaching, washed pyrite oxidation by T. ferrooxidans, and unwashed pyrite oxidation by T. ferrooxidans, respectively. The last reaction was competitively inhibited by increasing concentrations of cells, with a K(i) value of 0.13 mg of wet cells per ml. T. ferrooxidans cells also increased the rate of Fe production from Fe plus pyrite. PMID:16348054

  3. Adsorption characteristics of thiobacillus ferrooxidans on surface of sulfide minerals

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-she; XIE Xue-hui; LI Bang-mei; DONG Qing-hai

    2005-01-01

    By using thiobacillus ferrooxidans (T.f) from Qixiashan, Hubei Province, China, the adsorption characteristics of T.f on surface of sulfide mineral were studied. The influences of adsorption time, pH value, temperature, initial inoculated concentration of bacteria, concentration of sulfide mineral powder, and variety of minerals on the adsorption characteristics were firstly investigated by using the ninhydrin colorimetric method, and the changes of contact angles and Zeta potentials of mineral surface during the bacterial adsorption were then determined. The results show that when the leaching experiments are performed for a long time from several days to a month, the maximal quantity of adsorption of T.f on the surface of pyrite is obtained under the following conditions: leaching for 20 d, pH value in range of 1-2 and temperature at 30 ℃, respectively; when the bio-leaching experiments are performed for a shorter leaching time, the maximal quantity of adsorption is obtained under the conditions: bio-leaching for 2 h, at 2.4×10 7 cell/mL of initial inoculated bacteria concentration, and at 10% of mineral powder concentration; and the adsorption quantities are different form one sulfide mineral to another, and the adsorption of T.f on the surface of sulfide minerals includes three phases: increasing phase, stationary phase and decreasing phase.

  4. Preservation of Thiobacillus ferrooxidans and Thiobacillus thiooxidans with activity check.

    Science.gov (United States)

    Gupta, S G; Agate, A D

    1986-01-01

    Cultures of Thiobacillus ferrooxidans and Thiobacillus thiooxidans, used in biohydrometallurgical processes of economic importance, are very difficult to preserve by conventional methods. Hence, to preserve the cultures with their activity intact, various techniques were tried, after determining their respective activity in terms of Iron Oxidation Rate (IOR) and Sulfur Oxidation Rate (SOR). Among the methods tested, along with the recommended method of serial transfer in a liquid medium, were methods such as lyophilization, storage in a liquid nitrogen and mixing with sterile, inert carriers like lignite or chalcopyrite ores. After a period check-up at 4 months and 8 months storage, it was found that out of these methods, mixing with sterile ore followed by storage at 8 degrees C, kept both types of activities intact. The temperature of storage was observed to have a definite effect on activity, in that when the preserved cultures were stored at 8 degrees C, the activity was retained, whereas at 28-30 degrees C (RT) storage, the activity of all the cultures preserved by various techniques, dropped significantly.

  5. Corrosion Behaviors of Steel A3 Exposed to Thiobacillus Ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    Jianhua LIU; Xin LIANG; Songmei LI

    2008-01-01

    The corrosion behaviors of steel A3 in synergistic action of Thiobacillus ferrooxidans (T.f) and electrochemically accelerated corrosion were studied by electrochemical, microbiology and surface analysis methods. The open circuit potential (Eocp) and electrochemical impedance spectroscopy (EIS) of the steel A3 electrodes were measured in leathen culture medium without and with T.f (simply called T.f solution in the following paper)in immersion electrode way at the time of the 2nd, 5th, 10th, 20th and 30th days, respectively. It was found that Eocp of the electrode for immersion in leathen culture medium shifted negatively with the immersion time while that for immersion in T.f solutions shifted negatively, then positively and finally negatively. On the 20th day, the corrosion of steel A3 for immersion in culture medium was in pitting initiation stage while that for immersion in T.f solutions was in pitting growth stage. It was found that the corrosion of steel A3 was accelerated by T.f. The morphology of corrosion product of steel A3 immersion in T.f solutions observed through scanning electron microscopy (SEM) transformed from solid globules to tabular plates and to spongy globules and plates.

  6. Identification of Thiobacillus ferrooxidans strains based on restriction fragment length polymorphism analysis of 16S rDNA.

    Science.gov (United States)

    Kamimura, K; Wakai, S; Sugio, T

    2001-01-01

    The 16S rDNA sequences from ten strains of Thiobacillus ferrooxidans were amplified by PCR. The products were compared by performing restriction fragment length polymorphism (RFLP) analysis with restriction endonucleases Alu I, Hap II, Hha I, and Hae III. The RFLP patterns revealed that T. ferrooxidans could be distinguished from other iron- or sulphur-oxidizing bacteria such as T. thiooxidans NB1-3, T. caldus GO-1, Leptospirillum ferrooxidans and the marine iron-oxidizing bacterium strain KU2-11. The RFLP patterns obtained with Alu I, Hap II, and Hae III were the same for nine strains of T. ferrooxidans except for strain ATCC 13661. The RFLP patterns for strains NASF-1 and ATCC 13661 with Hha I were distinct from those for other T. ferrooxidans strains. The 16S rDNA sequence of T. ferrooxidans NASF-1 possessed an additional restriction site for Hha I. These results show that iron-oxidizing bacteria isolated from natural environments were rapidly identified as T. ferrooxidans by the method combining RFLP analysis with physiological analysis. PMID:11414499

  7. Electricity generation from tetrathionate in microbial fuel cells by acidophiles.

    Science.gov (United States)

    Sulonen, Mira L K; Kokko, Marika E; Lakaniemi, Aino-Maija; Puhakka, Jaakko A

    2015-03-01

    Inorganic sulfur compounds, such as tetrathionate, are often present in mining process and waste waters. The biodegradation of tetrathionate was studied under acidic conditions in aerobic batch cultivations and in anaerobic anodes of two-chamber flow-through microbial fuel cells (MFCs). All four cultures originating from biohydrometallurgical process waters from multimetal ore heap bioleaching oxidized tetrathionate aerobically at pH below 3 with sulfate as the main soluble metabolite. In addition, all cultures generated electricity from tetrathionate in MFCs at pH below 2.5 with ferric iron as the terminal cathodic electron acceptor. The maximum current and power densities during MFC operation and in the performance analysis were 79.6 mA m(-2) and 13.9 mW m(-2) and 433 mA m(-2) and 17.6 mW m(-2), respectively. However, the low coulombic efficiency (below 5%) indicates that most of the electrons were directed to other processes, such as aerobic oxidation of tetrathionate and unmeasured intermediates. The microbial community analysis revealed that the dominant species both in the anolyte and on the anode electrode surface of the MFCs were Acidithiobacillus spp. and Ferroplasma spp. This study provides a proof of concept that tetrathionate serves as electron donor for biological electricity production in the pH range of 1.2-2.5.

  8. Metal resistance or tolerance? Acidophiles confront high metal loads via both abiotic and biotic mechanisms

    Directory of Open Access Journals (Sweden)

    Mark eDopson

    2014-04-01

    Full Text Available All metals are toxic at high concentrations and consequently their intracellular concentrations must be regulated. Acidophilic microorganisms have an optimum growth pH < 3 and proliferate in natural and anthropogenic low pH environments. Some acidophiles are involved in the catalysis of sulfide mineral dissolution, resulting in high concentrations of metals in solution. Acidophiles are often described as highly metal resistant via mechanisms such as multiple and/or more efficient active resistance systems than are present in neutrophiles. However, this is not the case for all acidophiles and we contend that their growth in high metal concentrations is partially due to an intrinsic tolerance as a consequence of the environment in which they live. In this perspective, we highlight metal tolerance via complexation of free metals by sulfate ions and passive tolerance to metal influx via an internal positive cytoplasmic transmembrane potential. These tolerance mechanisms have been largely ignored in past studies of acidophile growth in the presence of metals and should be taken into account.

  9. A novel acidophile community populating waste ore deposits at an acid mine drainage site

    Institute of Scientific and Technical Information of China (English)

    HAO Chun-bo; ZHANG Hong-xun; BAI Zhi-hui; HU Qing; ZHANG Bao-guo

    2007-01-01

    Waste ore samples (pH 3.0) were collected at an acid mine drainage site in Anhui, China. The present acidophilic microbial community in the waste ore was studied with 16S rRNA gene clone library and denaturing gradient gel electrophoresis (DGGE). Eighteen different clones were identified and affiliated with Actinobacteria, low G + C Gram-positives, Thermomicrobia, Acidobacteria, Proteobacteria, Candidate division TM7, and Planctomycetes. Phylogenetic analysis of 16S rRNA gene sequences revealed a diversity of acidophiles in the samples that were mostly novel. It is unexpected that the moderately thermophilic acidophiles were abundant in the acidic ecosystem and may play a great role in the generation of AMD. The result of DGGE was consistent with that of clone library analysis. These findings help in the better understanding of the generation mechanism of AMD and in developing a more efficient method to control AMD.

  10. Simulation of acid mine drainage generation around Küre VMS Deposits, Northern Turkey

    Science.gov (United States)

    Demirel, Cansu; Kurt, Mehmet Ali; Çelik Balci, Nurgül

    2015-04-01

    This study investigated comparative leaching characteristics of acidophilic bacterial strains under shifting environmental conditions at proposed two stages as formation stage or post acidic mine drainage (AMD) generation. At the first stage, initial reactions associated with AMD generation was simulated in shaking flasks containing massive pyritic chalcopyrite ore by using a pure strain Acidithiobacillus ferrooxidans and a mixed culture of Acidithiobacillus sp. mostly dominated by A. ferrooxidans and A. thiooxidans at 26oC. At the second stage, long term bioleaching experiments were carried out with the same strains at 26oC and 40oC to investigate the leaching characteristics of pyritic chalcopyrite ore under elevated heavy metal and temperature conditions. During the experiments, physicochemical characteristics (e.i. Eh, pH, EC) metal (Fe, Co, Cu, Zn) and sulfate concentration of the experimental solution were monitored during 180 days. Significant acid generation and sulfate release were determined during bioleaching of the ore by mixed acidophilic cultures containing both iron and sulfur oxidizers. In the early stage of the experiments, heavy metal release from the ore was caused by generation of acid due to accelerated bacterial oxidation of the ore. Generally high concentrations of Co and Cu were released into the solution from the experiments conducted by pure cultures of Acidithiobacillus ferrooxidans whereas high Zn and Fe was released into the solution from the mixed culture experiments. In the later stage of AMD generation and post AMD, chemical oxidation is accelerated causing excessive amounts of contamination, even exceeding the amounts resulted from bacterial oxidation by mixed cultures. Acidithibacillus ferrooxidans was found to be more effective in leaching Cu, Fe and Co at higher temperatures in contrary to mixed acidophiles that are more prone to operate at optimal moderate conditions. Moreover, decreasing Fe values are noted in bioleaching

  11. Bioleaching of pyrite by Thiobacillus ferrooxidans: fixed grains electrode to study superficial oxidized compounds

    Science.gov (United States)

    Toniazzo, Valérie; Lazaro, Isabelle; Humbert, Bernard; Mustin, Christian

    1999-04-01

    An electrode with fixed pyrite grains on a graphite and silicon paste has been used to study the electrochemical processes at the surface of powdered pyrite during bioleaching by Thiobacillus ferrooxidans. The study of an air-oxidized pyrite shows that the fixed grains electrode (FGE) is more sensitive than the classical Carbon Paste Electrode (CPE) already used by different authors to characterize various oxides and sulfurs. On the other hand, the concommitant Raman and electrochemical analysis of autoclaved pyrite shows that the cleaned mineral FeS 2 has no electrochemical reactivity, and points out that the electrochemical response of the oxidized mineral is exclusively due to the chemical compounds present at its surface. Therefore, the electrode acts as an efficient sensor for pyrite superficial oxidized phases, which are fundamental for the biooxidation process and is consequently very well adapted for the control of the oxidation state of pyrite powder during bioleaching by Thiobacillus ferrooxidans.

  12. Rate of Pyrite Bioleaching by Thiobacillus ferrooxidans: Results of an Interlaboratory Comparison

    OpenAIRE

    Olson, Gregory J.

    1991-01-01

    Ten laboratories participated in an interlaboratory comparison of determination of bioleaching rates of a pyrite reference material. A standardized procedure and a single strain of Thiobacillus ferrooxidans were used in this study. The mean rate of bioleaching of the pyrite reference material was 12.4 mg of Fe per liter per h, with a coefficient of variation (percent relative standard deviation) of 32% as determined by eight laboratories. These results show the precision among laboratories of...

  13. Effect of Applied Potentials on the Activity and Growth of Thiobacillus ferrooxidans

    OpenAIRE

    Natarajan, KA

    1992-01-01

    The effect of applied DC potentials both in the positive and negative range, on the activity and growth of Thiobacillus ferrooxidans, is discussed. In general, application of positive potentials up to +1000 mV in an acid bioleaching medium was found to be detrimental to bacterial activity, while the impression of negative potentials enhanced both their activity and growth through electrochemical regeneration of ferrous ions and an increase in the biomass. Ferrous-ferric ratios in a bioleachin...

  14. Genome Sequence of the Acidophilic Iron Oxidizer Ferrimicrobium acidiphilum Strain T23T

    Science.gov (United States)

    Eisen, Sebastian; Poehlein, Anja; Johnson, D. Barrie; Daniel, Rolf; Schlömann, Michael

    2015-01-01

    Extremely acidophilic iron-oxidizing bacteria have largely been characterized for the phyla Proteobacteria and Nitrospira. Here, we report the draft genome of an iron-oxidizing and -reducing heterotrophic mesophile of the Actinobacteria, Ferrimicrobium acidiphilum, which was isolated from an abandoned pyrite mine. The genome sequence comprises 3.08 Mb. PMID:25931604

  15. Genome Sequence of the Acidophilic Sulfate-Reducing Peptococcaceae Strain CEB3

    Science.gov (United States)

    Petzsch, Patrick; Poehlein, Anja; Johnson, D. Barrie; Daniel, Rolf; Schlömann, Michael

    2015-01-01

    We report the draft genome of the Peptococcaceae strain CEB3 that originated from an acidic (pH 2.5) stream draining an abandoned copper mine. Strain CEB3 is one of the very few reported acidophilic sulfate-reducing isolates. The 5.04-Mb draft genome harbors 5,069 predicted protein-encoding and 66 RNA genes. PMID:26251503

  16. Production of ferric sulphate from pyrite by thiobacillus ferrooxidans. Application to uranium ore leaching

    International Nuclear Information System (INIS)

    A process for uranium extraction by oxidizing solutions of ferric sulphate produced by T. ferrooxidans from pyrite is developed. A new counting method specific of T. ferrooxidans is designed. An uranium resistant wild strain, with oxidizing properties as high as the strain ATCC 19859, is isolated. Optimal conditions for ferric sulphate production from pyrite are defined (pH 1.8, density of the medium 1.2%, pyrite granulometry < 60 micrometers). The comparison of oxidation of 2 pyrites evidences the effect of composition and crystal type on bacterial activity. Latency period is reduced by preliminary adaptation of bacteria to pyrite, a relatively important inoculum and association of T. ferrooxidans to T. thiooxidans. Free bacteria, but not adsorbed bacteria, play an important part in pyrite oxidation, indirectly by regeneration of ferric iron and by maintaining a high redox potential. Leaching of an uranium ore column by an acidic solution of ferric iron increase not only uranium extraction yield but also to decrease acid consumption in respect to acid leaching only

  17. Enhanced productivity of a lutein-enriched novel acidophile microalga grown on urea.

    Science.gov (United States)

    Casal, Carlos; Cuaresma, Maria; Vega, Jose Maria; Vilchez, Carlos

    2011-01-01

    Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of β-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 × 10(8) cells/mL at the end of log phase). Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 μg·mL(·1) and 35 μg·mL(·1), respectively). Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO(2) as nitrogen and carbon sources (control cultures). Lutein accumulated up to 3.55 mg·g(·1) in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae. PMID:21339944

  18. Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

    Directory of Open Access Journals (Sweden)

    Carlos Vilchez

    2010-12-01

    Full Text Available Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related industries. The acidic culture medium (pH < 2.5 that prevents outdoor cultivation from non-desired microorganism growth is one of the main advantages of acidophile microalgae production. Conversely, acidophile microalgae growth rates are usually very low compared to common microalgae growth rates. In this work, we show that mixotrophic cultivation on urea efficiently enhances growth and productivity of an acidophile microalga up to typical values for common microalgae, therefore approaching acidophile algal production towards suitable conditions for feasible outdoor production. Algal productivity and potential for carotenoid accumulation were analyzed as a function of the nitrogen source supplied. Several nitrogen conditions were assayed: nitrogen starvation, nitrate and/or nitrite, ammonia and urea. Among them, urea clearly led to the best cell growth (~4 ´ 108 cells/mL at the end of log phase. Ammonium led to the maximum chlorophyll and carotenoid content per volume unit (220 mg·mL-1 and 35 mg·mL-1, respectively. Interestingly, no significant differences in growth rates were found in cultures grown on urea as C and N source, with respect to those cultures grown on nitrate and CO2 as nitrogen and carbon sources (control cultures. Lutein accumulated up to 3.55 mg·g-1 in the mixotrophic cultures grown on urea. In addition, algal growth in a shaded culture revealed the first evidence for an active xanthophylls cycle operative in acidophile microalgae.

  19. Enumeration and Characterization of Acidophilic Microorganisms Isolated from a Pilot Plant Stirred-Tank Bioleaching Operation

    OpenAIRE

    Okibe, Naoko; Gericke, Mariekie; Hallberg, Kevin B.; Johnson, D. Barrie

    2003-01-01

    Microorganisms were enumerated and isolated on selective solid media from a pilot-scale stirred-tank bioleaching operation in which a polymetallic sulfide concentrate was subjected to biologically accelerated oxidation at 45°C. Four distinct prokaryotes were isolated: three bacteria (an Acidithiobacillus caldus-like organism, a thermophilic Leptospirillum sp., and a Sulfobacillus sp.) and one archaeon (a Ferroplasma-like isolate). The relative numbers of these prokaryotes changed in the three...

  20. Dominance of Acidithiobacillus at ore surface of Zijinshan commercial low-grade copper bioleaching heap

    Institute of Scientific and Technical Information of China (English)

    LIU Xing-yu; CHEN Bo-wei; WEN Jian-kang

    2008-01-01

    The microbial community structure in the ore surface of Zijinshan commercial low-grade copper bioleaching heap was investigated by 16S rRNA gene clone library.For both bacteria and Archaea,105 clones were sequenced.The dominant bacteria species present in the ore surface were Acidithiobacillus and Leptospirillum,accounting for 51.42% and 48.57%,respectively.However,for the Archaea,only one operational taxonomic unit (OUT) belonged to Ferroplasma acidiphilum.These results indicate that function of genus Acidithiobacillus in the commercial low-grade copper bioleaching heap may be underestimated.More detailed and quantitative information on microbial community structure over time are now under investigation.

  1. Evaluation of a Fluorescent Lectin-Based Staining Technique for Some Acidophilic Mining Bacteria

    OpenAIRE

    Fife, Dee Jay; Bruhn, Debby F.; Miller, Karen S.; Stoner, Daphne L.

    2000-01-01

    A fluorescence-labeled wheat germ agglutinin staining technique (R. K. Sizemore et al., Appl. Environ. Microbiol. 56:2245–2247, 1990) was modified and found to be effective for staining gram-positive, acidophilic mining bacteria. Bacteria identified by others as being gram positive through 16S rRNA sequence analyses, yet clustering near the divergence of that group, stained weakly. Gram-negative bacteria did not stain. Background staining of environmental samples was negligible, and pyrite an...

  2. Copper, zinc, and iron bioleaching from polymetallic sulphide concentrate%多金属硫化精矿中铜、锌和铁的生物浸出

    Institute of Scientific and Technical Information of China (English)

    Vesna T. CONIĆ; Mirjana M. RAJČIĆ VUJASINOVIĆ; Vlastimir K. TRUJIĆ; Vladimir B. CVETKOVSKI

    2014-01-01

    Bioleaching of low-grade complex Cu−Zn−Pb−Fe−Ag−Au sulphide concentrate (of Majdanpek ore body, RTB Bor, Serbia) was carried out in an aerated bioleach reactor in the presence of mesophilic mixed bacterial culture ofAcidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans, andLeptospirillum ferrooxidans. A mesophilic acidophiles culture was isolated from the acidic solution of the underground copper mine of Bor, Serbia. The nutrient medium was 9K at pH 1.6. 87% of the particles were<10 µm in size, with a pulp density of 8% (w/v). Bioleaching efficiencies of 89% for zinc, 83% for copper, and 68% for iron can be achieved in the examined conditions. Kinetic analysis shows that the change in leaching corresponds to the Spencer-Topley kinetic model for diffusion-controlled topochemical reactions.%利用嗜温混合菌Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans和 Leptospirillum ferrooxidans对低品位复杂Cu−Zn−Pb−Fe−Ag−Au硫化精矿在曝气生物浸出反应器中进行生物浸出。该菌种为从塞尔维亚Bor地下铜矿的酸性溶液中筛选出一种嗜热嗜酸菌。营养液为pH 1.6的9K营养液。87%的矿物粒度大于10μm,矿浆密度为8%(w/v)。在测试条件下,锌、铜和铁的浸出率分别达到89%、83%和68%。动力学分析表明,浸出过程与Spencer-Topley模型相符,受局部反应扩散控制。

  3. Examination of Lipopolysaccharide (O-Antigen) Populations of Thiobacillus ferrooxidans from Two Mine Tailings

    OpenAIRE

    Southam, G.; Beveridge, T. J.

    1993-01-01

    Net acid-generating capacities of 39.74 kg of H2SO4 per ton (ca. 0.05 kg/kg) (pH 2.68) for the Lemoine copper mine tailings (closed ca. 8 years ago; located 40 km west of Chibougamau, Quebec, Canada) and 16.07 kg of H2SO4 per ton (ca. 0.02 kg/kg) (pH 3.01) for the Copper Rand tailings (in current use and 50 km distant [east] from those of Lemoine) demonstrate that these sulfide tailings can support populations of acidophilic thiobacilli. Oxidized regions in both tailings environments were rea...

  4. Distribution, ecology and inhibition of Thiobacillus ferrooxidans in relation to acid drainage from Witwatersrand gold mine dumps

    International Nuclear Information System (INIS)

    The distribution and ecology of Thiobacillus ferrooxidans in gold mine dumps and possible means for its inhibition were investigated. A literature survey of the micro-ecology of mine waste dumps in various parts of the world was undertaken. A linear alkylbenzene sulphonate (LAS), NANSA 80/S, and a cetyl pyridinium chloride, Ceepryn, were tested as possible inhibitors for mine dump application. The LAS was rejected because it is poorly soluble in water and required higher concentrations than SLS for the inhibition of T.ferrooxidans. Ceepryn was an efficient inhibitor, but its efficiency was dramatically impeded in the presence of mine dump sand making it unsuitable for application on dumps. The SLS and LAS were tested against a mixed population of T.ferrooxidans from gold mine dumps and these bacteria were shown to be marginally more resistant to the inhibitors than the pure T.ferrooxidans culture. Sampling from mine dumps on the Witwatersrand suggested that the major T.ferrooxidans populations occurred in the moist sand of the drainage areas at the base of dumps, with few viable iron-oxidising bacteria located on the surfaces or in the centre of dumps. Sites of low moisture in dumps contained few or no viable bacteria. In the laboratory the bacterial viability decreased rapidly with loss of moisture from the sand. Moisture was shown to be important to bacterial activity and should be considered with respect to acid drainage control. Experimental sand columns showed that iron was leached with water from mine dump sand in the absence and presence of bacteria. In this study substrates, moisture, oxygen and carbon dioxide availability, ph, temperature, microorganisms and metal pollutants of uranium waste dumps are also covered

  5. Existence of Two Kinds of Sulfur-reducing Systems in Iron-oxidizing Bacterium Thiobacillus ferrooxidans.

    Science.gov (United States)

    Ng, K Y; Inoue, S; Fujioka, A; Kamimura, K; Sugio, T

    1999-01-01

    Intact cells of Thiobacillus ferrooxidans NASF-1 incubated under anaerobic conditions in a reaction mixture containing 0.5% colloidal sulfur produced hydrogen sulfide (H2S) extracellularly. The amount of H2S produced by cells increased corresponding to the cell amounts and colloidal sulfur. Two activity peaks of H2S production were observed at pH 1.5 and 7.5. We tentatively called the enzyme activities pH 1.5- and pH 7.5-sulfur reducing systems, respectively. Seven strains of T. ferrooxidans tested had both the activities of pH 1.5- and pH 7.5-sulfur reducing systems, but at different levels. T. ferrooxidans NASF-1 showed the highest activity of the pH 1.5-sulfur reducing system and strain 13598 from ATCC showed the highest activity of the pH 7.5-sulfur reducing system. Further characteristics of H2S production were studied with intact cells of NASF-1. The optimum temperatures for pH 1.5- and pH 7.5-sulfur reducing systems of NASF-1 were 40°C. Hydrogen sulfide production continued for 8 days and total amounts of H2S produced at pH 7.5 and 1.5 were 832 and 620 nmol/mg protein, respectively. The pH 7.5-sulfur reducing system used only colloidal sulfur as the electron acceptor. However, the pH 1.5-sulfur reducing system used both colloidal sulfur and tetrathionate. Thiosulfate, dithionate, and sulfite could not be used as the electron acceptor for both of the sulfur reducing systems. Potassium cyanide activated by 3- fold the pH 1.5-sulfur reducing system activity at 0.5 mM but did not affect the activity of the pH 7.5-sulfur reducing system. An inhibitor of sulfite reductase, p-chloromercuribenzene sulfonic acid, did not affect either enzyme activity. Sodium molybdate and monoiodoacetic acid strongly inhibited the activity of the pH 1.5-sulfur reducing system at 1.0 mM, but not the activity of pH 7.5-sulfur reducing system. PMID:27385566

  6. Production of hydrogen sulfide from tetrathionate by the iron-oxidizing bacterium Thiobacillus ferrooxidans NASF-1.

    Science.gov (United States)

    Ng, K Y; Kamimura, K; Sugio, T

    2000-01-01

    When incubated under anaerobic conditions, five strains of Thiobacillus ferrooxidans tested produced hydrogen sulfide (H2S) from elemental sulfur at pH 1.5. However, among the strains, T. ferrooxidans NASF-1 and AP19-3 were able to use both elemental sulfur and tetrathionate as electron acceptors for H2S production at pH 1.5. The mechanism of H2S production from tetrathionate was studied with intact cells of strain NASF-1. Strain NASF-1 was unable to use dithionate, trithionate, or pentathionate as an electron acceptor. After 12 h of incubation under anaerobic conditions at 30 degrees C, 1.3 micromol of tetrathionate in the reaction mixture was decomposed, and 0.78 micromol of H2S and 0.6 micromol of trithionate were produced. Thiosulfate and sulfite were not detected in the reaction mixture. From these results, we propose that H2S is produced at pH 1.5 from tetrathionate by T. ferrooxidans NASF-1, via the following two-step reaction, in which AH2 represents an unknown electron donor in NASF-1 cells. Namely, tetrathionate is decomposed by tetrathionate-decomposing enzyme to give trithionate and elemental sulfur (S4O6(2-)-->S3O6(2-) + S(o), Eq. 1), and the elemental sulfur thus produced is reduced by sulfur reductase using electrons from AH2 to give H2S (S(o) + AH2-->H2S + A, Eq. 2). The optimum pH and temperature for H2S production from tetrathionate under argon gas were 1.5 and 30 degrees C, respectively. Under argon gas, the H2S production from tetrathionate stopped after 1 d of incubation, producing a total of 2.5 micromol of H2S/5 mg protein. In contrast, under H2 conditions, H2S production continued for 6 d, producing a total of 10.0 micromol of H2S/5 mg protein. These results suggest that electrons from H2 were used to reduce elemental sulfur produced as an intermediate to give H2S. Potassium cyanide at 0.5 mM slightly inhibited H2S production from tetrathionate, but increased that from elemental sulfur 3-fold. 2,4-Dinitrophenol at 0.05 mM, carbonylcyanide

  7. Enhanced bioleaching on attachment of indigenous acidophilic bacteria to pyrite surface

    Science.gov (United States)

    Wi, D. W.; Cho, K. H.; Kim, B. J.; Choi, N. C.; Park, C. Y.

    2012-04-01

    In recent years, bioleaching has been widely applied on an industrial scale due to the advantages of low cost and environment friendliness. The direct contact mechanism of bioleaching assumes the action of a metal sulfide-attached cell oxidizing the mineral by an enzyme system with oxygen to sulfate and metal cations. Fundamental surface properties of sulfide particles and leaching-bacteria in bioleaching play the key role in the efficiency of this process. The aim of this work is to investigate of direct contact bioleaching mechanism on pyrite through attachment properties between indigenous acidophilic bacteria and pyrite surfaces. The bacteria were obtained from sulfur hot springs, Hatchobaru thermal electricity plant in Japan. And pyrite was collected from mine waste from Gwang-yang abandoned gold mines, Korea. In XRD analyses of the pyrite, x-ray diffracted d-value belong to pyrite was observed. The indigenous acidophilic bacteria grew well in a solution and over the course of incubation pH decreased and Eh increased. In relation to a bacterial growth-curve, the lag phase was hardly shown while the exponential phase was very fast. Bioleaching experiment result was showed that twenty days after the indigenous acidophilic bacteria were inoculated to a pyrite-leaching medium, the bacterial sample had a greater concentration of Fe and Zn than within the control sample. In SEM-EDS analyses, rod-shaped bacteria and round-shaped microbes were well attached to the surface of pyrite. The size of the rod-shaped bacteria ranged from 1.05~1.10 ? to 4.01~5.38 ?. Round-shaped microbes were more than 3.0 ? in diameter. Paired cells of rod-shaped bacteria were attached to the surface of pyrite linearly.

  8. Life at acidic pH imposes an increased energetic cost for a eukaryotic acidophile.

    Science.gov (United States)

    Messerli, Mark A; Amaral-Zettler, Linda A; Zettler, Erik; Jung, Sung-Kwon; Smith, Peter J S; Sogin, Mitchell L

    2005-07-01

    Organisms growing in acidic environments, pHpH. We begin to investigate this premise by determining the magnitude of the transmembrane electrochemical H+ gradient in an acidophilic Chlamydomonas sp. (ATCC PRA-125) isolated from the Rio Tinto, a heavy metal laden, acidic river (pH 1.7-2.5). This acidophile grows most rapidly at pH 2 but is capable of growth over a wide pH range (1.5-7.0), while Chlamydomonas reinhardtii is restricted to growth at pH>or=3 with optimal growth between pH 5.5 and 8.5. With the fluorescent H+ indicator, 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF), we show that the acidophilic Chlamydomonas maintains an average cytosolic pH of 6.6 in culture medium at both pH 2 and pH 7 while Chlamydomonas reinhardtii maintains an average cytosolic pH of 7.1 in pH 7 culture medium. The transmembrane electric potential difference of Chlamydomonas sp., measured using intracellular electrodes at both pH 2 and 7, is close to 0 mV, a rare value for plants, animals and protists. The 40,000-fold difference in [H+] could be the result of either active or passive mechanisms. Evidence for active maintenance was detected by monitoring the rate of ATP consumption. At the peak, cells consume about 7% more ATP per second in medium at pH 2 than at pH 7. This increased rate of consumption is sufficient to account for removal of H+ entering the cytosol across a membrane with relatively high permeability to H+ (7x10(-8) cm s-1). Our results indicate that the small increase in the rate of ATP consumption can account for maintenance of the transmembrane H+ gradient without the imposition of cell surface H+ barriers.

  9. Culture-independent detection of "TM7" bacteria in a streptomycin-resistant acidophilic nitrifying process

    Science.gov (United States)

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T.; Hiraishi, A.

    2014-02-01

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at bacteria of the candidate phylum "TM7" as the major constituents of the microbial community. In light of the fact that the 16S rRNA of TM7 bacteria has a highly atypical base substitution possibly responsible for resistance to streptomycin at the ribosome level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L-1 was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

  10. Draft Genome Sequence of the Extremophile Acidithiobacillus thiooxidans A01, Isolated from the Wastewater of a Coal Dump.

    Science.gov (United States)

    Yin, Huaqun; Zhang, Xian; Liang, Yili; Xiao, Yunhua; Niu, Jiaojiao; Liu, Xueduan

    2014-01-01

    The draft genome of Acidithiobacillus thiooxidans A01 contains 3,820,158 bp, with a G+C content of 53.08% and 3,660 predicted coding sequences (CDSs). The bacterium contains a series of specific genes involved in the oxidation of elemental sulfur and reduced inorganic sulfur compounds (RISCs).

  11. Bacterial CS2 Hydrolases from Acidithiobacillus thiooxidans Strains Are Homologous to the Archaeal Catenane CS2 Hydrolase

    NARCIS (Netherlands)

    Smeulders, M.J.; Pol, A. van der; Venselaar, H.; Barends, T.R.; Hermans, J.; Jetten, M.S.M.; Camp, H.J.M. op den

    2013-01-01

    Carbon disulfide (CS2) and carbonyl sulfide (COS) are important in the global sulfur cycle, and CS2 is used as a solvent in the viscose industry. These compounds can be converted by sulfur-oxidizing bacteria, such as Acidithiobacillus thiooxidans species, to carbon dioxide (CO2) and hydrogen sulfide

  12. Transfer of IncP Plasmids to Extremely Acidophilic Thiobacillus thiooxidans

    OpenAIRE

    Jin, S. M.; Yan, W. M.; Wang, Z. N.

    1992-01-01

    The broad-host-range IncP plasmids RP4, R68.45, RP1::Tn501, and and pUB307 were transferred directly to extremely acidophilic Thiobacillus thiooxidans from Escherichia coli by conjugation at frequencies of 10-5 to 10-7 per recipient. The ability of T. thiooxidans to receive and express the antibiotic resistance markers was examined. The plasmid RP4 was transferred back to E. coli from T. thiooxidans at a frequency of 1.0 × 10-3 per recipient.

  13. Transfer of IncP Plasmids to Extremely Acidophilic Thiobacillus thiooxidans.

    Science.gov (United States)

    Jin, S M; Yan, W M; Wang, Z N

    1992-01-01

    The broad-host-range IncP plasmids RP4, R68.45, RP1::Tn501, and and pUB307 were transferred directly to extremely acidophilic Thiobacillus thiooxidans from Escherichia coli by conjugation at frequencies of 10 to 10 per recipient. The ability of T. thiooxidans to receive and express the antibiotic resistance markers was examined. The plasmid RP4 was transferred back to E. coli from T. thiooxidans at a frequency of 1.0 x 10 per recipient.

  14. EPS-contact-leaching mechanism of chalcopyrite concentrates by A. ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    YU Run-lan; TAN Jian-xi; YANG Peng; SUN Jing; OU Yang; XIONG Jing; DAI Yun-jie

    2008-01-01

    The effect of extracelluar polymeric substances(EPS) on the bioleaching chalcopyrite concentrates in the presence of iron- and sulphur-oxidizing bacteria (A.ferrooxidans) was studied.The bacterial number,pH,redox potential,and the concentrations of Fe2+and Cu2+ ions were investigated.The leached residues were analyzed by the X-ray diffraction and FT-IR.The results indicate that the EPS makes the bacteria adhere to the chalcopyrite surface easily and it is helpful for bacteria in disadvantageous environment.At the same time,EPS film layer with Fe3+ deposits on the surface of chalcopyrite and becomes a barrier of oxygen transfer to chalcopyrite to passivate chalcopyrite,and creates the high redox potential space through concentrating Fe3+ ions to accelerate bioleaching pyrite in chalcopyrite concentrates.The results suggest that EPS formation promotes bioleaching pyrite and inhibits bioleaching chalcopyrite,especially under high potential condition.

  15. Leptosririllum ferrooxidans-sulfide mineral interactions with reference to bioflotation nad bioflocculation

    Institute of Scientific and Technical Information of China (English)

    A.VILINSKA; K.HANUMANTHA RAO

    2008-01-01

    The adhesion of ferrous ions grown Leptospirillum ferrooxidans cells on pyrite and chalcopyrite minerals was investigated through adsorption,Zeta-potential and diffuse reflectance FT-IR measurements.The influence of bacterial species on minerals floatability was determined by Hallimond flotation tests while the flocculation behaviour was examined by Turbiscan measurements.The minerals iso-electric point (pH 6.5-7.5) after interaction with bacterial cells shifted towards cells iso-electric point (pH 3.3),indicating the chemical nature of cells adsorption on mineral surfaces.The FT-IR spectra of minerals treated with bacterial cells showed the presence of all the cell functional groups signifying cells adsorption.The bacterial cells adsorption on chalcopyrite was higher compared with pyrite,which agreed with cells greater depression effect on chalcopyrite flotation and pronounced flocculation behaviour in comparison with pyrite.

  16. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Debaraj [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, Dong J. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of)], E-mail: djkim@kigam.re.kr; Ralph, David E. [AJ Parker CRC for Hydrometallurgy, Murdoch University, South Street Murdoch, Perth 6153 (Australia); Ahn, Jong G. [Mineral and Material Processing Division, Korea Institute of Geosciences and Mineral Resources, Daejeon 305-350 (Korea, Republic of); Rhee, Young H. [Department of Microbiology, Chungnam National University, Daejeon 305-764 (Korea, Republic of)

    2008-04-15

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO{sub 3}. Bioleach residues were characterized by EDX and XRD.

  17. Bioleaching of spent hydro-processing catalyst using acidophilic bacteria and its kinetics aspect

    International Nuclear Information System (INIS)

    Bioleaching of metals from hazardous spent hydro-processing catalysts was attempted in the second stage after growing the bacteria with sulfur in the first stage. The first stage involved transformation of elemental sulfur particles to sulfuric acid through an oxidation process by acidophilic bacteria. In the second stage, the acidic medium was utilized for the leaching process. Nickel, vanadium and molybdenum contained within spent catalyst were leached from the solid materials to liquid medium by the action of sulfuric acid that was produced by acidophilic leaching bacteria. Experiments were conducted varying the reaction time, amount of spent catalysts, amount of elemental sulfur and temperature. At 50 g/L spent catalyst concentration and 20 g/L elemental sulfur, 88.3% Ni, 46.3% Mo, and 94.8% V were recovered after 7 days. Chemical leaching with commercial sulfuric acid of the similar amount that produced by bacteria was compared. Thermodynamic parameters were calculated and the nature of reaction was found to be exothermic. Leaching kinetics of the metals was represented by different reaction kinetic equations, however, only diffusion controlled model showed the best correlation here. During the whole process Mo showed low dissolution because of substantiate precipitation with leach residues as MoO3. Bioleach residues were characterized by EDX and XRD

  18. Submicro-battery effect and selective bio-oxidation model of gold-bearing arsenopyrite by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    杨洪英; 杨立; 赵玉山; 陈刚; 吕久吉; 范有静

    2002-01-01

    Through the study by electronic probe it was found that many new cracks and holes appear on the surface of gold-bearing arsenopyrite crystal oxidized by Thiobacillus ferrooxidans, which are along with some directions. Then the selective bio-oxidation model of gold-bearing arsenopyrite was set up. The selective bio-oxidation resulting from the submicro-battery effect of gold/ arsenopyrite mineral pairs naturally forms in the gold-bearing arsenopyrite crystal. Thiobacillus ferrooxidans has priority to oxidize the place of gold-rich and oxidizes selectedly along with the crystal border, crystal face and crack. The bacteria oxidation process of gold-bearing arsenopyrite is divided into three stages: the first stage is the surface oxidation, the second stage is restraining oxidation and the third stage is the filament oxidation, bacteria oxidize along with cracks of arsenopyrite.

  19. Electro-generative mechanism for simultaneous leaching of pyrite and MnO2 in presence of A. ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A dual cell system was used to study the output power, output voltage, galvanic polarization of anode and cathode, and the relationship between the electric quantity(Q) and some factors, such as the dissolved Fe2+ magnitude, the time in the electrogenerative simultaneous leaching with bacteria(BEGSL) and without bacteria(EGSL). A three-electrode system was adopted to study their individual self-corrosion current, which was smaller compared with the galvanic current. The results show that the output power and voltage in BEGSL are higher than those in EGSL. The accumulated sulfur on the surface of sulfides produced in BEGSL can be oxidized by A. ferrooxidans, and the ratio of biologic electric quantity reaches 51.50% in 72 h. The first stage both in EGSL and in BEGSL is the dissolution of pyrite on the surface to ferrous ion and sulfur element, which was oxidized by A. ferrooxidans in the further procedure.

  20. Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Experiments with a Controlled Redox Potential Indicate No Direct Bacterial Mechanism

    OpenAIRE

    Fowler, T. A.; Crundwell, F. K.

    1998-01-01

    The role of Thiobacillus ferrooxidans in bacterial leaching of mineral sulfides is controversial. Much of the controversy is due to the fact that the solution conditions, especially the concentrations of ferric and ferrous ions, change during experiments. The role of the bacteria would be more easily discernible if the concentrations of ferric and ferrous ions were maintained at set values throughout the experimental period. In this paper we report results obtained by using the constant redox...

  1. Gene function analysis in environmental isolates: The nif regulon of the strict iron oxidizing bacterium Leptospirillum ferrooxidans

    Science.gov (United States)

    Parro, Víctor; Moreno-Paz, Mercedes

    2003-01-01

    A random genomic library from an environmental isolate of the Gram-negative bacterium Leptospirillum ferrooxidans has been printed on a microarray. Gene expression analysis was carried out with total RNA extracted from L. ferrooxidans cultures in the presence or absence of ammonium as nitrogen source under aerobic conditions. Although practically nothing is known about the genome sequence of this bacterium, this approach allowed us the selection and sequencing of only those clones bearing genes that showed an altered expression pattern. By sequence comparison, we have identified most of the genes of nitrogen fixation regulon in L. ferrooxidans, like the nifHDKENX operon, encoding the structural components of Mo-Fe nitrogenase; nifSU-hesB-hscBA-fdx operon, for Fe-S cluster assembly; the amtB gene (ammonium transporter); modA (molybdenum ABC type transporter); some regulatory genes like ntrC, nifA (the specific activator of nif genes); or two glnB-like genes (encoding the PII regulatory protein). Our results show that shotgun DNA microarrays are very powerful tools to accomplish gene expression studies with environmental bacteria whose genome sequence is still unknown, avoiding the time and effort necessary for whole genome sequencing projects. PMID:12808145

  2. 嗜酸糖苷水解酶研究进展%Research Progress on Acidophilic Glycoside Hydrolase

    Institute of Scientific and Technical Information of China (English)

    罗会颖; 姚斌; 范云六

    2013-01-01

    随着极端微生物及极端酶的广泛研究,嗜酸酶因其在极端酸性环境中具有高的酶活性和稳定性而倍受关注,并取得了较大的研究进展。嗜酸糖苷水解酶是嗜酸酶中最重要的一类,在生物能源、饲料、食品等工业中具有重要的应用前景。综述了重要嗜酸糖苷水解酶,包括嗜酸淀粉酶、嗜酸纤维素酶、嗜酸木聚糖酶和甘露聚糖酶在基因的挖掘、表达、分子改良嗜酸机制研究以及应用等方面国内外的研究进展,展望了嗜酸糖苷水解酶未来可能的研究方向和发展前景。%Extremophiles and enzymes from extremophiles are widely studied. Of them, acidophilic enzyme attracts much attention, due to its high activity and stability under extreme acidic conditions, and this research has made rapid progress. Acidophilic glycosyl hydrolase is one of the most important acidophilic enzymes, and has significant application prospect in bio-energy, animal feed, food and other industries. This paper reviewed the gene cloning, heterologous expression, molecular modification and acidophilic mechanisms of important acidophilic glycosyl hydrolases, including amylase, cellulase, xylanase, and mannanase. The research orientation and development prospects were also elucidated in this paper.

  3. Purification and properties of thiosulfate dehydrogenase from Acidithiobacillus thiooxidans JCM7814.

    Science.gov (United States)

    Nakamura, K; Nakamura, M; Yoshikawa, H; Amano, Y

    2001-01-01

    A key enzyme of the thiosulfate oxidation pathway in Acidithiobacillus thiooxidans JCM7814 was investigated. As a result of assaying the enzymatic activities of thiosulfate dehydrogenase, rhodanese, and thiosulfate reductase at 5.5 of intracellular pH, the activity of thiosulfate dehydrogenase was measured as the key enzyme. The thiosulfate dehydrogenase of A. thiooxidans JCM7814 was purified using three chromatographies. The purified sample was electrophoretically homogeneous. The molecular mass of the enzyme was 27.9 kDa and it was a monomer. This enzyme had cytochrome c. The optimum pH and temperature of this enzyme were 3.5 and 35 degrees C. The enzyme was stable in the pH range from 5 to 7, and it was stable up to 45 degrees C. The isoelectric point of the enzyme was 8.9. This enzyme reacted with thiosulfate as a substrate. The Km was 0.81 mM.

  4. Biochemical and molecular characterization of the NAD(+)-dependent isocitrate dehydrogenase from the chemolithotroph Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Inoue, Hiroyuki; Tamura, Takashi; Ehara, Nagisa; Nishito, Akira; Nakayama, Yumi; Maekawa, Makiko; Imada, Katsumi; Tanaka, Hidehiko; Inagaki, Kenji

    2002-08-27

    An isocitrate dehydrogenase (ICDH) with an unique coenzyme specificity from Acidithiobacillus thiooxidans was purified and characterized, and its gene was cloned. The native enzyme was homodimeric with a subunit of M(r) 45000 and showed a 78-fold preference for NAD(+) over NADP(+). The cloned ICDH gene (icd) was expressed in an icd-deficient strain of Escherichia coli EB106; the activity was found in the cell extract. The gene encodes a 429-amino acid polypeptide and is located between open reading frames encoding a putative aconitase gene (upstream of icd) and a putative succinyl-CoA synthase beta-subunit gene (downstream of icd). A. thiooxidans ICDH showed high sequence similarity to bacterial NADP(+)-dependent ICDH rather than eukaryotic NAD(+)-dependent ICDH, but the NAD(+)-preference of the enzyme was suggested due to residues conserved in the coenzyme binding site of the NAD(+)-dependent decarboxylating dehydrogenase.

  5. [Expression of phosphofructokinase gene from Escherichia coli K-12 in obligately autotrophic bacterium Acidithiobacillus thiooxidans].

    Science.gov (United States)

    Tian, Keli; Lin, Jianqun; Liu, Xiangmei; Liu, Ying; Zhang, Changkai

    2003-10-01

    A plasmid pSDK-1 containing the Escherichia coli phosphofructokinase-1 (EC 2.7.1. 11) gene (pfkA) was constructed and transferred into Acidithiobacillus thiooxidans Tt-Z2 by conjugation. The transfer frequency of plasmid from E. coli to Tt-Z2 was 2.6 x 10(-6). More than 68% of Tt-Z2 cells carried the recombinant plasmids after being cultured for 50 generations without selective pressure, which showed that pSDK-1 was maintained consistently in Tt-Z2. The pfkA gene from E. coli could be expressed in this obligately autotrophic bacterium but the enzyme activity (14 U/g was lower than that in E. coli (K-12: 86 U/g; DF1010 carrying plasmid pSDK-1: 97 U/g). In th presence of glucose, the Tt-Z2 transconjugant consumed glucose leading to a better growth yield.

  6. The inhibitory effect of antimicrobial zeolite on the biofilm of Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Haile, Tesfaalem; Nakhla, George

    2010-02-01

    The inhibitory effect of antimicrobial zeolite coated concrete specimens (Z2) against Acidithiobacillus thiooxidans was studied by measuring biomass dry cell weight (DCW), biological sulphate generation, and oxygen uptake rates (OURs). Uncoated (UC), and blank zeolite coated without antimicrobial agent (ZC) concrete specimens were used as controls. The study was undertaken by exposing inoculated basal nutrient medium (BNM) to the various specimens. The coating material was prepared by mixing zeolite, epoxy and cure with ratios, by weight of 2:2:1. Concrete specimens were characterized before and after exposure to inoculated or sterile BNM by field emission-scanning electron microscopy (FE-SEM). Gypsum, which was absent in the other test concrete specimens, was detected in uncoated specimens exposed to the bacterium. In UC and ZC, the growth of the bacteria increased throughout the duration of the experiment. However, significant biomass inhibition was observed in experiments where Z2 was used. The overall biomass growth rate in suspension before the specimens were placed ranged from 3.18 to 3.5 mg DCW day(-1). After the bacterium was exposed to UC and ZC, growth continued with a corresponding value of 4 + or - 0.4 and 5.5 + or - 0.6 mg DCW day(-1), respectively. No biomass growth was observed upon exposure of the bacterium to Z2. Similarly, while biological sulphur oxidation rates in UC and ZC were 88 + or - 13 and 238 + or - 25 mg SO(4)(2-) day(-1), respectively, no sulphate production was observed in experiments where Z2 concrete specimens were used. Peak OURs for UC and ZC ranged from 2.6 to 5.2 mg l(-1) h(-1), and there was no oxygen uptake in those experiments where Z2 was used. The present study revealed that the antimicrobial zeolite inhibits the growth of both planktonic as well as biofilm populations of Acidithiobacillus thiooxidans.

  7. Potentiality of Acidithiobacillus thiooxidans in Microbial Solubilization of Phosphate Mine Tailings

    Directory of Open Access Journals (Sweden)

    S Dhakar

    2015-04-01

    Full Text Available This paper deals with the solubilization behavior of the tailings produced by the floatation of a complex low grade phosphate ore. The composition of the tailings was essentially dolomite (52.04% with minor amounts of phosphate, iron and aluminium oxides (10.4 and 0.5% respectively. The presence of these products created uncontrolled land pollution and severely affected groundwater. An initiative has been taken up for utilization of this waste to generate an eco-friendly product. First step towards this panorama is incorporation of suitable microorganisms for the biodegradation of this effluent. Sulphur oxidizing bacteria Acidithiobacillus thiooxidans produces sulphuric acid which neutralizes the dolomitic tailings and convert it into plant available forms. The solubilization activity was tested in sulphur medium with 5, 10, 15 and 20% concentration of tailings. The solubilization is graded on the basis of pH, Electrical conductivity (EC, soluble calcium and magnesium and soluble phosphate. The results from ex-situ experiments showed that the treatment with 15% tailings ended with highest solubilization. The values of pH, EC, soluble calcium and magnesium and soluble phosphate for this treatment were 4.92, 31.6 dS/m, 10.8 mL EDTA and 17.24 µg/mL respectively. Also, the results proved that sulphur oxidizing bacteria Acidithiobacillus thiooxidans is capable of solubilizing dolomitic tailings from the Jhamarkotra mines. Finally, an important factor taken into account was solubilization of residual phosphate along with dolomite in the tailings. This combined action affects the solubilization behaviour of the residue, which was also showed successfully with the assayed laboratory studies.

  8. 嗜酸氧化亚铁硫杆菌的高效培养及浸出黄铜矿初探%Efficient culture of Acidithiobacillus ferrooxidans and preliminary study on chalcopyrite bioleaching

    Institute of Scientific and Technical Information of China (English)

    康文亮; 杨海麟; 冯守帅; 张玲; 冷云伟; 王武

    2011-01-01

    By feeding of ferrous sulfate into sulfide m ineralsm edium to maintain the Fe 2+ With in the concentration range from 4 g/L to 8 g/L , the biom ass of A cidith iobacillus ferroox idans could reach 6 .25 ×l08 cells/m L with in 39 hours . At the same time the conversion rate and production in tensity was improved without reducing the special growth rate . The prelim inary study on low-grade chalcopyrite bioleaching at low redox potentials was carried out . The results showed that the leaching rate of copper could reach 28 .5 percent with in 30 days, and the Fe2+ . rather than sulfide minerals , w as utilized as the bacteria growth energy in that leaching period .%采用向硫化矿培养基中补加FeSO4的方式以维持Fe2+ 浓度为4~8 g/L,可使嗜酸氧化亚铁硫杆菌菌浓在培养39 h时达到6.25×108 cells/mL,并在比生长速率几乎不降低的前提下提高了转化率和生产强度.然后对低氧化还原电位下低品位黄铜矿的浸出进行初步研究,结果表明经过30 d浸出,铜的浸出率可达28.5%,且此浸出过程中菌的能源物质是Fe2+而不是硫化矿物.

  9. Isolation and Identifaction of Acidithiobacillus thiooxidans with Strong Phosphorous Ore Bioleaching Ability%一株高浸磷嗜酸氧化硫硫杆菌的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    吕早生; 关海燕; 李凌凌; 贾伟伟

    2011-01-01

    从矿山土样中分离到一株嗜酸的浸磷矿细菌HY-01,观察其形态并研究其培养特征.结果显示,该菌株为革兰氏阴性、短杆状运动细菌,菌体长1~2μm,宽0.5~0.7 μm,能在pH 1.5~8.0的范围内生长,最适生长温度为37℃,最适pH为1.5~3.0.该菌株可以KNO3、NH4NO3、(NH4)2CO3、NH4H2PO4、(NH4)2SO4以及蛋白胨为氮源,以元素硫和黄铁矿中的硫为能源,不能利用有机物质以及硫代硫酸钠、硫酸亚铁等无机物为能源生长.形态、生理生化特性研究以及16SrDNA序列分析表明,该菌株为嗜酸氧化硫硫杆菌.浸矿实验结果表明其具有很高的磷矿浸出能力.图6表1参18%Acidophilic sulfur-oxidizing bacterium HY-01 was isolated from mine soil. Strain HY-01 was motile, gram-negative, rod-shaped and 0.5 to 0.7 μm x 1 to 2 um in size. The strain grew optimally with initial pH 2.0-2.5 and temperature 37 °C. It could grow with potassium nitrate, ammonium nitrate, ammonirm carbonate, ammonium dihydrogen phosphate, ammonium sulfate and tryptone as nitrogen sources. It could use elemental sulfur and pyrite as energy sources, but not organic minerals and inorganic minerals, including sodium thiosulfate and ferrous sulfate. The morphological, biochemical and physiological characteristics of the strain and the analysis based on 16S rDNA gene sequence indicated that strain HY-01 was most closely related to Acidithiobacillus thiooxidans. The sulfur-oxidizing bacteria could positively increase the dissolution rate and percentage of phosphorus recovery from phosphate ore. Fig 6, Tab 1, Ref 18

  10. 三株氧化硫硫杆菌的分离与鉴定%Isolation and Characterization of three strains of Acidithiobacillus thiooxidans and its bioleaching of chalcopyrite

    Institute of Scientific and Technical Information of China (English)

    符波; 周洪波; 张倩; 邱冠周

    2008-01-01

    Three strains of mesophilic and acidophilic sulfur-oxidizing bacteria were isolated from coal heap drainage. The bacteria are motile, Gram-negative, rod-shaped, and measures 0.4 to 0.7 by 1 to 2 μm. They grow optimally at 30 ℃ and initial pH 2.0~2.5. The strains grow autotrophically by using elemental sulfur, sodium thiosulfate and potassium tetrathionate as energy sources. The strains can not use organic matter and inorganic minerals including ferrous sulfate, pyrite and chalcopyrite as energy sources. The morphological, biochemical and physiological characterization and analysis based on 16S rRNA gene sequence indicated that the strains are most closely related to Acidithiobacillus thiooxidans (>99% similarity in gene sequence). The presence of sulfur-oxidizing bacteria positively increased the dissolution rate and the percentage recovery of copper from chalcopyrite by producing acid.%从煤堆废水中分离得到3株嗜温嗜酸硫氧化细菌.这3株菌株为革兰氏阴性、菌体大小0.4~0.7 μm×1~2 μm、短杆状运动细菌,其最适生长温度为 30 ℃和最适生长pH 2.0~2.5.它们能够利用元素硫,硫代硫酸钠和连四硫酸钾为能源进行自养生长,不能利用有机物质以及硫酸亚铁、黄铁矿和黄铜矿等无机物质作为能源生长.细菌的形态、生理生化特性研究以及基于16S rRNA序列同源性构建的系统发育树结果表明,这3株细菌初步鉴定为氧化硫硫杆菌.氧化硫硫杆菌能够通过产酸有效促进黄铜矿的浸出速率和浸出率.

  11. Optimized Production of Xylitol from Xylose Using a Hyper-Acidophilic Candida tropicalis

    Directory of Open Access Journals (Sweden)

    Elena Tamburini

    2015-08-01

    Full Text Available The yeast Candida tropicalis DSM 7524 produces xylitol, a natural, low-calorie sweetener, by fermentation of xylose. In order to increase xylitol production rate during the submerged fermentation process, some parameters-substrate (xylose concentration, pH, aeration rate, temperature and fermentation strategy-have been optimized. The maximum xylitol yield reached at 60–80 g/L initial xylose concentration, pH 5.5 at 37 °C was 83.66% (w/w on consumed xylose in microaerophilic conditions (kLa = 2·h−1. Scaling up on 3 L fermenter, with a fed-batch strategy, the best xylitol yield was 86.84% (w/w, against a 90% of theoretical yield. The hyper-acidophilic behaviour of C. tropicalis makes this strain particularly promising for industrial application, due to the possibility to work in non-sterile conditions.

  12. Gene Loss and Horizontal Gene Transfer Contributed to the Genome Evolution of the Extreme Acidophile "Ferrovum".

    Science.gov (United States)

    Ullrich, Sophie R; González, Carolina; Poehlein, Anja; Tischler, Judith S; Daniel, Rolf; Schlömann, Michael; Holmes, David S; Mühling, Martin

    2016-01-01

    Acid mine drainage (AMD), associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus "Ferrovum" are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of "Ferrovum" has proven to be extremely difficult and has so far only been successful for the designated type strain "Ferrovum myxofaciens" P3G. In this study, the genomes of two novel strains of "Ferrovum" (PN-J185 and Z-31) derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of "Ferrovum" sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G). Phylogenomic scrutiny suggests that the four strains represent three "Ferrovum" species that cluster in two groups (1 and 2). Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the "F. myxofaciens" strains (group 1) appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features contributed to the observed

  13. Gene loss and horizontal gene transfer contributed to the genome evolution of the extreme acidophile Ferrovum

    Directory of Open Access Journals (Sweden)

    Sophie Roxana Ullrich

    2016-05-01

    Full Text Available Acid mine drainage (AMD, associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus Ferrovum are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of Ferrovum has proven to be extremely difficult and has so far only been successful for the designated type strain Ferrovum myxofaciens P3G. In this study, the genomes of two novel strains of Ferrovum (PN-J185 and Z-31 derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of Ferrovum sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G. Phylogenomic scrutiny suggests that the four strains represent three Ferrovum species that cluster in two groups (1 and 2. Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the F. myxofaciens strains (group 1 appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features contributed to the observed

  14. Flow cytometry based techniques to study testicular acidophilic granulocytes from the protandrous fish gilthead seabream (Sparus aurata L.

    Directory of Open Access Journals (Sweden)

    Chaves-Pozo Elena

    2004-01-01

    Full Text Available The gilthead seabream is a protandrous seasonal breeding teleost that is an excellent model for studying the testicular regression process which occurs in both seasonal testicular involution and sex reversion. Little is known about the cell types and the molecular mechanisms involved in such processes, mainly because of the lack of appropriate methods for testis dissociation, and testicular cell isolation, culture and functional characterization. We have previously reported that gilthead seabream acidophilic granulocytes infiltrate the testis at post-spawning stage, settle close to the spermatogonia and accumulate intracellular interleukin-1&bgr;. In this paper, we report several flow cytometry based assays which allow to establish the role played by gilthead seabream testicular acidophilic granulocytes and permits their quantification.

  15. Microbial populations identified by fluorescence in situ hybridization in a constructed wetland treating acid coal mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nicomrat, D.; Dick, W.A.; Tuovinen, O.H. [Ohio State University, Wooster, OH (United States). Environmental Science Graduate Programme

    2006-07-15

    Microorganisms are an integral part of the biogeochemical processes in wetlands, yet microbial communities in sediments within constructed wetlands receiving acid mine drainage (AMD) are only poorly understood. The purpose of this study was to characterize the microbial diversity and abundance in a wetland receiving AMD using fluorescence in situ hybridization (FISH) analysis. Seasonal samples of oxic surface sediments, comprised of Fe(III) precipitates, were collected from two treatment cells of the constructed wetland system. The pH of the bulk samples ranged between pH 2.1 and 3.9. Viable counts of acidophilic Fe and S oxidizers and heterotrophs were determined with a most probable number (MPN) method. The MPN counts were only a fraction of the corresponding FISH counts. The sediment samples contained microorganisms in the Bacteria (including the subgroups of acidophilic Fe- and S-oxidizing bacteria and Acidiphilium spp.) and Eukarya domains. Archaea were present in the sediment surface samples at < 0.01% of the total microbial community. The most numerous bacterial species in this wetland system was Acidithiobacillus ferrooxidans, comprising up to 37% of the bacterial population. Acidithiobacillus thiooxidans was also abundant.

  16. Leaching of marine manganese nodules by acidophilic bacteria growing on elemental sulfur

    Science.gov (United States)

    Konishi, Yasuhiro; Asai, Satoru; Sawada, Yuichi

    1997-02-01

    This article describes the bioleaching of manganese nodules by thermophilic and mesophilic sulfuroxidizing bacteria, in which oxidized sulfur compounds are biologically produced from elemental sulfur added to liquid medium and are simultaneously used to leach nodules. The thermophile Acidianus brierleyi solubilized the manganese nodules faster at 65 °C than did the mesophiles Thiobacillus ferrooxidans and Thiobacillus thiooxidans at 30 °C. Leaching experiments with A. brierleyi growing on elemental sulfur were used to optimize various process parameters, such as medium pH, initial sulfur-liquid loading ratio, and initial cell concentration. The observed dependencies of the leaching rates at a pH optimum on the initial amounts of elemental sulfur and A. brierleyi cells were qualitatively consistent with model simulations for microbial sulfur oxidation. Under the conditions determined as optimum, the leaching of nodule particles (-330+500 mesh) by A. brierleyi yielded 100 pct extraction of both copper and zinc within 4 days and high extractions of nickel (85 pct), cobalt (70 pct), and manganese (55 pct) for 10 days. However, the iron leaching was practically negligible.

  17. Inhibition of microbial concrete corrosion by Acidithiobacillus thiooxidans with functionalised zeolite-A coating.

    Science.gov (United States)

    Haile, Tesfaalem; Nakhla, George

    2009-01-01

    The inhibition of the corrosive action of Acidithiobacillus thiooxidans on concrete specimens coated by functionalised zeolite-A containing 14% zinc and 5% silver by weight was studied. Uncoated concrete specimens, epoxy-coated concrete specimens (EP), and functionalised zeolite-A coated concrete specimens with epoxy to zeolite weight ratios of 3:1 (Z1), 2:2 (Z2) and 1:3 (Z3) were studied. Specimens were characterised by x-ray powder diffraction and field emission scanning electron microscopy for the identification of corrosion products and morphological changes. Biomass growth at the conclusion of the 32-day experiments was 4, 179 and 193 mg volatile suspended solids g(-1) sulphur for the uncoated, EP and Z1 specimens, whereas that of Z2 and Z3 were negligible. In the uncoated, EP and Z1 specimens, sulphate production rates were 0.83, 9.1 and 8.8 mM SO(4)(2-) day(-1) and the specific growth rates, mu, were 0.14, 0.57 and 0.47 day(-1), respectively. The corresponding values for Z2 and Z3 were negligible due to their bacterial inhibition characteristics. PMID:18846450

  18. Bioleaching of nickel from spent petroleum catalyst using Acidithiobacillus thiooxidans DSM- 11478.

    Science.gov (United States)

    Sharma, Mohita; Bisht, Varsha; Singh, Bina; Jain, Pratiksha; Mandal, Ajoy K; Lal, Banwari; Sarma, Priyangshu M

    2015-06-01

    The present work deals with optimization of culture conditions and process parameters for bioleaching of spent petroleum catalyst collected from a petroleum refinery. The efficacy of Ni bioleaching from spent petroleum catalyst was determined using pure culture of Acidithiobacillus thiooxidans DSM- 11478. The culture conditions of pH, temperature and headspace volume to media volume ratio were optimized. EDX analysis was done to confirm the presence of Ni in the spent catalyst after roasting it to decoke its surface. The optimum temperature for A. thiooxidans DSM-11478 growth was found to be 32 degrees C. The enhanced recovery of nickel at very low pH was attributed to the higher acidic strength of sulfuric acid produced in the culture medium by the bacterium. During the bioleaching process, 89% of the Ni present in the catalyst waste could be successfully recovered in optimized conditions. This environment friendly bioleaching process proved efficient than the chemical method. Taking leads from the lab scale results, bioleaching in larger volumes (1, 5 and 10 L) was also performed to provide guidelines for taking up this technology for in situ industrial waste management. PMID:26155679

  19. Occurrence and fluctuations of Acidithiobacillus ssp. in uranium mine effluents, Caldas, MG

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Michelle Burato de; Roque, Claudio Vitor; Gomes, Heliana de Azevedo [Brazilian Nuclear Energy Commission (CNEN-MG), Pocos de Caldas, MG (Brazil)]. E-mail: michelle_borato@hotmail.com; cvroque@cnen.gov.br; hgomes@cnen.gov.br

    2007-07-01

    Sulphide ores that are present in mining areas can cause serious environmental problems because of the action of chemolithotrophic bacteria of the Acidithiobacillus genera, mainly A. ferroxidans and A. thiooxidans. These microorganisms are capable of oxidizing sulphide minerals, elemental sulphur and ferrous ion, possibly mobilizing radionuclides such as uranium into the environment. In this context, the present study was undertaken in order to determine the occurrence and fluctuations of populations of A. ferroxidans and A. thiooxidans in effluents from an uranium mine, part of the Ore Treatment Unit (UTM) in Caldas, MG - Brazil, analyzing samples from 9 sampling points (CM, BS, D3, 25, 27, 32, 41, 75, and 76). The results showed that the population of A. thiooxidans occurs more often (44.4%) than the population of A. ferroxidans (31.5%). In the sample points within the UTM-environment interface, points 25 and 76 were considered the most susceptible to acid mine drainage and activity of bacteria involved in metal bioleaching. The seasonal behavior of some of the variables observed at points CM, D3, and BS, when evaluated simultaneously, such as high Eh values, low pH values, the detection of greater percentages of incidence and higher counts of A. ferroxidans and A. thiooxidans, showed that these points are the main locations for the occurrence of acid mine drainage and bacterial bioleaching in the UTM and should be considered as critical points for a possible decommissioning action. (author)

  20. Bioleaching of nickel from spent petroleum catalyst using Acidithiobacillus thiooxidans DSM- 11478.

    Science.gov (United States)

    Sharma, Mohita; Bisht, Varsha; Singh, Bina; Jain, Pratiksha; Mandal, Ajoy K; Lal, Banwari; Sarma, Priyangshu M

    2015-06-01

    The present work deals with optimization of culture conditions and process parameters for bioleaching of spent petroleum catalyst collected from a petroleum refinery. The efficacy of Ni bioleaching from spent petroleum catalyst was determined using pure culture of Acidithiobacillus thiooxidans DSM- 11478. The culture conditions of pH, temperature and headspace volume to media volume ratio were optimized. EDX analysis was done to confirm the presence of Ni in the spent catalyst after roasting it to decoke its surface. The optimum temperature for A. thiooxidans DSM-11478 growth was found to be 32 degrees C. The enhanced recovery of nickel at very low pH was attributed to the higher acidic strength of sulfuric acid produced in the culture medium by the bacterium. During the bioleaching process, 89% of the Ni present in the catalyst waste could be successfully recovered in optimized conditions. This environment friendly bioleaching process proved efficient than the chemical method. Taking leads from the lab scale results, bioleaching in larger volumes (1, 5 and 10 L) was also performed to provide guidelines for taking up this technology for in situ industrial waste management.

  1. Biosorption and biodegradation of a sulfur dye in high-strength dyeing wastewater by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Nguyen, Thai Anh; Fu, Chun-Chieh; Juang, Ruey-Shin

    2016-11-01

    The ability of the bacterial strain Acidithiobacillus thiooxidans to remove sulfur blue 15 (SB15) dye from water samples was examined. This bacterium could not only oxidize sulfur compounds to sulfuric acid but also promote the attachment of the cells to the surface of sulfidic particles, therefore serving as an efficient biosorbent. The biosorption isotherms were better described by the Langmuir equation than by the Freundlich or Dubinin-Radushkevich equation. Also, the biosorption process followed the pseudo-second-order kinetics. At pH 8.3 and SB15 concentrations up to 2000 mg L(-1) in the biomass/mineral salt solution, the dye removal and decolorization were 87.5% and 91.4%, respectively, following the biosorption process. Biodegradation was proposed as a subsequent process for the remaining dye (250-350 mg L(-1)). A central composite design was used to analyze independent variables in the response surface methodology study. Under the optimal conditions (i.e., initial dye concentration of 300 mg L(-1), initial biomass concentration of 1.0 g L(-1), initial pH of 11.7, and yeast extract dose of 60 mg L(-1)), up to 50% of SB15 was removed after 4 days of biodegradation.

  2. Influence of the sulfur species reactivity on biofilm conformation during pyrite colonization by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Lara, René H; García-Meza, J Viridiana; Cruz, Roel; Valdez-Pérez, Donato; González, Ignacio

    2012-08-01

    Massive pyrite (FeS₂) electrodes were potentiostatically modified by means of variable oxidation pulse to induce formation of diverse surface sulfur species (S(n)²⁻, S⁰). The evolution of reactivity of the resulting surfaces considers transition from passive (e.g., Fe(1-x )S₂) to active sulfur species (e.g., Fe(1-x )S(2-y ), S⁰). Selected modified pyrite surfaces were incubated with cells of sulfur-oxidizing Acidithiobacillus thiooxidans for 24 h in a specific culture medium (pH 2). Abiotic control experiments were also performed to compare chemical and biological oxidation. After incubation, the attached cells density and their exopolysaccharides were analyzed by confocal laser scanning microscopy (CLMS) and atomic force microscopy (AFM) on bio-oxidized surfaces; additionally, S(n)²⁻/S⁰ speciation was carried out on bio-oxidized and abiotic pyrite surfaces using Raman spectroscopy. Our results indicate an important correlation between the evolution of S(n)²⁻/S⁰ surface species ratio and biofilm formation. Hence, pyrite surfaces with mainly passive-sulfur species were less colonized by A. thiooxidans as compared to surfaces with active sulfur species. These results provide knowledge that may contribute to establishing interfacial conditions that enhance or delay metal sulfide (MS) dissolution, as a function of the biofilm formed by sulfur-oxidizing bacteria.

  3. Inhibition of microbial concrete corrosion by Acidithiobacillus thiooxidans with functionalised zeolite-A coating.

    Science.gov (United States)

    Haile, Tesfaalem; Nakhla, George

    2009-01-01

    The inhibition of the corrosive action of Acidithiobacillus thiooxidans on concrete specimens coated by functionalised zeolite-A containing 14% zinc and 5% silver by weight was studied. Uncoated concrete specimens, epoxy-coated concrete specimens (EP), and functionalised zeolite-A coated concrete specimens with epoxy to zeolite weight ratios of 3:1 (Z1), 2:2 (Z2) and 1:3 (Z3) were studied. Specimens were characterised by x-ray powder diffraction and field emission scanning electron microscopy for the identification of corrosion products and morphological changes. Biomass growth at the conclusion of the 32-day experiments was 4, 179 and 193 mg volatile suspended solids g(-1) sulphur for the uncoated, EP and Z1 specimens, whereas that of Z2 and Z3 were negligible. In the uncoated, EP and Z1 specimens, sulphate production rates were 0.83, 9.1 and 8.8 mM SO(4)(2-) day(-1) and the specific growth rates, mu, were 0.14, 0.57 and 0.47 day(-1), respectively. The corresponding values for Z2 and Z3 were negligible due to their bacterial inhibition characteristics.

  4. Occurrence and fluctuations of Acidithiobacillus ssp. in uranium mine effluents, Caldas, MG

    International Nuclear Information System (INIS)

    Sulphide ores that are present in mining areas can cause serious environmental problems because of the action of chemolithotrophic bacteria of the Acidithiobacillus genera, mainly A. ferroxidans and A. thiooxidans. These microorganisms are capable of oxidizing sulphide minerals, elemental sulphur and ferrous ion, possibly mobilizing radionuclides such as uranium into the environment. In this context, the present study was undertaken in order to determine the occurrence and fluctuations of populations of A. ferroxidans and A. thiooxidans in effluents from an uranium mine, part of the Ore Treatment Unit (UTM) in Caldas, MG - Brazil, analyzing samples from 9 sampling points (CM, BS, D3, 25, 27, 32, 41, 75, and 76). The results showed that the population of A. thiooxidans occurs more often (44.4%) than the population of A. ferroxidans (31.5%). In the sample points within the UTM-environment interface, points 25 and 76 were considered the most susceptible to acid mine drainage and activity of bacteria involved in metal bioleaching. The seasonal behavior of some of the variables observed at points CM, D3, and BS, when evaluated simultaneously, such as high Eh values, low pH values, the detection of greater percentages of incidence and higher counts of A. ferroxidans and A. thiooxidans, showed that these points are the main locations for the occurrence of acid mine drainage and bacterial bioleaching in the UTM and should be considered as critical points for a possible decommissioning action. (author)

  5. An Atypical Acidophil Cell Line Tumor Showing Focal Differentiation Toward Both Growth Hormone and Prolactin Cells.

    Science.gov (United States)

    Naritaka, Heiji; Kameya, Toru; Sato, Yuichi; Furuhata, Shigeru; Okui, Junichi; Kamiguchi, Yuji; Otani, Mitsuhiro; Toya, Shigeo

    1995-01-01

    We report a case of giant pituitary adenoma in a child. Computerized tomography (CT) scan revealed a suprasellar extension tumor mass with hydrocephalus. There was no clinical evidence of acromegaly, gigantism, and other hormonal symptoms. Endocrinologic studies showed within normal value of serum growth hormone (GH: 4.2 ng/mL) and slightly increased levels of prolactin (PRL: 78 ng/mL) and other pituitary hormone values were within normal range. On suppression test by bromocryptin, both GH and PRL levels were reduced. Histopathological findings revealed that the tumor consisted of predominantly chromophobic and partly eosinophilic adenoma cells. Immunohistochemical staining detected GH and PRL in a small number of distinctly different adenoma cells, respectively. Nonradioactive in situ hybridization (ISH) also showed GH and PRL mRNA expression in identical immunopositive cells. Electron microscopy (EM) demonstrated adenoma cells with moderate or small numbers of two types of dense granules and without fibrous body which are characteristic of sparsely granulated GH-cell adenomas. The adenoma does not fit into any classification but may be an atypical acidophil cell line tumor showing focal differentiation toward both GH and PRL cells. PMID:12114745

  6. Isolation and identification of moderately thermophilic acidophilic iron-oxidizing bacterium and its bioleaching characterization

    Institute of Scientific and Technical Information of China (English)

    ZENG Wei-min; WU Chang-bin; ZHANG Ru-bing; HU Pei-lei; QIU Guan-zhou; GU Guo-hua; ZHOU Hong-bo

    2009-01-01

    A moderately thermophilic acidophilic iron-oxidizing bacterium ZW-1 was isolated from Dexing mine, Jiangxi Province, China. The morphological, biochemical and physiological characteristics, 16S rRNA sequence and bioleaching characterization of strain ZW-1 were studied. The optimum growth temperature is 48 ℃, and the optimum initial pH is 1.9. The strain can grow autotrophically by using ferrous iron or elemental sulfur as sole energy sources. The strain is also able to grow heterotrophically by using peptone and yeast extract powder, but not glucose. The cell density of strain ZW-1 can reach up to 1.02×108 /mL with addition of 0.4 g/L peptone. A phylogenetic tree was constructed by comparing with the published 16S rRNA sequences of the relative bacteria species. In the phylogenetic tree, strain ZW-1 is closely relative to Sulfobacilus acidophilus with more than 99% sequence similarity. The results of bioleaching experiments indicate that the strain could oxidize Fe2+ efficiently, and the maximum oxidizing rate is 0.295 g/(L·h). It could tolerate high concentration of Fe3+ and Cu2+ (35 g/L and 25 g/L, respectively). After 20 d, 44.6% of copper is extracted from chalcopyrite by using strain ZW-1 as inocula.

  7. Effect of physical characteristics on bioleaching using indigenous acidophilic bacteria for recovering the valuable resources

    Science.gov (United States)

    Wi, D.; Kim, B.; Cho, K.; Choi, N.; Park, C.

    2011-12-01

    Bioleaching technology which is based on the ability of bacteria to transform solid compounds into soluble or extractable elements that can be recovered, has developed rapidly in recent decades for its advantages, such as mild reaction, low energy consumption, simple process, environmentally friendly and suitable for low-grade mine tailing and residues. This study investigated the bioleaching efficiency of copper matte under batch experimental conditions (various mineral particle size) using the indigenous acidophilic bacteria collected from acidic hot spring in Hatchnobaru, Japan. We conducted the batch experiments at three different mineral particle sizes: 0.06, 0.16 and 1.12mm. The results showed that the pH in the bacteria inoculating sample increased than initial condition, possibly due to buffer effects by phosphate ions in growth medium. After 22 days from incubation the leached accumulation content of Cu was 0.06 mm - 1,197 mg/L, 0.16 mm - 970 mg/L and 1.12 mm - 704 mg/L. Additionally, through SEM analysis we found of gypsum formed crystals which coated the copper matte surface 6 days after inoculation in 1.12mm case. This study informs basic knowledge when bacteria apply to eco-/economic resources utilization studies including the biomining and the recycling of mine waste system.

  8. Effect of adaptation and pulp density on bioleaching of mine waste using indigenous acidophilic bacteria

    Science.gov (United States)

    Cho, K.; Kim, B.; Lee, D.; Choi, N.; Park, C.

    2011-12-01

    Adaptation to environment is a natural phenomena that takes place in many animals, plants and microorganisms. These adapted organisms achieve stronger applicability than unadapted organisms after habitation in a specific environment for a long time. In the biohydrometallurgical industry, adaptation to special environment conditions by selective culturing is the most popular method for improving bioleaching activity of strains-although that is time consuming. This study investigated the influence of the bioleaching efficiency of mine waste under batch experimental conditions (adaptation and pulp density) using the indigenous acidophilic bacteria collected from acid mine drainage in Go-seong and Yeon-hwa, Korea. We conducted the batch experiments at the influences of parameters, such as the adaptation of bacteria and pulp density of the mine waste. In the adaptation case, the value of pH in 1'st adaptation bacteria sample exhibited lower than in 2'nd adaptation bacteria sample. And the content of both Cu and Zn at 1'st adaptation bacteria sample appeared lower than at 2'nd adaptation bacteria sample. In the SEM analysis, the rod-shaped bacteria with 1μm in length were observed on the filter paper (pore size - 0.45μm). The results of pulp density experiments revealed that the content of both Cu and Zn increased with increasing pulp density, since the increment of pulp density resulted in the enhancement of bioleaching capacity.

  9. Biodiversity and interactions of acidophiles: Key to understanding and optimizing microbial processing of ores and concentrates

    Institute of Scientific and Technical Information of China (English)

    D.B.JOHNSON

    2008-01-01

    Mining companies have become increasingly aware of the potential of microbiological approaches for recovering base and precious metals from low-grade ores,and for remediating acidic,metal-rich wastewaters that drain from both operating and abandoned mine sites.Biological systems offer a number of environmental and (sometimes) economical advantages over conventional approaches,such as pyrometallurgy,though their application is not appropriate in every situation.Mineral processing using micro-organisms has been exploited for extracting gold,copper,uranium and cobalt,and current developments are targeting other base metals.Recently,there has been a great increase in our knowledge and understanding of both the diversity of the microbiology of biomining environments,and of how the microorganisms interact with each other.The results from laboratory experiments which have simulated both stirred tank and heap bioreactor systems have shown that microbial consortia are more robust than pure cultures of mineral-oxidizing acidophiles,and also tend to be more effective at bioleaching and bio-oxidizing ores and concentrates.The paper presented a concise review of the nature and interactions of microbial consortia that are involved in the oxidation of sulfide minerals,and how these might be adapted to meet future challenges in biomining operations.

  10. Changes in biofilm structure during the colonization of chalcopyrite by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    García-Meza, J V; Fernández, J J; Lara, R H; González, I

    2013-07-01

    Biofilms of Acidithiobacillus thiooxidans were grown on the surface of massive chalcopyrite electrodes (MCE) where different secondary sulfur phases were previously formed by potentiostatic oxidation of MCE at 0.780≤Ean≤0.965 V (electrooxidized MCE, eMCE). The formation of mainly S⁰ and minor amounts of CuS and Sn²⁻ were detected on eMCEs. The eMCEs were incubated with A. thiooxidans cells for 1, 12, 24, 48, and 120 h in order to temporally monitor changes in eMCE's secondary phases, biofilm structure, and extracellular polymeric substance (EPS) composition (lipids, proteins, and polysaccharides) using microscopic, spectroscopic, electrochemical, and biochemical techniques. The results show significant cell attachments with stratified biofilm structure since the first hour of incubation and EPS composition changes, the most important being production after 48-120 h when the highest amount of lipids and proteins were registered. During 120 h, periodic oxidation/formation of S⁰/Sn²⁻ was recorded on biooxidized eMCEs, until a stable CuS composition was formed. In contrast, no evidence of CuS formation was observed on the eMCEs of the abiotic control, confirming that CuS formation results from microbial activity. The surface transformation of eMCE induces a structural transformation of the biofilm, evolving directly to a multilayered biofilm with more hydrophobic EPS and proteins after 120 h. Our results suggest that A. thiooxidans responded to the spatial and temporal distribution and chemical reactivity of the Sn²⁻/S⁰/CuS phases throughout 120 h. These results suggested a strong correlation between surface speciation, hydrophobic domains in EPS, and biofilm organization during chalcopyrite biooxidation by A. thiooxidans.

  11. Bioleaching of heavy metals from sewage sludge by Acidithiobacillus thiooxidans. A comparative study

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Ye-Ming; Wang, Qing-Ping; Chen, Zu-Liang [Fujian Normal Univ., Fuzhou (China). School of Environmental Science and Engineering; Tang, Caixian [La Trobe Univ., Melbourne, VIC (Australia). Dept. of Agricultural Sciences

    2012-06-15

    To understand the bioleaching of metals from sludge by Acidithiobacillus thiooxidans, the aims of this study were to evaluate the experimental conditions affecting the efficiency of removal of the metals, including solids concentration, initial pH, sulfur concentration and inoculum level were examined, and following the bioleaching mechanism was proposed. Materials and methods: A. thiooxidans were isolated from collected sludge samples containing bacteria from Fuzhou Jingshan sewage treatment plant, and identification of bacteria by sequencing the 16 s rDNA gene sequences. Conditions affecting the bioleaching and application were conducted by batch experiments. The analysis of Cr, Cu, Pb, and Zn was carried out using an atomic absorption spectrophotometer, and the pH and oxidation-reduction potential (ORP) were measured using a pH meter and an ORP meter. The results show that a high metal leaching efficiency was achieved at low solid concentrations due to decreases in buffering capacity. In addition, the best conditions of the bioleaching included 2 % (w/{nu}) solid concentration, 5.0 gL{sup -1} sulfur concentration, and 10 % ({nu}/{nu}) inoculum concentration, where the removal efficiencies of Cr, Cu, Pb, and Zn in sewage sludge was 43.6 %, 96.2 %, 41.6 %, and 96.5 %, respectively. We found that the bioleaching of Zn was governed by direct and indirect mechanisms, while the bioleaching of Cu, Pb, and Cr was mainly dominated by the bioleaching indirect mechanism. After processing with the proposed techniques, the heavy metals in the sewage sludge did meet the requirement of the national standards. (orig.)

  12. Influence of the surface speciation on biofilm attachment to chalcopyrite by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Lara, René H; García-Meza, J Viridiana; González, Ignacio; Cruz, Roel

    2013-03-01

    Surfaces of massive chalcopyrite (CuFeS2) electrodes were modified by applying variable oxidation potential pulses under growth media in order to induce the formation of different secondary phases (e.g., copper-rich polysulfides, S n(2-); elemental sulfur, S(0); and covellite, CuS). The evolution of reactivity (oxidation capacity) of the resulting chalcopyrite surfaces considers a transition from passive or inactive (containing CuS and S n(2-)) to active (containing increasing amounts of S(0)) phases. Modified surfaces were incubated with cells of sulfur-oxidizing bacteria (Acidithiobacillus thiooxidans) for 24 h in a specific culture medium (pH 2). Abiotic control experiments were also performed to compare chemical and biological oxidation. After incubation, the density of cells attached to chalcopyrite surfaces, the structure of the formed biofilm, and their exopolysaccharides and nucleic acids were analyzed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy coupled to dispersive X-ray analysis (SEM-EDS). Additionally, CuS and S n(2-)/S(0) speciation, as well as secondary phase evolution, was carried out on biooxidized and abiotic chalcopyrite surfaces using Raman spectroscopy and SEM-EDS. Our results indicate that oxidized chalcopyrite surfaces initially containing inactive S n(2-) and S n(2-)/CuS phases were less colonized by A. thiooxidans as compared with surfaces containing active phases (mainly S(0)). Furthermore, it was observed that cells were partially covered by CuS and S(0) phases during biooxidation, especially at highly oxidized chalcopyrite surfaces, suggesting the innocuous effect of CuS phases during A. thiooxidans performance. These results may contribute to understanding the effect of the concomitant formation of refractory secondary phases (as CuS and inactive S n(2-)) during the biooxidation of chalcopyrite by sulfur-oxidizing microorganisms in bioleaching systems.

  13. Growth inhibition by tungsten in the sulfur-oxidizing bacterium Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Negishi, Atsunori; Muraoka, Tadashi; Maeda, Terunobu; Takeuchi, Fumiaki; Kanao, Tadayoshi; Kamimura, Kazuo; Sugio, Tsuyoshi

    2005-11-01

    Growth of five strains of sulfur-oxidizing bacteria Acidithiobacillus thiooxidans, including strain NB1-3, was inhibited completely by 50 microM of sodium tungstate (Na(2)WO(4)). When the cells of NB1-3 were incubated in 0.1 M beta-alanine-SO(4)(2-) buffer (pH 3.0) with 100 microM Na(2)WO(4) for 1 h, the amount of tungsten bound to the cells was 33 microg/mg protein. Approximately 10 times more tungsten was bound to the cells at pH 3.0 than at pH 7.0. The tungsten binding to NB1-3 cells was inhibited by oxyanions such as sodium molybdenum and ammonium vanadate. The activities of enzymes involved in elemental sulfur oxidation of NB1-3 cells such as sulfur oxidase, sulfur dioxygenase, and sulfite oxidase were strongly inhibited by Na(2)WO(4). These results indicate that tungsten binds to NB1-3 cells and inhibits the sulfur oxidation enzyme system of the cells, and as a result, inhibits cell growth. When portland cement bars supplemented with 0.075% metal nickel and with 0.075% metal nickel and 0.075% calcium tungstate were exposed to the atmosphere of a sewage treatment plant containing 28 ppm of H(2)S for 2 years, the weight loss of the portland cement bar with metal nickel and calcium tungstate was much lower than the cement bar containing 0.075% metal nickel.

  14. Bioleaching of arsenic from highly contaminated mine tailings using Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Lee, Eunseong; Han, Yosep; Park, Jeonghyun; Hong, Jeongsik; Silva, Rene A; Kim, Seungkon; Kim, Hyunjung

    2015-01-01

    The behavior of arsenic (As) bioleaching from mine tailings containing high amount of As (ca. 34,000 mg/kg) was investigated using Acidithiobacillus thiooxidans to get an insight on the optimal conditions that would be applied to practical heap and/or tank bioleaching tests. Initial pH (1.8-2.2), temperature (25-40 °C), and solid concentration (0.5-4.0%) were employed as experimental parameters. Complementary characterization experiments (e.g., XRD, SEM-EDS, electrophoretic mobility, cell density, and sulfate production) were also carried out to better understand the mechanism of As bioleaching. The results showed that final As leaching efficiency was similar regardless of initial pH. However, greater initial As leaching rate was observed at initial pH 1.8 than other conditions, which could be attributed to greater initial cell attachment to mine tailings. Unlike the trend observed when varying the initial pH, the final As leaching efficiency varied with the changes in temperature and solid concentration. Specifically, As leaching efficiency tended to decrease with increasing temperature due to the decrease in the bacterial growth rate at higher temperature. Meanwhile, As leaching efficiency tended to increase with decreasing solid concentration. The results for jarosite contents in mine tailings residue after bioleaching revealed that much greater amount of the jarosite was formed during the bioleaching reaction at higher solid concentration, suggesting that the coverage of the surface of the mine tailings by jarosite and/or the co-precipitation of the leached As with jarosite could be a dominant factor reducing As leaching efficiency.

  15. Evolution of biofilms during the colonization process of pyrite by Acidithiobacillus thiooxidans.

    Science.gov (United States)

    González, Dulce M; Lara, René H; Alvarado, Keila N; Valdez-Pérez, Donato; Navarro-Contreras, Hugo R; Cruz, Roel; García-Meza, Jessica Viridiana

    2012-01-01

    We have applied epifluorescence principles, atomic force microscopy, and Raman studies to the analysis of the colonization process of pyrite (FeS(2)) by sulfuroxidizing bacteria Acidithiobacillus thiooxidans after 1, 15, 24, and 72 h. For the stages examined, we present results comprising the evolution of biofilms, speciation of S (n) (2-) /S(0) species, adhesion forces of attached cells, production and secretion of extracellular polymeric substances (EPS), and its biochemical composition. After 1 h, highly dispersed attached cells in the surface of the mineral were observed. The results suggest initial non-covalent, weak interactions (e.g., van der Waal's, hydrophobic interactions), mediating an irreversible binding mechanism to electrooxidized massive pyrite electrode (eMPE), wherein the initial production of EPS by individual cells is determinant. The mineral surface reached its maximum cell cover between 15 to 24 h. Longer biooxidation times resulted in the progressive biofilm reduction on the mineral surface. Quantification of attached cell adhesion forces indicated a strong initial mechanism (8.4 nN), whereas subsequent stages of mineral colonization indicated stability of biofilms and of the adhesion force to an average of 4.2 nN. A variable EPS (polysaccharides, lipids, and proteins) secretion at all stages was found; thus, different architectural conformation of the biofilms was observed during 120 h. The main EPS produced were lipopolysaccharides which may increase the hydrophobicity of A. thiooxidans biofilms. The highest amount of lipopolysaccharides occurred between 15-72 h. In contrast with abiotic surfaces, the progressive depletion of S (n) (2-) /S(0) was observed on biotic eMPE surfaces, indicating consumption of surface sulfur species. All observations indicated a dynamic biooxidation mechanism of pyrite by A. thiooxidans, where the biofilms stability and composition seems to occur independently from surface sulfur species depletion.

  16. Culture-independent detection of 'TM7' bacteria in a streptomycin-resistant acidophilic nitrifying process

    Energy Technology Data Exchange (ETDEWEB)

    Kurogi, T.; Linh, N. T. T.; Kuroki, T.; Yamada, T. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580 (Japan); Hiraishi, A. [Department of Environmental and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan and Electronics-inspired Interdisciplinary Institute (EIIRIS), Toyohashi University of Technology, Toyohashi 441-8580 (Japan)

    2014-02-20

    Nitrification in biological wastewater treatment processes has been believed for long time to take place under neutral conditions and is inhibited under acidic conditions. However, we previously constructed acidophilic nitrifying sequencing-batch reactors (ANSBRs) being capable of nitrification at < pH 4 and harboring bacteria of the candidate phylum 'TM7' as the major constituents of the microbial community. In light of the fact that the 16S rRNA of TM7 bacteria has a highly atypical base substitution possibly responsible for resistance to streptomycin at the ribosome level, this study was undertaken to construct streptomycin-resistant acidophilic nitrifying (SRAN) reactors and to demonstrate whether TM7 bacteria are abundant in these reactors. The SRAN reactors were constructed by seeding with nitrifying sludge from an ANSBR and cultivating with ammonium-containing mineral medium (pH 4.0), to which streptomycin at a concentration of 10, 30 and 50 mg L{sup −1} was added. In all reactors, the pH varied between 2.7 and 4.0, and ammonium was completely converted to nitrate in every batch cycle. PCR-aided denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes revealed that some major clones assigned to TM7 bacteria and Gammaproteobacteria were constantly present during the overall period of operation. Fluorescence in situ hybridization (FISH) with specific oligonucleotide probes also showed that TM7 bacteria predominated in all SRAN reactors, accounting for 58% of the total bacterial population on average. Although the biological significance of the TM7 bacteria in the SRAN reactors are unknown, our results suggest that these bacteria are possibly streptomycin-resistant and play some important roles in the acidophilic nitrifying process.

  17. Microalgae as a safe food source for animals: nutritional characteristics of the acidophilic microalga Coccomyxa onubensis

    Directory of Open Access Journals (Sweden)

    Francisco Navarro

    2016-10-01

    Full Text Available Background: Edible microalgae are marine or fresh water mesophilic species. Although the harvesting of microalgae offers an abundance of opportunities to the food and pharmaceutical industries, the possibility to use extremophilic microalgae as a food source for animals is not well-documented. Objective: We studied the effects of dietary supplementation of a powdered form of the acidophilic microalga Coccomyxa onubensis on growth and health parameters of laboratory rats. Method: Four randomly organized groups of rats (n=6 were fed a standard diet (Diet 1, control or with a diet in which 0.4% (Diet 2, 1.25% (Diet 3, or 6.25% (Diet 4 (w/w of the standard diet weight was substituted with dried microalgae powder, respectively. The four groups of animals were provided ad libitum access to feed for 45 days. Results: C. onubensis biomass is rich in protein (44.60% of dry weight and dietary fiber (15.73%, and has a moderate carbohydrate content (24.8% and a low lipid content (5.4% in which polyunsaturated fatty acids represent 65% of the total fatty acid. Nucleic acids are present at 4.8%. No significant difference was found in growth rates or feed efficiency ratios of the four groups of rats. Histological studies of liver and kidney tissue revealed healthy organs in control and C. onubensis-fed animals, while plasma hematological and biochemical parameters were within healthy ranges for all animals. Furthermore, animals fed a microalgae-enriched diet exhibited a statistically significant decrease in both blood cholesterol and triglyceride levels. The blood triglyceride content and very low density lipoprotein-cholesterol levels decreased by about 50% in rats fed Diet 4. Conclusions: These data suggest that C. onubensis may be useful as a food supplement for laboratory animals and may also serve as a nutraceutical in functional foods. In addition, microalgae powder-supplemented diets exerted a significant hypocholesterolemic and hypotriglyceridemic

  18. Leaching of pyrite by acidophilic heterotrophic iron-oxidizing bacteria in pure and mixed cultures

    Energy Technology Data Exchange (ETDEWEB)

    Bacelar-Nicolau, P.; Johnson, D.B. [Univ. of Wales, Bangor (United Kingdom). School of Biological Sciences

    1999-02-01

    Seven strains of heterotrophic iron-oxidizing acidophilic bacteria were examined to determine their abilities to promote oxidative dissolution of pyrite (FeS{sub 2}) when they were grown in pure cultures and in mixed cultures with sulfur-oxidizing Thiobacillus spp. Only one of the isolates (strain T-24) oxidized pyrite when it was grown in pyrite-basal salts medium. However, when pyrite-containing cultures were supplemented with 0.02% (wt/vol) yeast extract, most of the isolates oxidized pyrite, and one (strain T-24) promoted rates of mineral dissolution similar to the rates observed with the iron-oxidizing autotroph Thiobacillus ferroxidans. Pyrite oxidation by another isolate (strain T-21) occurred in cultures containing between 0.005 and 0.05% (wt/vol) yeast extract but was completely inhibited in cultures containing 0.5% yeast extract. Ferrous iron was also needed for mineral dissolution by the iron-oxidizing heterotrophs, indicating that these organisms oxidize pyrite via the indirect mechanism. Mixed cultures of three isolates (strains T-21, T-232, and T-24) and the sulfur-oxidizing autotroph Thiobacillus thiooxidans promoted pyrite dissolution; since neither strains T-21 and T-23 nor T. thiooxidans could oxidize this mineral in yeast extract-free media, this was a novel example of bacterial synergism. Mixed cultures of strains T-21 and T-23 and the sulfur-oxidizing mixotroph Thiobacillus acidophilus also oxidized pyrite but to a lesser extent than did mixed cultures containing T. thiooxidans. Pyrite leaching by strain T -23 grown in an organic compound-rich medium and incubated either shaken or unshaken was also assessed. The potential environmental significance of iron-oxidizing heterotrophs in accelerating pyrite oxidation is discussed.

  19. The acidophilic microorganisms diversity present in lignite and pit coal from Paroseni, Halânga, Turceni mines

    Directory of Open Access Journals (Sweden)

    Carmen Madalina CISMASIU

    2009-11-01

    Full Text Available Pollution from coal combustion is the largest problem in the current use of coal and the biggest constraint on the increased use of coal. When these fossil fuels are combusted, sulphur-di-oxide is released into the atmosphere causing acid rains which dissolves buildings, kills forest. Knowing the physiological groups of microorganisms present in the coal samples has an ecological importance, completing the knowledge in the field of the microorganism’s ecology and a practical importance, being a source of new microorganisms with biotechnological potential. The microbial communities evidenced in such sites include both groups of chemolithotrophic microorganisms involved in the metals biosolubilization processes and groups of heterotrophic microorganisms involved in the processes of bioaccumulation or biofixation of metallic ions. In this context, this paper presents the study regarding the main physiological groups of microorganisms present in the pit coal and lignite samples after the industrial processing of coal. The results revealed that the microorganisms belonging to the following physiological groups: aerobic heterotrophic acidophilic bacteria, strictly anaerobic heterotrophic (sulphur-reducing, nitrifying bacteria (nitrite and nitrate bacteria, denitrifying bacteria and acidophilic chemolithotrophic bacteria on Fe2+, on S0 and on S2O3.

  20. Solid and liquid media for isolating and cultivating acidophilic and acid-tolerant sulfate-reducing bacteria.

    Science.gov (United States)

    Ňancucheo, Ivan; Rowe, Owen F; Hedrich, Sabrina; Johnson, D Barrie

    2016-05-01

    Growth media have been developed to facilitate the enrichment and isolation of acidophilic and acid-tolerant sulfate-reducing bacteria (aSRB) from environmental and industrial samples, and to allow their cultivation in vitro The main features of the 'standard' solid and liquid devised media are as follows: (i) use of glycerol rather than an aliphatic acid as electron donor; (ii) inclusion of stoichiometric concentrations of zinc ions to both buffer pH and to convert potentially harmful hydrogen sulphide produced by the aSRB to insoluble zinc sulphide; (iii) inclusion of Acidocella aromatica (an heterotrophic acidophile that does not metabolize glycerol or yeast extract) in the gel underlayer of double layered (overlay) solid media, to remove acetic acid produced by aSRB that incompletely oxidize glycerol and also aliphatic acids (mostly pyruvic) released by acid hydrolysis of the gelling agent used (agarose). Colonies of aSRB are readily distinguished from those of other anaerobes due to their deposition and accumulation of metal sulphide precipitates. Data presented illustrate the effectiveness of the overlay solid media described for isolating aSRB from acidic anaerobic sediments and low pH sulfidogenic bioreactors. PMID:27036143

  1. Effect of VOCs and methane in the biological oxidation of the ferrous ion by an acidophilic consortium.

    Science.gov (United States)

    Almenglo, F; Ramírez, M; Gómez, J M; Cantero, D; Revah, S; González-Sánchez, A

    2012-01-01

    During the elimination of H2S from biogas in an aqueous ferric sulphate solution, volatile organic compounds (VOCs) and methane are absorbed and may have an effect on the subsequent biological regeneration of ferric ion. This study was conducted to investigate the effect of maximum concentrations of methane and some VOCs found in biogas on the ferrous oxidation of an acidophilic microbial consortium (FO consortium). The presence and impact of heterotrophic microorganisms on the activity of the acidophilic consortium was also evaluated. No effect on the ferrous oxidation rate was found with gas concentrations of 1500 mg toluene m(-3), 1400 mg 2-butanol m(-3) or 1250 mg 1,2-dichloroethane m(-3), nor with methane at gas concentrations ranging from 15-25% (v/v). A tenfold increase in VOCs concentrations totally inhibited the microbial activity of the FO consortium and the heterotrophs. The presence of a heterotrophic fungus may promote the autotrophic growth of the FO consortium. PMID:22629626

  2. Thiol/Disulfide system plays a crucial role in redox protection in the acidophilic iron-oxidizing bacterium Leptospirillum ferriphilum.

    Directory of Open Access Journals (Sweden)

    Javiera Norambuena

    Full Text Available Thiol/disulfide systems are involved in the maintenance of the redox status of proteins and other molecules that contain thiol/disulfide groups. Leptospirillum ferriphilum DSM14647, an acidophilic bacterium that uses Fe(2+ as electron donor, and withstands very high concentrations of iron and other redox active metals, is a good model to study how acidophiles preserve the thiol/disulfide balance. We studied the composition of thiol/disulfide systems and their role in the oxidative stress response in this extremophile bacterium. Bioinformatic analysis using genomic data and enzymatic assays using protein extracts from cells grown under oxidative stress revealed that the major thiol/disulfide system from L. ferriphilum are a cytoplasmic thioredoxin system (composed by thioredoxins Trx and thioredoxin reductase TR, periplasmic thiol oxidation system (DsbA/DsbB and a c-type cytochrome maturation system (DsbD/DsbE. Upon exposure of L. ferriphilum to reactive oxygen species (ROS-generating compounds, transcriptional activation of the genes encoding Trxs and the TR enzyme, which results in an increase of the corresponding activity, was observed. Altogether these data suggest that the thioredoxin-based thiol/disulfide system plays an important role in redox protection of L. ferriphilum favoring the survival of this microorganism under extreme environmental oxidative conditions.

  3. Simultaneous removal of H2S and NH3 in biofilter inoculated with Acidithiobacillus thiooxidans TAS.

    Science.gov (United States)

    Lee, Eun Young; Cho, Kyung-Suk; Ryu, Hee Wook

    2005-06-01

    H2S and NH3 gases are toxic, corrosive and malodorous air pollutants. Although there are numerous well-established physicochemical techniques presently available for the treatment of these gases, the growing demand for a more economical and improved process has prompted investigations into biological alternatives. In biological treatment methods, H2S is oxidized to SO4(2-) by sulfur-oxidizing bacteria, and then NH3 is removed by chemical neutralization with SO4(2-) to (NH4)2SO4. Since the accumulated (NH4)2SO4 can inhibit microbial activity, it is important to utilize an effective sulfur-oxidizing bacterium that has tolerance to high concentrations of (NH4)2SO4 for the simultaneous removal of H2S and NH3. In this study, a sulfur-oxidizing bacterium with tolerance to high concentrations of (NH4)2SO4 was isolated from activated sludge and identified as Acidithiobacillus thiooxidans TAS. A. thiooxidans TAS could display its sulfur-oxidizing activity in a medium supplemented with 60 g.l(-1) (NH4)2SO4, even though its growth and sulfur-oxidizing activity were completely inhibited in 80 g.l(-1) (NH4)2SO4. When H2S alone was supplied to a ceramic biofilter inoculated with A. thiooxidans TAS, an almost 100% H2S removal efficiency was maintained until the inlet H2S concentration was increased up to 900 microl.l(-1) and the space velocity up to 500 h(-1), at which the amount of H2S eliminated was 810 g-S.m(-3).h(-1). However, when NH3 (50-500 microl.l(-1)) was simultaneously supplied to the biofilter with H2S, the maximum amount of H2S eliminated decreased to 650 g-S.m(-3).h(-1). The inhibition of H2S removal by low NH3 concentrations (50-200 microl.l(-1)) was similar to that by high NH3 concentrations (300-500 microl.l(-1)). The critical inlet H2S load that resulted in over 99% removal was determined as 400 g-S.m(-3).h(-1) in the presence of NH3.

  4. Removal of hydrogen sulfide by sulfate-resistant Acidithiobacillus thiooxidans AZ11.

    Science.gov (United States)

    Lee, Eun Young; Lee, Nae Yoon; Cho, Kyung-Suk; Ryu, Hee Wook

    2006-04-01

    Toxic H2S gas is an important industrial pollutant that is applied to biofiltration. Here, we examined the effects of factors such as inlet concentration and space velocity on the removal efficiency of a bacterial strain capable of tolerating high sulfate concentrations and low pH conditions. We examined three strains of Acidithiobacillus thiooxidans known to have sulfur-oxidizing activity, and identified strain AZ11 as having the highest tolerance for sulfate. A. thiooxidans AZ11 could grow at pH 0.2 in the presence of 74 g l(-1) sulfate, the final oxidation product of elemental sulfur, in the culture broth. Under these conditions, the specific sulfur oxidation rate was 2.9 g-S g-DCW (dry cell weight)(-1) d(-1). The maximum specific sulfur oxidation rate of A. thiooxidans AZ11 was 21.2 g-S g-DCW(-1) d(-1), which was observed in the presence of 4.2 g-SO4(2-) l(-1) and pH 1.5, in the culture medium. To test the effects of various factors on biofiltration by this strain, A. thiooxidans AZ11 was inoculated into a porous ceramic biofilter. First, a maximum inlet loading of 670 g-S m(-3) h(-1) was applied with a constant space velocity (SV) of 200 h(-1) (residence time, 18 s) and the inlet concentration of H2S was experimentally increased from 200 ppmv to 2200 ppmv. Under these conditions, less than 0.1 ppmv H2S was detected at the biofilter outlet. When the inlet H2S was maintained at a constant concentration of 200 ppmv and the SV was increased from 200 h(-1) to 400 h(-1) (residence time, 9 s), an H2S removal of 99.9% was obtained. However, H2S removal efficiencies decreased to 98% and 94% when the SV was set to 500 h(-1) (residence time, 7.2 s) and 600 h(-1) (residence time, 6 s), respectively. The critical elimination capacity guaranteeing 96% removal of the inlet H2S was determined to be 160 g-S m(-3) h(-1) at a space velocity of 600 h(-1). Collectively, these findings show for the first time that a sulfur oxidizing bacterium has a high sulfate tolerance and a high

  5. Leaching of Zinc Sulfide by Thiobacillus ferrooxidans: Bacterial Oxidation of the Sulfur Product Layer Increases the Rate of Zinc Sulfide Dissolution at High Concentrations of Ferrous Ions

    OpenAIRE

    Fowler, T. A.; Crundwell, F. K.

    1999-01-01

    This paper reports the results of leaching experiments conducted with and without Thiobacillus ferrooxidans at the same conditions in solution. The extent of leaching of ZnS with bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, while no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shr...

  6. Influence of initial pH on bioleaching of heavy metals from contaminated soil employing indigenous Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Kumar, R Naresh; Nagendran, R

    2007-01-01

    Bioleaching of heavy metals from contaminated soil was carried out employing indigenous sulfur oxidizing bacterium Acidithiobacillus thiooxidans. Experiments were carried out to assess the influence of initial pH of the system on bioleaching of chromium, zinc, copper, lead and cadmium from metal contaminated soil. pH at the end of four weeks of bioleaching at different initial pH of 3-7 was between 0.9 and 1.3, ORP between 567 and 617mV and sulfate production was in the range of 6090-8418mgl(-1). Chromium, zinc, copper, lead and cadmium solubilization ranged from "59% to 98%" at different initial pH. A. thiooxidans was not affected by the increasing pH of the bioleaching system towards neutral and it was able to utilize elemental sulfur. The results of the present study are encouraging to develop the bioleaching process for decontamination of heavy metal contaminated soil.

  7. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans

    Energy Technology Data Exchange (ETDEWEB)

    NareshKumar, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)], E-mail: nareshkrish@hotmail.com; Nagendran, R. [Centre for Environmental Studies, Anna University, Chennai 600025 (India)

    2008-08-15

    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application.

  8. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans.

    Science.gov (United States)

    NareshKumar, R; Nagendran, R

    2008-08-15

    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application.

  9. Changes in nutrient profile of soil subjected to bioleaching for removal of heavy metals using Acidithiobacillus thiooxidans

    International Nuclear Information System (INIS)

    Studies were carried out to assess changes in nitrogen, phosphorus and potassium contents in soil during bioleaching of heavy metals from soil contaminated by tannery effluents. Indigenous sulfur oxidizing bacteria Acidithiobacillus thiooxidans isolated from the contaminated soil were used for bioremediation. Solubilization efficiency of chromium, cadmium, copper and zinc from soil was 88, 93, 92 and 97%, respectively. However, loss of nitrogen, phosphorus and potassium from the soil was 30, 70 and 68%, respectively. These findings indicate that despite its high potential for removal of heavy metals from contaminated soils, bioleaching results in undesirable dissolution/loss of essential plant nutrients. This aspect warrants urgent attention and detailed studies to evaluate the appropriateness of the technique for field application

  10. Environmental transcriptome analysis reveals physiological differences between biofilm and planktonic modes of life of the iron oxidizing bacteria Leptospirillum spp. in their natural microbial community

    Directory of Open Access Journals (Sweden)

    Parro Víctor

    2010-06-01

    Full Text Available Abstract Background Extreme acidic environments are characterized by their high metal content and lack of nutrients (oligotrophy. Macroscopic biofilms and filaments usually grow on the water-air interface or under the stream attached to solid substrates (streamers. In the Río Tinto (Spain, brown filaments develop under the water stream where the Gram-negative iron-oxidizing bacteria Leptospirillum spp. (L. ferrooxidans and L. ferriphilum and Acidithiobacillus ferrooxidans are abundant. These microorganisms play a critical role in bioleaching processes for industrial (biominery and environmental applications (acid mine drainage, bioremediation. The aim of this study was to investigate the physiological differences between the free living (planktonic and the sessile (biofilm associated lifestyles of Leptospirillum spp. as part of its natural extremely acidophilic community. Results Total RNA extracted from environmental samples was used to determine the composition of the metabolically active members of the microbial community and then to compare the biofilm and planktonic environmental transcriptomes by hybridizing to a genomic microarray of L. ferrooxidans. Genes up-regulated in the filamentous biofilm are involved in cellular functions related to biofilm formation and maintenance, such as: motility and quorum sensing (mqsR, cheAY, fliA, motAB, synthesis of cell wall structures (lnt, murA, murB, specific proteases (clpX/clpP, stress response chaperons (clpB, clpC, grpE-dnaKJ, groESL, etc. Additionally, genes involved in mixed acid fermentation (poxB, ackA were up-regulated in the biofilm. This result, together with the presence of small organic acids like acetate and formate (1.36 mM and 0.06 mM respectively in the acidic (pH 1.8 water stream, suggests that either L. ferrooxidans or other member of the microbial community are producing acetate in the acidophilic biofilm under microaerophilic conditions. Conclusions Our results indicate that the

  11. Atuação de Acidithiobacillus na solubilização de fosfato natural em solo de tabuleiro cultivado com jacatupé (Pachyrhizus erosus Effect of Acidithiobacillus on solubilization of natural phosphate in a coastal tableland soil under yam bean (Pachyrhizus erosus crop

    Directory of Open Access Journals (Sweden)

    N. P. Stamford

    2004-02-01

    Full Text Available Realizou-se um experimento em casa de vegetação para avaliar a atuação do enxofre (S inoculado com Acidithiobacillus na disponibilidade de fósforo (P de fosfato natural (FN, em diferentes modos de aplicação do fertilizante, em um Espodossolo Ferrocárbico Órtico, do tabuleiro costeiro da Zona da Mata de Pernambuco, cultivado com jacatupé (Pachyrhizus erosus. As plantas foram inoculadas com rizóbio (NFB 747 e NFB 748 e adicionado tratamento-controle sem inoculação com rizóbio. Os tratamentos com P foram: (1 FN revestindo o enxofre inoculado com Acidithiobacillus (FN S*, (2 FN revestido com S e com Acidithiobacillus (S* FN, (3 mistura FN com S e com Acidithiobacillus (FN + S*, (4 mistura FN com S e sem Acidithiobacillus (FN + S, (5 superfosfato triplo (ST e (6 sem aplicação de fósforo (P0. Os tratamentos foram aplicados: (a na superfície, (b em sulco 10 cm abaixo da semente, e (c em sulco 10 cm abaixo e ao lado da semente. A biomassa nodular foi maior no tratamento (FN + S* com melhor efeito quando aplicado ao lado e abaixo das sementes. O (FN + S* também aumentou a altura das plantas, a biomassa da parte aérea e das túberas e o N total da parte aérea, especialmente quando aplicado 10 cm abaixo das sementes. O P total da parte aérea foi mais elevado com (S* FN aplicado 10 cm abaixo das sementes. Os melhores teores de P no solo foram obtidos com (FN + S* e (S* FN, com efeito mais evidente quando aplicados 10 cm abaixo das sementes.A greenhouse experiment was carried out to evaluate the effect of sulphur (S inoculated with Acidithiobacillus on phosphorus (P availability from natural phosphate (NP using different fertilizer application methods on yam bean (Pachyrhizus erosus grown in a "Tableland Forest" soil (Podzol Hydromorphic dystrophic of the "Zona da Mata" in the State of Pernambuco, Brazil. Plants were inoculated with rhizobia strains (NFN 747 and NFB 748 and control treatments added without rhizobia inoculation. The P

  12. Synthesis of silver nanoparticles from two acidophilic strains of Pilimelia columellifera subsp. pallida and their antibacterial activities.

    Science.gov (United States)

    Golińska, Patrycja; Wypij, Magdalena; Rathod, Dnyaneshwar; Tikar, Sagar; Dahm, Hanna; Rai, Mahendra

    2016-05-01

    Biosynthesis of silver nanoparticles (AgNPs) is an eco-friendly approach by using different biological sources; for example, plants and microorganisms such as bacteria, fungi, and actinobacteria. In this report, we present the biological synthesis of silver nanoparticles (AgNPs) by acidophilic actinomycetes SL19 and SL24 strains isolated from pine forest soil (pH Pseudomonas aeruginosa, and uropathogens such as Enterobacter, S. aureus, P. aeruginosa, K. pneumoniae, and E. coli. The lowest MIC (40 μg ml(-1) ) was demonstrated by AgNPs synthesized from SL24 against E. coli. However, the AgNPs of SL19 showed lowest MIC (70 μg ml(-1) ) against S. aureus. The activity of antibiotic was enhanced, when tested in combination with silver nanoparticles synthesized from both actinobacterial strains. PMID:27151174

  13. Growth rate characteristics of acidophilic heterotrophic organisms from mine waste rock piles

    Science.gov (United States)

    Yacob, T. W.; Silverstein, J.; Jenkins, J.; Andre, B. J.; Rajaram, H.

    2010-12-01

    Autotrophic iron oxidizing bacteria play a key role in pyrite oxidation and generation of acid mine drainage AMD. Scarcity of organic substrates in many disturbed sites insures that IOB have sufficient oxygen and other nutrients for growth. It is proposed that addition of organic carbon substrate to waste rock piles will result in enrichment of heterotrophic microorganisms limiting the role of IOB in AMD generation. Previous researchers have used the acidophilic heterotroph Acidiphilium cryptum as a model to study the effects of organic substrate addition on the pyrite oxidation/AMD cycle. In order to develop a quantitative model of effects such as competition for oxygen, it is necessary to use growth and substrate consumption rate expressions, and one approach is to choose a model strain such as A. cryptum for kinetic studies. However we have found that the growth rate characteristics of A. cryptum may not provide an accurate model of the remediation effects of organic addition to subsurface mined sites. Fluorescent in-situ hybridization (FISH) assays of extracts of mine waste rock enriched with glucose and yeast extract did not produce countable numbers of cells in the Acidiphilium genus, with a detection limit of3 x 104 cells/gram rock, despite evidence of the presence of well established heterotrophic organisms. However, an MPN enrichment produced heterotrophic population estimates of 1x107 and 1x109 cells/gram rock. Growth rate studies of A. cryptum showed that cultures took 120 hours to degrade 50% of an initial glucose concentration of 2,000 mg/L. However a mixed culture enriched from mine waste rock consumed 100% of the same amount of glucose in 24 hours. Substrate consumption data for the mixed culture were fit to a Monod growth model: {dS}/{dt} = μ_{max}S {( {X_0}/{Y} + S_0 -S )}/{(K_s +S)} Kinetic parameters were estimated utilizing a non linear regression method coupled with an ODE solver. The maximum specific growth rate of the mixed population with

  14. Gene Loss and Horizontal Gene Transfer Contributed to the Genome Evolution of the Extreme Acidophile “Ferrovum”

    Science.gov (United States)

    Ullrich, Sophie R.; González, Carolina; Poehlein, Anja; Tischler, Judith S.; Daniel, Rolf; Schlömann, Michael; Holmes, David S.; Mühling, Martin

    2016-01-01

    Acid mine drainage (AMD), associated with active and abandoned mining sites, is a habitat for acidophilic microorganisms that gain energy from the oxidation of reduced sulfur compounds and ferrous iron and that thrive at pH below 4. Members of the recently proposed genus “Ferrovum” are the first acidophilic iron oxidizers to be described within the Betaproteobacteria. Although they have been detected as typical community members in AMD habitats worldwide, knowledge of their phylogenetic and metabolic diversity is scarce. Genomics approaches appear to be most promising in addressing this lacuna since isolation and cultivation of “Ferrovum” has proven to be extremely difficult and has so far only been successful for the designated type strain “Ferrovum myxofaciens” P3G. In this study, the genomes of two novel strains of “Ferrovum” (PN-J185 and Z-31) derived from water samples of a mine water treatment plant were sequenced. These genomes were compared with those of “Ferrovum” sp. JA12 that also originated from the mine water treatment plant, and of the type strain (P3G). Phylogenomic scrutiny suggests that the four strains represent three “Ferrovum” species that cluster in two groups (1 and 2). Comprehensive analysis of their predicted metabolic pathways revealed that these groups harbor characteristic metabolic profiles, notably with respect to motility, chemotaxis, nitrogen metabolism, biofilm formation and their potential strategies to cope with the acidic environment. For example, while the “F. myxofaciens” strains (group 1) appear to be motile and diazotrophic, the non-motile group 2 strains have the predicted potential to use a greater variety of fixed nitrogen sources. Furthermore, analysis of their genome synteny provides first insights into their genome evolution, suggesting that horizontal gene transfer and genome reduction in the group 2 strains by loss of genes encoding complete metabolic pathways or physiological features

  15. Sulfidogenesis in low pH (3.8-4.2) media by a mixed population of acidophilic bacteria.

    Science.gov (United States)

    Kimura, Sakurako; Hallberg, Kevin B; Johnson, D Barrie

    2006-03-01

    A defined mixed bacterial culture was established which catalyzed dissimilatory sulfate reduction, using glycerol as electron donor, at pH 3.8-4.2. The bacterial consortium comprised a endospore-forming sulfate reducing bacterium (isolate M1) that had been isolated from acidic sediment in a geothermal area of Montserrat (West Indies) and which had 94% sequence identity (of its 16S rRNA gene) to the Gram-positive neutrophile Desulfosporosinus orientis, and a Gram-negative (non sulfate-reducing) acidophile (isolate PFBC) that shared 99% gene identity with Acidocella aromatica. Whilst M1 was an obligate anaerobe, isolate PFBC, as other Acidocella spp., only grew in pure culture in aerobic media. Analysis of microbial communities, using a combination of total bacterial counts and fluorescent in situ hybridization, confirmed that concurrent growth of both bacteria occurred during sulfidogenesis under strictly anoxic conditions in a pH-controlled fermenter. In pure culture, M1 oxidized glycerol incompletely, producing stoichiometric amounts of acetic acid. In mixed culture with PFBC, however, acetic acid was present only in small concentrations and its occurrence was transient. Since M1 did not oxidize acetic acid, it was inferred that this metabolite was catabolized by Acidocella PFBC which, unlike glycerol, was shown to support the growth of this acidophile under aerobic conditions. In fermenter cultures maintained at pH 3.8-4.2, sulfidogenesis resulted in the removal of soluble zinc (as solid phase ZnS) whilst ferrous iron remained in solution. Potential syntrophic interactions, involving hydrogen transfer between M1 and PFBC, are discussed, as is the potential of sulfidogenesis in acidic liquors for the selective recovery of heavy metals from wastewaters. PMID:16456614

  16. Acidophilic denitrifiers dominate the N2O production in a 100-year-old tea orchard soil.

    Science.gov (United States)

    Huang, Ying; Long, Xi-En; Chapman, Stephen J; Yao, Huaiying

    2015-03-01

    Aerobic denitrification is the main process for high N2O production in acid tea field soil. However, the biological mechanisms for the high emission are not fully understood. In this study, we examined N2O emission and denitrifier communities in 100-year-old tea soils with four pH levels (3.71, 5.11, 6.19, and 7.41) and four nitrate concentration (0, 50, 200, and 1000 mg kg(-1) of NO3 (-)-N) addition. Results showed the highest N2O emission (10.1 mg kg(-1) over 21 days) from the soil at pH 3.71 with 1000 mg kg(-1) NO3 (-) addition. The N2O reduction and denitrification enzyme activity in the acid soils (pH pH 7.41. Moreover, TRF 78 of nirS and TRF 187 of nosZ dominated in soils of pH 3.71, suggesting an important role of acidophilic denitrifiers in N2O production and reduction. CCA analysis also showed a negative correlation between the dominant denitrifier ecotypes (nirS TRF 78, nosZ TRF 187) and soil pH. The representative sequences were identical to those of cultivated denitrifiers from acidic soils via phylogenetic tree analysis. Our results showed that the acidophilic denitrifier adaptation to the acid environment results in high N2O emission in this highly acidic tea soil. PMID:25273518

  17. A kinetic study of the depyritization of oil shale HCl-kerogen concentrate by Thiobacillus ferrooxidans at different temperatures

    Directory of Open Access Journals (Sweden)

    OLGA CVETKOVIC

    2003-05-01

    Full Text Available The results of kinetic studies of bacterial depyritization of HCl-kerogen concentrate of Aleksinac (Serbia oil shale by the chemolithoautotrophic thionic bacteria Thiobacillus ferrooxidans under discontinuous laboratory conditions at various temperatures (0, 20, 28 and 37°C at a pH of ca. 1.5 are presented in this paper. Low pH prevents the occurrence of the precipitation of iron(III-ion hydrolysis products on the substrate particles and thereby reduces the process efficiency. Bacterial depyritization is developed as per kinetics of the first order. The activation energy which points to a successive mechanism of pyrite biooxidation, was computed from the Arrhenius plot. The biochemical kinetics indicators point to a high affinity of the bacteria toward pyrite but small values of Vmax, which are probably the result of decelerated metabolic processes due to the low pH value of the environment resp. the large difference of the pH between the external medium and the cell interior.

  18. Purification and some properties of sulfur reductase from the iron-oxidizing bacterium Thiobacillus ferrooxidans NASF-1.

    Science.gov (United States)

    Ng, K Y; Sawada, R; Inoue, S; Kamimura, K; Sugio, T

    2000-01-01

    Thiobacillus ferrooxidans strain NASF-1 grown aerobically in an Fe2+ (3%)-medium produces hydrogen sulfide (H2S) from elemental sulfur under anaerobic conditions with argon gas at pH 7.5. Sulfur reductase, which catalyzes the reduction of elemental sulfur (S0) with NAD(P)H as an electron donor to produce hydrogen sulfide (H2S) under anaerobic conditions, was purified 69-fold after 35-65% ammonium sulfate precipitation and Q-Sepharose FF, Phenyl-Toyopearl 650 ML, and Blue Sepharose FF column chromatography, with a specific activity of 57.6 U (mg protein)(-1). The purified enzyme was quite labile under aerobic conditions, but comparatively stable in the presence of sodium hydrosulfite and under anaerobic conditions, especially under hydrogen gas conditions. The purified enzyme showed both sulfur reductase and hydrogenase activities. Both activities had an optimum pH of 9.0. Sulfur reductase has an apparent molecular weight of 120,000 Da, and is composed of three different subunits (M(r) 54,000 Da (alpha), 36,000 Da (beta), and 35,000 Da (gamma)), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This is the first report on the purification of sulfur reductase from a mesophilic and obligate chemolithotrophic iron-oxidizing bacterium. PMID:16232842

  19. Alicyclobacillus sp. strain CC2, a thermo-acidophilic bacterium isolated from Deception Island (Antarctica) containing a thermostable superoxide dismutase enzyme

    Institute of Scientific and Technical Information of China (English)

    Daniela N. Correa-Llantén; Maximiliano J. Amenábar; Patricio A. Muñoz; María T. Monsalves; Miguel E. Castro; Jenny M.Blamey

    2014-01-01

    A gram-positive, rod-shaped, aerobic, thermo-acidophilic bacterium CC2 (optimal temperature 55℃and pH 4.0), belonging to the genus Alicyclobacillus was isolated from geothermal soil collected from“Cerro Caliente”, Deception Island, Antarctica. Owing to the harsh environmental conditions found in this territory, microorganisms are exposed to conditions that trigger the generation of reactive oxygen species (ROS). They must have an effective antioxidant defense system to deal with this oxidative stress. We focused on one of the most important enzymes: superoxide dismutase, which was partially purified and characterized. This study presents the ifrst report of a thermo-acidophilic bacterium isolated from Deception Island with a thermostable superoxide dismutase (SOD).

  20. Mathematical modelling of demineralisation of high sulphur coal by bioleaching

    Energy Technology Data Exchange (ETDEWEB)

    Weerasekara, N.S.; Frutos, F.J.G.; Cara, J.; Lockwood, F.C. [University of London Imperial College of Science Technology & Medicine, London (United Kingdom)

    2008-02-15

    During coal combustion various toxic compounds are generated from its sulphur content. Their environmental impacts are considered to be very important. While there are various conventional preparation methods to remove the sulphur in the fuel, recent work reveals that newly-isolated micro-organisms, naturally present in coal, have the ability to reduce its sulphur content. The removal of sulphur using biological leaching involving acidophilic iron oxidising bacteria like Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans are examined and a computational technique based on computational fluid dynamics is developed to model the biological leaching of sulphur from coal. The model was validated against a pack-column experiment carried out for iron separation during 60 days. The mathematical model predicted iron separation over time is similar to experimental measurements, with an average difference of 5.5%. According to the experimental results, there was an overall reduction of 33% of pyrite, whereas the model prediction was 32%. The model results shows overall good agreement with pack-column experimental data.

  1. Research on the growth condition of Acidithiobacillus thiooxidans TT03%氧化硫硫杆菌(Acidithiobacillus thiooxidans)TT03的生长条件研究

    Institute of Scientific and Technical Information of China (English)

    党阿丽; 郭立姝; 陈立娟; 曹亚彬; 于丽萍; 殷博; 甄涛

    2013-01-01

    针对前期筛选鉴定的氧化硫硫杆菌(Acidithiobacillus thiooxidans) TT03,为进一步了解和掌握其培养方法进行了本项研究.结果表明:TT03适宜在初始pH2.0~6.0与温度25℃~35℃的范围内生长;以硫酸铵为第一氮源,也可利用尿素和硝酸盐生长;为保证稳定的培养,需要加大接种量到2.0%以上;适量的氧气供给对TT03的生长是有利的;在二氧化碳的浓度达6%以上时生长受到抑制,而在6%以下时,对TT03的生长有促进作用.

  2. Arsenopyrite oxidation - A review

    International Nuclear Information System (INIS)

    Arsenopyrite (FeAsS) is the most common As-bearing sulfide mineral. Under oxidising conditions, such as those in mine waste systems, it breaks down to release acids of As and S into the environment, resulting in acid mine drainage with high concentrations of dissolved As. In this communication, current knowledge of arsenopyrite oxidation is reviewed based on a survey of the existing literature, which has focused on processes and reactions at the mineral surface. X-ray photoelectron spectroscopy (XPS) has shown that the oxidation of arsenopyrite in acid is more rapid than in air, water, or in alkaline solutions. Oxidation products reported by XPS include Fe(III) oxide, As(III), As(V), SO32- and SO42-. The elemental constituents of arsenopyrite oxidise at different rates, although there is no consensus as to which is the fastest or slowest to oxidise. Electrochemical studies have highlighted the formation of elemental S on the arsenopyrite surface, while XPS studies suggest that only oxy-anions of S form. Kinetic studies of arsenopyrite oxidation suggest that O2 and Fe3+ are the dominant inorganic agents causing arsenopyrite dissolution. The bacterially-mediated oxidation of arsenopyrite by acidophilic Fe- and S-oxidising bacteria such as Acidithiobacillus ferrooxidans and Acidithiobacillus caldus, is more extensive than abiotic oxidation. The literature pertaining to arsenopyrite oxidation is divided regarding the reaction stoichiometry, and the composition and layering of surface overlayers.

  3. 氧化亚铁硫杆菌对金属铜的加工%BIOMACHINING OF METAL COPPEY BY THIOBACILLUS FERROOXIDANS

    Institute of Scientific and Technical Information of China (English)

    李雅芹; 张德远; 吴依陶

    2000-01-01

    Thiobacillus ferrooxidans was employed in the biomachining process of metal copper(Cuo). The bacteria growth and the changes of Fe3+ concentration during machining processes have been studied. Biomachining and chemical machining have been compared.The results showed that the concentrations of bacteria and Fe3+ determine the speed of machining copper. The biomachining is more fast that chemical maching because bacteria are able to regenerate Fe3+ oxidizing copper. It was also found that the Cu2 + produced from the machining processes inhibit the growth of bacteria. Cu2+ has to be removed.

  4. Activities of methionine-γ-lyase in the acidophilic archaeon “Ferroplasma acidarmanus” strain fer1

    Directory of Open Access Journals (Sweden)

    Khan MA

    2013-04-01

    Full Text Available M A Khan,1 Madeline M López-Muñoz,2 Charles W Kaspar,3 Kai F Hung1 1Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA; 2Department of Biology, Universidad de Puerto Rico, Mayaguez, Puerto Rico; 3Bacteriology Department, University of Wisconsin, Madison, WI, USA Abstract: Biogeochemical processes on exposed pyrite ores result in extremely high levels of sulfuric acid at these locations. Acidophiles that thrive in these conditions must overcome significant challenges, including an environment with proton concentrations at pH 3 or below. The role of sulfur metabolism in the archaeon “Ferroplasma acidarmanus” strain fer1's ability to thrive in this environment was investigated due to its growth-dependent production of methanethiol, a volatile organic sulfur compound. Two putative sequences for methionine-γ-lyase (EC 4.4.1.11, an enzyme known to carry out α, γ-elimination on L-methionine to produce methanethiol, were identified in fer1. Bioinformatic analyses identified a conserved pyridoxal-5'-phosphate (PLP binding domain and a partially conserved catalytic domain in both putative sequences. Detection of PLP-dependent and L-methionine-dependent production of α-keto compounds and thiol groups in fer1 confirmed the presence of methionine-γ-lyase activity. Further, fer1 lysate was capable of processing related substrates, including D-methionine, L-cysteine, L-cystathionine, and L/D-homocysteine. When the two putative fer1 methionine-γ-lyase gene-coded proteins were expressed in Escherichia coli cells, one sequence demonstrated an ability to carry out α, γ-elimination activity, while the other exhibited γ-replacement activity. These fer1 methionine-γ-lyases also exhibited optimum pH, substrate specificity, and catalytic preferences that are different from methionine-γ-lyases from other organisms. These differences are discussed in the context of molecular phylogeny constructed using a maximum

  5. A Description of an Acidophilic, Iron Reducer, Geobacter sp. FeAm09 Isolated from Tropical Soils

    Science.gov (United States)

    Healy, O.; Souchek, J.; Heithoff, A.; LaMere, B.; Pan, D.; Hollis, G.; Yang, W. H.; Silver, W. L.; Weber, K. A.

    2014-12-01

    Iron (Fe) is the fourth most abundant element in the Earth's crust and plays a significant role controlling the geochemistry in soils, sediments, and aquatic systems. As part of a study to understand microbially-catalysed iron biogeochemical cycling in tropical soils, an iron reducing isolate, strain FeAm09, was obtained. Strain FeAm09 was isolated from acidic, Fe-rich soils collected from a tropical forest (Luquillo Experimental Forest, Puerto Rico). Strain FeAm09 is a rod-shaped, motile, Gram-negative bacterium. Taxonomic analysis of the near complete 16S rRNA gene sequence revealed that strain FeAm09 is 94.7% similar to Geobacter lovleyi, placing it in the genus Geobacter within the Family Geobacteraceae in the Deltaproteobacteria. Characterization of the optimal growth conditions revealed that strain FeAm09 is a moderate acidophile with an optimal growth pH of 5.0. The optimal growth temperature was 37°C. Growth of FeAm09 was coupled to the reduction of soluble Fe(III), Fe(III)-NTA, with H2, fumarate, ethanol, and various organic acids and sugars serving as the electron donor. Insoluble Fe(III), in the form of synthetic ferrihydrite, was reduced by strain FeAm09 using acetate or H2 as the electron donor. The use of H2 as an electron donor in the presence of CO2 and absence of organic carbon and assimilation of 14C-labelled CO2 into biomass indicate that strain FeAm09 is an autotrophic Fe(III)-reducing bacterium. Together, these data describe the first acidophilic, autotrophic Geobacter species. Iron reducing bacteria were previously shown to be as abundant in tropical soils as in saturated sediments (lake-bottoms) and saturated soils (wetlands) where Fe(III) reduction is more commonly recognized as a dominant mode of microbial respiration. Furthermore, Fe(III) reduction was identified as a primary driver of carbon mineralization in these tropical soils (Dubinsky et al. 2010). In addition to mineralizing organic carbon, Geobacter sp. FeAm09 is likely to also

  6. Mechanism of electro-generating leaching of chalcopyrite-MnO2 in presence of Acidithiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    XIAO Li; LIU Jian-she; FANG Zheng; QIU Guan-zhou

    2008-01-01

    A dual cell system with chalcopyrite anode and MnO2 cathode was used to study the relations between time and such data as the electric quantity and the dissolution rates of the two minerals in the electro-generating leaching(EGL) and the bio-electro-generating leaching(BEGL),respectively.The results showed that the dissolution rates for Cu2+ and Fe2+ in BEGL were almost 2 times faster than those in EGL,and nearly 3 times for Mn2+; the electric output increased nearly by 3 times.The oxidation residue of chalcopyrite was represented by TEM and XRD,whose pattern was similar to that of the raw ore in EGL.The mechanism for leaching of CuFeS2-MnO2 in the presence of Acidithiobacillus thiooxidans was proposed as a successive reaction of two independent sub-processes for the anode.The first stage,common to both processes,is dissolution of chalcopyrite to produce Cu2+,Fe2+ and sulfur.The second stage is subsequent oxidization of sulfur only in BEGL,which is the controlling step of the process.However,the dissolution of MnO2 lasts until the reaction of chalcopyrite stops or the ores exhaust in two types of leaching.

  7. Existence of aa3-type ubiquinol oxidase as a terminal oxidase in sulfite oxidation of Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Sugio, Tsuyoshi; Hisazumi, Tomohiro; Kanao, Tadayoshi; Kamimura, Kazuo; Takeuchi, Fumiaki; Negishi, Atsunori

    2006-07-01

    It was found that Acidithiobacillus thiooxidans has sulfite:ubiquinone oxidoreductase and ubiquinol oxidase activities in the cells. Ubiquinol oxidase was purified from plasma membranes of strain NB1-3 in a nearly homogeneous state. A purified enzyme showed absorption peaks at 419 and 595 nm in the oxidized form and at 442 and 605 nm in the reduced form. Pyridine ferrohaemochrome prepared from the enzyme showed an alpha-peak characteristic of haem a at 587 nm, indicating that the enzyme contains haem a as a component. The CO difference spectrum of ubiquinol oxidase showed two peaks at 428 nm and 595 nm, and a trough at 446 nm, suggesting the existence of an aa(3)-type cytochrome in the enzyme. Ubiquinol oxidase was composed of three subunits with apparent molecular masses of 57 kDa, 34 kDa, and 23 kDa. The optimum pH and temperature for ubiquinol oxidation were pH 6.0 and 30 degrees C. The activity was completely inhibited by sodium cyanide at 1.0 mM. In contrast, the activity was inhibited weakly by antimycin A(1) and myxothiazol, which are inhibitors of mitochondrial bc(1) complex. Quinone analog 2-heptyl-4-hydoroxyquinoline N-oxide (HOQNO) strongly inhibited ubiquinol oxidase activity. Nickel and tungstate (0.1 mM), which are used as a bacteriostatic agent for A. thiooxidans-dependent concrete corrosion, inhibited ubiquinol oxidase activity 100 and 70% respectively.

  8. Optimization of two-step bioleaching of spent petroleum refinery catalyst by Acidithiobacillus thiooxidans using response surface methodology.

    Science.gov (United States)

    Srichandan, Haragobinda; Pathak, Ashish; Kim, Dong Jin; Lee, Seoung-Won

    2014-01-01

    A central composite design (CCD) combined with response surface methodology (RSM) was employed for maximizing bioleaching yields of metals (Al, Mo, Ni, and V) from as-received spent refinery catalyst using Acidithiobacillus thiooxidans. Three independent variables, namely initial pH, sulfur concentration, and pulp density were investigated. The pH was found to be the most influential parameter with leaching yields of metals varying inversely with pH. Analysis of variance (ANOVA) of the quadratic model indicated that the predicted values were in good agreement with experimental data. Under optimized conditions of 1.0% pulp density, 1.5% sulfur and pH 1.5, about 93% Ni, 44% Al, 34% Mo, and 94% V was leached from the spent refinery catalyst. Among all the metals, V had the highest maximum rate of leaching (Vmax) according to the Michaelis-Menten equation. The results of the study suggested that two-step bioleaching is efficient in leaching of metals from spent refinery catalyst. Moreover, the process can be conducted with as received spent refinery catalyst, thus making the process cost effective for large-scale applications.

  9. The effects of metabolites from the indigenous Acidithiobacillus thiooxidans and temperature on the bioleaching of cadmium from soil.

    Science.gov (United States)

    Liu, Hsuan-Liang; Chiu, Chi-Wei; Cheng, Yang-Chu

    2003-09-20

    The effect of metabolites from the indigenous Acidithiobacillus thiooxidans and temperature on the bioleaching of cadmium from soil was investigated in the present study. Bioleaching was found to be more effective than chemical leaching of cadmium. The metabolite, mainly sulfuric acid, which was shown to be growth-associated in the exponential phase, plays a major role in bioleaching. The maximum amount of cadmium leached was obtained after 8 days of precultivation when cells were directly involved in the leaching process. It indicates that cells in the exponential growth phase exhibit higher activity toward bioleaching. In contrast, the maximum amount of cadmium leached and the maximum initial rate for bioleaching were reached after 16 days of precultivation when only metabolites were involved in the bioleaching process. It implies that higher sulfuric acid concentration results in higher leaching efficiency. In addition, higher temperature leads to higher leaching efficiency. The optimal operation condition for bioleaching was determined to be a two-stage process: The first stage involves the precultivation of the indigenous A. thiooxidans at 30 degrees C for 8 days followed by 20 minutes of centrifugation to discard cells. The second stage involves the bioleaching with the subsequent supernatant at 50 degrees C.

  10. Comparative study of nickel resistance of pure culture and co-culture of Acidithiobacillus thiooxidans and Leptospirillum ferriphilum.

    Science.gov (United States)

    Xu, Ying; Yin, Huaqun; Jiang, Huidan; Liang, Yili; Guo, Xue; Ma, Liyuan; Xiao, Yunhua; Liu, Xueduan

    2013-09-01

    The effect of Ni²⁺ on the growth and functional gene expression of the pure culture and co-culture of Acidithiobacillus thiooxidans and Leptospirillum ferriphilum has been studied. Compared with the pure culture, the co-culture showed a stronger sulfur and ferrous ion oxidation activity. At 100 mM, A. thiooxidans in co-culture grew faster and had 48 h shorter lag phases. The cell number of A. thiooxidans in co-culture was about 5 times higher than that in pure culture. The existence of A. thiooxidans in co-culture activated the expression of some metal resistance genes in L. ferriphilum at least 16 h in advance. A. thiooxidans in co-culture tends to chose more efficient pathways to transport nickel ion, ensuring the export of heavy metal was faster and more effective than that in pure culture. All the data indicated that there were synergetic interactions between iron- and sulfur-oxidizing bacteria under the stress of Ni²⁺.

  11. Hydrogen sulfide oxidation in novel Horizontal-Flow Biofilm Reactors dominated by an Acidithiobacillus and a Thiobacillus species.

    Science.gov (United States)

    Gerrity, S; Kennelly, C; Clifford, E; Collins, G

    2016-09-01

    Hydrogen Sulfide (H2S) is an odourous, highly toxic gas commonly encountered in various commercial and municipal sectors. Three novel, laboratory-scale, Horizontal-Flow Biofilm Reactors (HFBRs) were tested for the removal of H2S gas from air streams over a 178-day trial at 10°C. Removal rates of up to 15.1 g [H2S] m(-3) h(-1) were achieved, demonstrating the HFBRs as a feasible technology for the treatment of H2S-contaminated airstreams at low temperatures. Bio-oxidation of H2S in the reactors led to the production of H(+) and sulfate (SO(2-)4) ions, resulting in the acidification of the liquid phase. Reduced removal efficiency was observed at loading rates of 15.1 g [H2S] m(-3) h(-1). NaHCO3 addition to the liquid nutrient feed (synthetic wastewater (SWW)) resulted in improved H2S removal. Bacterial diversity, which was investigated by sequencing and fingerprinting 16S rRNA genes, was low, likely due to the harsh conditions prevailing in the systems. The HFBRs were dominated by two species from the genus Acidithiobacillus and Thiobacillus. Nonetheless, there were significant differences in microbial community structure between distinct HFBR zones due to the influence of alkalinity, pH and SO4 concentrations. Despite the low temperature, this study indicates HFBRs have an excellent potential to biologically treat H2S-contaminated airstreams. PMID:26829048

  12. Influence Of Used Bacterial Culture On Zinc And Aluminium Bioleaching From Printed Circuit Boards

    OpenAIRE

    Mrazikova Anna; Marcincakova Renata; Kadukova Jana; Velgosova Oksana; Balintova Magdalena

    2015-01-01

    Bioleaching processes were used to solubilize metals (Cu, Ni, Zn and Al) from printed circuit boards (PCBs). In this study, a PCBs-adapted pure culture of Acidithiobacillus ferrooxidans, pure culture of Acidithiobacillus thiooxidans and PCBs-adapted mixed culture of A. ferrooxidans and A. thiooxidans were used for recovery of the metals. The study showed that the mixed bacterial culture has the greatest potential to dissolve metals. The maximum metal bioleaching efficiencies were found to be ...

  13. 嗜酸菌对废旧印刷线路板金属铜的浸出研究%Research of Bio-leaching Cu from Printed-circuit Board by Acidophilus Strains

    Institute of Scientific and Technical Information of China (English)

    赵德龙; 谌书; 王中琪

    2012-01-01

    选用嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称T.f)、氧化硫硫杆菌(Thiobacillus thiooxidans,简称T.t)作为实验菌种研究其对线路板(Printed circuit board)粉金属铜的浸出;试验以单一菌种、混合菌种、无菌培养基及酸性蒸馏水进行浸出实验研究,通过对比不同条件下的浸出效果,得出单一氧化亚铁硫杆菌(T.f)的浸出效果最好,浸出率达到92.1%.通过对浸出过程中pH、ORP及Fe2+、Fe3+变化分析,发现Fe3+的氧化作用在铜的浸出过程中起主导作用,酸浸也有一定的贡献;对浸出后残余的PCB进行XRD及SEM观察分析发现,PCB组成成分中含有大量的酚烃、苯酚及邻、对位取代酚以及少量的长链烷烃及其脂肪烃,此类有机物在浸出过程中均与细菌或其代谢物发生了作用.%Two acidophilic strains, i.e, Acidithiobacillus ferrooxidans and Thiobacillus thiooxidans, were used to extract copper from the powder of printed circuit board (PCB). The experiment was conducted using different single strains and mixed bacteria, compared with others showing, the leaching behavior of, single Acidithiobacillus ferrooxidans was the best with leaching rate up to 92.1%. It was found that oxidation of Fe3+ was essential in bio-leaching of copper, and some organic compounds remained in PCB residues after the bio-leaching treatment, such as phenol hydrocarbons, phenol and osubstituted phenol and a small amount of long-chain alkanes and aliphatic hydrocarbons, with which the bacteria and their metabolites had reacted during the bio-leaching process.

  14. Acquisition of useful and high ability genes for acidophilic bacteria; Kosansei saikin ni takai noryoku wo fuyosuru idenshi no kakutoku

    Energy Technology Data Exchange (ETDEWEB)

    Senda, T.; Inoue, C.; Shinbori, Y. [Tohoku University, Sendai (Japan)

    1997-02-01

    This effort aims at the development of high-performance bacteria usable in bio-leaching in metal smelting by acquiring genes capable of realizing such. A method is used of choosing some isolated strains exhibiting high-performance traits and acquiring target genes therefrom by use of genetic engineering. Approximately 200 kinds in the aggregate of acidophilic bacteria are currently available for the study, including isolated iron-oxidizing and sulfur-oxidizing bacteria, standard species acquired for the study, and strains previously isolated by the laboratory. The bacteria are tested with respect to their Fe{sup 2+}-oxidizing rates, sulfur-oxidizing capabilities, and strength to withstand inhibiting substances (Ag{sup +}, Cl{sup -}, Mo{sup 6+}, etc.), which results in the nomination of 8 strains. The study planned to follow includes processes involving the extraction of chromosome DNAs from the 8 strains and their refinement, gene cloning by the Southern hybridization method, determination of their base sequences, determination of the difference between the strains in point of gene expression, and investigations of the relations that the results of these processes bear toward the said high-performance traits. Also under way is a study about the infuence-exerting factors revealed during the evaluation of the abilities of acidphlic bacteria. 2 refs., 2 tabs.

  15. A novel acidophilic, thermophilic iron and sulfur-oxidizing archaeon isolated from a hot spring of tengchong, yunnan, China

    Directory of Open Access Journals (Sweden)

    Jiannan Ding

    2011-06-01

    Full Text Available A novel thermoacidophilic iron and sulfur-oxidizing archaeon, strain YN25, was isolated from an in situ enriched acid hot spring sample collected in Yunnan, China. Cells were irregular cocci, about 0.9-1.02 µm×1.0-1.31 µm in the medium containing elemental sulfur and 1.5-2.22 µm×1.8-2.54 µm in ferrous sulfate medium. The ranges of growth and pH were 50-85 (optimum 65 and pH 1.0-6.0 (optimum 1.5-2.5. The acidophile was able to grow heterotrophically on several organic substrates, including various monosaccharides, alcohols and amino acids, though the growth on single substrate required yeast extract as growth factor. Growth occurred under aerobic conditions or via anaerobic respiration using elemental sulfur as terminal electron acceptor. Results of morphology, physiology, fatty acid analysis and analysis based on 16S rRNA gene sequence indicated that the strain YN25 should be grouped in the species Acidianus manzaensis. Bioleaching experiments indicated that this strain had excellent leaching capacity, with a copper yielding ratio up to 79.16% in 24 d. The type strain YN25 was deposited in China Center for Type Culture Collection (=CCTCCZNDX0050.

  16. Metabolites Associated with Adaptation of Microorganisms to an Acidophilic, Metal-Rich Environment Identified by Stable-Isotope-Enabled Metabolomics

    Science.gov (United States)

    Mosier, Annika C.; Justice, Nicholas B.; Bowen, Benjamin P.; Baran, Richard; Thomas, Brian C.; Northen, Trent R.; Banfield, Jillian F.

    2013-01-01

    ABSTRACT Microorganisms grow under a remarkable range of extreme conditions. Environmental transcriptomic and proteomic studies have highlighted metabolic pathways active in extremophilic communities. However, metabolites directly linked to their physiology are less well defined because metabolomics methods lag behind other omics technologies due to a wide range of experimental complexities often associated with the environmental matrix. We identified key metabolites associated with acidophilic and metal-tolerant microorganisms using stable isotope labeling coupled with untargeted, high-resolution mass spectrometry. We observed >3,500 metabolic features in biofilms growing in pH ~0.9 acid mine drainage solutions containing millimolar concentrations of iron, sulfate, zinc, copper, and arsenic. Stable isotope labeling improved chemical formula prediction by >50% for larger metabolites (>250 atomic mass units), many of which were unrepresented in metabolic databases and may represent novel compounds. Taurine and hydroxyectoine were identified and likely provide protection from osmotic stress in the biofilms. Community genomic, transcriptomic, and proteomic data implicate fungi in taurine metabolism. Leptospirillum group II bacteria decrease production of ectoine and hydroxyectoine as biofilms mature, suggesting that biofilm structure provides some resistance to high metal and proton concentrations. The combination of taurine, ectoine, and hydroxyectoine may also constitute a sulfur, nitrogen, and carbon currency in the communities. PMID:23481603

  17. Thermo-acidophillic biohydrogen production from rice bran de-oiled wastewater by Selectively enriched mixed culture

    Directory of Open Access Journals (Sweden)

    D.Sivaramakrishna, D.Sreekanth, V.Himabindu, M.Lakshmi Narasu

    2010-07-01

    Full Text Available The present study focuses on the biohydrogen production in an anaerobic batch reactor operated at thermophillic (570C and acidophilic conditions (pH 6 with rice bran de-oiled wastewater (RBOW as substrate. The hydrogen generating mixed microflora was enriched from slaughter house sludge (SHS through acid treatment (pH 3-4, for 24h coupled with heat treatment (1h at 1000C to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB prior to inoculation in the reactor. The hydrogen production rate was maximum at 570C (1861±14ml/L-WW/d compared to 370C (651±30ml/L-ww/d. The Hydrogen yield increased with temperature from 1.1 to 2.2 molH2/mol of substrate respectively. The optimum pH range for hydrogen production in this system was observed in between 5.5 to 6. Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production.

  18. Thermo-acidophillic biohydrogen production from rice bran de-oiled wastewater by Selectively enriched mixed culture

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishna, D.; Sreekanth, D.; Himabindu, V. [Centre for Environment, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085 (India); Narasu, M. Lakshmi [Centre for Biotechnology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally Hyderabad-500 085 (India)

    2010-07-01

    The present study focuses on the biohydrogen production in an anaerobic batch reactor operated at thermophillic (570C) and acidophilic conditions (pH 6) with rice bran de-oiled wastewater (RBOW) as substrate. The hydrogen generating mixed microflora was enriched from slaughter house sludge (SHS) through acid treatment (pH 3-4, for 24h) coupled with heat treatment (1h at 1000C) to eliminate non-spore forming bacteria and to inhibit the growth of methanogenic bacteria (MB) prior to inoculation in the reactor. The hydrogen production rate was maximum at 570C (1861 +- 14ml/L-WW/d) compared to 370C (651 +- 30ml/L-ww/d). The Hydrogen yield increased with temperature from 1.1 to 2.2 molH2/mol of substrate respectively. The optimum pH range for hydrogen production in this system was observed in between 5.5 to 6. Acid-forming pathway with butyric acid as a major metabolite dominated the metabolic flow during the hydrogen production.

  19. The Effects of Amino Acid Nutrition of Lag Phase in Growth of Thiobacillus ferrooxidans%氨基酸营养对At.f菌生长迟缓期的影响

    Institute of Scientific and Technical Information of China (English)

    张一

    2011-01-01

    [Objective] The effects of amino acid nutrition of lag phase in growth of thiobacillus ferrooxidans were researched. [Methods] The thiobacillus ferrooxidans were cultured in 20 different amino acids culture mediums. Use potassium dichromate titration to determination the u-tilization of Fe2+ all time, and the pH change of culture medium after added amino acids were studied. [ Results ] Non-polar amino acids have better effect to reduce the Lag phase of thiobacillus ferrooxidans, phenylalanine, tyrosine, proline and tryptophan also have similar effects. Ser-ine, glutamine and histidine are inhibited to reduced lag phase of thiobacillus ferrooxidans. [ Conclusion ] Non-polar amino acids can shorten the lag phase of thiobacillus ferrooxidans effectively, and several polar amino acids have the opposite effects.%[目的]研究氨基酸营养对At.f菌生长迟缓期的影响.[方法]将At.f在分别加入20种氨基酸的培养基中培养,利用重铬酸钾滴定法测定各时段Fe2+利用情况,并检测添加氨基酸后培养基pH的变化.[结果]非极性氨基酸对缩短At.f菌的迟缓期的效果较明显;苯丙氨酸、酪氨酸、脯氨酸、色氨酸四种成环氨基酸有较好的效果;丝氨酸、谷氨酰胺、组氨酸有明显的抑制作用.[结论]非极性氨基酸能有效缩短At.f菌生长迟缓期,部分极性氨基酸则起到相反效果.

  20. The Effect of Oxygen Supply on the Dual Growth Kinetics of Acidithiobacillus thiooxidans under Acidic Conditions for Biogas Desulfurization

    Directory of Open Access Journals (Sweden)

    Hyeong-Kyu Namgung

    2015-01-01

    Full Text Available In this study, to simulate a biogas desulfurization process, a modified Monod-Gompertz kinetic model incorporating a dissolved oxygen (DO effect was proposed for a sulfur-oxidizing bacterial (SOB strain, Acidithiobacillus thiooxidans, under extremely acidic conditions of pH 2. The kinetic model was calibrated and validated using experimental data obtained from a bubble-column bioreactor. The SOB strain was effective for H2S degradation, but the H2S removal efficiency dropped rapidly at DO concentrations less than 2.0 mg/L. A low H2S loading was effectively treated with oxygen supplied in a range of 2%–6%, but a H2S guideline of 10 ppm could not be met, even with an oxygen supply greater than 6%, when the H2S loading was high at a short gas retention time of 1 min and a H2S inlet concentration of 5000 ppm. The oxygen supply should be increased in the aerobic desulfurization to meet the H2S guideline; however, the excess oxygen above the optimum was not effective because of the decline in oxygen efficiency. The model estimation indicated that the maximum H2S removal rate was approximately 400 ppm/%-O2 at the influent oxygen concentration of 4.9% under the given condition. The kinetic model with a low DO threshold for the interacting substrates was a useful tool to simulate the effect of the oxygen supply on the H2S removal and to determine the optimal oxygen concentration.

  1. Insights on the structure and stability of Licanantase: a trimeric acid-stable coiled-coil lipoprotein from Acidithiobacillus thiooxidans

    Directory of Open Access Journals (Sweden)

    Fernando Abarca

    2014-08-01

    Full Text Available Licanantase (Lic is the major component of the secretome of Acidithiobacillus thiooxidans when grown in elemental sulphur. When used as an additive, Lic improves copper recovery from bioleaching processes. However, this recovery enhancement is not fully understood. In this context, our aim is to predict the 3D structure of Lic, to shed light on its structure-function relationships. Bioinformatics analyses on the amino acid sequence of Lic showed a great similarity with Lpp, an Escherichia coli Lipoprotein that can form stable trimers in solution. Lic and Lpp share the secretion motif, intracellular processing and alpha helix structure, as well as the distribution of hydrophobic residues in heptads forming a hydrophobic core, typical of coiled-coil structures. Cross-linking experiments showed the presence of Lic trimers, supporting our predictions. Taking the in vitro and in silico evidence as a whole, we propose that the most probable structure for Lic is a trimeric coiled-coil. According to this prediction, a suitable model for Lic was produced using the de novo algorithm “Rosetta Fold-and-Dock”. To assess the structural stability of our model, Molecular Dynamics (MD and Replica Exchange MD simulations were performed using the structure of Lpp and a 14-alanine Lpp mutant as controls, at both acidic and neutral pH. Our results suggest that Lic was the most stable structure among the studied proteins in both pH conditions. This increased stability can be explained by a higher number of both intermonomer hydrophobic contacts and hydrogen bonds, key elements for the stability of Lic’s secondary and tertiary structure.

  2. The effect of oxygen supply on the dual growth kinetics of Acidithiobacillus thiooxidans under acidic conditions for biogas desulfurization.

    Science.gov (United States)

    Namgung, Hyeong-Kyu; Song, JiHyeon

    2015-02-01

    In this study, to simulate a biogas desulfurization process, a modified Monod-Gompertz kinetic model incorporating a dissolved oxygen (DO) effect was proposed for a sulfur-oxidizing bacterial (SOB) strain, Acidithiobacillus thiooxidans, under extremely acidic conditions of pH 2. The kinetic model was calibrated and validated using experimental data obtained from a bubble-column bioreactor. The SOB strain was effective for H2S degradation, but the H2S removal efficiency dropped rapidly at DO concentrations less than 2.0 mg/L. A low H2S loading was effectively treated with oxygen supplied in a range of 2%-6%, but a H2S guideline of 10 ppm could not be met, even with an oxygen supply greater than 6%, when the H2S loading was high at a short gas retention time of 1 min and a H2S inlet concentration of 5000 ppm. The oxygen supply should be increased in the aerobic desulfurization to meet the H2S guideline; however, the excess oxygen above the optimum was not effective because of the decline in oxygen efficiency. The model estimation indicated that the maximum H2S removal rate was approximately 400 ppm/%-O2 at the influent oxygen concentration of 4.9% under the given condition. The kinetic model with a low DO threshold for the interacting substrates was a useful tool to simulate the effect of the oxygen supply on the H2S removal and to determine the optimal oxygen concentration.

  3. Chemical and surface analysis during evolution of arsenopyrite oxidation by Acidithiobacillus thiooxidans in the presence and absence of supplementary arsenic.

    Science.gov (United States)

    Ramírez-Aldaba, Hugo; Valles, O Paola; Vazquez-Arenas, Jorge; Rojas-Contreras, J Antonio; Valdez-Pérez, Donato; Ruiz-Baca, Estela; Meraz-Rodríguez, Mónica; Sosa-Rodríguez, Fabiola S; Rodríguez, Ángel G; Lara, René H

    2016-10-01

    Bioleaching of arsenopyrite presents a great interest due to recovery of valuable metals and environmental issues. The current study aims to evaluate the arsenopyrite oxidation by Acidithiobacillus thiooxidans during 240h at different time intervals, in the presence and absence of supplementary arsenic. Chemical and electrochemical characterizations are carried out using Raman, AFM, SEM-EDS, Cyclic Voltammetry, EIS, electrophoretic and adhesion forces to comprehensively assess the surface behavior and biooxidation mechanism of this mineral. These analyses evidence the formation of pyrite-like secondary phase on abiotic control surfaces, which contrast with the formation of pyrite (FeS2)-like, orpiment (As2S3)-like and elementary sulfur and polysulfide (Sn(2-)/S(0)) phases found on biooxidized surfaces. Voltammetric results indicate a significant alteration of arsenopyrite due to (bio)oxidation. Resistive processes determined with EIS are associated with chemical and electrochemical reactions mediated by (bio)oxidation, resulting in the transformation of arsenopyrite surface and biofilm direct attachment. Charge transfer resistance is increased when (bio)oxidation is performed in the presence of supplementary arsenic, in comparison with lowered abiotic control resistances obtained in its absence; reinforcing the idea that more stable surface products are generated when As(V) is in the system. Biofilm structure is mainly comprised of micro-colonies, progressively enclosed in secondary compounds. A more compact biofilm structure with enhanced formation of secondary compounds is identified in the presence of supplementary arsenic, whereby variable arsenopyrite reactivity is linked and attributed to these secondary compounds, including Sn(2-)/S(0), pyrite-like and orpiment-like phases.

  4. Insights on the structure and stability of Licanantase: a trimeric acid-stable coiled-coil lipoprotein from Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Abarca, Fernando; Gutierrez-Maldonado, Sebastian E; Parada, Pilar; Martinez, Patricio; Maass, Alejandro; Perez-Acle, Tomas

    2014-01-01

    Licanantase (Lic) is the major component of the secretome of Acidithiobacillus thiooxidans when grown in elemental sulphur. When used as an additive, Lic improves copper recovery from bioleaching processes. However, this recovery enhancement is not fully understood. In this context, our aim is to predict the 3D structure of Lic, to shed light on its structure-function relationships. Bioinformatics analyses on the amino acid sequence of Lic showed a great similarity with Lpp, an Escherichia coli Lipoprotein that can form stable trimers in solution. Lic and Lpp share the secretion motif, intracellular processing and alpha helix structure, as well as the distribution of hydrophobic residues in heptads forming a hydrophobic core, typical of coiled-coil structures. Cross-linking experiments showed the presence of Lic trimers, supporting our predictions. Taking the in vitro and in silico evidence as a whole, we propose that the most probable structure for Lic is a trimeric coiled-coil. According to this prediction, a suitable model for Lic was produced using the de novo algorithm "Rosetta Fold-and-Dock". To assess the structural stability of our model, Molecular Dynamics (MD) and Replica Exchange MD simulations were performed using the structure of Lpp and a 14-alanine Lpp mutant as controls, at both acidic and neutral pH. Our results suggest that Lic was the most stable structure among the studied proteins in both pH conditions. This increased stability can be explained by a higher number of both intermonomer hydrophobic contacts and hydrogen bonds, key elements for the stability of Lic's secondary and tertiary structure.

  5. [The use of real-time PCR technology to assess the effectiveness of methods of DNA extraction from cultures of acidophilic chemolithotrophic microorganisms].

    Science.gov (United States)

    Rogatykh, S V; Dokshukina, A A; Khaĭnasova, T S; Muradov, S V; Kofiadi, I A

    2011-01-01

    Comparative evaluation of efficiency of several methods of DNA extraction from storage cultures of acidophilic chemolithotrophic microorganism communities isolated from sulfide ores of Shanuch ore deposit (Kamchatka peninsula) was conducted. DNA extraction methods in various combinations of physical (heating to 65-98 degrees C, grinding with SiO2 particles), enzymatic (treatment with lysozyme and proteinase K), and chemical (GuSCN, CTAB and KOH) treatments were tested. The evaluation of efficiency was performed using Real-time PCR. The best result was obtained for the combined method based on GuSCN lysis activity (lysis at 65 degrees C) followed by purification with phenol and chloroform.

  6. Cytochrome 572 is a conspicuous membrane protein with iron oxidation activity purified directly from a natural acidophilic microbial community.

    Science.gov (United States)

    Jeans, Chris; Singer, Steven W; Chan, Clara S; Verberkmoes, Nathan C; Shah, Manesh; Hettich, Robert L; Banfield, Jillian F; Thelen, Michael P

    2008-05-01

    Recently, there has been intense interest in the role of electron transfer by microbial communities in biogeochemical systems. We examined the process of iron oxidation by microbial biofilms in one of the most extreme environments on earth, where the inhabited water is pH 0.5-1.2 and laden with toxic metals. To approach the mechanism of Fe(II) oxidation as a means of cellular energy acquisition, we isolated proteins from natural samples and found a conspicuous and novel cytochrome, Cyt(572), which is unlike any known cytochrome. Both the character of its covalently bound prosthetic heme group and protein sequence are unusual. Extraction of proteins directly from environmental biofilm samples followed by membrane fractionation, detergent solubilization and gel filtration chromatography resulted in the purification of an abundant yellow-red protein. The purified protein has a cytochrome c-type heme binding motif, CxxCH, but a unique spectral signature at 572 nm, and thus is called Cyt(572). It readily oxidizes Fe(2+) in the physiologically relevant acidic regime, from pH 0.95-3.4. Other physical characteristics are indicative of a membrane-bound multimeric protein. Circular dichroism spectroscopy indicates that the protein is largely beta-stranded, and 2D Blue-Native polyacrylamide gel electrophoresis and chemical crosslinking independently point to a multi-subunit structure for Cyt(572). By analyzing environmental genomic information from biofilms in several distinctly different mine locations, we found multiple genetic variants of Cyt(572). MS proteomics of extracts from these biofilms substantiated the prevalence of these variants in the ecosystem. Due to its abundance, cellular location and Fe(2+) oxidation activity at very low pH, we propose that Cyt(572) provides a critical function for fitness within the ecological niche of these acidophilic microbial communities.

  7. Alicyclobacillus dauci sp. nov., a slightly thermophilic, acidophilic bacterium isolated from a spoiled mixed vegetable and fruit juice product.

    Science.gov (United States)

    Nakano, Chisa; Takahashi, Naoto; Tanaka, Naoto; Okada, Sanae

    2015-02-01

    A novel, moderately thermophilic, acidophilic, Gram-variable, rod-shaped, endospore-forming bacterium was isolated from a spoiled mixed vegetable and fruit juice product that had the off-flavour of guaiacol. The bacterium, strain 4F(T), grew aerobically at 20-50 °C (optimum 40 °C) and pH 3.0-6.0 (optimum pH 4.0) and produced acid from glycerol, d-galactose and d-glucose. It contained menaquinone-7 (MK-7) as the major isoprenoid quinone and the DNA G+C content was 49.6 mol%. The predominant cellular fatty acids of strain 4F(T) were ω-alicyclic (ω-cyclohexane fatty acids), which are characteristic of the genus Alicyclobacillus. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belongs to the Alicyclobacillus cluster, and is related most closely to the type strains of Alicyclobacillus acidoterrestris (97.4 % similarity) and Alicyclobacillus fastidiosus (97.3 %). Strain 4F(T) produced guaiacol from vanillic acid. It can be distinguished from related species by its acid production type and guaiacol production. On the basis of phenotypic characteristics, phylogenetic analysis and DNA-DNA relatedness values, it can be concluded that the strain represents a novel species of the genus Alicyclobacillus, for which the name Alicyclobacillus dauci sp. nov. is proposed; the type strain is 4F(T) ( = DSM 28700(T) = NBRC 108949(T) = NRIC 0938(T)). PMID:25505343

  8. Characterization of the Calcination Products of the Precipitates Obtained from the Bio-Oxidation with Thiobacillus Ferrooxidans of Sulphuric Water Pickling Liquors

    Science.gov (United States)

    Marco, J. F.; Gancedo, J. R.; López, F. A.

    1998-12-01

    The characterization of the calcination products of the precipitates obtained from the bio-oxidation with Thiobacillus ferrooxidans of sulphuric water pickling liquors has been carried out by means of Mössbauer spectroscopy, x-ray powder diffraction, infrared spectroscopy and transmission electron microscopy. The results show that a full transformation of the precipitates into α-Fe2O3 is achieved at temperatures higher than 850°C. Calcination at 700°C during two hours results in the formation of α-Fe2O3, ζ-Fe2O3 and Fe12O3(SO4)15. The Mössbauer parameters of ζ-Fe2O3 and Fe12O3(SO4)15 at 298 and 17K are reported.

  9. In situ spectroscopy on intact Leptospirillum ferrooxidans reveals that reduced cytochrome 579 is an obligatory intermediate in the aerobic iron respiratory chain

    Directory of Open Access Journals (Sweden)

    Robert C Blake

    2012-04-01

    Full Text Available Electron transfer reactions among colored biomolecules in intact bacterial cells were monitored using an integrating cavity absorption meter that permitted the acquisition of accurate absorbance data in suspensions of cells that scatter light. The aerobic iron respiratory chain of Leptospirillum ferrooxidans was dominated by the redox status of an abundant cellular cytochrome that had an absorbance peak at 579 nanometers in the reduced state. Intracellular cytochrome 579 was reduced within the time that it took to mix a suspension of the bacteria with soluble ferrous iron at pH 1.7. Steady state turnover experiments were conducted where the initial concentrations of ferrous iron were less than or equal to that of the oxygen concentration. Under these conditions, the initial absorbance spectrum of the oxidized bacterium was always regenerated from that of the iron-reduced bacterium. The kinetics of aerobic respiration on soluble iron by intact L. ferrooxidans conformed to the Michaelis-Menten formalism, where the reduced intracellular cytochrome 579 represented the Michaelis complex whose subsequent oxidation appeared to be the rate-limiting step in the overall aerobic respiratory process. The velocity of formation of ferric iron at any time point was directly proportional to the concentration of the reduced cytochrome 579. Further, the integral over time of the concentraton of the reduced cytochrome was directly proportional to the total concentration of ferrous iron in each reaction mixture. These kinetic data obtained using whole cells were consistent with the hypothesis that reduced cytochrome 579 is an obligatory steady state intermediate in the iron respiratory chain of this bacterium. The capability of conducting visible spectroscopy in suspensions of intact cells comprises a powerful post-reductionist means to study cellular respiration in situ under physiological conditions for the organism.

  10. Acidophilic green alga Pseudochlorella sp. YKT1 accumulates high amount of lipid droplets under a nitrogen-depleted condition at a low-pH.

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    Shunsuke Hirooka

    Full Text Available Microalgal storage lipids are considered to be a promising source for next-generation biofuel feedstock. However, microalgal biodiesel is not yet economically feasible due to the high cost of production. One of the reasons for this is that the use of a low-cost open pond system is currently limited because of the unavoidable contamination with undesirable organisms. Extremophiles have an advantage in culturing in an open pond system because they grow in extreme environments toxic to other organisms. In this study, we isolated the acidophilic green alga Pseudochlorella sp. YKT1 from sulfuric acid mine drainage in Nagano Prefecture, Japan. The vegetative cells of YKT1 display the morphological characteristics of Trebouxiophyceae and molecular phylogenetic analyses indicated it to be most closely related to Pseudochlorella pringsheimii. The optimal pH and temperature for the growth of YKT1 are pH 3.0-5.0 and a temperature 20-25°C, respectively. Further, YKT1 is able to grow at pH 2.0 and at 32°C, which corresponds to the usual water temperature in the outdoors in summer in many countries. YKT1 accumulates a large amount of storage lipids (∼30% of dry weigh under a nitrogen-depleted condition at low-pH (pH 3.0. These results show that acidophilic green algae will be useful for industrial applications by acidic open culture systems.

  11. Aplicação de técnicas eletroquímicas no estudo da dissolução oxidativa da covelita (CuS por Thiobacillus ferrooxidans Electrochemical techniques applied to study the oxidative dissolution of the covellite: CuS by Thiobacillus ferrooxidans

    Directory of Open Access Journals (Sweden)

    Christiane Medina Teixeira

    2002-02-01

    Full Text Available Among the copper sulphides, chalcopyrite (CuFeS2, covellite (CuS and chalcocite (Cu2S are the most important source of minerals for copper mining industry. The acknowledge of behaviour of these sulphides related with bacterial leaching process are essential for optimization procedures. Despite of its importance, covellite has not deserved much interest of researchers regarding this matter. In this work it was studied the oxidation of covellite by the chemolithotrophic bacterium Thiobacillus ferrooxidans by using electrochemical techniques, such as open circuit potentials with the time and cyclic voltammetry. The experiments were carried out in acid medium (pH 1.8, containing or not Fe2+ as additional energy source, and in different periods of incubation; chemical controls were run in parallel. The results showed that a sulphur layer is formed spontaneously due the acid attack, covering the sulphide in the initial phase of incubation, blocking the sulphide oxidation. However, the bacterium was capable to oxidize this sulphur layer. In the presence of Fe2+ as supplemental energy source, the corrosion process was facilitated, because ocurred an indirect oxidation of covellite by Fe3+, which was produced by T. ferrooxidans oxidation of the Fe2+ added in the medium.

  12. Complete genome sequence of the extremely acidophilic methanotroph isolate V4, Methylacidiphilum infernorum, a representative of the bacterial phylum Verrucomicrobia

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    Stott Matthew B

    2008-07-01

    Full Text Available Abstract Background The phylum Verrucomicrobia is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the Verrucomicrobia, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia. Results We report the complete genome sequence of strain V4, the first one from a representative of the Verrucomicrobia. Isolate V4, initially named "Methylokorus infernorum" (and recently renamed Methylacidiphilum infernorum is an autotrophic bacterium with a streamlined genome of ~2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of M. infernorum was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C1-utilization pathways compared to other known methylotrophs. The M. infernorum genome does not encode tubulin, which was previously discovered in bacteria of the genus Prosthecobacter, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping Planctomycetes, Verrucomicrobia and Chlamydiae into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the M. infernorum lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of M. infernorum shows apparent adaptations for existence under extremely

  13. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Science.gov (United States)

    Castro, Matías; Deane, Shelly M; Ruiz, Lina; Rawlings, Douglas E; Guiliani, Nicolas

    2015-01-01

    An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs) and degraded by phosphodiesterases (PDEs). We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319) that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process.

  14. Isolation and characterization of a novel Acidithiobacillus ferrivorans strain from the Chilean Altiplano: attachment and biofilm formation on pyrite at low temperature.

    Science.gov (United States)

    Barahona, Sergio; Dorador, Cristina; Zhang, Ruiyong; Aguilar, Pablo; Sand, Wolfgang; Vera, Mario; Remonsellez, Francisco

    2014-11-01

    Microorganisms are used to aid the extraction of valuable metals from low-grade sulfide ores in mines worldwide, but relatively little is known about this process in cold environments. This study comprises a preliminary analysis of the bacterial diversity of the polyextremophilic acid River Aroma located in the Chilean Altiplano, and revealed that Betaproteobacteria was the most dominant bacterial group (Gallionella-like and Thiobacillus-like). Taxa characteristic of leaching environments, such Acidithiobacillus and Leptospirillum, were detected at low abundances. Also, bacteria not associated with extremely acidic, metal-rich environments were found. After enrichment in iron- and sulfur-oxidizing media, we isolated and identified a novel psychrotolerant Acidithiobacillus ferrivorans strain ACH. This strain can grow using ferrous iron, sulfur, thiosulfate, tetrathionate and pyrite, as energy sources. Optimal growth was observed in the presence of pyrite, where cultures reached a cell number of 6.5 · 10(7) cells mL(-1). Planktonic cells grown with pyrite showed the presence of extracellular polymeric substances (10 °C and 28 °C), and a high density of cells attached to pyrite grains were observed at 10 °C by electron microscopy. The attachment of cells to pyrite coupons and the presence of capsular polysaccharides were visualized by using epifluorescence microscopy, through nucleic acid and lectin staining with Syto(®)9 and TRITC-Con A, respectively. Interestingly, we observed high cell adhesion including the formation of microcolonies within 21 days of incubation at 4 °C, which was correlated with a clear induction of capsular polysaccharides production. Our data suggests that attachment to pyrite is not temperature-dependent in At. ferrivorans ACH. The results of this study highlight the potential of this novel psychrotolerant strain in oxidation and attachment to minerals under low-temperature conditions.

  15. Bioremoval of Hydrogen Sulfide by Acidithiobacillus thiooxidans%氧化硫硫杆菌脱除硫化氢的研究

    Institute of Scientific and Technical Information of China (English)

    晏磊; 刘权; 张爽; 王伟东; 王彦杰; 荆瑞勇

    2014-01-01

    The bioremoval characteristics of hydrogen sulfide by Acidithiobacillus thiooxidans ATCC19377 (A. thiooxidans ATCC19377) were investigated as a function of pH,operation time,gas flow,initial hydrogen sulfide concentration and bacterial biomass dosage (OD600).The removal conditions of hydrogen sulfide were analyzed by the single-factor experiments.Results indicated that the optimum conditions for hydrogen sulfide removal were pH 2.5,operation time 180 min,gas flow 40 mL·min-1,initial hydrogen sulfide concentration 8 g·m -3 and bacterial biomass dosage (OD600)0.40.Establishment of bioremoval conditions could provide theoretic foundation for industrial desulfurization of gas.%研究利用Acidithiobacillus thiooxidans ATCC19377(A. thiooxidans ATCC19377)对硫化氢的脱除条件进行研究,考察pH,反应器运行时间,气流量,初始硫化氢浓度以及细菌生物量即600 nm处吸收值(OD600)对脱除效能的影响。采用单因素实验法对A. thiooxidans脱除硫化氢的条件进行了研究。A. thiooxidans脱除硫化氢的最佳条件为:pH 2.5、反应器运行时间180 min、气体流量40 mL·min-1、初始硫化氢浓度8 g·m-3、细菌生物量即600 nm处吸收值0.40。初步确定了A. thiooxidans脱除硫化氢的条件,为工业气体脱硫提供理论依据。

  16. Diguanylate cyclase null mutant reveals that C-Di-GMP pathway regulates the motility and adherence of the extremophile bacterium Acidithiobacillus caldus.

    Directory of Open Access Journals (Sweden)

    Matías Castro

    Full Text Available An understanding of biofilm formation is relevant to the design of biological strategies to improve the efficiency of the bioleaching process and to prevent environmental damages caused by acid mine/rock drainage. For this reason, our laboratory is focused on the characterization of the molecular mechanisms involved in biofilm formation in different biomining bacteria. In many bacteria, the intracellular levels of c-di-GMP molecules regulate the transition from the motile planktonic state to sessile community-based behaviors, such as biofilm development, through different kinds of effectors. Thus, we recently started a study of the c-di-GMP pathway in several biomining bacteria including Acidithiobacillus caldus. C-di-GMP molecules are synthesized by diguanylate cyclases (DGCs and degraded by phosphodiesterases (PDEs. We previously reported the existence of intermediates involved in c-di-GMP pathway from different Acidithiobacillus species. Here, we report our work related to At. caldus ATCC 51756. We identified several putative-ORFs encoding DGC and PDE and effector proteins. By using total RNA extracted from At. caldus cells and RT-PCR, we demonstrated that these genes are expressed. We also demonstrated the presence of c-di-GMP by mass spectrometry and showed that genes for several of the DGC enzymes were functional by heterologous genetic complementation in Salmonella enterica serovar Typhimurium mutants. Moreover, we developed a DGC defective mutant strain (Δc1319 that strongly indicated that the c-di-GMP pathway regulates the swarming motility and adherence to sulfur surfaces by At. caldus. Together, our results revealed that At. caldus possesses a functional c-di-GMP pathway which could be significant for ores colonization during the bioleaching process.

  17. Résilience d'une prairie subalpine acidophile au chaulage et à la fertilisation de courte durée

    OpenAIRE

    Spiegelberger, T.; Deléglise, C.; DeDanieli, S.; Bernard-Brunet, C.

    2010-01-01

    / Une expérience de fertilisation a débuté en 1989 dans les Alpes françaises, sur une prairie acidophile située à 2000 m d'altitude, où de la chaux (« chaulage ») et des scories enrichies par chlorure de potassium (« fertilisation ») ont été apportés jusqu'en 1992. Depuis, aucun autre amendement n'a été appliqué. En 2007 nous avons revisité l'expérience et avons observé que le pH du sol était toujours sensiblement plus haut sur les placettes chaulées, alors que les concentrations du sol e...

  18. 化学合成独立栄養細菌 Acidithiobacillus thiooxidans 由来アコニターゼの遺伝子解析と大腸菌での発現

    OpenAIRE

    金原, 陽平; 田村, 隆; 徳田, 千束; 中村, 淳雄; 松川, 寛和; 稲垣, 賢二

    2005-01-01

    An aconitase from Acidithiobacillus thiooxidans was purified and characterized, and its gene was cloned. The cloned aconitase gene (acn) was expressed in Escherichia coli JM 109; aconitase activity was found in the cell extarct. The acn gene encodes a 646-amino acid polypeptide and is located upstream of the isocitrate dehydrogenase gene (icd). A. thiooxidans aconitase showes high sequence similar to pig heart aconitase and E.coli aconitase B. Twenty-five of twenty-seven active site residues ...

  19. Cowpea nodulation, biomass yield and nutrient uptake, as affected by biofertilizers and rhizobia, in a sodic soil amended with Acidithiobacillus - doi: 10.4025/actasciagron.v35i4.16994

    Directory of Open Access Journals (Sweden)

    Newton Pereira Stamford

    2013-05-01

    Full Text Available Sodic soils require application of amendments as gypsum and organic matter. Many types of compost have been tested in sodic soils reclamation; however, these materials often do not provide satisfactory pH reduction. A recent study reported effective effects applying mixture of gypsum and sulfur inoculated with Acidithiobacillus in sodic soils with high pH and exchangeable sodium, though the effects on plant parameters were not evaluated. The present study was conducted to verify the effects of BPK rock biofertilizers on nodulation, biomass yield and nutrient uptake in cowpea compared with mineral fertilizer after sodic soil amendment. The BPK biofertilizers and PK mineral fertilizer were applied at different rates, and plants were inoculated with effective rhizobia strains. A control that did not receive PK fertilization was included. The results indicated that gypsum and sulfur with Acidithiobacillus reduced the soil’s pH and the amount of soil exchangeable sodium. BPK rock biofertilizer increased cowpea nodulation, biomass yield and nutrient uptake. The native rhizobia in the soil exhibited effectiveness in cowpea growth; displaying similar results compared with the rhizobia inoculated plants. BPK biofertilizers may be used as alternative to mineral PK fertilizers in sodic soils after the application of gypsum and sulfur inoculated with Acidithiobacillus.

  20. Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture.

    Science.gov (United States)

    Jiang, Huidan; Liang, Yili; Yin, Huaqun; Xiao, Yunhua; Guo, Xue; Xu, Ying; Hu, Qi; Liu, Hongwei; Liu, Xueduan

    2015-01-01

    The response of iron-oxidizing Leptospirillum ferriphilum YSK and sulfur-oxidizing Acidithiobacillus thiooxidans A01 to arsenite under pure culture and coculture was investigated based on biochemical characterization (concentration of iron ion and pH value) and related gene expression. L. ferriphilum YSK and At. thiooxidans A01 in pure culture could adapt up to 400 mM and 800 mM As(III) after domestication, respectively, although arsenite showed a negative effect on both strains. The coculture showed a stronger sulfur and ferrous ion oxidation activity when exposed to arsenite. In coculture, the pH value showed no significant difference when under 500 mM arsenite stress, and the cell number of At. thiooxidans was higher than that in pure culture benefiting from the interaction with L. ferriphilum. The expression profile showed that the arsenic efflux system in the coculture was more active than that in pure culture, indicating that there is a synergetic interaction between At. thiooxidans A01 and L. ferriphilum YSK. In addition, a model was proposed to illustrate the interaction between arsenite and the ars operon in L. ferriphilum YSK and At. thiooxidans A01. This study will facilitate the effective application of coculture in the bioleaching process by taking advantage of strain-strain communication and coordination.

  1. Effects of Arsenite Resistance on the Growth and Functional Gene Expression of Leptospirillum ferriphilum and Acidithiobacillus thiooxidans in Pure Culture and Coculture

    Directory of Open Access Journals (Sweden)

    Huidan Jiang

    2015-01-01

    Full Text Available The response of iron-oxidizing Leptospirillum ferriphilum YSK and sulfur-oxidizing Acidithiobacillus thiooxidans A01 to arsenite under pure culture and coculture was investigated based on biochemical characterization (concentration of iron ion and pH value and related gene expression. L. ferriphilum YSK and At. thiooxidans A01 in pure culture could adapt up to 400 mM and 800 mM As(III after domestication, respectively, although arsenite showed a negative effect on both strains. The coculture showed a stronger sulfur and ferrous ion oxidation activity when exposed to arsenite. In coculture, the pH value showed no significant difference when under 500 mM arsenite stress, and the cell number of At. thiooxidans was higher than that in pure culture benefiting from the interaction with L. ferriphilum. The expression profile showed that the arsenic efflux system in the coculture was more active than that in pure culture, indicating that there is a synergetic interaction between At. thiooxidans A01 and L. ferriphilum YSK. In addition, a model was proposed to illustrate the interaction between arsenite and the ars operon in L. ferriphilum YSK and At. thiooxidans A01. This study will facilitate the effective application of coculture in the bioleaching process by taking advantage of strain-strain communication and coordination.

  2. Enhanced Cr bioleaching efficiency from tannery sludge with coinoculation of Acidithiobacillus thiooxidans TS6 and Brettanomyces B65 in an air-lift reactor.

    Science.gov (United States)

    Fang, Di; Zhou, Li-Xiang

    2007-09-01

    Bioleaching process has been demonstrated to be an effective technology in removing Cr from tannery sludge, but a large quantity of dissolved organic matter (DOM) present in tannery sludge often exhibits a marked toxicity to chemolithoautotrophic bioleaching bacteria such as Acidithiobacillus thiooxidans. The purpose of the present study was therefore to enhance Cr bioleaching efficiencies through introducing sludge DOM-degrading heterotrophic microorganism into the sulfur-based sludge bioleaching system. An acid-tolerant DOM-degrading yeast strain Brettanomyces B65 was successfully isolated from a local Haining tannery sludge and it could metabolize sludge DOM as a source of energy and carbon for growth. A combined bioleaching experiment (coupling Brettanomyces B65 and A. thiooxidans TS6) performed in an air-lift reactor indicated that the rates of sludge pH reduction and ORP increase were greatly improved, resulting in enhanced Cr solubilization. Compared with the 5 days required for maximum solubilization of Cr for the control (single bioleaching process without inoculation of Brettanomyces B65), the bioleaching period was significantly shorten to 3 days for the combined bioleaching system. Moreover, little nitrogen and phosphorous were lost and the content of Cr was below the permitted levels for land application after 3 days of bioleaching treatment.

  3. Biotechnology for uranium extraction and environmental control

    International Nuclear Information System (INIS)

    India is looking forward to augmenting mining and extraction of uranium mineral for its nuclear energy needs. Being a radio-active mineral, mining and processing of uranium ore deposits need be carried out in an environmentally acceptable fashion. In this respect, a biotechnological approach holds great promise since it is environment-friendly, cost-effective and energy-efficient. There are several types of microorganisms which inhabit uranium ore bodies and biogenesis plays an important role in the mineralisation and transport of uranium-bearing minerals under the earth's crust. Uranium occurrences in India are only meagre and it becomes essential to tap effectively all the available resources. Uraninite and pitchblende occurring along with sulfide mineralisation such as pyrite are ideal candidates for bioleaching. Acidithiobacillus ferrooxidans present ubiquitously in the ore deposits can be isolated, cultured and utilised to bring about efficient acidic dissolution of uranium. Many such commercial attempts to extract uranium from even lean ores using acidophilic autotrophic bacteria have been made in different parts of the world. Anaerobes such a Geobacter and Sulfate Reducing Bacteria (SRB) can be effectively used in uranium mining for environmental control. Radioactive uranium mined wastes and tailing dumps can be cleaned and protected using microorganisms. In this lecture use of biotechnology in uranium extraction and bioremediation is illustrated with practical examples. Applicability of environment-friendly biotechnology for mining and extraction of uranium from Indian deposits is outlined. Commercial potentials for bioremediation in uranium-containing wastes are emphasised. (author)

  4. Bacterial phylogenetic diversity in a constructed wetland system treating acid coal mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nicorarat, D.; Dick, W.A.; Dopson, M.; Tuovinen, O.H. [Ohio State University, Columbus, OH (USA)

    2008-02-15

    Microorganisms in acid mine drainage are typically acidophiles that mediate the oxidation of reduced compounds of iron and sulfur. However, microbial populations in wetland systems constructed to treat acid mine drainage are not well characterized. This study was to analyze bacterial diversity, using cultivation-independent molecular ecological techniques, in a constructed wetland that received acid drainage from an abandoned underground coal mine. DNA was purified from Fe(III)-precipitates from the oxidized surface zone of wetland sediments and 16S rRNA gene sequences were amplified and cloned. A total of 200 clones were analyzed by restriction fragment length polymorphism (RFLP) and 77 unique RFLP patterns were obtained with four restriction enzymes. Of these patterns, 30 most dominant unique clones were selected for sequencing of their 16S rRNA genes. Half of these 30 clones could be matched with autotrophic iron- and sulfur-oxidizing bacteria (Acidithiohacillus ferrooxidans and Acidithiobacillus thiooxidans). Several clones also formed a clade with heterotrophic iron-oxidizing bacteria (TRA2-10, TRA3-20, and TRA5-3) and heterotrophic bacteria (Stenotrophomas maltophilia, Bordetella spp., Alcalgenes sp., Alcaligenesfaecalis, and Alcaligenes xylosoxidans). Approximately 40% and 35% of the analyzed RFLP restriction patterns were consistent with A. ferrooxidans and A. thiooxidans, respectively. The relatively high frequency of acidithiobacilli is consistent with the chemical and physical characteristics of this site i.e., continuous, abundant supply of reduced iron and sulfur compounds, pH 3-4, ambient temperature, and limited organics originating from the coal seam and from vegetation or soil surrounding the inlet channel to the wetland.

  5. Influence of water chemistry on the distribution of an acidophilic protozoan in an acid mine drainage system at the abandoned Green Valley coal mine, Indiana, USA

    Energy Technology Data Exchange (ETDEWEB)

    Brake, S.S.; Dannelly, H.K.; Connors, K.A.; Hasiotis, S.T. [Indiana State University, Terre Haute, IN (United States). Dept. of Geography Geology & Anthropology

    2001-07-01

    Euglena mutabilis, a benthic photosynthetic protozoan that intracellularly sequesters Fe, is variably abundant in the main effluent channel that contains acid mine drainage (AMD) discharging from the Green Valley coal mine site in western Indiana. Samples of effluent (pH 3.0-4.6) taken from the main channel and samples of contaminated stream water (pH 3.3 to 8.0) collected from an adjacent stream were analyzed to evaluate the influence of water chemistry on E. mutabilis distribution. E. mutabilis communities were restricted to areas containing unmixed effluent with the thickest (up to 3 mm) benthic communities residing in effluent containing high concentrations of total Fe (up to 12110 mg/l), SO{sub 4}(up to 2940 mg/l), Al (up to 1846 mg/l), and Cl (up to 629 mg/l). Communities were also present, but much less abundant, in areas with effluent containing lower concentrations of these same constituents. In effluent where SO{sub 4} was most highly concentrated, E. mutabilis was largely absent, suggesting that extremely high concentrations of SO{sub 4} may have an adverse effect on this potentially beneficial Fe-mediating, acidophilic protozoan.

  6. Thermoanaerobacterium aotearoense sp. nov., a slightly acidophilic, anaerobic thermophile isolated from various hot springs in New Zealand, and emendation of the genus Thermoanaerobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Shu-Ying Liu; Wiegel, J. [Univ. of Georiga, Athens, GA (United States); Rainey, F.A. [Deutsche Sammlung von Mikroorganismen und Zellkulturen, Braunschweig (Germany)] [and others

    1996-04-01

    Six moderately acidophilic, thermophilic bacterial strains with similar properties were isolated from geothermally heated water and sediment samples collected in New Zealand. These Gram stain-negative but Gram type-positive, rod-shaped bacteria formed oval terminal endospores. The cells were peritrichously flagellated and exhibited tumbling motility. At 60{degrees}C the pH range for growth was 3.8 to 6.8, and the optimum pH was 5.2 when the organisms were grown with xylose. At pH 5.2 the temperature range for growth was 35 to 66{degrees}C, and the optimum temperature was 60 to 63{degrees}C. The fermentation products from flucose or xylose were ethanol, acetate, lactate, CO{sub 2}, and H{sub 2}. The DNA G+C content was 34.5 to 35 mol%. On the basis of properties such as formation of elemental sulfur from thiosulfate, growth at acidic pH values at elevated temperatures, and the results of a 16S rRNA sequence comparison performed with previously validly published species belonging to the genus Thermoanaerobacterium, we propose that strain JW/SL-NZ613{sup T} (T = type strain) and five similar strains isolated from samples collected in New Zealand represent a new species, Thermoanaerobacterium aotearoense. Strain JW/SL-NZ613{sup T} (= DSM 10170) is the type strain of this species.

  7. Genomic insights into a new acidophilic, copper-resistant Desulfosporosinus isolate from the oxidized tailings area of an abandoned gold mine.

    Science.gov (United States)

    Mardanov, Andrey V; Panova, Inna A; Beletsky, Alexey V; Avakyan, Marat R; Kadnikov, Vitaly V; Antsiferov, Dmitry V; Banks, David; Frank, Yulia A; Pimenov, Nikolay V; Ravin, Nikolai V; Karnachuk, Olga V

    2016-08-01

    Microbial sulfate reduction in acid mine drainage is still considered to be confined to anoxic conditions, although several reports have shown that sulfate-reducing bacteria occur under microaerophilic or aerobic conditions. We have measured sulfate reduction rates of up to 60 nmol S cm(-3) day(-1) in oxidized layers of gold mine tailings in Kuzbass (SW Siberia). A novel, acidophilic, copper-tolerant Desulfosporosinus sp. I2 was isolated from the same sample and its genome was sequenced. The genomic analysis and physiological data indicate the involvement of transporters and additional mechanisms to tolerate metals, such as sequestration by polyphosphates. Desulfosporinus sp. I2 encodes systems for a metabolically versatile life style. The genome possessed a complete Embden-Meyerhof pathway for glycolysis and gluconeogenesis. Complete oxidation of organic substrates could be enabled by the complete TCA cycle. Genomic analysis found all major components of the electron transfer chain necessary for energy generation via oxidative phosphorylation. Autotrophic CO2 fixation could be performed through the Wood-Ljungdahl pathway. Multiple oxygen detoxification systems were identified in the genome. Taking into account the metabolic activity and genomic analysis, the traits of the novel isolate broaden our understanding of active sulfate reduction and associated metabolism beyond strictly anaerobic niches. PMID:27222219

  8. 氧化硫硫杆菌对难选恩施赤铁矿脱磷的影响%Study on Application ofAcidithiobacillus thiooxidans in Dephosphorization of Hematite in Enshi

    Institute of Scientific and Technical Information of China (English)

    孙灵芝; 李士琦; 汪玉娇; 高金涛; 吴龙; 金晓晖

    2011-01-01

    Dephosphorization of phosphorus-containing 0.90% high-phosphorus hematite ore in Enshi with the strain of Acidithiobacillus thiooxidans (At.t) was studied. The preliminary results showed that the maximum dephosphorization rate could reach up to 71%, which meant that Acidithiobacillus thiooxidans had a better dephosphorization effect. 10% of the strain concentration, 75 urn of hematite particles, 4.0 of initial culture pH value were obtained as the optimized leaching conditions by studying the growth characteristics of At.t and effects of different pH values, hematite particle sizes and At.t concentrations on the bioleaching process.%利用嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans,At.t)菌种,对含磷为0.90%的恩施高磷赤铁矿进行了微生物降磷实验.对At.t浓度、培养基初始pH值和赤铁矿粒度对磷浸出效果的影响进行了系统研究.结果表明,用At.t对高磷赤铁矿进行磷浸出的最佳工艺条件为:At.t浓度10%,培养基初始pH值4.0,赤铁矿粒度75 μm,在此条件下得到的磷磷浸出率高达71%,At.t具有较好的降磷效果.

  9. Use of sulfur-oxidizing bacteria as recognition elements in hydrogen sulfide biosensing system.

    Science.gov (United States)

    Janfada, Behdokht; Yazdian, Fatemeh; Amoabediny, Ghassem; Rahaie, Mahdi

    2015-01-01

    Four sulfur-oxidizing bacteria (Thiobacillus thioparus, Acidithiobacillus thiooxidans PTCC1717, Acidithiobacillus ferrooxidans PTCC1646, and Acidithiobacillus ferrooxidans PTCC1647) were used as biorecognition elements in a hydrogen sulfide biosensing system. All the experiments were performed in 0.1 M phosphate buffer solution containing 1-20 ppm H2S with optimum pH and temperature for each species. Although H2 S was applied to the biosensing system, the dissolved O2 content decreased. Dissolved O2 consumed by cells in both free and immobilized forms was measured using a dissolved oxygen sensor. Free bacterial cells exhibit fast response (thiooxidans retained more than 50% of activity after 30 days of immobilization. According to the data, A. thiooxidans and A. ferrooxidans are appropriate species for hydrogen sulfide biosensor.

  10. Effects of cell condition, pH, and temperature on lead, zinc, and copper sorption to Acidithiobacillus caldus strain BC13

    International Nuclear Information System (INIS)

    Research highlights: →At. caldus sorbs lead, zinc, and copper across a range of pH and temperature. →At. caldus shows a relatively high sorption capacity for zinc and copper at low pH. → Lead, zinc, and copper sorption decreases in tertiary mixtures. → Copper appears to sorb via a different mechanism(s) than lead or zinc. - Abstract: This study describes the effects of cell condition, pH, and temperature on lead, zinc, and copper sorption to Acidithiobacillus caldus strain BC13 with a Langmuir model. Copper exhibited the highest loading capacity, 4.76 ± 0.28 mmol g-1, to viable cells at pH 5.5. The highest kL (binding-site affinity) observed was 61.2 ± 3.0 L mmol-1 to dehydrated cells at pH 4.0. The pHs that maximized loading capacities and binding-site affinities were generally between 4.0 and 5.5, where the sum of free-proton and complexed-metal concentrations was near a minimum. Of additional importance, lead, zinc, and copper sorbed to viable cells at pH values as low as 1.5. Previous studies with other acidithiobacilli did not measure viable-cell sorption below pH 4.0. In separate experiments, desorption studies showed that far less copper was recovered from viable cells than any other metal or cell condition, suggesting that uptake may play an important role in copper sorption by At. caldus strain BC13. To reflect an applied system, the sorption of metal mixtures was also studied. In these experiments, lead, zinc, and copper sorption from a tertiary mixture were 40.2 ± 4.3%, 28.7 ± 3.8%, and 91.3 ± 3.0%, respectively, of that sorbed in single-metal systems.

  11. A new acidophilic endo-β-1,4-xylanase from Penicillium oxalicum: cloning, purification, and insights into the influence of metal ions on xylanase activity.

    Science.gov (United States)

    Liao, Hanpeng; Sun, Shaowei; Wang, Pan; Bi, Wenli; Tan, Shiyong; Wei, Zhong; Mei, Xinlan; Liu, Dongyang; Raza, Waseem; Shen, Qirong; Xu, Yangchun

    2014-07-01

    A new acidophilic xylanase (XYN11A) from Penicillium oxalicum GZ-2 has been purified, identified and characterized. Synchronized fluorescence spectroscopy was used for the first time to evaluate the influence of metal ions on xylanase activity. The purified enzyme was identified by MALDI TOF/TOF mass spectrometry, and its gene (xyn11A) was identified as an open reading frame of 706 bp with a 68 bp intron. This gene encodes a mature protein of 196 residues with a predicted molecular weight of 21.3 kDa that has the 100 % identity with the putative xylanase from the P. oxalicum 114-2. The enzyme shows a structure comprising a catalytic module family 10 (GH10) and no carbohydrate-binding module family. The specific activities were 150.2, 60.2, and 72.6 U/mg for beechwood xylan, birchwood xylan, and oat spelt xylan, respectively. XYN11A exhibited optimal activity at pH 4.0 and remarkable pH stability under extremely acidic condition (pH 3). The specific activity, K m and V max values were 150.2 U/mg, 30.7 mg/mL, and 403.9 μmol/min/mg for beechwood xylan, respectively. XYN11A is a endo-β-1,4-xylanase since it release xylobiose and xylotriose as the main products by hydrolyzing xylans. The activity of XYN11A was enhanced 155 % by 1 mM Fe(2+) ions, but was inhibited strongly by Fe(3+). The reason of enhancing the xylanase activity of XYN11A with 1 mM Fe(2+) treatment may be responsible for the change of microenvironment of tryptophan residues studied by synchronous fluorescence spectrophotometry. Inhibition of the xylanase activity by Fe(3+) was first time demonstrated to associate tryptophan fluorescence quenching. PMID:24818699

  12. Acidophilic granulocytes in the gills of gilthead seabream Sparus aurata: evidence for their responses to a natural infection by a copepod ectoparasite.

    Science.gov (United States)

    Lui, Alice; Manera, Maurizio; Giari, Luisa; Mulero, Victoriano; Dezfuli, Bahram Sayyaf

    2013-09-01

    Immunohistochemical and ultrastructural studies were conducted on the gills of gilthead seabream, Sparus aurata L., naturally infected with the copepod ectoparasite Ergasilus lizae (Krøyer, 1863) in order to assess pathology and the host immune cell response. Gills of 56 gilthead seabream were screened for ectoparasites; 36 specimens (64.3%) harbored E. lizae. Intensity of infection was 32.7 ± 8.7 (mean ± SE). Pathological alterations to the gills of the host were more pronounced in close proximity to the copepod site of attachment. The parasite attached to the gills by means of its modified second antennae, occluded the arteries, provoked epithelial hyperplasia and hemorrhages and most often caused lamellar disruption. Numerous granular cells were encountered near the site of E. lizae attachment. In both infected and uninfected gills, the granular cells lay within the filaments and frequently occurred within the connective tissue inside and outside the blood vessels of the filaments. The type of granular cell was identified by immunohistochemical staining by using the monoclonal antibody G7 (mAb G7), which specifically recognizes acidophilic granulocytes (AGs) of S. aurata and with an anti-histamine antibody (as a marker for mast cells, MCs) on sections from 13 uninfected gills and 21 parasitized gills. The use of mAb G7 revealed that, in gills harboring copepods, the number of G7-positive cells (i.e., AGs; 32.9 ± 3.9, mean number of cells per 45,000 μm2 ± SE) was significantly higher than the density of the same cells in uninfected gills (15.3 ± 3.8; ANOVA, P < 0.05). Few histamine-positive granular cells (i.e., MCs) were found in the uninfected and parasitized gills. Here, we show, for the first time in S. aurata infected gills, that AGs rather than MCs are recruited and involved in the response to E. lizae infection in seabream. PMID:23644766

  13. Bioleaching of chalcopyrite by pure and mixed culture

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-sheng; QIN Wen-qing; WANG Jun; ZHEN Shi-jie; YANG Cong-ren; ZHANG Jian-wen; NAI Shao-shi; QIU Guan-zhou

    2008-01-01

    The bioleaching of chalcopyrite in shake flasks was investigated by using pure Acidithiobacillus ferrooxidans and mixed culture isolated from the acid mine drainage in Yushui and Dabaoshan Copper Mine in China,marked as YS and DB,respectively.The mixed culture consisted mainly of Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans,and Leptospirillum spp.(Leptospirillum ferriphilum and Leptospirillum ferrooxians).The results show that the mixed culture is more efficient than the pure Acidithiobacillus ferrooxidans because of the presence of the sulfur-oxidizing cultures that positively increase the dissolution rate and the recovery of copper from chalcopyrite.The pH value decreases with the decrease of chalcopyrite leaching rate,because of the formation of jarosite as a passivation layer on the mineral surface during bioleaching.In the bioleaching using the mixed culture,low pH is got from the sulfur oxidizing inhibiting,the formation of jarosite.The copper extraction reaches 46.27% in mixed culture and 30.37% in pure Acidithiobacillus ferrooxidans after leaching for 75 d.

  14. Influences of Extracellular Polymeric Substances on the Dewaterability of Sewage Sludge during Bioleaching

    OpenAIRE

    Zhou, Jun; Zheng, Guanyu; Zhang, Xueying; Zhou, Lixiang

    2014-01-01

    Extracellular polymeric substances (EPS) play important roles in regulating the dewaterability of sludge. This study sought to elucidate the influence of EPS on the dewaterability of sludge during bioleaching process. Results showed that, in bioleaching system with the co-inoculation of Acidithiobacillus thiooxidans TS6 and Acidithiobacillus ferrooxidans LX5 (A. t+A. f system), the capillary suction time (CST) of sludge reduced from 255.9 s to 25.45 s within 48 h, which was obviously better t...

  15. Microbial iron management mechanisms in extremely acidic environments: comparative genomics evidence for diversity and versatility

    Directory of Open Access Journals (Sweden)

    Nieto Pamela A

    2008-11-01

    Full Text Available Abstract Background Iron is an essential nutrient but can be toxic at high intracellular concentrations and organisms have evolved tightly regulated mechanisms for iron uptake and homeostasis. Information on iron management mechanisms is available for organisms living at circumneutral pH. However, very little is known about how acidophilic bacteria, especially those used for industrial copper bioleaching, cope with environmental iron loads that can be 1018 times the concentration found in pH neutral environments. This study was motivated by the need to fill this lacuna in knowledge. An understanding of how microorganisms thrive in acidic ecosystems with high iron loads requires a comprehensive investigation of the strategies to acquire iron and to coordinate this acquisition with utilization, storage and oxidation of iron through metal responsive regulation. In silico prediction of iron management genes and Fur regulation was carried out for three Acidithiobacilli: Acidithiobacillus ferrooxidans (iron and sulfur oxidizer A. thiooxidans and A. caldus (sulfur oxidizers that can live between pH 1 and pH 5 and for three strict iron oxidizers of the Leptospirillum genus that live at pH 1 or below. Results Acidithiobacilli have predicted FeoB-like Fe(II and Nramp-like Fe(II-Mn(II transporters. They also have 14 different TonB dependent ferri-siderophore transporters of diverse siderophore affinity, although they do not produce classical siderophores. Instead they have predicted novel mechanisms for dicitrate synthesis and possibly also for phosphate-chelation mediated iron uptake. It is hypothesized that the unexpectedly large number and diversity of Fe(III-uptake systems confers versatility to this group of acidophiles, especially in higher pH environments (pH 4–5 where soluble iron may not be abundant. In contrast, Leptospirilla have only a FtrI-Fet3P-like permease and three TonB dependent ferri-dicitrate siderophore systems. This paucity of iron

  16. 嗜酸性氧化硫硫杆菌的分离鉴定及其产酸特性%Isolation, Identification of an Acidithiobacillus Thiooxidan Strain and Its Characteristic of Acid Production

    Institute of Scientific and Technical Information of China (English)

    杨期勇; 邱秀文; 程鹏飞; 李也; 韩金凤; 蒋晟; 单瑶瑶; 孙超

    2015-01-01

    Acidithiobacillus thiooxidan is the major microorganism in bioleaching of heavy metal from sewage sludge. The biological oxidation of sulfur by Acidithiobacillus thiooxidan is the committed step of bioleaching of heavy metal. In order to isolate and cultivate efficientAcidithiobacillus thiooxidan, its characteristic of acid production is studied, and then the method of improving the effect of its acid production is selected. An autotrophic sulfur-oxidizing bacterium (strain JJU-1) was isolated from the activated sludge of a sewage plant. According to its colonial morphology, SEM image of strain, physiological-biochemical properties and its16S rRNA gene sequence analysis, the strain was identified as Acidithiobacillus thiooxidan. Sulfur oxidation by JJU-1 was studied from four aspects, such as initial pH, quantity of sulfur, size of sulfur particle and concentration of surfactant agent (Tween 60). The culture mediums with different initial pH were studied and the results indicated that the initial pH of culture medium almost had no effect on growth ofAcidithiobacillus thiooxidanin later stage, more specifically, the pH of culture mediums were almost the same on the 7th day. The experiment results also showed the growth of microorganism was restrained at pH below 1. Considering the influence by different amount of substrate sulfur added into the culture mediums, the rate of sulfate formation by JJU-1 strain was higher when the sulfur amount increased. On the 8th day the maximum difference of the culture mediums pH with different amount of sulfur was 0.54. The rate of sulfate formation by JJU-1strain increased with the decrease in sulfur particle size. The sulfur particles passing through 180μm yielded lower rates of sulfate formation than these of size below 180μm. The addition of Tween 60 had some effect on sulfate formation by JJU-1 strain. When the concentration of Tween 60 was at 0.4~1.6 g·L-1, it would increase the rate of sulfate formation. However, when the

  17. Is Mars a habitable environment for extremophilic microorganisms from Earth?

    Science.gov (United States)

    Rettberg, Petra; Reitz, Guenther; Flemming, Hans-Curt; Bauermeister, Anja

    In the last decades several sucessful space missions to our neighboring planet Mars have deepened our knowledge about its environmental conditions substantially. Orbiters with intruments for remote sensing and landers with sophisticated intruments for in situ investigations resulted in a better understanding of Mars’ radiation climate, atmospheric composition, geology, and mineralogy. Extensive regions of the surface of Mars are covered with sulfate- and ferric oxide-rich layered deposits. These sediments indicate the possible existence of aqueous, acidic environments on early Mars. Similar environments on Earth harbour a specialised community of microorganisms which are adapted to the local stress factors, e.g. low pH, high concentrations of heavy metal ions, oligotrophic conditions. Acidophilic iron-sulfur bacteria isolated from such habitats on Earth could be considered as model organisms for an important part of a potential extinct Martian ecosystem or an ecosystem which might even exist today in protected subsurface niches. Acidithiobacillus ferrooxidans was chosen as a model organism to study the ability of these bacteria to survive or grow under conditions resembling those on Mars. Stress conditions tested included desiccation, radiation, low temperatures, and high salinity. It was found that resistance to desiccation strongly depends on the mode of drying. Biofilms grown on membrane filters can tolerate longer periods of desiccation than planktonic cells dried without any added protectants, and drying under anaerobic conditions is more favourable to survival than drying in the presence of oxygen. Organic compounds such as trehalose and glycine betaine had a positive influence on survival after drying and freezing. A. ferrooxidans was shown to be sensitive to high salt concentrations, ionizing radiation, and UV radiation. However, the bacteria were able to utilize the iron minerals in Mars regolith mixtures as sole energy source. The survival and growth of

  18. Bioleaching of ilmenite and basalt in the presence of iron-oxidizing and iron-scavenging bacteria

    Science.gov (United States)

    Navarrete, Jesica U.; Cappelle, Ian J.; Schnittker, Kimberlin; Borrok, David M.

    2013-04-01

    Bioleaching has been suggested as an alternative to traditional mining techniques in extraterrestrial environments because it does not require extensive infrastructure and bulky hardware. In situ bioleaching of silicate minerals, such as those found on the moon or Mars, has been proposed as a feasible alternative to traditional extraction techniques that require either extreme heat and/or substantial chemical treatment. In this study, we investigated the biotic and abiotic leaching of basaltic rocks (analogues to those found on the moon and Mars) and the mineral ilmenite (FeTiO3) in aqueous environments under acidic (pH ˜ 2.5) and circumneutral pH conditions. The biological leaching experiments were conducted using Acidithiobacillus ferrooxidans, an iron (Fe)-oxidizing bacteria, and Pseudomonas mendocina, an Fe-scavenging bacteria. We found that both strains were able to grow using the Fe(II) derived from the tested basaltic rocks and ilmenite. Although silica leaching rates were the same or slightly less in the bacterial systems with A. ferrooxidans than in the abiotic control systems, the extent of Fe, Al and Ti released (and re-precipitated in new solid phases) was actually greater in the biotic systems. This is likely because the Fe(II) leached from the basalt was immediately oxidized by A. ferrooxidans, and precipitated into Fe(III) phases which causes a change in the equilibrium of the system, i.e. Le Chatelier's principle. Iron(II) in the abiotic experiment was allowed to build up in solution which led to a decrease in its overall release rate. For example, the percentage of Fe, Al and Ti leached (dissolved + reactive mineral precipitates) from the Mars simulant in the A. ferrooxidans experimental system was 34, 41 and 13% of the total Fe, Al and Ti in the basalt, respectively, while the abiotic experimental system released totals of only 11, 25 and 2%. There was, however, no measurable difference in the amounts of Fe and Ti released from ilmenite in the

  19. The isolation, identification and characteristics of a sulfur-oxidizing bacterium,Acidithiobacillus thiooxidans%一株嗜酸硫氧化细菌的分离鉴定及生长特性

    Institute of Scientific and Technical Information of China (English)

    王锐; 邱丽娜; 关景洋; 佟莹; 罗佳; 弓爱君; 闫海

    2010-01-01

    从北京清河污泥中分离出一株硫氧化细菌,命名为QH-1,并对该菌株进行了分离鉴定,同时,初步研究了该菌株对几种重金属离子的耐受能力.结果发现,该菌株为革兰氏阴性,短杆状,需氧型,可从氧化还原态的硫元素中获得能量.QH-1菌株具有很好的产酸和耐酸能力,培养24h后pH即可下降到2.0,1周内可达到1.0以下,对数生长期为15d.进入稳定期时pH降为0.6.QH-1菌株的16S rRNA基因测序与分析表明,该菌株与Acidithiobacillus thiooxidans strain AAU具有99%以上的16S rRNA基因序列相似性.通过构建该菌株在相关种属中的系统发育树,并结合形态与生理生化特征分析,将QH-1菌株鉴定为氧化硫嗜酸硫杆菌(Acidithiobacillus thiooxidans).QH-1菌株对Zn~(2+)和Cu~(2+)有一定的耐受性,对Mo~(2+)的耐受性较差.

  20. Microbial aspects of acid mine drainage and its bioremediation

    Institute of Scientific and Technical Information of China (English)

    K.A.NATARAJAN

    2008-01-01

    The role of chemolithotrophs such as Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans which were isolated from some abandoned mines and processed waste tailings in the generation of acid mine drainage and toxic metal dissolution was discussed.Mechanisms of acid formation and dissolution of copper,zinc,iron and arsenic from copper,lead-zinc and arsenopyrite-bearing sulfide ores and tailings were established in the presence of Acidithiobacillus group of bacteria.Sulphate Reducing Bacteria(SRB) isolated from the above mine sites could be used to precipitate dissolved metals such as copper,zinc,iron and arsenic.Arsenic bioremediation was demonstrated through the use of native microorganisms such Thiomonas spp.which could oxidize arsenite to arsenate.Bioremoval of arsenic through the use of jarosite precipitates generated by Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans was also found to be very effective.Biotechnological processes hold great promise in the remediation of acid mine drainage and efficient removal of toxic metal ions such as copper,zinc and arsenic.

  1. GenBank blastx search result: AK242773 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK242773 J090053L15 AB206839.1 AB206839 Acidithiobacillus ferrooxidans atpI, atpB, atpE, atpF, atpH, atp...A, atpG, atpD, atpC genes for hypothetical protein, a subunit of F1F0-ATP synthase, c s

  2. GenBank blastx search result: AK105071 [KOME

    Lifescience Database Archive (English)

    Full Text Available AK105071 001-045-C11 AB206839.1 Acidithiobacillus ferrooxidans atpI, atpB, atpE, atpF, atpH, atpA, atpG, atp...D, atpC genes for hypothetical protein, a subunit of F1F0-ATP synthase, c subunit o

  3. Generation of acid mine drainage around the Karaerik copper mine (Espiye, Giresun, NE Turkey): implications from the bacterial population in the Acısu effluent.

    Science.gov (United States)

    Sağlam, Emine Selva; Akçay, Miğraç; Çolak, Dilşat Nigar; İnan Bektaş, Kadriye; Beldüz, Ali Osman

    2016-09-01

    The Karaerik Cu mine is a worked-out deposit with large volumes of tailings and slags which were left around the mine site without any protection. Natural feeding of these material and run-off water from the mineralised zones into the Acısu effluent causes a serious environmental degradation and creation of acid mine drainage (AMD) along its entire length. This research aims at modelling the formation of AMD with a specific attempt on the characterisation of the bacterial population in association with AMD and their role on its occurrence. Based on 16SrRNA analyses of the clones obtained from a composite water sample, the bacterial community was determined to consist of Acidithiobacillus ferrivorans, Ferrovum myxofaciens, Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans as iron-oxidising bacteria, Acidocella facilis, Acidocella aluminiidurans, Acidiphilium cryptum and Acidiphilium multivorum as iron-reducing bacteria, and Acidithiobacillus ferrivorans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidiphilium cryptum as sulphur-oxidising bacteria. This association of bacteria with varying roles was interpreted as evidence of a concomitant occurrence of sulphur and iron cycles during the generation of AMD along the Acısu effluent draining the Karaerik mine. PMID:27338270

  4. 极端嗜酸硫杆菌高效筛选、高密度发酵及保藏方法的研究%The study on efficient screening, high-density fermentation and preservation methods for extremely Acidithiobacillus sp.

    Institute of Scientific and Technical Information of China (English)

    冯守帅; 杨海麟; 高凯; 陈金才; 计云鹤; 王武

    2014-01-01

    [目的]针对嗜酸硫杆菌极端特殊的生化特性,分别建立双层平板培养高效筛选方法和补料分批高密度发酵策略,并优选最佳保藏方法,以强化对该类菌种资源的利用和储备效率.[方法]分别采用以异养型微生物Sacchromyces ellipsoideu和Rhodotorula sp.为底层培养物的双层平板培养嗜酸硫杆菌,并结合透射电子显微镜技术(TEM)考察细胞形态差异.结合硫化矿培养基设计及单质硫补料培养策略,延长Acidithiobacillus thiooxidans对数期,提高比生长速率.分析不同保藏方法对嗜酸硫杆菌细胞存活率的影响.[结果]采用异养微生物——Rhodotorula sp.作为底层培养物的双层平板培养法在缩减1/3检出周期的同时将Acidithiobacillus ferrooxidans和Acidithiobacillus thiooxidans的检出率提高了3倍左右.TEM结果表明双层培养中细胞形态更为规则.采用基于Starkey-硫化矿培养基的补料分批发酵策略提高了Acidithiobacillus thiooxidans平均比生长速率,硫对生物量转化率和生产强度分别比分批培养提高31.1%和187.9%.4℃低温保藏方式更适于嗜酸硫杆菌的保藏,有效保藏期1-3月.[结论]Rhodotorula sp.为辅助培养物的双层平板培养法可有效提高嗜酸硫杆菌的筛选效率.设计的Starkey-硫化矿培养基结合补料分批培养策略可实现Acidithiobacillus thiooxidans高密度培养.简单高效的4℃低温保藏方式更适合于嗜酸硫杆菌的中短期保藏.

  5. Bacterial consortium for copper extraction from sulphide ore consisting mainly of chalcopyrite

    Science.gov (United States)

    Romo, E.; Weinacker, D.F.; Zepeda, A.B.; Figueroa, C.A.; Chavez-Crooker, P.; Farias, J.G.

    2013-01-01

    The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum) were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control. PMID:24294251

  6. Bacterial consortium for copper extraction from sulphide ore consisting mainly of chalcopyrite

    Directory of Open Access Journals (Sweden)

    E. Romo

    2013-01-01

    Full Text Available The mining industry is looking forward for bacterial consortia for economic extraction of copper from low-grade ores. The main objective was to determine an optimal bacterial consortium from several bacterial strains to obtain copper from the leach of chalcopyrite. The major native bacterial species involved in the bioleaching of sulphide ore (Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans and Leptospirillum ferriphilum were isolated and the assays were performed with individual bacteria and in combination with At. thiooxidans. In conclusion, it was found that the consortium integrated by At. ferrooxidans and At. thiooxidans removed 70% of copper in 35 days from the selected ore, showing significant differences with the other consortia, which removed only 35% of copper in 35 days. To validate the assays was done an escalation in columns, where the bacterial consortium achieved a higher percentage of copper extraction regarding to control.

  7. Insights to the effects of free cells on community structure of attached cells and chalcopyrite bioleaching during different stages.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2016-01-01

    The effects of free cells on community structure of attached cells and chalcopyrite bioleaching by Acidithiobacillus sp. during different stages were investigated. The attached cells of Acidithiobacillus thiooxidans owned the community advantage from 14thd to the end of bioprocess in the normal system. The community structure of attached cells was greatly influenced in the free cells-deficient systems. Compared to A. thiooxidans, the attached cells community of Acidithiobacillus ferrooxidans had a higher dependence on its free cells. Meanwhile, the analysis of key biochemical parameters revealed that the effects of free cells on chalcopyrite bioleaching in different stages were diverse, ranging from 32.8% to 64.3%. The bioleaching contribution of free cells of A. ferrooxidans in the stationary stage (8-14thd) was higher than those of A. thiooxidans, while the situation was gradually reversed in the jarosite passivation inhibited stage (26-40thd). These results may be useful in guiding chalcopyrite bioleaching.

  8. Microbial community succession mechanism coupling with adaptive evolution of adsorption performance in chalcopyrite bioleaching.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    The community succession mechanism of Acidithiobacillus sp. coupling with adaptive evolution of adsorption performance were systematically investigated. Specifically, the μmax of attached and free cells was increased and peak time was moved ahead, indicating both cell growth of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was promoted. In the mixed strains system, the domination courses of A. thiooxidans was dramatically shortened from 22th day to 15th day, although community structure finally approached to the normal system. Compared to A. ferrooxidans, more positive effects of adaptive evolution on cell growth of A. thiooxidans were shown in either single or mixed strains system. Moreover, higher concentrations of sulfate and ferric ions indicated that both sulfur and iron metabolism was enhanced, especially of A. thiooxidans. Consistently, copper ion production was improved from 65.5 to 88.5 mg/L. This new adaptive evolution and community succession mechanism may be useful for guiding similar bioleaching processes.

  9. Microbial community succession mechanism coupling with adaptive evolution of adsorption performance in chalcopyrite bioleaching.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2015-09-01

    The community succession mechanism of Acidithiobacillus sp. coupling with adaptive evolution of adsorption performance were systematically investigated. Specifically, the μmax of attached and free cells was increased and peak time was moved ahead, indicating both cell growth of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was promoted. In the mixed strains system, the domination courses of A. thiooxidans was dramatically shortened from 22th day to 15th day, although community structure finally approached to the normal system. Compared to A. ferrooxidans, more positive effects of adaptive evolution on cell growth of A. thiooxidans were shown in either single or mixed strains system. Moreover, higher concentrations of sulfate and ferric ions indicated that both sulfur and iron metabolism was enhanced, especially of A. thiooxidans. Consistently, copper ion production was improved from 65.5 to 88.5 mg/L. This new adaptive evolution and community succession mechanism may be useful for guiding similar bioleaching processes. PMID:25978855

  10. Insights to the effects of free cells on community structure of attached cells and chalcopyrite bioleaching during different stages.

    Science.gov (United States)

    Feng, Shoushuai; Yang, Hailin; Wang, Wu

    2016-01-01

    The effects of free cells on community structure of attached cells and chalcopyrite bioleaching by Acidithiobacillus sp. during different stages were investigated. The attached cells of Acidithiobacillus thiooxidans owned the community advantage from 14thd to the end of bioprocess in the normal system. The community structure of attached cells was greatly influenced in the free cells-deficient systems. Compared to A. thiooxidans, the attached cells community of Acidithiobacillus ferrooxidans had a higher dependence on its free cells. Meanwhile, the analysis of key biochemical parameters revealed that the effects of free cells on chalcopyrite bioleaching in different stages were diverse, ranging from 32.8% to 64.3%. The bioleaching contribution of free cells of A. ferrooxidans in the stationary stage (8-14thd) was higher than those of A. thiooxidans, while the situation was gradually reversed in the jarosite passivation inhibited stage (26-40thd). These results may be useful in guiding chalcopyrite bioleaching. PMID:26492170

  11. Structure/function relationship of the rusticyanin among thiobacillus ferroxidans: from the fermenter to the crystal; Relations structure/fonction de la rusticyanine chez thiobacillus ferrooxidans: du fermenteur au cristal

    Energy Technology Data Exchange (ETDEWEB)

    Nunzi, F.

    1996-09-23

    The commercial extraction of copper and uranium from ores by microbial leaching turns to account the iron oxidation capacity of Thiobacillus ferroxidans. The iron oxidation involves an electron transport chain localized in the peri-plasmic space of the cell. The aim of our work is to study the structure-function relationships of rusticyanin, the most important component of this respiratory chain. Rusticyanin is a blue copper protein and has been characterized from a new strain of Thilbacillus ferrooxidans. A preliminary electrochemical study has been made with a new modified-gold electrode and we have examined, in particular, the pH dependence of the high redox potential of rusticyanin. Its amino acid sequence has been determined and a comparison with two other rusticyanin sequences, isolated from different strains, shows a high degree of homology. A structural alignment with six other blue copper proteins allows to propose four residues as copper ligands, His 84, Cys 138, His 143 and Met 148. The supposed factors responsible for the high redox potential of rusticyanin are discussed. (author)

  12. Reconstitution of supramolecular organization involved in energy metabolism at electrochemical interfaces for biosensing and bioenergy production.

    Science.gov (United States)

    Roger, M; de Poulpiquet, A; Ciaccafava, A; Ilbert, M; Guiral, M; Giudici-Orticoni, M T; Lojou, E

    2014-02-01

    How the redox proteins and enzymes involved in bioenergetic pathways are organized is a relevant fundamental question, but our understanding of this is still incomplete. This review provides a critical examination of the electrochemical tools developed in recent years to obtain knowledge of the intramolecular and intermolecular electron transfer processes involved in metabolic pathways. Furthermore, better understanding of the electron transfer processes associated with energy metabolism will provide the basis for the rational design of biotechnological devices such as electrochemical biosensors, enzymatic and microbial fuel cells, and hydrogen production factories. Starting from the redox complexes involved in two relevant bacterial chains, i.e., from the hyperthermophile Aquifex aeolicus and the acidophile Acidithiobacillus ferrooxidans, examination of protein-protein interactions using electrochemistry is first reviewed, with a focus on the orientation of a protein on an electrochemical interface mimic of a physiological interaction between two partners. Special attention is paid to current research in the electrochemistry of essential membrane proteins, which is one mandatory step toward the understanding of energy metabolic pathways. The complex and challenging architectures built to reconstitute a membrane-like environment at an electrode are especially considered. The role played by electrochemistry in the attempt to consider full bacterial metabolism is finally emphasized through the study of whole cells immobilized at electrodes as suspensions or biofilms. Before the performances of biotechnological devices can be further improved to make them really attractive, questions remain to be addressed in this particular field of research. We discuss the bottlenecks that need to be overcome in the future. PMID:24292430

  13. 两种硫杆菌对河涌底泥重金属的生物沥滤%Bioleaching of heavy metals from brooklet sediment by Thiobacillus ferrooxidans and Thiobacillus thiooxidans

    Institute of Scientific and Technical Information of China (English)

    张再利; 贾晓珊

    2008-01-01

    自矿山酸性废水中分离纯化得到氧化亚铁硫杆菌(Thiobacillus ferrooxidans,T.f)与氧化硫硫杆菌(Thiobacillus thiooxidans,T.t),利用这2种硫杆菌对广州郭村河涌底泥中Cd、Cr、Pb、Ni、Cu和Zn 6种重金属进行序批式生物沥滤试验.结果表明,T.f菌对重金属的浸出能力高于T.t菌.对Cd、Cr、Ni、Cu和Zn的浸出率Y.f菌最高可达60%、45%、70%、90%和75%,T.t菌则分别为45%、34%、50%、65%和55%.二者对Pb的去除率相当,均在25%左右.向T.f菌分别提供S粉与Fe2+,2种底物对Cd、Ni、Cu和Zn的浸出效果无明显影响,而对Cr和Pb的浸出,投加S粉的浸出效果更好.同时向T.f菌投加S粉与Fe2+2种底物,其浸出效果反而下降.可能是T.f菌代谢生成的SO42与Fe3+易生成黄铁矾等沉淀物质,与溶出的重金属发生共沉淀,从而降低其浸出效果.

  14. The protein ORF80 from the acidophilic and thermophilic archaeon Sulfolobus islandicus binds highly site-specifically to double-stranded DNA and represents a novel type of basic leucine zipper protein

    Science.gov (United States)

    Lipps, Georg; Ibanez, Pablo; Stroessenreuther, Thomas; Hekimian, Katya; Krauss, Gerhard

    2001-01-01

    The cryptic high copy number plasmid pRN1 from the thermophilic and acidophilic crenarchaeote Sulfolobus islandicus shares three conserved open reading frames with other S.islandicus plasmids. One of the open reading frames, namely orf80, encodes a 9.5 kDa protein that has no homology to any characterised protein. Recombinant ORF80 purified from Escherichia coli binds to double-stranded DNA in a sequence-specific manner as suggested by EMSA experiments and DNase I footprints. Two highly symmetrical binding sites separated by ∼60 bp were found upstream of the orf80 gene. Both binding sites contain two TTAA motifs as well as other conserved bases. Fluorescence measurements show that short duplex DNAs derived from a single binding site sequence are bound with submicromolar affinity and moderate cooperativity by ORF80. On DNA fragments carrying both binding sites, a rather large protein–DNA complex is formed in a highly cooperative manner. ORF80 contains an N-terminal leucine zipper motif and a highly basic domain at its C-terminus. Compared to all known basic leucine zipper proteins the order of the domains is reversed in ORF80. ORF80 may therefore constitute a new subclass of basic leucine zipper DNA-binding proteins. PMID:11812827

  15. Incorporating Geochemical And Microbial Kinetics In Reactive Transport Models For Generation Of Acid Rock Drainage

    Science.gov (United States)

    Andre, B. J.; Rajaram, H.; Silverstein, J.

    2010-12-01

    Acid mine drainage, AMD, results from the oxidation of metal sulfide minerals (e.g. pyrite), producing ferrous iron and sulfuric acid. Acidophilic autotrophic bacteria such as Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans obtain energy by oxidizing ferrous iron back to ferric iron, using oxygen as the electron acceptor. Most existing models of AMD do not account for microbial kinetics or iron geochemistry rigorously. Instead they assume that oxygen limitation controls pyrite oxidation and thus focus on oxygen transport. These models have been successfully used for simulating conditions where oxygen availability is a limiting factor (e.g. source prevention by capping), but have not been shown to effectively model acid generation and effluent chemistry under a wider range of conditions. The key reactions, oxidation of pyrite and oxidation of ferrous iron, are both slow kinetic processes. Despite being extensively studied for the last thirty years, there is still not a consensus in the literature about the basic mechanisms, limiting factors or rate expressions for microbially enhanced oxidation of metal sulfides. An indirect leaching mechanism (chemical oxidation of pyrite by ferric iron to produce ferrous iron, with regeneration of ferric iron by microbial oxidation of ferrous iron) is used as the foundation of a conceptual model for microbially enhanced oxidation of pyrite. Using literature data, a rate expression for microbial consumption of ferrous iron is developed that accounts for oxygen, ferrous iron and pH limitation. Reaction rate expressions for oxidation of pyrite and chemical oxidation of ferrous iron are selected from the literature. A completely mixed stirred tank reactor (CSTR) model is implemented coupling the kinetic rate expressions, speciation calculations and flow. The model simulates generation of AMD and effluent chemistry that qualitatively agrees with column reactor and single rock experiments. A one dimensional reaction

  16. 氧化硫硫杆菌TS6的生长条件及其对重金属耐受性研究%Optimum growth condition of Acidithiobacillus thiooxidans TS6 and its resistance to heavy metals

    Institute of Scientific and Technical Information of China (English)

    黄峰源; 王世梅; 周立祥

    2006-01-01

    采用纯培养的方法研究了温度和介质起始pH以及重金属对嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans TS6)菌株生长与活性的影响.研究表明,菌株TS6的最适生长温度为28℃,最适起始生长pH范围为2.0~6.0.在上述条件下,TS6旺盛生长,表现出氧化硫能力最强.通过检测TS6对几种重金属(Cr3+、Cu2+、Zn2+、Ni2+)的耐受性,结果发现TS6对上述重金属均有较强的耐受性,至少可耐受Cr3+、Cu2+、Zn2+、Ni2+的浓度分别达1500、400、1000和250mg·L-1.在相同的浓度下,不同重金属对TS6生长产酸作用的影响由小到大依次为Cr3+、Zn2+、Cu2+、Ni2+.随着TS6菌株驯化时间的延长,它们对重金属的耐受性可望得到进一步的增强,完全满足对各种污水污泥进行生物淋滤处理的条件.

  17. Estudo da dissolução oxidativa microbiológica de uma complexa amostra mineral contendo pirita (FeS2, Pirrotita (Fe1-xS e Molibdenita (MoS2 Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS2, pyrrotite (Fe1-xS and molybdenite (MoS2

    Directory of Open Access Journals (Sweden)

    Wilmo E. Francisco Jr

    2007-10-01

    Full Text Available This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferrooxidans. This study was performed by respirometric essays and bioleaching in shake flasks. Respirometric essays yielded the kinetics of mineral oxidation. The findings showed that sulfide oxidation followed classical Michaelis-Menten kinetics. Bioleaching in shake flasks allowed evaluation of chemical and mineralogical changes resulting from sulfide oxidation. The results demonstrated that pyrrotite and pyrite were completely oxidized in A. ferrooxidans cultures whereas molybdenite was not consumed. These data indicated that molybdenite was the most recalcitrant sulfide in the sample.

  18. Repetitive sequence based polymerase chain reaction to differentiate close bacteria strains in acidic sites

    Institute of Scientific and Technical Information of China (English)

    XIE Ming; YIN Hua-qun; LIU Yi; LIU Jie; LIU Xue-duan

    2008-01-01

    To study the diversity of bacteria strains newly isolated from several acid mine drainage(AMD) sites in China,repetitive sequence based polymerase chain reaction (rep-PCR),a well established technology for diversity analysis of closely related bacteria strains,was conducted on 30 strains of bacteria Leptospirillum ferriphilium,8 strains of bacteria Acidithiobacillus ferrooxidans,as well as the Acidithiobacillus ferrooxidans type strain ATCC (American Type Culture Collection) 23270.The results showed that,using ERIC and BOX primer sets,rep-PCR produced highly discriminatory banding patterns.Phylogenetic analysis based on ERIC-PCR banding types was made and the results indicated that rep-PCR could be used as a rapid and highly discriminatory screening technique in studying bacterial diversity,especially in differentiating bacteria within one species in AMD.

  19. Cross-Comparison of Leaching Strains Isolated from Two Different Regions: Chambishi and Dexing Copper Mines

    Directory of Open Access Journals (Sweden)

    Baba Ngom

    2014-01-01

    Full Text Available A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa and Dexing copper mine (China, Asia, was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.

  20. Effect of Cu2+ ions on bioleaching of marmatite

    Institute of Scientific and Technical Information of China (English)

    CHEN Song; QIN Wen-qing; QIU Guan-zhou

    2008-01-01

    The effect of Cu2+ ions on bioleaching of marmatite was investigated through shake leaching experiments.The bacteria inoculated are a mixed culture of Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans and Lepthospirillum ferrooxidans.The results show that zinc is selectively leached,and the addition of appropriate content of Cu2+ ions has positive effect on the bioleaching of marmatite.SEM and EDX analyses of the leaching residue reveal that a product layer composed of iron sulfide,elemental sulfur and jarosite forms on the mineral surface.The biooxidation of elemental sulfur is catalyzed by the Cu2+ ions,which eliminate the barrier to bioleaching of marmatite and keep low pH value.With the addition of 0.5 g/L Cu2+ ions,the maximum zinc extraction rate reaches 73% after 23 d at the temperature of 30 ℃ with the pulp density of 10%,while that of iron is only about 10%.

  1. Influence Of Used Bacterial Culture On Zinc And Aluminium Bioleaching From Printed Circuit Boards

    Directory of Open Access Journals (Sweden)

    Mrazikova Anna

    2015-06-01

    Full Text Available Bioleaching processes were used to solubilize metals (Cu, Ni, Zn and Al from printed circuit boards (PCBs. In this study, a PCBs-adapted pure culture of Acidithiobacillus ferrooxidans, pure culture of Acidithiobacillus thiooxidans and PCBs-adapted mixed culture of A. ferrooxidans and A. thiooxidans were used for recovery of the metals. The study showed that the mixed bacterial culture has the greatest potential to dissolve metals. The maximum metal bioleaching efficiencies were found to be 100, 92, 89 and 20% of Cu, Ni, Zn and Al, respectively. The mixed culture revealed higher bacterial stability. The main factor responsible for high metal recovery was the ability of the mixed culture to maintain the low pH during the whole process. The pure culture of A. thiooxidans had no significant effect on metal bioleaching from PCBs.

  2. Cross-comparison of leaching strains isolated from two different regions: Chambishi and Dexing copper mines.

    Science.gov (United States)

    Ngom, Baba; Liang, Yili; Liu, Xueduan

    2014-01-01

    A cross-comparison of six strains isolated from two different regions, Chambishi copper mine (Zambia, Africa) and Dexing copper mine (China, Asia), was conducted to study the leaching efficiency of low grade copper ores. The strains belong to the three major species often encountered in bioleaching of copper sulfide ores under mesophilic conditions: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirillum ferriphilum. Prior to their study in bioleaching, the different strains were characterized and compared at physiological level. The results revealed that, except for copper tolerance, strains within species presented almost similar physiological traits with slight advantages of Chambishi strains. However, in terms of leaching efficiency, native strains always achieved higher cell density and greater iron and copper extraction rates than the foreign microorganisms. In addition, microbial community analysis revealed that the different mixed cultures shared almost the same profile, and At. ferrooxidans strains always outcompeted the other strains.

  3. Estudo da dissolução oxidativa microbiológica de uma complexa amostra mineral contendo pirita (FeS2), Pirrotita (Fe1-xS) e Molibdenita (MoS2) Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS2), pyrrotite (Fe1-xS) and molybdenite (MoS2)

    OpenAIRE

    Wilmo E. Francisco Jr; Denise Bevilaqua; Oswaldo Garcia Jr

    2007-01-01

    This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferrooxidans. This study was performed by respirometric essays and bioleaching in shake flasks. Respirometric essays yielded the kinetics of mineral oxidation. The findings showed that sulfide oxidation followed classical Michaelis-Menten kinetics. Bioleaching in shake flasks allowed evaluation of chemical and mineralogical changes resulting from sulfide oxidation. ...

  4. Influence of physical and chemical factors on biological leaching process of copper from printed circuit boards

    OpenAIRE

    Willner, J

    2013-01-01

    The article presents the results of the research regarding the biological leaching of this metal from electronic wastes components in the form of printed circuit boards. The purpose of the study was to evaluate the influence of some physical and chemical factors (e.g. pH, oxidation-reduction potential) on bioleaching process and efficiency of copper transfer from solid phase into solution. Bioleaching experiments were carried out with pure cultures of Acidithiobacillus ferrooxidans. The obtai...

  5. Acidophilic Methanotrophic Communities from Sphagnum Peat Bogs

    OpenAIRE

    Dedysh, Svetlana N.; Nicolai S. Panikov; Tiedje, James M.

    1998-01-01

    Highly enriched methanotrophic communities (>25 serial transfers) were obtained from acidic ombrotrophic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (20°C), and pH values of 3 to 6. Enriched communities contained a mixture of rod-shaped bacteria arran...

  6. Comparative genomic analysis of carbon and nitrogen assimilation mechanisms in three indigenous bioleaching bacteria: predictions and validations

    Directory of Open Access Journals (Sweden)

    Ehrenfeld Nicole

    2008-12-01

    Full Text Available Abstract Background Carbon and nitrogen fixation are essential pathways for autotrophic bacteria living in extreme environments. These bacteria can use carbon dioxide directly from the air as their sole carbon source and can use different sources of nitrogen such as ammonia, nitrate, nitrite, or even nitrogen from the air. To have a better understanding of how these processes occur and to determine how we can make them more efficient, a comparative genomic analysis of three bioleaching bacteria isolated from mine sites in Chile was performed. This study demonstrated that there are important differences in the carbon dioxide and nitrogen fixation mechanisms among bioleaching bacteria that coexist in mining environments. Results In this study, we probed that both Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans incorporate CO2 via the Calvin-Benson-Bassham cycle; however, the former bacterium has two copies of the Rubisco type I gene whereas the latter has only one copy. In contrast, we demonstrated that Leptospirillum ferriphilum utilizes the reductive tricarboxylic acid cycle for carbon fixation. Although all the species analyzed in our study can incorporate ammonia by an ammonia transporter, we demonstrated that Acidithiobacillus thiooxidans could also assimilate nitrate and nitrite but only Acidithiobacillus ferrooxidans could fix nitrogen directly from the air. Conclusion The current study utilized genomic and molecular evidence to verify carbon and nitrogen fixation mechanisms for three bioleaching bacteria and provided an analysis of the potential regulatory pathways and functional networks that control carbon and nitrogen fixation in these microorganisms.

  7. Influence of organics and silica on Fe(II) oxidation rates and cell-mineral aggregate formation by the green-sulfur Fe(II)-oxidizing bacterium Chlorobium ferrooxidans KoFox - Implications for Fe(II) oxidation in ancient oceans

    Science.gov (United States)

    Gauger, Tina; Byrne, James M.; Konhauser, Kurt O.; Obst, Martin; Crowe, Sean; Kappler, Andreas

    2016-06-01

    Most studies on microbial phototrophic Fe(II) oxidation (photoferrotrophy) have focused on purple bacteria, but recent evidence points to the importance of green-sulfur bacteria (GSB). Their recovery from modern ferruginous environments suggests that these photoferrotrophs can offer insights into how their ancient counterparts grew in Archean oceans at the time of banded iron formation (BIF) deposition. It is unknown, however, how Fe(II) oxidation rates, cell-mineral aggregate formation, and Fe-mineralogy vary under environmental conditions reminiscent of the geological past. To address this, we studied the Fe(II)-oxidizer Chlorobium ferrooxidans KoFox, a GSB living in co-culture with the heterotrophic Geospirillum strain KoFum. We investigated the mineralogy of Fe(III) metabolic products at low/high light intensity, and in the presence of dissolved silica and/or fumarate. Silica and fumarate influenced the crystallinity and particle size of the produced Fe(III) minerals. The presence of silica also enhanced Fe(II) oxidation rates, especially at high light intensities, potentially by lowering Fe(II)-toxicity to the cells. Electron microscopic imaging showed no encrustation of either KoFox or KoFum cells with Fe(III)-minerals, though weak associations were observed suggesting co-sedimentation of Fe(III) with at least some biomass via these aggregates, which could support diagenetic Fe(III)-reduction. Given that GSB are presumably one of the most ancient photosynthetic organisms, and pre-date cyanobacteria, our findings, on the one hand, strengthen arguments for photoferrotrophic activity as a likely mechanism for BIF deposition on a predominantly anoxic early Earth, but, on the other hand, also suggest that preservation of remnants of Fe(II)-oxidizing GSB as microfossils in the rock record is unlikely.

  8. Optimum condition in Cr3+ bioleaching of tannery sludge with Thiobacillus ferrooxidans LX5, Thiobacillus thiooxidans TS6 and Rhodotorula sp. R30%酵母菌与两种硫杆菌复合对污泥中三价铬的去除

    Institute of Scientific and Technical Information of China (English)

    王世梅; 周立祥; 黄峰源

    2006-01-01

    研究了氧化亚铁硫杆菌LX5(Thiobacillus ferrooxidans LX5)、氧化硫硫杆菌TS6(Thiobacillus thiooxidans TS6)和耐酸性酵母菌R30(Rhodotorula sp.R30)对重金属铬(Cr3+)的耐受性.结果表明,700mg/L的Cr3+对硫杆菌LX5、TS6的生长和氧化活性影响不大,但Cr3+浓度大于500mg/L时明显抑制酵母菌R30的生长.酵母菌R30与硫杆菌LX5和TS6复合能明显加速污泥淋滤的进程,最佳复合比为酵母菌R30接种量2.0%,硫杆菌LX5和TS6接种量10%.分别用含酵母菌R30数量为104个/mL和102个/mL的酸化污泥作接种物进行污泥淋滤,发现淋滤过程中pH值下降的速度没有明显差异,而在淋滤起始时添加2.0%的酵母菌R30,则淋滤反应提前36h结束.由此可见,在其它条件相同的污泥淋滤中,污泥中所含耐酸性酵母菌的数量是加快淋滤的关键.

  9. PROPERTIES OF NEW STRAINS CHEMOLITHOTROPHIC BACTERIA ISOLATED FROM INDUSTRIAL SUBSTRATES

    Directory of Open Access Journals (Sweden)

    I. A.

    2015-12-01

    Full Text Available The purpose of the research was determination of strains Acidithiobacillus ferrooxidans MFLv37 and Acidithiobacillus ferrooxidans MFLad27, isolated from aboriginal consortium of coal beneficiation dumps and fly ash from coal combustion, resistance to heavy metals, forming part of these waste, as well as adaption ability of the strains to new substrates. New strains increased resistance to heavy metal ions as compared to A. ferrooxidans standard and collection strains is found; minimal inhibitory concentrations of heavy and toxic metals are determined; a number of metals that have negative impact on growth of isolated cultures are identified. It is shown that the minimal metals concentrations, at which strains growth still happens, are several times higher than their concentrations in technogenic waste. It has been established that isolated strains differed in their ability to adapt, as well as in growth rate and substrates oxidation. This is due to the specific conditions of microbiocenoses formation in making and further storage of rock dumps and fly ash, whereof the appropriate strains are isolated. The investigations indicate the necessity in directional selection of strains that are resistant to the toxic compounds and are able to oxidize various mineral substrates, as well as in their adaptation to new substrates for the extraction of heavy metals.

  10. Astrobiological Significance of Microbial Extremophiles

    Science.gov (United States)

    Pikuta, Elena V.; Hoover, Richard B.

    2007-01-01

    The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath and the ice crusts of icy moons of Jupiter and Saturn. The importance of study alkaliphilic microorganisms for astrobiology was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology. The study of halophilic microorganisms was started from work with saline soils and lakes, and one of the record of good growth for Haloferax mediterranei was shown at 30 percent NaC1. Although alkali-tolerant nitrifying bacteria had previously been reported, the first described alkaliphilic microorganism was the bacterium Streptococcus faecalis. Halophilic and alkaliphilic forms are relevant to conditions that might be found in closed impact basins and craters on Mars filled with evaporite deposits. The first obligately acidophilic bacterium described was Acidithiobacillus ferrooxydans (formally Thiobacillus ferrooxidans). Later thermophilic lithotrophic acidophiles were found, and the hyperacidophilic moderately thermophilic species of the genus Picrophilus were found to grow at negative p

  11. Isolation and characterisation of mineral-oxidising "Acidibacillus" spp. from mine sites and geothermal environments in different global locations.

    Science.gov (United States)

    Holanda, Roseanne; Hedrich, Sabrina; Ňancucheo, Ivan; Oliveira, Guilherme; Grail, Barry M; Johnson, D Barrie

    2016-09-01

    Eight strains of acidophilic bacteria, isolated from mine-impacted and geothermal sites from different parts of the world, were shown to form a distinct clade (proposed genus "Acidibacillus") within the phylum Firmicutes, well separated from the acidophilic genera Sulfobacillus and Alicyclobacillus. Two of the strains (both isolated from sites in Yellowstone National Park, USA) were moderate thermophiles that oxidised both ferrous iron and elemental sulphur, while the other six were mesophiles that also oxidised ferrous iron, but not sulphur. All eight isolates reduced ferric iron to varying degrees. The two groups shared <95% similarity of their 16S rRNA genes and were therefore considered to be distinct species: "Acidibacillus sulfuroxidans" (moderately thermophilic isolates) and "Acidibacillus ferrooxidans" (mesophilic isolates). Both species were obligate heterotrophs; none of the eight strains grew in the absence of organic carbon. "Acidibacillus" spp. were generally highly tolerant of elevated concentrations of cationic transition metals, though "A. sulfuroxidans" strains were more sensitive to some (e.g. nickel and zinc) than those of "A. ferrooxidans". Initial annotation of the genomes of two strains of "A. ferrooxidans" revealed the presence of genes (cbbL) involved in the RuBisCO pathway for CO2 assimilation and iron oxidation (rus), though with relatively low sequence identities.

  12. 脱硫混合菌系构建及其脱除H2S的性能研究%Construction of Desulfurated Mixed Microbial Culture and Potential for H2S Removal

    Institute of Scientific and Technical Information of China (English)

    胡慧欣; 冯丹丹; 赵丹; 郝亚杰; 高超; 孙士男; 翟贺玲; 晏磊

    2014-01-01

    通过考察A cidithiobacillus ferrooxidans (A.ferrooxidans)和Acidithiobacillus thiooxidans (A.thiooxidans)的混合比例对Fe2+和S2O32-氧化及对H2S脱除的影响,来构建一组脱硫混合菌系.结果表明,当A.ferrooxidans和A.thiooxidans的最佳混合比例为1∶2时,Fe2+的氧化率达最大值99.6%,S2O32-氧化导致的pH降至最低1.03,而H2S的脱除率可达99.2%.因此,构建的脱硫混合菌系具有较好的应用潜力,可以用于H2S的脱除.

  13. Biodesulfurization of two Colombian coals with native microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Cardona, Isabel Cristina; Marquez, Marco Antonio [Applied Mineralogy Group, National University of Colombia, Medellin, 05001000 (Colombia)

    2009-09-15

    A biodesulfurization process was carried out for two coals from the southwest of Colombia using a consortium of native microorganisms Acidithiobacillus ferrooxidans-like and Acidithiobacillus thiooxidans-like. Characterization techniques as X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM/EDX) and chemical analysis were used in order to establish the mineralogy of the process. The sulfur content in coals varies from 2.6% to 5.7%, and pyrite is the main sulphide present in the inorganic phase. Other minerals in the substrates include kaolinite, calcite, dolomite and quartz. An 85-95% reduction of pyritic sulfur and 31-51% of total sulfur in a period of 30 days were achieved, for a particle size of - 74 {mu}m, 10% w/v pulp density and 30 C. (author)

  14. Biodesulfurization of vanadium-bearing titanomagnetite concentrates and pH control of bioleaching solution

    Science.gov (United States)

    Liu, Xiao-rong; Jiang, Sheng-cai; Liu, Yan-jun; Li, Hui; Wang, Hua-jun

    2013-10-01

    Vanadium-bearing titanomagnetite concentrates were desulfurized with Acidithiobacillus ferrooxidans ( A. ferrooxidans). The sulfur content of the concentrates was reduced from 0.69wt% to 0.14wt% after bioleaching for 15 d with a 10% pulp density at 30°C. Maintaining a stable pH value during biodesulfurization was critical because of high acid consumption, resulting from a combination of nonoxidative and oxidative dissolution of pyrrhotite in acid solution. It is discovered that the citric acid-disodium hydrogen phosphate buffer of pH 2.0 can control the solution pH value smoothly in the optimal range of 2.0-3.0 for A. ferrooxidans growth. Using the buffer in the volume fraction range of 5.0%-15.0% stimulates A. ferrooxidans growth and improves the biodesulfurization efficiency. Compared with the buffer-free control case, the maximum increase of biodesulfurization rate is 29.7% using a 10.0vol% buffer. Bioleaching provides an alternative process for desulfurization of vanadium-bearing titanomagnetite ores.

  15. Extracellular polymeric bacterial coverages as minimal surfaces

    CERN Document Server

    Saa, A; Saa, Alberto; Teschke, Omar

    2005-01-01

    Surfaces formed by extracellular polymeric substances enclosing individual and some small communities of {\\it Acidithiobacillus ferrooxidans} on plates of hydrophobic silicon and hydrophilic mica are analyzed by means of atomic force microscopy imaging. Accurate nanoscale descriptions of such coverage surfaces are obtained. The good agreement with the predictions of a rather simple but realistic theoretical model allows us to conclude that they correspond, indeed, to minimal area surfaces enclosing a given volume associated with the encased bacteria. This is, to the best of our knowledge, the first shape characterization of the coverage formed by these biomolecules, with possible applications to the study of biofilms.

  16. Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS2), pyrrotite (Fe1-xS) and molybdenite (MoS2)

    International Nuclear Information System (INIS)

    This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferroxidans. This study was performed by respirometric essays and bioleaching in shake flasks. Respirometric essays yielded the kinetics of mineral oxidation. The findings showed that sulfide oxidation followed classical Michaelis-Menten kinetics. Bioleaching in shake flasks allowed evaluation of chemical and mineralogical changes resulting from sulfide oxidation. The results demonstrated that pyrrotite and pyrite were completely oxidized in A. ferrooxidans cultures whereas molybdenite was not consumed. These data indicated that molybdenite was the most recalcitrant sulfide in the sample. (author)

  17. Escalado de un proceso de biooxidación de residuos de minería ricos en sulfuros usando reactores de tanque agitado

    OpenAIRE

    MUÑOZ ECHEVERRI, LAURA MARÍA

    2015-01-01

    Resumen: En este trabajo se presenta el escalado y evaluación del proceso de biooxidación de un residuo de minería aurífera (proveniente de la mina La Maruja, Marmato-Caldas), desde una escala de laboratorio hasta un nivel de planta piloto en reactores de tanque agitado. Para procurar el éxito del escalado, se realizó una caracterización mineralógica inicial del residuo y una adaptación del agente biológico, Acidithiobacillus ferrooxidans, al mineral. A escala de laboratorio se determinó el n...

  18. Microbiological oxidative dissolution of a complex mineral sample containing pyrite (FeS{sub 2}), pyrrotite (Fe{sub 1-x}S) and molybdenite (MoS{sub 2}); Estudo da dissolucao oxidativa microbiologica de uma complexa amostra mineral contendo pirita (FeS{sub 2}), Pirrotita (Fe{sub 1-x}S) e Molibdenita (MoS{sub 2})

    Energy Technology Data Exchange (ETDEWEB)

    Francisco Junior, Wilmo E.; Bevilaqua, Denise; Garcia Junior, Oswaldo [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Bioquimica e Tecnologia Quimica]. E-mail: wilmojr@bol.com.br

    2007-09-15

    This work aims to study the oxidation of a complex molybdenite mineral which contains pyrite and pyrrotite, by Acidithiobacillus ferroxidans. This study was performed by respirometric essays and bioleaching in shake flasks. Respirometric essays yielded the kinetics of mineral oxidation. The findings showed that sulfide oxidation followed classical Michaelis-Menten kinetics. Bioleaching in shake flasks allowed evaluation of chemical and mineralogical changes resulting from sulfide oxidation. The results demonstrated that pyrrotite and pyrite were completely oxidized in A. ferrooxidans cultures whereas molybdenite was not consumed. These data indicated that molybdenite was the most recalcitrant sulfide in the sample. (author)

  19. Influence of physical and chemical factors on biological leaching process of copper from printed circuit boards

    Directory of Open Access Journals (Sweden)

    J. Willner

    2013-04-01

    Full Text Available The article presents the results of the research regarding the biological leaching of this metal from electronic wastes components in the form of printed circuit boards. The purpose of the study was to evaluate the influence of some physical and chemical factors (e.g. pH, oxidation-reduction potential on bioleaching process and efficiency of copper transfer from solid phase into solution. Bioleaching experiments were carried out with pure cultures of Acidithiobacillus ferrooxidans. The obtained results were discussed.

  20. Electrochemistry of a semiconductor chalcopyrite concentrate leaching by Thiobacillus ferrooxidans

    Science.gov (United States)

    Torma, A. E.

    1991-05-01

    Using carbon-paste-CuFeS2 electrodes and a cyclic voltammetric technique, it was found that a large number of intermediate electrochemical oxidation reactions were associated with the dissolution of chalcopyrite in presence and absence of bacteria. The effects of concentrations of copper, ferrous and ferric ions, as well as of agitation on the peaks of cyclic voltammograms were measured. It was established that chalcopyrite oxidation was solid-state controlled as suggested by the data of chronopotentiometric and chronoamperometric measurements. The activation energy of solid state diffusion of chalcopyrite leaching was determined by the Sand's method to be delta E(sub a) = 20.5 kJ. The leaching mechanism is discussed in terms of solid-state properties (energy bonding) of the n-type semiconductor chalcopyrite and energy density states of redox systems of acidic bacterial leach media. A generalized model for the mechanism of chalcopyrite leaching in presence and absence of bacteria is presented.

  1. 净化SO2的生物膜填料塔中微生物类群分析%Analysis of microbial composition on biotrickling filter used to remove SO2

    Institute of Scientific and Technical Information of China (English)

    王泉; 孙珮石; 王树坤; 王洁; 王海玉; 毕晓伊; 周小兰; 王恒颖; 董琳茜

    2011-01-01

    In this work, a bacterial strain Acidithiobacillus thiooxidans IEL001 and an acidophilic fungal strain Bispora sp. IEL002 was isolated from the biotrickling filter used to remove suffur dioxide. Due to the extremely acidic environment and scarcity of organic nutrition in the biotrickling filters, only a low microbial diversity was observed. It was also found that Bispora sp. IEL002 could facilitate Acidithiobacillus thiooxidans IEL001 in oxidizing sulfur, but Bispora sp. IEL002 itself could not oxidize sulfur at all.%对净化废气中SO2的生物膜填料塔内的微生物进行了分离纯化并做鉴定,得到一株嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxdans IEL001)和一株分类地位非常接近链二孢属(Bispora sp.)的极端嗜酸真IEL002,生物膜填料塔内的极端酸性环境和有机营养的缺乏导致生物膜上的微生物种类较为单一,多样性程度不高.本研究还发现IEL002自身并不能氧化单质硫,但它能促进Acidithiobacillus thiooxdans IEL001对单质硫的氧化.

  2. Purification and characterization of 3-isopropylmalate dehydrogenase from Thiobacillus thiooxidans.

    Science.gov (United States)

    Kawaguchi, H; Inagaki, K; Matsunami, H; Nakayama, Y; Tano, T; Tanaka, H

    2000-01-01

    3-Isopropylmalate dehydrogenase was purified to homogeneity from the acidophilic autotroph Thiobacillus thiooxidans. The native enzyme was a dimer of molecular weight 40,000. The apparent K(m) values for 3-isopropylmalate and NAD+ were estimated to be 0.13 mM and 8.7 mM, respectively. The optimum pH for activity was 9.0 and the optimum temperature was 65 degrees C. The properties of the enzyme were similar to those of the Thiobacillus ferrooxidans enzyme, expect for substrate specificity. T. thiooxidans 3-isopropylmalate dehydrogenase could not utilize malate as a substrate.

  3. Biohydrometallurgical process to produce the coagulant ferric sulfate from the pyrite present in coal tailings

    Energy Technology Data Exchange (ETDEWEB)

    Colling, A.V.; Santos Menezes dos, J.C.S.; Silveira, P.S.; Schneider, I.A.H. [South Rio Grande Federal Univ., Porto Alegre (Brazil). Graduate Program in Mining, Metallurgical and Materials Technology Center

    2010-07-01

    This paper presented details of a biohydrometallurgical study conducted to characterize the production of a ferric sulfate coagulate from pyrite (FeS{sub 2}) contained in coal tailings. Leaching experiments were conducted with coal tailings samples from the Santa Catarina mining site in Brazil. The experiments were conducted for sterile and non-sterile samples, as well as samples inoculated with acidophilic bacteria and acidophilic bacteria with the addition of nutrients. Samples were collected weekly in order to analyze total iron, sulfate, and the amounts of Acidithiobacillus ferroxidans bacteria. An analysis of the samples showed that the pyrite oxidation, iron sulfate production, and quantities of bacteria were higher in the column inoculated with the bacteria and nutrient additions. The samples produced an aqueous solution that was rich in ferric sulfate. Water treatment tests demonstrated that the resulting coagulant is as efficient as conventionally-produced coagulants. 8 refs., 2 tab., 2 figs.

  4. 利用嗜酸混合菌从尼日利亚闪锌矿和方铅矿中生物浸出Zn(Ⅱ)和Pb(Ⅱ)%Bioleaching of Zn(Ⅱ) and Pb(Ⅱ) from Nigerian sphalerite and galena ores by mixed culture of acidophilic bacteria

    Institute of Scientific and Technical Information of China (English)

    AlafaraA.BABA; Folahan A.ADEKOLA; Rasaq F.ATATA; Risikat N.AHMED; Sandeep PANDA4

    2011-01-01

    Zn(Ⅱ) and Pb(Ⅱ) from Nigerian sphalerite and galena ores were bioleached by a mixed culture of acidophilic bacteria.The influences ofpH and ferric ion on the bioleaching rates of sphalerite and galena were examined.The result shows that pH 2.1 and 2.7 are favourable for the leaching of Zn(Ⅱ) and Pb(Ⅱ) from sphalerite and galena,respectively.It was observed that the use of agarose-simulated media caused cells to excrete exopolymers containing ferric ions which enhanced oxidation.The oxidation equilibrium for sphalerite and galena took 3 and 4 d,respectively.About 38.3% sphalerite and 34.2% galena were leached within 1 d and approximately 92.0% Zn(Ⅱ) and 89.0% Pb(Ⅱ) were recovered in 5 d,respectively.The unleached residual products were examined by X-ray diffraction for sphalerite,revealing the presence of elemental sulphur(S),zinc sulphate (ZnSO4) and few traces of calcium aluminate (Ca3Al2O6).The XRD pattern also indicates the presence of elemental sulphur (S),lead sulphate (PbSO4) and few traces ofitoite [Pb(S,Ge)(O,OH)4] and cobalt lead silicate [Pb8C0(Si2O7)3] in the urdeached galena ore.%利用嗜酸混合菌在尼日利亚闪锌矿和方铅矿中生物浸出Zn(Ⅱ)和Pb(Ⅱ),研究pH值和铁离子对闪锌矿和方铅矿浸出率的影响.结果表明:闪锌矿和方铅矿中Zn(Ⅱ)和Pb(Ⅱ)的氧化物在pH值分别为2.1和2.7时浸出效果最好.用模拟的琼脂糖培养基使细胞分泌出含铁离子的外聚合物,以此加强氧化.闪锌矿和方铅矿达到氧化平衡分别需要3和4d.闪锌矿和方铅矿在ld内的浸出率分别为38.3%和34.2%,5d内zn(Ⅱ)和Pb(Ⅱ)分别还原92.0%和89.0%.使用XRD研究两种矿物的未浸出的剩余产物,闪锌矿的组成为S、ZnSO4和少量Ca3Al2O6,方铅矿的组成为S、PbSO4和少量的Pb(S,Ge)(O,OH)4和Pb8Co(Si2O7)3.

  5. Familial relationships in hyperthermo- and acidophilic archaeal viruses

    DEFF Research Database (Denmark)

    Happonen, Lotta Johanna; Redder, Peter; Peng, Xu;

    2010-01-01

    Archaea often live in extreme, harsh environments such as acidic hot springs and hypersaline waters. To date, only two icosahedrally symmetric, membrane-containing archaeal viruses, SH1 and Sulfolobus turreted icosahedral virus (STIV), have been described in detail. We report the sequence and three...

  6. Bioleaching of hexavalent chromium from soils using acidithiobacillus thiooxidans

    OpenAIRE

    Fonseca, Bruna; Rodrigues, Joana; Queiroz, A.M.; Tavares, Teresa

    2010-01-01

    The continuous and growing degradation of the environment, due to several anthropogenic activities, is a main concern of the scientific community. Consequently, the development of low cost techniques to clean air, water and soils are under intense investigation. In this study, the focused problem is the soil contamination by hexavalent chromium, which is known for its several industrial applications - production of stainless steel, textile dyes, wood preservation and leather tanning - its hig...

  7. Sequential biological process for molybdenum extraction from hydrodesulphurization spent catalyst.

    Science.gov (United States)

    Vyas, Shruti; Ting, Yen-Peng

    2016-10-01

    Spent catalyst bioleaching with Acidithiobacillus ferrooxidans has been widely studied and low Mo leaching has often been reported. This work describes an enhanced extraction of Mo via a two stage sequential process for the bioleaching of hydrodesulphurization spent catalyst containing Molybdenum, Nickel and, Aluminium. In the first stage, two-step bioleaching was performed using Acidithiobacillus ferrooxidans, and achieved 89.4% Ni, 20.9% Mo and 12.7% Al extraction in 15 days. To increase Mo extraction, the bioleached catalyst was subjected to a second stage bioleaching using Escherichia coli, during which 99% of the remaining Mo was extracted in 25 days. This sequential bioleaching strategy selectively extracted Ni in the first stage and Mo in the second stage, and is a more environmentally friendly alternative to sequential chemical leaching with alkaline reagents for improved Mo extraction. Kinetic modelling to establish the rate determining step in both stages of bioleaching showed that in the first stage, Mo extraction was chemical reaction controlled whereas in the subsequent stage, product layer diffusion model provided the best fit. PMID:27351900

  8. Sequential biological process for molybdenum extraction from hydrodesulphurization spent catalyst.

    Science.gov (United States)

    Vyas, Shruti; Ting, Yen-Peng

    2016-10-01

    Spent catalyst bioleaching with Acidithiobacillus ferrooxidans has been widely studied and low Mo leaching has often been reported. This work describes an enhanced extraction of Mo via a two stage sequential process for the bioleaching of hydrodesulphurization spent catalyst containing Molybdenum, Nickel and, Aluminium. In the first stage, two-step bioleaching was performed using Acidithiobacillus ferrooxidans, and achieved 89.4% Ni, 20.9% Mo and 12.7% Al extraction in 15 days. To increase Mo extraction, the bioleached catalyst was subjected to a second stage bioleaching using Escherichia coli, during which 99% of the remaining Mo was extracted in 25 days. This sequential bioleaching strategy selectively extracted Ni in the first stage and Mo in the second stage, and is a more environmentally friendly alternative to sequential chemical leaching with alkaline reagents for improved Mo extraction. Kinetic modelling to establish the rate determining step in both stages of bioleaching showed that in the first stage, Mo extraction was chemical reaction controlled whereas in the subsequent stage, product layer diffusion model provided the best fit.

  9. Electrochemical studies on interplay of mineralogical variation and particle size on bioleaching low grade complex sulphide ores

    Institute of Scientific and Technical Information of China (English)

    P. A. OLUBAMBI; J. H. POTGIETER; S. NDLOVU; J. O. BORODE

    2009-01-01

    The interplay of mineralogical variation and mineral phase distribution within varying particle sizes on the dissolution behaviour of a low grade complex sulphide ore was investigated through bioleaching experiments and electrochemical technique. Investigations were carried out utilizing mineralogical data on the variations in mineral and phase distribution within particle sizes of<53 μm, 53-75 μm, 75-106 μm and 106-150 μm in mixed mesophilic cultures of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans. Electrochemical behaviour was studied using particulate electrodes from the four varying particle sizes and from massive electrodes prepared from the two major sulphide mineral rich phases (sphalerite-rich and galena-rich) and a complex mineralogical phase of the bulk ore. Bioleaching studies reveal the highest recoveries at a particle size of 75 μm, while electrochemical investigations reveal the highest dissolution at particle size of 106 μm. Electrochemical results show that sphalerite rich phase has the highest dissolution rate while galena-rich complex phase has the least. SEM studies confirm the highest bacterial attack at the sphalerite-rich phase. The discrepancies between the dissolutions within particle sizes obtained from bioleaching experiments and electrochemical studies are consistent with and attributed both to the physical and mineralogical influences. Electrochemical behaviour is influenced and controlled by galvanic interaction resulting from mineralogical variation, while bioleaching behaviour is influenced by mineralogical variation as well as physical effect of particle size.

  10. Bioleaching of multiple heavy metals from contaminated sediment by mesophile consortium.

    Science.gov (United States)

    Gan, Min; Zhou, Shuang; Li, Mingming; Zhu, Jianyu; Liu, Xinxing; Chai, Liyuan

    2015-04-01

    A defined mesophile consortium including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptospirilum ferriphilum was applied in bioleaching sediments contaminated with multiple heavy metals. Flask experiments showed that sulfur favored the acidification in the early stage while pyrite led to a great acidification potential in the later stage. An equal sulfur/pyrite ratio got the best acidification effect. Substrate utilization started with sulfur in the early stage, and then the pH decline and the community shift give rise to the utilization of pyrite. Solubilization efficiency of Zn, Cu, Mn, and Cd reached 96.1, 93.3, 92.13, and 87.65%, respectively. Bioleaching efficiency of other elements (As, Hg, Pb) was not more than 30%. Heavy metal solubilization was highly negatively correlated with pH variation. Logistic models were well fitted with the solubilization efficiency, which can be used to predict the bioleaching process. The dominant species in the early stage of bioleaching were A. ferrooxidans and A. thiooxidans, and the abundance of L. ferriphilum increased together with pyrite utilization and pH decline. PMID:25384695

  11. Bioleaching of uranium in batch stirred tank reactor: Process optimization using Box–Behnken design

    International Nuclear Information System (INIS)

    Highlights: ► High amount of uranium recovery achieved using Acidithiobacillus ferrooxidans. ► ANOVA shows individual variables and their squares are statistically significant. ► The model can accurately predict the behavior of uranium recovery. ► The model shows that pulp density has the greatest effect on uranium recovery. - Abstract: To design industrial reactors, it is important to identify and optimize the effective parameters of the process. Therefore, in this study, a three-level Box–Behnken factorial design was employed combining with a response surface methodology to optimize pulp density, agitation speed and aeration rate in uranium bioleaching in a stirred tank reactor using a pure native culture of Acidithiobacillus ferrooxidans. A mathematical model was then developed by applying the least squares method using the software Minitab Version 16.1.0. The second order model represents the uranium recovery as a function of pulp density, agitation speed and aeration rate. An analysis of variance was carried out to investigate the effects of individual variables and their combined interactive effects on uranium recovery. The results showed that the linear and quadratic terms of variables were statistically significant whilst the interaction terms were statistically insignificant. The model estimated that a maximum uranium extraction (99.99%) could be obtained when the pulp density, agitation speed and aeration rate were set at optimized values of 5.8% w/v, 510 rpm and 250 l/h, respectively. A confirmatory test at the optimum conditions resulted in a uranium recovery of 95%, indicating a marginal error of 4.99%. Furthermore, control tests were performed to demonstrate the effect of A. ferrooxidans in uranium bioleaching process and showed that the addition of this microorganism greatly increases the uranium recovery

  12. Microbial life in volcanic/geothermal areas: how soil geochemistry shapes microbial communities

    Science.gov (United States)

    Gagliano, Antonina Lisa; D'Alessandro, Walter; Franzetti, Andrea; Parello, Francesco; Tagliavia, Marcello; Quatrini, Paola

    2015-04-01

    Extreme environments, such as volcanic/geothermal areas, are sites of complex interactions between geosphere and biosphere. Although biotic and abiotic components are strictly related, they were separately studied for long time. Nowadays, innovative and interdisciplinary approaches are available to explore microbial life thriving in these environments. Pantelleria island (Italy) hosts a high enthalpy geothermal system characterized by high CH4 and low H2S fluxes. Two selected sites, FAV1 and FAV2, located at Favara Grande, the main exhalative area of the island, show similar physical conditions with a surface temperature close to 60° C and a soil gas composition enriched in CH4, H2 and CO2. FAV1 soil is characterized by harsher conditions (pH 3.4 and 12% of H2O content); conversely, milder conditions were recorded at site FAV2 (pH 5.8 and 4% of H2O content). High methanotrophic activity (59.2 nmol g-1 h-1) and wide diversity of methanotrophic bacteria were preliminary detected at FAV2, while no activity was detected at FAV1(1). Our aim was to investigate how the soil microbial communities of these two close geothermal sites at Pantelleria island respond to different geochemical conditions. Bacterial and Archaeal communities of the sites were investigated by MiSeq Illumina sequencing of hypervariable regions of the 16S rRNA gene. More than 33,000 reads were obtained for Bacteria and Archaea from soil samples of the two sites. At FAV1 99% of the bacterial sequences were assigned to four main phyla (Proteobacteria, Firmicutes, Actinobacteria and Chloroflexi). FAV2 sequences were distributed in the same phyla with the exception of Chloroflexi that was represented below 1%. Results indicate a high abundance of thermo-acidophilic chemolithotrophs in site FAV1 dominated by Acidithiobacillus ferrooxidans (25%), Nitrosococcus halophilus (10%), Alicyclobacillus spp. (7%) and the rare species Ktedonobacter racemifer (11%). The bacterial community at FAV2 soil is dominated by

  13. Investigation of the microbial diversity of an extremely acidic, metal-rich water body (Lake Robule, Bor, Serbia

    Directory of Open Access Journals (Sweden)

    Stanković Srđan

    2014-01-01

    Full Text Available An investigation of the microbial diversity of the extremely acidic, metal-rich Lake Robule was carried out using culture-dependant and culture-independent (T-RFLP methods, and the ability of indigenous bacteria from the lake water to leach copper from a mineral concentrate was tested. T-RFLP analysis revealed that the dominant bacteria in lake water samples were the obligate heterotroph Acidiphilium cryptum (~50% of total bacteria and the iron-oxidizing autotroph Leptospirillum ferrooxidans (~40% The iron/sulfur-oxidizing autotroph Acidithiobacillus ferrooxidans had been reported to be the most abundant bacteria in the lake in an earlier study by other authors, but it was not detected in the present study using T-RFLP. Although it was isolated on solid media and detected in enrichment (bioleaching cultures. The presence of the two bacterial species detected by T-RFLP (L. ferrooxidans and A. cryptum was also confirmed by cultivation on solid media. The presence and relative abundance of bacteria inhabiting Lake Robule was explained by the physiological characteristics of the bacteria and the physico-chemical characteristics of the lake water. [Projekat Ministarstva nauke Republike Srbije, br. 176016 i br.173048

  14. Influence of ferrous ions on extracellular polymeric substances content and sludge dewaterability during bioleaching.

    Science.gov (United States)

    Wong, Jonathan W C; Zhou, Jun; Kurade, Mayur B; Murugesan, Kumarasamy

    2015-03-01

    Pretreatment of activated sludge with sulfuric acid and bioleaching using Acidithiobacillus ferrooxidans along with addition of Fe(2+) on sludge dewaterability was investigated. The sludge dewatering efficiency in terms of capillary suction time (CST) and specific resistant to filtration (SRF) was increased with a decrease in sludge pH. A pH of 2.67 was found to be optimum for dewatering, at which 81% and 63% reduction of CST and SRF were achieved, respectively. The dewaterability of sludge was enhanced after the addition of Fe(2+) and A. ferrooxidans. Ideal concentration of Fe(2+) was 2 g/L for sludge dewaterability, which showed 96% and 88% reduction in CST and SRF, respectively. In the control sludge, maximum part of the biopolymeric macromolecules was contributing by the tightly bound extracellular polymeric substances (TB-EPS). At optimum Fe(2+) concentration, total EPS was reduced by 73%, enhancing sludge dewaterability. Bioleaching conducted by A. ferrooxidans could solubilized 88% Cu and 99% Zn within 120 h. PMID:25528607

  15. A Comparative Study of the Microbial Communities Between the Mineral Surface and the Bioleaching Solution Using the Microarray Method

    Institute of Scientific and Technical Information of China (English)

    GAO Jian; KANG Jian

    2011-01-01

    In order to explore the bioleaching mechanism and improve the bioleaching efficiency,the microbial community in the bioleaching solution was compared with that on the surface of minerals based on the microarray analysis.Meanwhile,the elements composition in the bioleaching solution was analyzed using the ICP-AES method.Results showed that there was a high concentration of S and Cu in the leaching solution which up to 2380 mg/L and 1378 mg/L,respectively,after continuously bioleaching of copper-ore concentrate for 30 days by a mixed culture associated with 12 species of bioleaching microorganisms.Based on the data of microarray,the total of cell number in the surface of minerals was far higher than that in the bioleaching solution.Furthermore,the dominant communities on the surface of minerals,such as Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans and Acidithiobacillus caldus,were similar to that in the bioleaching solution.However,the relative level of some bacteria,such as Sulfobacillus acidophilus and Sulfobacillus thermosulfidooxidans,showed great discrepancy with lower presence in the bioleaching solution with respect to the mineral surface.

  16. Interactions of the metal tolerant heterotrophic microorganisms and iron oxidizing autotrophic bacteria from sulphidic mine environment during bioleaching experiments.

    Science.gov (United States)

    Jeremic, Sanja; Beškoski, Vladimir P; Djokic, Lidija; Vasiljevic, Branka; Vrvić, Miroslav M; Avdalović, Jelena; Gojgić Cvijović, Gordana; Beškoski, Latinka Slavković; Nikodinovic-Runic, Jasmina

    2016-05-01

    Iron and sulfur oxidizing chemolithoautotrophic acidophilic bacteria, such as Acidithiobacillus species, hold the dominant role in mine environments characterized by low pH values and high concentrations of reduced sulfur and iron compounds, such as ores, rocks and acid drainage waters from mines. On the other hand, heterotrophic microorganisms, especially their biofilms, from these specific niches are receiving increased attention, but their potential eco-physiological roles have not been fully understood. Biofilms are considered a threat to human health, but biofilms also have beneficial properties as they are deployed in waste recycling and bioremediation systems. We have analyzed interactions of the metal tolerant heterotrophic microorganisms in biofilms with iron oxidizing autotrophic bacteria both from the sulphidic mine environment (copper mine Bor, Serbia). High tolerance to Cu(2+), Cd(2+) and Cr(6+) and the presence of genetic determinants for the respective metal tolerance and biofilm-forming ability was shown for indigenous heterotrophic bacteria that included strains of Staphylococcus and Rhodococcus. Two well characterized bacteria- Pseudomonas aeruginosa PAO1 (known biofilm former) and Cupriavidus metallidurans CH34 (known metal resistant representative) were also included in the study. The interaction and survivability of autotrophic iron oxidizing Acidithiobacillus bacteria and biofilms of heterotrophic bacteria during co-cultivation was revealed. Finally, the effect of heterotrophic biofilms on bioleaching process with indigenous iron oxidizing Acidithiobacillus species was shown not to be inhibitory under in vitro conditions. PMID:26942859

  17. Fe2+ oxidation rate drastically affect the formation and phase of secondary iron hydroxysulfate mineral occurred in acid mine drainage

    International Nuclear Information System (INIS)

    During the processes of secondary iron hydroxysulfate mineral formation, Fe2+ ion was oxidized by the following three methods: (1) biooxidation treatment by Acidithiobacillus ferrooxidans (A. ferrooxidans); (2) rapid abiotic oxidation of Fe2+ with H2O2 (rapid oxidation treatment); (3) slow abiotic oxidation of Fe2+ with H2O2 (slow oxidation treatment). X-ray diffraction (XRD) patterns, element composition, precipitate weight and total Fe removal efficiency were analyzed. The XRD patterns and element composition of precipitates synthesized through the biooxidation and the slow oxidation treatments well coincide with those of potassium jarosite, while precipitates formed at the initial stage of incubation in the rapid oxidation treatment showed a similar XRD pattern to schwertmannite. With the ongoing incubation, XRD patterns and element composition of the precipitates that occurred in the rapid oxidation treatment were gradually close to those in the biooxidation and the slow oxidation treatments. Due to the inhibition of A. ferrooxidans itself and its extracellular polymeric substances (EPS) in aggregation of precipitates, the amount of precipitates and soluble Fe removal efficiency were lower in the biooxidation treatment than in the slow oxidation treatment. Therefore, it is concluded that Fe2+ oxidation rate can greatly affect the mineral phase of precipitates, and slow oxidation of Fe2+ is helpful in improving jarosite formation. - Highlights: ► Slow oxidation of Fe2+ is helpful in jarosite formation. ► The already-formed schwertmannite can be gradually transformed to jarosite. ► Precipitates formation can be inhibited probably by EPS from A. ferrooxidans.

  18. Microbial ecology of a novel sulphur cycling consortia from AMD: implications for acid generation

    Science.gov (United States)

    Loiselle, L. M.; Norlund, K. L.; Hitchcock, A. P.; Warren, L. A.

    2009-05-01

    Recent work1 identified a novel microbial consortia consisting of two bacterial strains common to acid mine drainage (AMD) environments (autotrophic sulphur oxidizer Acidithiobacillus ferrooxidans and heterotrophic Acidiphilium spp.) in an environmental enrichment from a mine tailings lake. The two strains showed a specific spatial arrangement within an EPS macrostructure or "pod" allowing linked metabolic redox cycling of sulphur. Sulphur species characterisation of the pods using scanning transmission X-ray microscopy (STXM) indicated that autotrophic tetrathionate disproportionation by A. ferrooxidans producing colloidal elemental sulphur (S0) is coupled to heterotrophic S0 reduction by Acidiphilium spp. Geochemical modelling of the microbial sulphur reactions indicated that if they are widespread in AMD environments, then global AMD-driven CO2 liberation from mineral weathering have been overestimated by 40-90%1. Given the common co-occurrence of these two bacteria in AMD settings, the purpose of this study was to evaluate if these pods could be induced in the laboratory by pure strains and if so, whether their combined sulphur geochemistry mimicked the previous findings. Laboratory batch experiments assessed the development of pods with pure strain type cultures (A. ferrooxidans ATCC 19859 with mixotroph Acidiphilium acidophilum ATCC 738 or strict heterotroph Acp. cryptum ATCC 2158) using fluorescent in situ hybridization (FISH) imaging. The microbial sulphur geochemistry was characterized under autotrophic conditions identical to those used with the environmental AMD enrichment in which the pods were discovered. Results showed that the combined pure strain A. ferrooxidans and Acp. acidophilum form pods identical in structure to the AMD enrichment. To test the hypothesis that these pods form for mutual metabolic benefit, experiments were performed amending pure strain and AMD enrichment bacterial treatments with organic carbon and/or additional sulphur to

  19. Biolixiviação de cobre de sucata eletrônica Bioleaching of copper from electronic scrap

    Directory of Open Access Journals (Sweden)

    Luciana Harue Yamane

    2011-09-01

    Full Text Available O presente trabalho investigou a influência da suplementação de ferro e da adaptação bacteriana sobre a biolixiviação de cobre de placas de circuito impresso usando a bactéria Acidithiobacillusferrooxidans-LR. Placas de circuito impresso de computadores obsoletos foram mecanicamente processadas através de cominuição seguida de separação magnética. A bactéria Acidithiobacillusferrooxidans-LR foi crescida e adaptada à presença de amostras de placas de circuito impresso cominuídas. Um estudo de frascos agitados foi realizado usando um shaker a 30ºC e 185 rpm. Os parâmetros analisados foram pH, concentração de íon ferroso e concentração de metais (ICP-OES. Os resultados demonstram que o processo de adaptação bacteriana aumentou a taxa de extração de cobre. A biolixiviação com Acidithiobacillusferrooxidans-LR adaptada lixiviou 56% do cobre das placas de circuito impresso (fração não-magnética no meio suplementado pelo íon ferroso após 30 dias.The present work investigated the influence of ferrous iron supplementation on bioleaching to recover copper from printed circuit boards using Acidithiobacillus ferrooxidans-LR bacteria. Printed wiring boards from obsolete computers were mechanically processed through cominution followed by magnetic separation. The Acidithiobacillus ferrooxidans-LR bacteria were grown and adapted in the presence of printed wiring board samples. A shake flask study was carried out on the printed circuit board samples using a rotary shaker at 30ºC and 185 rpm. The analyzed parameters were: the pH of the medium, the initial ferrous iron concentration and the metal concentrations (ICP-OES. The results showed that the bacterial adaptation process enhanced the copper extraction rate. The bioleaching with adapted Acidithiobacillus ferrooxidans-LR leached out 56% of the copper from printed circuit boards (non-magnetic fraction with the medium being supplemented by ferrous iron after 30 days.

  20. Bacterial leaching kinetics for copper dissolution from a lowgrade Indian chalcopyrite ore Cinética de lixiviação por bactéria para a dissolução de cobre de um minério de calcopirita de baixo teor encontrado na Índia

    Directory of Open Access Journals (Sweden)

    Abhilash

    2013-06-01

    Full Text Available Bio-leaching of copper (0.3% from a low grade Indian chalcopyrite ore of Malanjkhand copper mines, using a native mesophilic isolate predominantly Acidithiobacillus ferrooxidans (A.ferrooxidans, is reported. A bio-recovery of 72% Cu was recorded in the presence of this culture (not adapted, which increased to 75% with an ore adapted culture after 35 days at 35ºC and pH 2.0 with Biolixiviação de cobre (0,3% de um minério de calcopirita de baixo teor, extraído em minas de Malanjkhand, usando um isolador mesofílico nativo, predominante Acidithiobacillus ferrooxidans (A.ferrooxidans, é apresentada. Uma biorrecuperação de 72% Cu foi registrada na presença dessa cultura (não adaptada, que aumentou para 75% com a cultura do minério adaptado e cultivado por 35 dias ao 35ºC e pH 2,0, com <50um partículas. Os dados cinemáticos mostraram mais adequados para o modelo básico de encolhimento controlado por difusão, exibindo lotes lineares de [1- 2/3X- (1-X2/3] vs temp (X - fração lixiviada. Parece que o papel da bactéria, no processo, é o de converter o íon ferroso para o estado férrico, que oxida a calcopirita para poder dissolver o cobre, mantendo o alto potencial redoxante. O valor da energia de ativação (E foi calculado em 96 e 108 kJ/mol, para as culturas sem e com adaptação, respectivamente, com temperaturas entre 25-35ºC. Esse mecanismo de lixiviação foi corroborado por identificação fásica XR D e em estudos da resídua da lixiviação.

  1. 元素硫对黄铜矿生物浸出行为及群落结构的影响%Relationships among bioleaching performance, additional elemental sulfur,microbial population dynamics and its energy metabolism in bioleaching of chalcopyrite

    Institute of Scientific and Technical Information of China (English)

    夏乐先; 汤露; 夏金兰; 尹礎; 柴立元; 赵小娟; 聂珍媛; 柳建设; 邱冠周

    2012-01-01

    To estimate the relationships among bioleaching performance,additional elemental sulfur (S0),microbial population dynamics and its energy metabolism,bioleaching of chalcopyrite by three typical sulfur- and/or iron-oxidizing bacteria,Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum and Acidithiobacillus thiooxidans with different levels of sulfur were studied in batch shake flask cultures incubated at 30 ℃.Copper dissolution capability (71%) was increased with the addition of 3.193 g/L S0,compared to that (67%) without S0.However,lower copper extraction was obtained in bioleaching with excessive sulfur.Microbial population dynamics during chalcopyrite bioleaching process was monitored by using PCR-restrietion fragment length polymorphism (PCR-RFLP).Additional S0 accelerated the growth of sulfur-oxidizing bacteria,inhibited the iron-oxidizing metabolism and led to the decrease of iron-oxidizing microorganisms,finally affected iron concentration,redox potential and bioleaching performance.It is suggested that mixed iron and sulfur-oxidizing microorganisms with further optimized additional S0 concentration could improve copper recovery from chalcopyrite.%研究3种典型铁/硫代谢菌-Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum及Acidithiobacillus thiooxidans混合浸出黄铜矿过程中铁/硫氧化活性、群落结构(PCR-RFLP)的变化,以及不同浓度的元素硫对其影响.结果发现,加入3.193 g/L元素硫能促进细菌的表观硫氧化活性,改变浸矿体系的群落结构,并进一步影响钝化层的形成、金属离子的溶出,其浸出率(71%)较未添加硫的(67%)有一定程度的提高.而过量的元素硫会抑制铜的浸出(浸出率44%).

  2. Study on Several Complicated Factors Effect in Bacterial Leaching of Chalcopyrite%黄铜矿细菌浸出过程中的多因素影响

    Institute of Scientific and Technical Information of China (English)

    任浏祎; 覃文庆; 王军; 张雁生; 何小娟

    2008-01-01

    运用取自大宝山(简称DB)的嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,简称A.f)和嗜酸氧化硫硫杆菌(Acidi-thiobacillus thiooxidans,简称A.t)的混合菌对广东某硫化铜矿的黄铜矿进行摇瓶浸出试验研究.结果表明,黄铜矿摇瓶细菌浸出率受菌种、矿浆浓度、pH值、接种量多种因素的影响.细菌浸出黄铜矿的适宜条件为温度30℃,矿浆浓度5%,pH值为2.0,接种量为3×107个/mL.

  3. Desulphurization of coal: bioleaching versus bioconditioning and flotation

    Energy Technology Data Exchange (ETDEWEB)

    M. Zeki Dogan; Gulhan Ozbayoglu [Istanbul Technical University, Istanbul (Turkey). Faculty of Mining

    2007-07-01

    There are two bio-desulphurization methods for the removal of pyritic sulphur, namely, bacterial leaching and bacterial conditioning for pyrite depression followed by flotation of coal. Bacterial leaching is a slow process, consequently, microbial desulphurization is focused on conditioning coal by bacteria for a short time, followed by flotation. The application of Acidithiobacillus ferrooxidans in bioconditioning followed by flotation process help the oxidation of pyrite surface and enhance its depression during the flotation of coal. By bacterial conditioning for 4 hours followed by flotation, almost 78 % pyritic sulphur removal was attained with the yield of 78 % in the floated coal, whereas bacterial leaching resulted in pyritic sulphur removal of 56.60 % in 10 days. 17 refs., 5 tabs.

  4. Microbial pathways for the mobilization of mercury as Hg(O) in anoxic subsurface environments

    Energy Technology Data Exchange (ETDEWEB)

    Barkay, Tamar

    2005-06-01

    The goal of our project which was initiated in June 2005 is focused on the presence of merA in microbial communities of anoxic environments and the effect of anaerobic respiratory pathways on MR expression and activities. The following progress has been made to date: PCR primers were designed to span the known phylogenetic range of merA genes of Gram-negative bacteria. In control experiments, these primers successfully amplified a 288 bp region at the 3? end of previously characterized merA genes from Shewanella putrefaciens pMERPH, Acidithiobacillus ferrooxidans, Pseudomonas stutzeri pPB, Tn5041, Pseudomonas sp. K-62, and Serratia marcescens pDU1358.

  5. [Determination of minimal concentrations of biocorrosion inhibitors by a bioluminescence method in relation to bacteria, participating in biocorrosion].

    Science.gov (United States)

    Efremenko, E N; Azizov, R E; Makhlis, T A; Abbasov, V M; Varfolomeev, S D

    2005-01-01

    By using a bioluminescence ATP assay, we have determined the minimal concentrations of some biocorrosion inhibitors (Katon, Khazar, VFIKS-82, Nitro-1, Kaspii-2, and Kaspii-4) suppressing most common microbial corrosion agents: Desulfovibrio desulfuricans, Desulfovibrio vulgaris, Pseudomonas putida, Pseudomonas fluorescens, and Acidithiobacillus ferrooxidans. The cell titers determined by the bioluminescence method, including not only dividing cells but also their dormant living counterparts, are two- to sixfold greater than the values determined microbiologically. It is shown that the bioluminescence method can be applied to determination of cell titers in samples of oil-field waters in the presence of iron ions (up to 260 mM) and iron sulfide (to 186 mg/l) and in the absence or presence of biocidal corrosion inhibitors.

  6. Preliminary Study on Bio-trickling Filter Extracellular Polymeric Substances%关于生物滴滤塔内胞外聚合物的初步研究

    Institute of Scientific and Technical Information of China (English)

    张英; 杨榕; 张超; 党鹏刚

    2015-01-01

    为探究生物滴滤塔内EPS与生物量的关系,通过对氧化亚铁硫杆菌EPS提取方法进行对比,得出EDTA法EPS的提取效果最好;生物滴滤塔中活性炭表面生物量与T. f菌EPS有较大相关性,它的存在起到保护微生物、协助菌体吸附营养成分的作用;活性炭表面挂膜菌种后,其表面EPS主要为糖脂类、蛋白类物质,它们为微生物生长创造好的营养环境,能提高生物滴滤塔对SO2气体净化效果。%To explore the relationship between EPS of Bio-trickling Filter and biomass, by comparing extraction methods of extracellular polymeric substances of acidithiobacillus ferrooxidans, it was obtained that EDTA extraction method by EPS was best. The biomass of charcoal surface in the Biological trickling filter and the EPS of Acidithiobacillus ferrooxidans had greater relevance. It can protect microbes and help it to adsorb nutrients. EPS of charcoal surface was composed mainly by Glycolipids and Proteins. After biofilm bacteria in the surface of activated carbon, the EPS mainly was glycolipids and protein substances. It was a good environment for microbial growth nutrients. It can enhance the biological trickling filter purifying efficiency for SO2.

  7. Assessment of the microbial community in a constructed wetland that receives acid coal mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nicomrat, D.; Dick, W.A.; Tuovinen, O.H. [Ohio State University, Columbus, OH (United States)

    2006-01-15

    Constructed wetlands are used to treat acid drainage from surface or underground coal mines. However, little is known about the microbial communities in the receiving wetland cells. The purpose of this work was to characterize the microbial population present in a wetland that was receiving acid coal mine drainage (AMD). Samples were collected from the oxic sediment zone of a constructed wetland cell in southeastern Ohio that was treating acid drainage from an underground coal mine seep. Samples comprised Fe(Ill) precipitates and were pretreated with ammonium oxalate to remove interfering iron, and the DNA was extracted and purified by agarose gel electrophoresis prior to amplification of portions of the 16S rRNA gene. Amplified products were separated by denaturing gradient gel electrophoresis and DNA from seven distinct bands was excised from the gel and sequenced. The sequences were matched to sequences in the GenBank bacterial 16S rDNA database. The DNA in two of the bands yielded matches with Acidithiobacillus ferrooxidans and the DNA in each of the remaining five bands was consistent with one of the following microorganisms: Acidithiobacillus thiooxidans, strain TRA3-20 (a eubacterium), strain BEN-4 (an arsenite-oxidizing bacterium), an Alcaligenes sp., and a Bordetella sp. Low bacterial diversity in these samples reflects the highly inorganic nature of the oxic sediment layer where high abundance of iron- and sulfur-oxidizing bacteria would be expected. The results we obtained by molecular methods supported our findings, obtained using culture methods, that the dominant microbial species in an acid receiving, oxic wetland are A. thiooxidans and A. ferrooxidans.

  8. Implications for global climate change from microbially-produced acid mine drainage

    Science.gov (United States)

    Norlund, K. L.; Hitchcock, A. P.; Warren, L. A.

    2009-05-01

    Microbial catalysis of sulphur cycling in acid mine drainage (AMD) environments is well known but the reaction pathways are poorly characterised. These reaction pathways involve both acid-consuming and acid- generating steps, with important consequences for overall AMD production as well as sulphur and carbon global biogeochemical cycles. Mining-associated sulphuric acid has been implicated in climate change through the weathering of carbonate minerals resulting in the release of 29 Tg C/year as carbon dioxide. Understanding of microbial AMD generation is based predominantly on studies of Acidithiobacillus ferrooxidans despite the knowledge that other environmentally common strains of bacteria are also active sulphur oxidizers and that microbial consortia are likely very important in environmental processes. Using an integrated experimental approach including geochemical experimentation, scanning transmission X-ray microscopy (STXM) and fluorescent in situ hybridization (FISH), we document a novel syntrophic sulphur metabolism involving two common mine bacteria: autotrophic sulphur oxidizing Acidithiobacillus ferrooxidans and heterotrophic Acidiphilium spp. The proposed sulphur geochemistry associated with this bacterial consortium produces 40-90% less acid than expected based on abiotic AMD models, with significant implications for both AMD mitigation and AMD carbon flux modelling. The two bacterial strains are specifically spatially segregated within a macrostructure of extracellular polymeric substance (EPS) that provides the necessary microgeochemical conditions for coupled sulphur oxidation and reduction reactions. STXM results identify multiple sulphur oxidation states associated with the pods, indicating that they are the sites of active sulphur disproportionation and recycling. Recent laboratory experimentation using type culture strains of the bacteria involved in pod-formation suggesting that this phenomenon is likely to be widespread in environments

  9. Fluoride tolerance of co­culture of bioleaching microorganisms and community dynamics under fluoride stress%浸矿微生物共培养体系的耐氟特性及其在氟胁迫下的群落动态分析

    Institute of Scientific and Technical Information of China (English)

    李乾; 丁德馨; 王清良; 胡鄂明; 史文革; 马丽媛; 刘学端

    2014-01-01

    In order to explore the fluoride tolerance and the community dynamics of mixed bioleaching microorganisms, a co­culture including five typical bioleaching strains (Acidithiobacillus ferrooxidans ATCC 23270, Leptospirillum ferriphilum YSK, Sulfobacillus thermosulfidooxidans ST, Acidithiobacills thiooxidans A01, Acidithiobacills caldus S1) was constructed. The results show that the growth of the co­culture is inhibited by fluoride stress, and the co­culture keeps the stable cell density at high fluoride stress. The sulfur activity of the co­culture is not affected by fluoride stress. Microbial community dynamics of the co­culture was analyzed by real­time fluorescent quantitative PCR technology. The results show that L. ferriphilum YSK and A. caldus S1 are always the dominant species at fluoride stress or non­stress, while the minor is A. ferrooxidans ATCC 23270, S. thermosulfidooxidans ST and A. thiooxidans A01. Besides,S. thermosulfidooxidans ST is inhibited most obviously in the co­culture at fluoride stress, secondly A. caldus S1, A. thiooxidans A01 and A. ferrooxidans ATCC 23270, while the L. ferriphilum YSK still maintains a very stable growth.%为了探明混合浸矿微生物的耐氟特性及其群落动态,构建5株浸矿细菌(Acidithiobacillus ferrooxidans ATCC 23270, Leptospirillum ferriphilum YSK, Sulfobacillus thermosulfidooxidans ST, Acidithiobacills thiooxidans A01, Acidithiobacills caldus S1)的共培养体系。结果表明:氟胁迫在一定程度上抑制了该共培养体系的生长繁殖,对于高浓度的氟胁迫,共培养体系也保持较为平稳的生长延滞状态;氟胁迫对共培养体系硫氧化活性的影响并不明显。采用实时荧光定量 PCR 技术对其培养体系的群落动态进行分析。结果表明,不论是氟胁迫下还是无氟胁迫下, L. ferriphilum YSK和A. caldus S1,都是群落中的优势种群;而A. ferrooxidans ATCC 23270、S. thermosulfidooxidans ST和A. thiooxidans A01

  10. Catalytic effect of light illumination on bioleaching of chalcopyrite.

    Science.gov (United States)

    Zhou, Shuang; Gan, Min; Zhu, Jianyu; Li, Qian; Jie, Shiqi; Yang, Baojun; Liu, Xueduan

    2015-04-01

    The influence of visible light exposure on chalcopyrite bioleaching was investigated using Acidithiobacillus ferrooxidans. The results indicated, in both shake-flasks and aerated reactors with 8500-lux light, the dissolved Cu was 91.80% and 23.71% higher, respectively, than that in the controls without light. The catalytic effect was found to increase bioleaching to a certain limit, then plateaued as the initial chalcopyrite concentration increased from 2% to 4.5%. Thus a balanced mineral concentration is highly amenable to bioleaching via offering increased available active sites for light adsorption while eschewing mineral aggregation and screening effects. Using semiconducting chalcopyrite, the light facilitated the reduction of Fe(3+) to Fe(2+) as metabolic substrates for A.ferrooxidans, leading to better biomass, lower pH and redox potential, which are conducive to chalcopyrite leaching. The light exposure on iron redox cycling was further confirmed by chemical leaching tests using Fe(3+), which exhibited higher Fe(2+) levels in the light-induced system. PMID:25722073

  11. Direct Detection of Fe(II) in Extracellular Polymeric Substances (EPS) at the Mineral-Microbe Interface in Bacterial Pyrite Leaching.

    Science.gov (United States)

    Mitsunobu, Satoshi; Zhu, Ming; Takeichi, Yasuo; Ohigashi, Takuji; Suga, Hiroki; Jinno, Muneaki; Makita, Hiroko; Sakata, Masahiro; Ono, Kanta; Mase, Kazuhiko; Takahashi, Yoshio

    2016-03-26

    We herein investigated the mechanisms underlying the contact leaching process in pyrite bioleaching by Acidithiobacillus ferrooxidans using scanning transmission X-ray microscopy (STXM)-based C and Fe near edge X-ray absorption fine structure (NEXAFS) analyses. The C NEXAFS analysis directly showed that attached A. ferrooxidans produces polysaccharide-abundant extracellular polymeric substances (EPS) at the cell-pyrite interface. Furthermore, by combining the C and Fe NEXAFS results, we detected significant amounts of Fe(II), in addition to Fe(III), in the interfacial EPS at the cell-pyrite interface. A probable explanation for the Fe(II) in detected EPS is the leaching of Fe(II) from the pyrite. The detection of Fe(II) also indicates that Fe(III) resulting from pyrite oxidation may effectively function as an oxidizing agent for pyrite at the cell-pyrite interface. Thus, our results imply that a key role of Fe(III) in EPS, in addition to its previously described role in the electrostatic attachment of the cell to pyrite, is enhancing pyrite dissolution. PMID:26947441

  12. Direct Detection of Fe(II) in Extracellular Polymeric Substances (EPS) at the Mineral-Microbe Interface in Bacterial Pyrite Leaching.

    Science.gov (United States)

    Mitsunobu, Satoshi; Zhu, Ming; Takeichi, Yasuo; Ohigashi, Takuji; Suga, Hiroki; Jinno, Muneaki; Makita, Hiroko; Sakata, Masahiro; Ono, Kanta; Mase, Kazuhiko; Takahashi, Yoshio

    2016-01-01

    We herein investigated the mechanisms underlying the contact leaching process in pyrite bioleaching by Acidithiobacillus ferrooxidans using scanning transmission X-ray microscopy (STXM)-based C and Fe near edge X-ray absorption fine structure (NEXAFS) analyses. The C NEXAFS analysis directly showed that attached A. ferrooxidans produces polysaccharide-abundant extracellular polymeric substances (EPS) at the cell-pyrite interface. Furthermore, by combining the C and Fe NEXAFS results, we detected significant amounts of Fe(II), in addition to Fe(III), in the interfacial EPS at the cell-pyrite interface. A probable explanation for the Fe(II) in detected EPS is the leaching of Fe(II) from the pyrite. The detection of Fe(II) also indicates that Fe(III) resulting from pyrite oxidation may effectively function as an oxidizing agent for pyrite at the cell-pyrite interface. Thus, our results imply that a key role of Fe(III) in EPS, in addition to its previously described role in the electrostatic attachment of the cell to pyrite, is enhancing pyrite dissolution.

  13. Direct Detection of Fe(II) in Extracellular Polymeric Substances (EPS) at the Mineral-Microbe Interface in Bacterial Pyrite Leaching

    Science.gov (United States)

    Mitsunobu, Satoshi; Zhu, Ming; Takeichi, Yasuo; Ohigashi, Takuji; Suga, Hiroki; Jinno, Muneaki; Makita, Hiroko; Sakata, Masahiro; Ono, Kanta; Mase, Kazuhiko; Takahashi, Yoshio

    2016-01-01

    We herein investigated the mechanisms underlying the contact leaching process in pyrite bioleaching by Acidithiobacillus ferrooxidans using scanning transmission X-ray microscopy (STXM)-based C and Fe near edge X-ray absorption fine structure (NEXAFS) analyses. The C NEXAFS analysis directly showed that attached A. ferrooxidans produces polysaccharide-abundant extracellular polymeric substances (EPS) at the cell-pyrite interface. Furthermore, by combining the C and Fe NEXAFS results, we detected significant amounts of Fe(II), in addition to Fe(III), in the interfacial EPS at the cell-pyrite interface. A probable explanation for the Fe(II) in detected EPS is the leaching of Fe(II) from the pyrite. The detection of Fe(II) also indicates that Fe(III) resulting from pyrite oxidation may effectively function as an oxidizing agent for pyrite at the cell-pyrite interface. Thus, our results imply that a key role of Fe(III) in EPS, in addition to its previously described role in the electrostatic attachment of the cell to pyrite, is enhancing pyrite dissolution. PMID:26947441

  14. Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.

  15. 多金属硫化精矿中铜、锌和铁的生物浸出(英文)

    Institute of Scientific and Technical Information of China (English)

    Vesna; T.CONI?; Mirjana; M.RAJ?I?; VUJASINOVI?; Vlastimir; K.TRUJI?; Vladimir; B.CVETKOVSKI

    2014-01-01

    利用嗜温混合菌Acidithiobacillus ferrooxidans,Acidithiobacillus thiooxidans和Leptospirillum ferrooxidans对低品位复杂Cu-Zn-Pb-Fe-Ag-Au硫化精矿在曝气生物浸出反应器中进行生物浸出。该菌种为从塞尔维亚Bor地下铜矿的酸性溶液中筛选出一种嗜热嗜酸菌。营养液为p H 1.6的9K营养液。87%的矿物粒度大于10μm,矿浆密度为8%(w/v)。在测试条件下,锌、铜和铁的浸出率分别达到89%、83%和68%。动力学分析表明,浸出过程与Spencer-Topley模型相符,受局部反应扩散控制。

  16. Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling.Firstly,penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated.Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do.In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270,high leaching efficiency were obtained on A1,Si,and Ca,and extremely low leaching performance was,however,shown on the rest of elements i.e.,Na,Mn,and Zn.Under the strain TM-32 use,relatively high leaching performance was recognized on Al,Si,Ca,Na,Mn,and Zn.In the experiment of bioleaching for spent refractory copper melting furnace,almost the same leaching trends were shown on Cu,Zn,Al,and Si under the strains ACTT23270 and TM-32 uses.

  17. Bioleaching of Nickel and Cobalt from Spent Nickel Metal Hydride Batteries by Acidithiobacilli spp

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Acidithiobacillus ferrooxidans(At.f) and Acidithiobacillus thiooxidans (At.t) were used in bio-dissolution experiments of heavy metals in spent MH/Ni batteries. The influences of the initial pH value, the concentration of electrode materials, the temperature and substrate concentration on the leaching rate of heavy metal Ni, Co have been investigated. The obtained results indicate that the efficiency of nickel extraction and cobalt extraction is dependent on all of the mentioned factors. Especially, the initial pH value and the temperature have more effect than other factors for these microorganisms. In addition, the results show that the optimal leaching rate of Ni and Co in the spent MH/Ni batteries reaches to 95.7% and 72.4% respectively after 20 days under the conditions of the initial pH value 1.0, concentration of electrode materials 1.0%, temperature 30℃ and substrate(sulfur) concentration 4.0g·L-1.

  18. 元素硫对黄铜矿生物浸出行为及群落结构的影响(英文)

    Institute of Scientific and Technical Information of China (English)

    夏乐先; 汤露; 夏金兰; 尹磁; 柴立元; 赵小娟; 聂珍媛; 柳建设; 邱冠周

    2012-01-01

    研究3种典型铁/硫代谢菌—Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum及Acidithiobacillus thiooxidans混合浸出黄铜矿过程中铁/硫氧化活性、群落结构(PCR-RFLP)的变化,以及不同浓度的元素硫对其影响。结果发现,加入3.193g/L元素硫能促进细菌的表观硫氧化活性,改变浸矿体系的群落结构,并进一步影响钝化层的形成、金属离子的溶出,其浸出率(71%)较未添加硫的(67%)有一定程度的提高。而过量的元素硫会抑制铜的浸出(浸出率44%)。

  19. EVALUACIÓN Y CARACTERIZACIÓN MINERALÓGICA DEL PROCESO DE BIOOXIDACIÓN EN UN REACTOR CONTINUO DE TANQUE AGITADO

    Directory of Open Access Journals (Sweden)

    DIANA ARROYAVE G.

    2010-01-01

    Full Text Available La biooxidación del mineral refractario de oro de la mina El Zancudo (TitiribíAntioquia se realizó en un reactor continuo de tanque agitado usando microorganismos nativos acidófilos compatibles con Acidithiobacillus ferrooxidans y Acidithiobacillus thiooxidans. El reactor se operó inicialmente en discontinuo para alcanzar la máxima concentración de hierro férrico en solución, antes de iniciar el proceso en continuo. La caracterización mineralógica se hizo a muestras recolectadas en discontinuo, estado transitorio y estacionario en continuo, usando Microscopia Electrónica de Barrido (SEM y Difracción de Rayos X (DRX. La caracterización mineralógica mostró una oxidación avanzada de la pirita y arsenopirita en discontinuo y parcial en continuo. Adicionalmente, se encontró la formación de silicatos, jarosita y brushita. Los resultados indican que el sistema alcanzó el estado estacionario después de 8 días de operación en continuo, logrando una concentración de hierro férrico en solución de 8.3 g/l, correspondiente a un porcentaje de extracción de oro y plata de 78 y 80 %, respectivamente.

  20. Removal of Heavy Metals from Activated Sludge by Bioleaching Method%生物淋滤法去除污泥中的重金属

    Institute of Scientific and Technical Information of China (English)

    王聪; 李强; 李保宾; 孙村民; 邓飞; 王淑芳; 宋存江

    2010-01-01

    本研究从剩余活性污泥中分离得到两株土著硫杆菌.对两株菌进行了分类鉴定.确立二者分别为嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f)和嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans,A.t).将二者的单菌和混合菌分别接种于剩余活性污泥中,进行了为期9 d的生物淋滤,对淋滤过程中的pH变化,氧化还原电位(ORP)以及重金属含量进行了检测.结果表明,生物淋滤9 d混合菌对于As、Cr、Cu、Ni和Zn的去除效果最好;去除率分别达到了96.09%、93.47%、98.32%、97.88%和98.60%.对于Cd和Pb混合菌生物淋滤的去除率在第6天之后迅速下降,但是A.t单菌淋滤保持较高的去除率.

  1. Putative bacterial interactions from metagenomic knowledge with an integrative systems ecology approach.

    Science.gov (United States)

    Bordron, Philippe; Latorre, Mauricio; Cortés, Maria-Paz; González, Mauricio; Thiele, Sven; Siegel, Anne; Maass, Alejandro; Eveillard, Damien

    2016-02-01

    Following the trend of studies that investigate microbial ecosystems using different metagenomic techniques, we propose a new integrative systems ecology approach that aims to decipher functional roles within a consortium through the integration of genomic and metabolic knowledge at genome scale. For the sake of application, using public genomes of five bacterial strains involved in copper bioleaching: Acidiphilium cryptum, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferriphilum, and Sulfobacillus thermosulfidooxidans, we first reconstructed a global metabolic network. Next, using a parsimony assumption, we deciphered sets of genes, called Sets from Genome Segments (SGS), that (1) are close on their respective genomes, (2) take an active part in metabolic pathways and (3) whose associated metabolic reactions are also closely connected within metabolic networks. Overall, this SGS paradigm depicts genomic functional units that emphasize respective roles of bacterial strains to catalyze metabolic pathways and environmental processes. Our analysis suggested that only few functional metabolic genes are horizontally transferred within the consortium and that no single bacterial strain can accomplish by itself the whole copper bioleaching. The use of SGS pinpoints a functional compartmentalization among the investigated species and exhibits putative bacterial interactions necessary for promoting these pathways. PMID:26677108

  2. Comparison of microbial communities in three different mine drainages and their bioleaching efficiencies to low grade of chalcopyrite

    Institute of Scientific and Technical Information of China (English)

    YIN Hua-qun; QIU Guan-zhou; WANG Dian-zuo; CAO Lin-hui; DAI Zhi-min; WANG Jie-wei; LIU Xue-duan

    2007-01-01

    Microbial community diversities in the drainage from three mines (Dexing Copper Mine, Qibaoshan Copper Mine and Yaogangxian Tungsten Mine, China) were analyzed using 16S rDNA PCR-RFLP approach. The efficiencies of chalcopyrite bioleaching were compared using enrichment of the three cultures. Phylogenetic analysis indicates that the dominant microorganisms are clustered with the Proteobacteria, the remaining is affiliated with Nitrospira, Acidobacteria and Actinobacteria.At the genus level, Acidithiobacillus is the dominant group in both YTW and QBS samples, while Spingomonas is dominant in YGX sample. Moreover, the principal component analysis (PCA) reveals that QBS and YTW have similar geochemical character and microbial communities. The results also show that pH value and tungsten concentration play a key role in microbial community distribution and relative abundance. The bioleaching efficiency of the enrichment cultures from YTW and QBS is similar. After 15 d,the bioleaching rates of low grade chalcopyrite (0.99%) are both up to 99.5% when using 10 g/L pulp density due to the similar microbial composition of YTW and QBS. Moreover, the leaching efficiencies of enrichment cultures containing multiple bioleaching microorganisms are higher than that of pure culture Acidithiobacillus ferrooxidans.

  3. Efecto de la cisteína en un proceso de biodepiritización de carbones en lecho empacado

    Directory of Open Access Journals (Sweden)

    Gerardo Andrés Caicedo Pineda

    2016-05-01

    Full Text Available Biodesulphurization processes of a two sulphur-rich coals from Colombia (“Mina Vieja” y “Vampiro” were carried out at packed-bed reactors at erlenmeyer level, using a consortium of Acidithiobacillus ferrooxidans (ATCC 23270 and Acidithiobacillus thiooxidans (ATCC 15494. Cysteine addition were evaluated. The assays were monitored by measurements of iron content, pH, and redox potential. X-ray diffraction (XRD were used to establish the mineralogy before and after the process. The assays without cysteine respectively reached a pyrite oxidation of 45.3% (“Mina Vieja” and 57.9% (“Vampiro” after 38 days. Cysteine addition improved pyrite oxidation by 14.9% (“Mina Vieja” and 6.4% (“Vampiro”. On the other hand, all the assays removed kaolinite by interaction with sulphuric acid of the media. In base to the results, coal compounds influence bacterial growth and affects the efficiency of cysteine over pyrite oxidation.

  4. Leaching of Metals from Waste Printed Circuit Boards Using Acidithiobacillus thiooxidans%Acidithiobacillus thiooxidans浸出印刷线路板中金属的研究

    Institute of Scientific and Technical Information of China (English)

    赵伟; 陈晨; 王玉光; 周洪波

    2010-01-01

    印刷线路板(PCB)作为电子垃圾的主要成分,传统的处理方法环境污染严重,而且造成资源的严重浪费,因此找到无污染和可回收再利用的处理技术显得尤为重要.实验检测了利用嗜酸浸矿微生物处理印刷线路板回收其中金属的可行性,选用本实验室筛选的A.thiooxidans,对PCB中的金属进行了摇瓶浸出试验.在摇瓶培养中,10%的接种量,添加1.0 g样品时,Cu的浸出率达到了59.76%,而同期对照的H2SO4漫出试验中,其浸出率只有42.94%,对其他金属元素也有较好的效果.结果表明,利用 A.thiooxidans比纯酸浸更能取得良好的效果.

  5. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    Science.gov (United States)

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus. PMID:24842376

  6. Carbon dioxide and hydrogen sulfide associations with regional bacterial diversity patterns in microbially induced concrete corrosion.

    Science.gov (United States)

    Ling, Alison L; Robertson, Charles E; Harris, J Kirk; Frank, Daniel N; Kotter, Cassandra V; Stevens, Mark J; Pace, Norman R; Hernandez, Mark T

    2014-07-01

    The microbial communities associated with deteriorating concrete corrosion fronts were characterized in 35 samples taken from wastewater collection and treatment systems in ten utilities. Bacterial communities were described using Illumina MiSeq sequencing of the V1V2 region of the small subunit ribosomal ribonucleic acid (SSU-rRNA) gene recovered from fresh corrosion products. Headspace gas concentrations (hydrogen sulfide, carbon dioxide, and methane), pore water pH, moisture content, and select mineralogy were tested for correlation to community outcomes and corrosion extent using pairwise linear regressions and canonical correspondence analysis. Corroding concrete was most commonly characterized by moisture contents greater than 10%, pore water pH below one, and limited richness (100 ppm) and carbon dioxide (>1%) gases, conditions which also were associated with low diversity biofilms dominated by members of the acidophilic sulfur-oxidizer genus Acidithiobacillus.

  7. Influences of Extracellular Polymeric Substances on the Dewaterability of Sewage Sludge during Bioleaching

    Science.gov (United States)

    Zhang, Xueying; Zhou, Lixiang

    2014-01-01

    Extracellular polymeric substances (EPS) play important roles in regulating the dewaterability of sludge. This study sought to elucidate the influence of EPS on the dewaterability of sludge during bioleaching process. Results showed that, in bioleaching system with the co-inoculation of Acidithiobacillus thiooxidans TS6 and Acidithiobacillus ferrooxidans LX5 (A. t+A. f system), the capillary suction time (CST) of sludge reduced from 255.9 s to 25.45 s within 48 h, which was obviously better than the controls. The correlation analysis between sludge CST and sludge EPS revealed that the sludge EPS significantly impacted the dewaterability of sludge. Sludge CST had correlation with protein content in slime and both protein and polysaccharide contents in TB-EPS and Slime+LB+TB layers, and the decrease of protein content in slime and decreases of both protein and polysaccharide contents in TB-EPS and Slime+LB+TB layers improved sludge dewaterability during sludge bioleaching process. Moreover, the low sludge pH (2.92) and the increasing distribution of Fe in the solid phase were another two factors responsible for the improvement of sludge dewaterability during bioleaching. This study suggested that during sludge bioleaching the growth of Acidithiobacillus species resulted in the decrease of sludge pH, the increasing distribution of Fe in the solid phase, and the decrease of EPS content (mainly including protein and/or polysaccharide) in the slime, TB-EPS, and Slime+LB+TB layers, all of which are helpful for sludge dewaterability enhancement. PMID:25050971

  8. Influences of extracellular polymeric substances on the dewaterability of sewage sludge during bioleaching.

    Directory of Open Access Journals (Sweden)

    Jun Zhou

    Full Text Available Extracellular polymeric substances (EPS play important roles in regulating the dewaterability of sludge. This study sought to elucidate the influence of EPS on the dewaterability of sludge during bioleaching process. Results showed that, in bioleaching system with the co-inoculation of Acidithiobacillus thiooxidans TS6 and Acidithiobacillus ferrooxidans LX5 (A. t+A. f system, the capillary suction time (CST of sludge reduced from 255.9 s to 25.45 s within 48 h, which was obviously better than the controls. The correlation analysis between sludge CST and sludge EPS revealed that the sludge EPS significantly impacted the dewaterability of sludge. Sludge CST had correlation with protein content in slime and both protein and polysaccharide contents in TB-EPS and Slime+LB+TB layers, and the decrease of protein content in slime and decreases of both protein and polysaccharide contents in TB-EPS and Slime+LB+TB layers improved sludge dewaterability during sludge bioleaching process. Moreover, the low sludge pH (2.92 and the increasing distribution of Fe in the solid phase were another two factors responsible for the improvement of sludge dewaterability during bioleaching. This study suggested that during sludge bioleaching the growth of Acidithiobacillus species resulted in the decrease of sludge pH, the increasing distribution of Fe in the solid phase, and the decrease of EPS content (mainly including protein and/or polysaccharide in the slime, TB-EPS, and Slime+LB+TB layers, all of which are helpful for sludge dewaterability enhancement.

  9. Biofilm forming and leaching mechanism during bioleaching chalcopyrite by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    傅建华; 胡岳华; 邱冠周; 柳建设; 徐竞

    2004-01-01

    The mechanism of attachment and leaching of thiobacillus ferrooxcidans (T. f. ) on chalcopyrite were studied. The shaking flasks with bacteria were observed by SEM. The process of T. f attached to the surface of the mineral sample and the biofilm forming were described. The promoting role of the biofilm for bioleaching was discussed. The existence of Fe2+ in the exopolysaccharide layer of T. f was demonstrated by EM(electronic microscope)cell-chemistry analysis. These results show that under the proper growth condition of bacteria, bioleaching of chalcopyrite results in the formation of complete biofilm after 2 - 3 weeks. There are iron ions in the outer layer polymer of T. f. , which provides the micro-environment for themselves, and can guaruntee the energy needed for the bacteria growth in the biofilm. At the same time, Fe3+ ions produced oxidize sulfide which brings about the increase of both growth rate of the bacterial and leaching rate of sulfide minerals.

  10. Bioleaching of refractory gold ore (Ⅲ)--Fluid leaching Jinya refractory gold concentrate by Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    闵小波; 柴立元; 陈为亮; 于霞; 张传福; 邝中

    2002-01-01

    A novel fluidized-bed reactor was designed and installed for bioleaching in a semi-continuous way,by which a process for bioleaching-cyanidation of Jinya refractory gold arsenical concentrate was studied.The arsenic extraction rate reaches 82.5% after 4-day batch biooxidation of the concentrate under the optimized condition of pH 2.0,ferric ion concentration 6.5 g/L and pulp concentration 10%.And leached rate of gold in the following cyanidation is over 90%.The parameters of three series fluidized-bed reactors exhibit stability during the semi-continuous bioleaching of the concentrate.Arsenic in the concentrate can be got rid of 91% after 6-day leaching.Even after 4 days,82% of arsenic extraction rate was still obtained.The recovery rates of gold are 92% and 87.5% respectively in cyaniding the above bioleached residues.The results will provide a base for further commercial production of gold development.

  11. Role of Ferrous Ions in Synthetic Cobaltous Sulfide Leaching of Thiobacillus ferrooxidans

    OpenAIRE

    Sugio, Tsuyoshi; Domatsu, Chitoshi; Tano, Tatsuo; Imai, Kazutami

    1984-01-01

    Microbiological leaching of synthetic cobaltous sulfide (CoS) was investigated with a pure strain of Thiobacillus ferroxidans. The strain could not grow on CoS-salts medium in the absence of ferrous ions (Fe2+). However, in CoS-salts medium supplemented with 18 mM Fe2+, the strain utilized both Fe2+ and the sulfur moiety in CoS for growth, resulting in an enhanced solubilization of Co2+. Cell growth on sulfur-salts medium was strongly inhibited by Co2+, and this inhibition was completely prot...

  12. UV-induced mutagenesis of oxidation activity of ferrous ion of Thiobacillus ferrooxidans

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An excellent strain named T. f6 was isolated and screened, the dose and other condition for the UV-induced mutagenesis were studied and the richened positive mutant m+ T. f6 was applied in the column leaching of copper-contain ing sulfides. The results show that T. f6 is characterized by rapid oxidation of ferrous ion and cupric sulfide, high tolerance of toxic ion and short generation time. The best mutagenic effectiveness can be obtained under the dose of low kill rate of UV and low temperature treatment, under which the best richened m+ T. f6 can be shortened 1.4h. It was shown by the column leaching of copper that the leaching rate can be enhanced by at least 11% compared with the original one by the mutants.

  13. Development and application of small-subunit rRNA probes for assessment of selected Thiobacillus species and members of the genus Acidiphilium.

    Science.gov (United States)

    Peccia, J; Marchand, E A; Silverstein, J; Hernandez, M

    2000-07-01

    Culture-dependent studies have implicated sulfur-oxidizing bacteria as the causative agents of acid mine drainage and concrete corrosion in sewers. Thiobacillus species are considered the major representatives of the acid-producing bacteria in these environments. Small-subunit rRNA genes from all of the Thiobacillus and Acidiphilium species catalogued by the Ribosomal Database Project were identified and used to design oligonucleotide DNA probes. Two oligonucleotide probes were synthesized to complement variable regions of 16S rRNA in the following acidophilic bacteria: Thiobacillus ferrooxidans and T. thiooxidans (probe Thio820) and members of the genus Acidiphilium (probe Acdp821). Using (32)P radiolabels, probe specificity was characterized by hybridization dissociation temperature (T(d)) with membrane-immobilized RNA extracted from a suite of 21 strains representing three groups of bacteria. Fluorochrome-conjugated probes were evaluated for use with fluorescent in situ hybridization (FISH) at the experimentally determined T(d)s. FISH was used to identify and enumerate bacteria in laboratory reactors and environmental samples. Probing of laboratory reactors inoculated with a mixed culture of acidophilic bacteria validated the ability of the oligonucleotide probes to track specific cell numbers with time. Additionally, probing of sediments from an active acid mine drainage site in Colorado demonstrated the ability to identify numbers of active bacteria in natural environments that contain high concentrations of metals, associated precipitates, and other mineral debris.

  14. Microbial community profiling of the Chinoike Jigoku ("Blood Pond Hell") hot spring in Beppu, Japan: isolation and characterization of Fe(III)-reducing Sulfolobus sp. strain GA1.

    Science.gov (United States)

    Masaki, Yusei; Tsutsumi, Katsutoshi; Hirano, Shin-Ichi; Okibe, Naoko

    2016-09-01

    Chinoike Jigoku ("Blood Pond Hell") is located in the hot spring town of Beppu on the southern island of Kyushu in Japan, and is the site of a red-colored acidic geothermal pond. This study aimed to investigate the microbial population composition in this extremely acidic environment and to isolate/characterize acidophilic microorganism with metal-reducing ability. Initially, PCR (using bacteria- and archaea-specific primers) of environmental DNA samples detected the presence of bacteria, but not archaea. This was followed by random sequencing analysis, confirming the presence of wide bacterial diversity at the site (123 clones derived from 18 bacterial and 1 archaeal genera), including those closely related to known autotrophic and heterotrophic acidophiles (Acidithiobacillus sp., Sulfobacillus sp., Alicyclobacillus sp.). Nevertheless, successive culture enrichment with Fe(III) under micro-aerobic conditions led to isolation of an unknown archaeal organism, Sulfolobus sp. GA1 (with 99.7% 16S rRNA gene sequence identity with Sulfolobus shibatae). Unlike many other known Sulfolobus spp., strain GA1 was shown to lack sulfur oxidation ability. Strain GA1 possessed only minor Fe(II) oxidation ability, but readily reduced Fe(III) during heterotrophic growth under micro-aerobic conditions. Strain GA1 was capable of reducing highly toxic Cr(VI) to less toxic/soluble Cr(III), demonstrating its potential utility in bioremediation of toxic metal species. PMID:27208660

  15. Microbial community profiling of the Chinoike Jigoku ("Blood Pond Hell") hot spring in Beppu, Japan: isolation and characterization of Fe(III)-reducing Sulfolobus sp. strain GA1.

    Science.gov (United States)

    Masaki, Yusei; Tsutsumi, Katsutoshi; Hirano, Shin-Ichi; Okibe, Naoko

    2016-09-01

    Chinoike Jigoku ("Blood Pond Hell") is located in the hot spring town of Beppu on the southern island of Kyushu in Japan, and is the site of a red-colored acidic geothermal pond. This study aimed to investigate the microbial population composition in this extremely acidic environment and to isolate/characterize acidophilic microorganism with metal-reducing ability. Initially, PCR (using bacteria- and archaea-specific primers) of environmental DNA samples detected the presence of bacteria, but not archaea. This was followed by random sequencing analysis, confirming the presence of wide bacterial diversity at the site (123 clones derived from 18 bacterial and 1 archaeal genera), including those closely related to known autotrophic and heterotrophic acidophiles (Acidithiobacillus sp., Sulfobacillus sp., Alicyclobacillus sp.). Nevertheless, successive culture enrichment with Fe(III) under micro-aerobic conditions led to isolation of an unknown archaeal organism, Sulfolobus sp. GA1 (with 99.7% 16S rRNA gene sequence identity with Sulfolobus shibatae). Unlike many other known Sulfolobus spp., strain GA1 was shown to lack sulfur oxidation ability. Strain GA1 possessed only minor Fe(II) oxidation ability, but readily reduced Fe(III) during heterotrophic growth under micro-aerobic conditions. Strain GA1 was capable of reducing highly toxic Cr(VI) to less toxic/soluble Cr(III), demonstrating its potential utility in bioremediation of toxic metal species.

  16. Development of a Simvastatin Selection Marker for a Hyperthermophilic Acidophile, Sulfolobus islandicus

    DEFF Research Database (Denmark)

    Zheng, Tao; Huang, Qihong; Zhang, Changyi;

    2012-01-01

    . islandicus was constructed using pyrEF marker and used as the host to obtain pSSRNherA transformant with simvastatin selection. While the gene knockout (¿herA) cells generated from the herA merodiploid cells failed to form colonies in the presence of 5-fluoroorotic acid (5-FOA), the mutant cells could...... be rescued by expression of the gene from a plasmid (pSSRNherA), because their transformants formed colonies on a solid medium containing 5-FOA and simvastatin. This demonstrates that HerA is essential for cell viability of S. islandicus. To our knowledge, this is the first application of an antibiotic...

  17. Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses

    OpenAIRE

    N. Kip; Ouyang, W.J.; van der Winden, J.; Raghoebarsing, A.; van Niftrik, L.; De Pol, A.; Pan, Y.; L. Bodrossy; van Donselaar, E. G.; G. J. Reichart; M. S. M. Jetten; J. S. Sinninghe Damsté; Op den Camp, H.J.M.

    2011-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphapr...

  18. Detection, Isolation, and Characterization of Acidophilic Methanotrophs from Sphagnum Mosses ▿ †

    OpenAIRE

    Kip, Nardy; Ouyang, Wenjing; van Winden, Julia; Raghoebarsing, Ashna; van Niftrik, Laura; Pol, Arjan; Pan, Yao; Bodrossy, Levente; Van Donselaar, Elly G.; Reichart, Gert-Jan; Jetten, Mike S. M.; Sinninghe Damsté, Jaap S.; Op Den Camp, Huub J M

    2011-01-01

    Sphagnum peatlands are important ecosystems in the methane cycle. Methane-oxidizing bacteria in these ecosystems serve as a methane filter and limit methane emissions. Yet little is known about the diversity and identity of the methanotrophs present in and on Sphagnum mosses of peatlands, and only a few isolates are known. The methanotrophic community in Sphagnum mosses, originating from a Dutch peat bog, was investigated using a pmoA microarray. A high biodiversity of both gamma- and alphapr...

  19. Optimized Production of Xylitol from Xylose Using a Hyper-Acidophilic Candida tropicalis

    OpenAIRE

    Elena Tamburini; Stefania Costa; Maria Gabriella Marchetti; Paola Pedrini

    2015-01-01

    The yeast Candida tropicalis DSM 7524 produces xylitol, a natural, low-calorie sweetener, by fermentation of xylose. In order to increase xylitol production rate during the submerged fermentation process, some parameters-substrate (xylose) concentration, pH, aeration rate, temperature and fermentation strategy-have been optimized. The maximum xylitol yield reached at 60–80 g/L initial xylose concentration, pH 5.5 at 37 °C was 83.66% (w/w) on consumed xylose in microaerophilic conditions (kLa ...

  20. Assimilation of methanol by an acidophilic bacterium of the genus Acetobacter

    Energy Technology Data Exchange (ETDEWEB)

    Babel, W.

    1984-01-01

    The assimilation of methanol can take place via several pathways. Acetobacter methanolicus prefers an acidic pH range for growth. The latter is interesting from a regulatory point of view because phosphofructokinase disappears during growth on glucose, which is assimilated via the hexosemonophosphate pathway. Although A. methanolicus uses the hexulosephosphate pathway the growth yield on methanol is smaller than with other 'hexulosephosphate pathway bacteria' e.g. with obligate methanol assimilating bacteria. The relationship between the dependence on and the protection from, high external proton concentration on the one hand and the causes of the low growth yield on the other are discussed.

  1. Novel cookie-with-chocolate carbon dots displaying extremely acidophilic high luminescence

    Science.gov (United States)

    Lu, Siyu; Zhao, Xiaohuan; Zhu, Shoujun; Song, Yubin; Yang, Bai

    2014-10-01

    A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+.A fluorescent carbon dot with a cookie-with-chocolate film structure (about 5 × 5 μm2) showed a high fluorescence quantum yield (61.12%) at low pH. It was hydrothermally synthesized from l-serine and l-tryptophan. The formation mechanism of the film with carbon dots (CDs) was investigated. The film structure was formed by hydrogen bonding and π-π stacking interactions between aromatic rings. The strong blue fluorescence of the CDs increased under strong acidic conditions owing to the changes in the N-groups. These cookie-like CDs are attractive for their potential use as effective fluorescent probes for the sensitive detection of aqueous H+ and Fe3+. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03965c

  2. Enhanced Productivity of a Lutein-Enriched Novel Acidophile Microalga Grown on Urea

    NARCIS (Netherlands)

    Casal, C.; Cuaresma, M.; Vega, J.M.; Vilchez, C.

    2011-01-01

    Coccomyxa acidophila is an extremophile eukaryotic microalga isolated from the Tinto River mining area in Huelva, Spain. Coccomyxa acidophila accumulates relevant amounts of b-carotene and lutein, well-known carotenoids with many biotechnological applications, especially in food and health-related i

  3. Methylmercury enters an aquatic food web through acidophilic microbial mats in Yellowstone National Park, Wyoming

    Science.gov (United States)

    Boyd, E.S.; King, S.; Tomberlin, J.K.; Nordstrom, D.K.; Krabbenhoft, D.P.; Barkay, T.; Geesey, G.G.

    2009-01-01

    Summary Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH ??? 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg +), while undetectable or near the detection limit (0.025 ng l -1) in the source water of the springs, was present at concentrations of 4-7 ng g-1 dry weight of mat biomass. Detection of MeHg + in tracheal tissue of larvae grazing the mat suggests that MeHg+ enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg+ was two to five times higher in larval tissue than mat biomass indicating MeHg+ biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg+ to species in the food web whose range extends beyond a particular geothermal feature of YNP. ?? 2008 The Authors. Journal compilation ?? 2008 Society for Applied Microbiology and Blackwell Publishing Ltd.

  4. Proteomic mapping of the hyperthermophilic and acidophilic archaeon Sulfolobus solfataricus P2

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Richard C.; Young, Mark J.; Stedman, Kenneth M.; Dratz, Edward A.

    2006-07-14

    A proteomic map of Sulfolobus solfataricus P2, an archaeon that grows optimally at 80 C and pH 3.2, was developed using high resolution two-dimensional gel electrophoresis and peptide mass fingerprinting. A total of 867 protein spots (659 aqueous tris-soluble spots and 208 aqueous tris-insoluble) were mapped over IPG 3-10, 4-7, and 6-11, with second dimension gels made of 8-18% polyacrylamide. 324 different gene products were represented by the 867 spots, with 274 gene products being identified in the tris-soluble fractions and 100 gene products in the tris-insoluble portion. Fifty gene products were found on gels from both fractions. Additionally, an average of 1.50 + 0.12 isoforms/per protein were identified. This mapping study confirmed the expression of proteins involved in numerous metabolic, transport, energy production, nucleic acid replication, translation, and transcription pathways. Of particular interest, phosphoenolpyruvate carboxykinase (SSO2537) was detected even though the pathway for gluconeogenesis is unknown for this archaeon. Tris-soluble fractions contained many cytosolic proteins while tris-insoluble fractions contained many membrane-associated proteins, including ABC transporters and an ATP synthase. This study provides an optimized 2-DE approach for investigating the biochemical pathways and post-translational modifications employed by Sulfolobus to survive in its extreme environment.

  5. Microalgae as human food: chemical and nutritional characteristics of the thermo-acidophilic microalga Galdieria sulphuraria.

    Science.gov (United States)

    Graziani, Giulia; Schiavo, Simona; Nicolai, Maria Adalgisa; Buono, Silvia; Fogliano, Vincenzo; Pinto, Gabriele; Pollio, Antonino

    2013-01-01

    The use of microalgae as a food source is still poorly developed because of the technical difficulties related to their cultivation and the limited knowledge about their chemical composition and nutritional value. The unicellular red microalga Galdieria sulphuraria has a very high daily productivity and its cultivation under acidic conditions avoided any bacterial contamination. G. sulphuraria can be cultured under autotrophic and heterotrophic conditions: in this study a screening of 43 strains showed that in the latter case a duplication of biomass production was obtained. The proximate composition (protein, carbohydrates, fiber and lipids), the micronutrient content (carotenoids, phycobiliproteins, chlorophylls and vitamins) together with the antioxidant activity of the biomass produced by a selected strain of G. sulphuraria under both cultivation conditions were determined. Results showed that the material is rich in proteins (26-32%) and polysaccharides (63-69%) and poor in lipids. Under heterotrophic cultivation conditions, the lipid moiety mainly contained monounsaturated fatty acids. Among micronutrients, some B group vitamins are present, beta-carotene is the main carotenoid and phycobiliproteins are present under both cultivating conditions. G. sulphuraria proteins are strictly associated with polysaccharide components and therefore not digestible. In the second part of the work, an extraction protocol using Viscozyme L, a commercial enzymatic preparation containing a mixture of polysaccharidases, was developed which made G. sulphuraria proteins a good substrate for human gastrointestinal enzymes. All in all, the data suggested that G. sulphuraria biomass has a potential use as food ingredients both for protein-rich or insoluble dietary fibre-rich applications. The low concentration of lipids and the absence of green color make this microalgae source particularly useful for the addition to many food preparations.

  6. Combined remediation technology for the reduction and bioleaching of hexavalent chromium from soils using acidithiobacillus thiooxidans

    OpenAIRE

    Fonseca, B.; Rodrigues, Joana Lúcia; Mendes, T.S.; Queiroz, A.M.; Tavares, T

    2014-01-01

    Contamination of soils due to the release of effluents or deposition of wastes containing hexavalent chromium has been arising serious environmental problems. Therefore, the development of cost effectiveness but also ecological cleaning techniques is a matter of great concern among the scientific community. Bioremediation is attracting more and more attention due to its efficiency, low impact in the ecosystems and low cost. In particular, this study approaches a bioleaching tec...

  7. Acidithiobacillus thiooxidans secretome containing a newly described lipoprotein Licanantase enhances chalcopyrite bioleaching rate

    OpenAIRE

    Bobadilla Fazzini, Roberto A.; Levican, Gloria; Parada, Pilar

    2010-01-01

    The nature of the mineral–bacteria interphase where electron and mass transfer processes occur is a key element of the bioleaching processes of sulfide minerals. This interphase is composed of proteins, metabolites, and other compounds embedded in extracellular polymeric substances mainly consisting of sugars and lipids (Gehrke et al., Appl Environ Microbiol 64(7):2743–2747, 1998). On this respect, despite Acidithiobacilli—a ubiquitous bacterial genera in bioleaching processes (Rawlings, Micr...

  8. Influencia de la concentración de hierro y pH iniciales en un proceso de biodesulfurización de carbón – ensayos a nivel de laboratorio

    Directory of Open Access Journals (Sweden)

    Gerardo Andrés Caicedo Pineda

    2012-06-01

    Full Text Available Normal 0 21 false false false ES-CO X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} Título en ingles: Particle size, iron concentration and pH influence in biodesulfurization process of coal – laboratory tests   Resumen   A un carbón proveniente del municipio de Puerto Libertador, Córdoba-Colombia (2.34% de azufre total, con 1.34% pirítico, 0.90% orgánico y 0.10% de sulfatos, se le aplicó un cultivo mixto de Acidithiobacillus ferrooxidans y Acidithiobacillus thiooxidans, con el fin de evaluar procesos de biodesulfurización en suspensión, a partir de variables que influyen en el proceso: concentración inicial de hierro y pH de la solución lixiviante, bajo dos configuraciones de tamaño de partícula: pasante malla 8 (-malla 8 y pasante malla 60 (-malla 60, acorde con la serie Tyler de tamices. Los procesos de biodesulfurización se evaluaron cada dos días, mediante mediciones de la concentración de hierro, pH, potencial de óxido-reducción y crecimiento celular, en la solución. A partir de los ensayos realizados, se alcanzaron oxidaciones de azufre pirítico por encima del 50%, después de 12 días de proceso. Se pudo constatar que tanto el tipo de carbón tratado, como de las condiciones evaluadas, inciden en el grado de lixiviación alcanzado. La mejor eficiencia del

  9. Removal of Heavy Metals from Activated Sludge by Bioleaching Method%污泥中重金属的生物淋滤

    Institute of Scientific and Technical Information of China (English)

    邱并生

    2010-01-01

    生物淋滤法(Bioleaching)是指利用自然界中一些微生物(硫细菌)的直接作用或其代谢产物的间接作用,产生氧化、还原、络合、吸附或溶解反应,将固相中某些不溶性成分(如重金属、硫及其他金属)分离浸提出来的技术.在生物淋滤中,嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans,A.f)和嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans,A.f)被用作有效的淋滤载体[1].这种嗜酸性的化能自养型细菌以大气中的CO2为碳源,以无机物铁或硫为能源来维持生长,不需要提供外来的碳源和电子供体.另外,由于pH值很低,抑制了其他细菌的生长,所以在实际的操作过程中不需要严格的无菌条件.氧化亚铁硫杆菌和氧化硫硫杆菌去除重金属适宜于污水处理厂的开放系统,采用土著嗜酸性氧化亚铁硫杆菌(A.f)和氧化硫硫杆菌(A.f)进行重金属去除.也就是说,处理什么地方的污泥,就在什么地方分离A.f和A.t,这样分离的微生物在生物淋滤过程中能发挥较好的作用.这也是微生物在自然界生长繁殖的特点之一. 本期介绍了王聪、宋存江等[2]从剩余活性污泥中分离得到两株土著硫杆菌,对两株菌进行了分类鉴定,确定二者分别为嗜酸性氧化亚铁硫杆菌杆(Acidithiobacillus ferrooxidans,A.f)和嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans,A.t),将二者的单菌和混合菌分别接种于剩余活性污泥中,进行了为期9 d的生物淋滤,对淋滤过程中的pH变化、氧化还原电位(ORP)以及重金属含量进行了检测.结果表明,生物淋滤9 d的混合菌对于As、Cr、Cu、Ni和Zn的去除效果最好,去除率分别达到了96.09%、93.47%、98.32%、97.88%和98.60%.混合菌生物淋滤对于Cd和Pb的去除率在第6天之后迅速下降,但是A.t单菌淋滤保持较高的去除率,此结果为进一步的应用打下了良好的基础.

  10. 镍黄铁矿电化学生物氧化过程的分解机理%Decomposition mechanism of pentlandite during electrochemical bio-oxidation process

    Institute of Scientific and Technical Information of China (English)

    李宏煦; 李超; 张祉倩

    2012-01-01

    Electrochemical measurements were carried out to elucidate decomposition mechanism of pentlandite using modified powder microelectrode with Acidithiobacillus ferrooxidans attached or without on the mineral powder surface.Cyclic voltammetry (CV) results show that at a low potential of about -0.2 V (vs SCE),the pentlandite was transformed to an intermediated phase like Fe4.5-yNi4.5-xSR-z when Fe and Ni ions were evacuated from mineral lattice; when the potential was changed from -0.2 V to 0.2 V,the unstable violarite (Fe3Ni3S4) and FeNi2S4 were formed which was accompanied by element sulfur formed on the mineral surface;when the potential increased over 0.2 V,the unstable intermediated phase decomposed entirely; at a higher potential of 0.7 V,the evacuated ferrous ion was oxidized to ferric ion.The presence of Acidithiobacillus ferrooxidans made the oxidation peak current increase with initial peak potential negatively moving,and the bacteria also contributed to the sulfur removing from mineral surface,which was demonstrated by the reduction characteristic at potential ranging from -0.75 to -0.5 V.Leaching experiments and electrochemical results show that the solution acidity increasing when pH<2 may impede the oxidation process slightly.%应用表面粘附和没有粘附Acidithiobacillus ferrooxidans的镍黄铁矿粉末微电极进行电化学测试,以说明镍黄铁矿氧化分解的机理.循环伏安CV结果显示,在-0.2 V的低电位区域,在镍、铁离子析出时镍黄铁矿转变为中间相Fe4.5-yNi4.5-xS8-z;当电位在-0.2 V到0.2 V区间时,有不稳定的紫硫镍矿Fe3Ni3S4和FeNi2S4形成并在表面伴有元素硫的产生;当电位增加到0.2 V以上时,不稳定相将全部分解:在高电位0.7 V时,析出的亚铁离子被氧化为高铁离子.嗜酸氧化亚铁硫杆菌Acidithiobacillus ferrooxidans的存在使峰电位增高,反应起始电位负移,并对表面形成的元素硫有氧化去除作用.这一过程可通过-0.75到-0

  11. 浸矿微生物共培养体系在氟胁迫下的基因调控机理探索%Gene Regulation Mechanism of a Bioleaching Microbial Co-culture upon Fluoride Stress

    Institute of Scientific and Technical Information of China (English)

    李乾; 孙静; 丁德馨; 王清良; 马丽媛; 刘学端

    2015-01-01

    为了探明混合浸矿微生物的耐氟性能及其基因调控机理,应用功能基因芯片(FGA-Ⅱ)研究了5株浸矿细菌(Acidithiobacillus ferrooxidans ATCC 23270,Leptospirillum ferriphilum YSK, Sulfobacillus thermosulfidooxidans ST, Acidithiobacills thiooxidans A01, Acidithiobacills caldus S1)所构成的共培养体系在4.8 mmol/L氟胁迫下的基因表达谱.结果表明,该共培养体系中与氟胁迫相关的基因主要涉及到硫代谢、细胞膜、电子传递、解毒、碳固定、氮代谢等多个方面功能的代谢途径,而且各个途径在短时间(120 min)氟胁迫各个途径更倾向于低效表达.芯片图谱分析表明,氟胁迫下共培养体系中起主导调节作用的是其中的优势种群,但是劣势种群在氟胁迫时很大程度上辅助了优势种群的生长及其氧化活性的保持.%In order to explore the fluoride tolerance and the gene regulation mechanisms of mixed bioleaching microorganisms,the gene expression profile of a co-culture including five typical bioleaching strains ( Acidithiobacillus ferrooxidans ATCC 23270 , Leptospirillum fer-riphilum YSK,Sulfobacillus thermosulfidooxidans ST,Acidithiobacills thiooxidans A01,Acid-ithiobacills caldus S1 ) upon 4 . 8 mmol/L fluoride stress was investigated using the func-tional gene array. The results showed, the genes associated with fluoride stress were in-volved with sulfur metabolism,cell membrane,electron transport,detoxification,carbon fix-ation,nitrogen metabolism,and so on. Additionally,majority of genes was induced upon the short time ( 120 min) fluoride stress. The effects of fluoride stress on different microbial population in the co-cul-ture were different. The results revealed that the dominant species in the co-culture played the crucial role for resisting fluoride stress,while the minor species to a large extent assis-ted the oxidation ability preservation and growth of the dominant species.

  12. Application of fuel cell for pyrite and heavy metal containing mining waste

    Science.gov (United States)

    Keum, H.; Ju, W. J.; Jho, E. H.; Nam, K.

    2015-12-01

    Once pyrite and heavy metal containing mining waste reacts with water and air it produces acid mine drainage (AMD) and leads to the other environmental problems such as contamination of surrounding soils. Pyrite is the major source of AMD and it can be controlled using a biological-electrochemical dissolution method. By enhancing the dissolution of pyrite using fuel cell technology, not only mining waste be beneficially utilized but also be treated at the same time by. As pyrite-containing mining waste is oxidized in the anode of the fuel cell, electrons and protons are generated, and electrons moves through an external load to cathode reducing oxygen to water while protons migrate to cathode through a proton exchange membrane. Iron-oxidizing bacteria such as Acidithiobacillus ferrooxidans, which can utilize Fe as an electron donor promotes pyrite dissolution and hence enhances electrochemical dissolution of pyrite from mining waste. In this study mining waste from a zinc mine in Korea containing 17 wt% pyrite and 9% As was utilized as a fuel for the fuel cell inoculated with A. ferrooxidans. Electrochemically dissolved As content and chemically dissolved As content was compared. With the initial pH of 3.5 at 23℃, the dissolved As concentration increased (from 4.0 to 13 mg/L after 20 d) in the fuel cell, while it kept decreased in the chemical reactor (from 12 to 0.43 mg/L after 20 d). The fuel cell produced 0.09 V of open circuit voltage with the maximum power density of 0.84 mW/m2. Dissolution of As from mining waste was enhanced through electrochemical reaction. Application of fuel cell technology is a novel treatment method for pyrite and heavy metals containing mining waste, and this method is beneficial for mining environment as well as local community of mining areas.

  13. Inhibition of bacterial oxidation of ferrous iron by lead nitrate in sulfate-rich systems

    Science.gov (United States)

    Wang, Hongmei; Gong, Linfeng; Cravotta, Charles A.; Yang, Xiaofen; Tuovinen, Olli H.; Dong, Hailiang; Fu, Xiang

    2013-01-01

    Inhibition of bacterial oxidation of ferrous iron (Fe(II)) by Pb(NO3)2 was investigated with a mixed culture of Acidithiobacillus ferrooxidans. The culture was incubated at 30 °C in ferrous-sulfate medium amended with 0–24.2 mM Pb(II) added as Pb(NO3)2. Anglesite (PbSO4) precipitated immediately upon Pb addition and was the only solid phase detected in the abiotic controls. Both anglesite and jarosite (KFe3(SO4)2(OH)6) were detected in inoculated cultures. Precipitation of anglesite maintained dissolved Pb concentrations at 16.9–17.6 μM regardless of the concentrations of Pb(NO3)2 added. Fe(II) oxidation was suppressed by 24.2 mM Pb(NO3)2 addition even when anglesite was removed before inoculation. Experiments with 0–48 mM KNO3 demonstrated that bacterial Fe(II) oxidation decreased as nitrate concentration increased. Therefore, inhibition of Fe(II) oxidation at 24.2 mM Pb(NO3)2 addition resulted from nitrate toxicity instead of Pb addition. Geochemical modeling that considered the initial precipitation of anglesite to equilibrium followed by progressive oxidation of Fe(II) and the precipitation of jarosite and an amorphous iron hydroxide phase, without allowing plumbojarosite to precipitate were consistent with the experimental time-series data on Fe(II) oxidation under biotic conditions. Anglesite precipitation in mine tailings and other sulfate-rich systems maintains dissolved Pb concentrations below the toxicity threshold of A. ferrooxidans.

  14. Copper isotope fractionation in acid mine drainage

    Science.gov (United States)

    Kimball, B.E.; Mathur, R.; Dohnalkova, A.C.; Wall, A.J.; Runkel, R.L.; Brantley, S.L.

    2009-01-01

    We measured the Cu isotopic composition of primary minerals and stream water affected by acid mine drainage in a mineralized watershed (Colorado, USA). The ??65Cu values (based on 65Cu/63Cu) of enargite (??65Cu = -0.01 ?? 0.10???; 2??) and chalcopyrite (??65Cu = 0.16 ?? 0.10???) are within the range of reported values for terrestrial primary Cu sulfides (-1??? fractionation (??aq-min = ??65Cuaq - ??65Cumin, where the latter is measured on mineral samples from the field system), equals 1.43 ?? 0.14??? and 1.60 ?? 0.14??? for chalcopyrite and enargite, respectively. To interpret this field survey, we leached chalcopyrite and enargite in batch experiments and found that, as in the field, the leachate is enriched in 65Cu relative to chalcopyrite (1.37 ?? 0.14???) and enargite (0.98 ?? 0.14???) when microorganisms are absent. Leaching of minerals in the presence of Acidithiobacillus ferrooxidans results in smaller average fractionation in the opposite direction for chalcopyrite (??aq-mino = - 0.57 ?? 0.14 ???, where mino refers to the starting mineral) and no apparent fractionation for enargite (??aq-mino = 0.14 ?? 0.14 ???). Abiotic fractionation is attributed to preferential oxidation of 65Cu+ at the interface of the isotopically homogeneous mineral and the surface oxidized layer, followed by solubilization. When microorganisms are present, the abiotic fractionation is most likely not seen due to preferential association of 65Cuaq with A. ferrooxidans cells and related precipitates. In the biotic experiments, Cu was observed under TEM to occur in precipitates around bacteria and in intracellular polyphosphate granules. Thus, the values of ??65Cu in the field and laboratory systems are presumably determined by the balance of Cu released abiotically and Cu that interacts with cells and related precipitates. Such isotopic signatures resulting from Cu sulfide dissolution should be useful for acid mine drainage remediation and ore prospecting purposes. ?? 2008 Elsevier Ltd.

  15. Variation Characteristics of Microbial Community Structure on Uranium Heap Leaching Process Based on Analysis with PCR-Sequencing Method%PCR-测序法分析铀生物堆浸过程中微生物群落结构变化特征

    Institute of Scientific and Technical Information of China (English)

    杨国斌

    2014-01-01

    文章采用PCR-直接测序法研究了铀生物堆浸不同浸铀阶段(前期酸化、酸化、前期菌液淋洗、菌液浸铀)微生物群落结构的变化.采用试剂盒法提取了矿石样品中宏基因组DNA,以细菌的16S rDNA通用引物27F/1492R扩增16S rDNA片段,建立16S rDNA克隆文库.从每个处理结果中筛选100个阳性克隆,阳性克隆子直接送测序,用NCBI Blastn程序进行基因数据比对分析,结果表明:从前期酸化阶段到菌液浸出阶段,菌落多样性呈减弱趋势,对浸铀有直接或间接作用的嗜酸性微生物:嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans)、嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)等的含量呈增加趋势.在菌液浸出阶段,pH值低于最小值1.8时,细菌多样性较高,对浸铀有直接或间接作用的嗜酸性微生物丰度较低.说明嗜酸性微生物对铀的浸出可能有重要作用,生物堆浸过程中需要严格调控pH值.

  16. Molecular Characterization of Bacterial Respiration on Minerals

    Energy Technology Data Exchange (ETDEWEB)

    Blake, Robert C.

    2013-04-26

    The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength

  17. Eficiência e efeito residual de biofertilizantes de rochas com PK e enxofre com Acidithiobacillus em alface Efficiency and residual effect of PK rock biofertilizers with sulfur and Acidithiobacillus on lettuce

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Matias de Lima

    2007-09-01

    Full Text Available Entre agosto e novembro de 2005 foi realizado um experimento em campo, com dois plantios consecutivos de alface (cv. Grand Rapids, em solo do Cariri cearense, visando avaliar a eficiência da fertilização com biofertilizantes de rocha fosfatada (BP e potássica (BK, em comparação com os fertilizantes minerais superfosfato simples(SFS e cloreto de potássio (KCl. Os fertilizantes minerais foram aplicados nos níveis recomendados com base na análise de solo para alface (SFS e KCl, e os biofertilizantes em três níveis (BP1 e BK1 metade da recomendação; BP2 e BK2 nível recomendado e BP3 e BK3 uma vez e meia o recomendado para SFS e KCl, e o tratamento controle (P0K0 sem aplicação de P e K. O delineamento experimental foi de blocos casualizados, em esquema fatorial 5², com quatro repetições. Os resultados demonstraram que o desempenho dos biofertilizantes com P e K foi equivalente ao dos fertilizantes minerais, especialmente com aplicação no nível BP2BK3. No segundo cultivo ficou evidenciado o efeito residual para produtividade da alface (biomassa fresca da parte aérea, altura, número de folhas, avaliação comercial e acumulação de P e K na parte aérea. Os resultados sugerem que os biofertilizantes de rochas com P e K podem ser usados como alternativa a fertilizantes minerais.Production of rock biofertilizers is a practical process with reduction of energy consumption and increasing nutrients availability in soils. To evaluate the agronomic efficiency and the residual effect of P rock biofertilizer (PB and potash rock (KB, compared to simple superphosphate (SSP and potassium chloride (KCl, a field experiment with two consecutive lettuce crops (cv. Grand Rapids was carried out in a soil at Cariri (Ceará, Brazil, from August to September 2005. The mineral fertilizers were applied in the levels recommended for lettuce (SSP and KCl, and the biofertilizers in three levels (PB1 and KB1 half of recommended levels; recommended levels PB2 and KB2 and 150% the recommended level PB3 and KB3 for SSP and KCl and a control treatment with no P and K (P0K0. The experimental design was a factorial 5² in the randomized block, with four replicates. There was similar performance of the PK rock biofertilizers compared to the mineral fertilizers, especially when the level BP2BK3 was applied. The consecutive crop showed residual effect on lettuce yield (fresh shoot biomass, height, number of leaves, commercial evaluation, and P and K accumulation on shoot dry biomass. The results suggest that P and K rock biofertilizers may be used as an alternative in mineral fertilization.

  18. The effect of Acidithiobacillus thiooxidans TT03 to alkaline soil%嗜酸性氧化硫硫杆菌(Acidithiobacillus thiooxidans)TT03对碱性土壤的作用效果

    Institute of Scientific and Technical Information of China (English)

    郭立姝; 于丽萍; 殷博; 曹亚彬; 吴皓琼; 牛彦波; 甄涛; 党阿丽

    2013-01-01

    针对前期研究中选育出的氧化硫硫杆菌TT03,为了解其对单质硫的转化作用而进行了试验.试验的结果表明,TT03与硫粉的加入,使得碱斑土壤与碱性耕作土壤的pH及性状发生改变,土壤向有利于耕作的方向发展;在碱性土壤中,培养到28d时pH下降到7.94,硫酸根含量达到187.4 mg/kg,单质硫转化率达56.4%;在培养至63d时,pH下降到7.73,硫酸根含量上升到232.3 mg/kg,单质硫转化率达71.4%.

  19. An XPS analytical approach for elucidating the microbially mediated enargite oxidative dissolution.

    Science.gov (United States)

    Fantauzzi, M; Rossi, G; Elsener, B; Loi, G; Atzei, D; Rossi, A

    2009-04-01

    In this work, the microbe-mediated oxidative dissolution of enargite surfaces (Cu(3)AsS(4)) was studied on powdered samples exposed to 9K nutrient solution (pH 2.3) inoculated by Acidithiobacillus ferrooxidans initially adapted to arsenopyrite. These conditions simulate the acid mine environment. The redox potential of the inoculated solutions increased up to +0.72 V vs normal hydrogen electrode (NHE), indicating the increase of the Fe(3+) to Fe(2+) ratio, and correspondingly the pH decreased to values as low as 1.9. In the sterile 9K control, the redox potential and pH remained constant at +0.52 V NHE and 2.34, respectively. Solution analyses showed that in inoculated medium Cu and As dissolved stoichiometrically with a dissolution rate of about three to five times higher compared to the sterile control. For the first time, X-ray photoelectron spectroscopy (XPS) was carried out on the bioleached enargite powder with the aim of clarifying the role of the microorganisms in the dissolution process. XPS results provide evidence of the formation of a thin oxidized layer on the mineral surface. Nitrogen was also detected on the bioleached surfaces and was attributed to the presence of an extracellular polymer substance layer supporting a mechanism of bacteria attachment via the formation of a biofilm a few nanometers thick, commonly known as nanobiofilm.

  20. Effect of neutralized solid waste generated in lime neutralization on the ferrous ion bio-oxidation process during acid mine drainage treatment.

    Science.gov (United States)

    Liu, Fenwu; Zhou, Jun; Zhou, Lixiang; Zhang, Shasha; Liu, Lanlan; Wang, Ming

    2015-12-15

    Bio-oxidation of ferrous ions prior to lime neutralization exhibits great potential for acid mine drainage (AMD) treatment, while slow ferrous ion bio-oxidation or total iron precipitation is a bottleneck in this process. In this study, neutralized solid waste (NSW) harvested in an AMD lime neutralization procedure was added as a crystal seed in AMD for iron oxyhydroxysulfate bio-synthesis. The effect of this waste on ferrous ion oxidation efficiency, total iron precipitation efficiency, and iron oxyhydroxysulfate minerals yield during ferrous ion bio-oxidation by Acidithiobacillus ferrooxidans was investigated. Ferrous ion oxidation efficiency was greatly improved by adding NSW. After 72 h incubation, total iron precipitation efficiency in treatment with 24 g/L of NSW was 1.74-1.03 times higher than in treatment with 0-12 g/L of NSW. Compared with the conventional treatment system without added NSW, the iron oxyhydroxysulfate minerals yield was increased by approximately 21.2-80.9% when 3-24 g/L of NSW were added. Aside from NSW, jarosite and schwertmannite were the main precipitates during ferrous ion bio-oxidation with NSW addition. NSW can thus serve as the crystal seed for iron oxyhydroxysulfate mineral bio-synthesis in AMD, and improve ferrous ion oxidation and total iron precipitation efficiency significantly.