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Mireille Bruschi - One of the best experts on this subject based on the ideXlab platform.
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conformational properties of multihemic cytochromes c from desulfuromonas acetoxidans
Thermochimica Acta, 2003Co-Authors: M T Giudiciorticoni, V M Lobachov, I I Protasevich, A. A. Makarov, Dusan Lexa, Mireille BruschiAbstract:Abstract In the classification of c-type cytochromes, the class III includes multihemic cytochromes c with low redox potential constituting the cytochrome c3 superfamily. Most of the cytochromes described have been isolated from sulfate or sulfur reducing Bacteria. We report here the comparison between two multihemic cytochromes, the newly characterized 50 kDa cytochrome from Desulfuromonas acetoxidans and the cytochrome c7 from the same strain in order to contribute to understanding the relationships between members of this superfamily. The thermostability of these cytochromes was studied by circular dichroism (CD) and differential scanning calorimetry (DSC). The influence of the temperature on the redox potential was also investigated. The data clearly indicate the presence of two domains in 50 kDa cytochrome and a drastic loss of stability of cytochrome c7 in comparison to cytochrome c3. The results are discussed in the light of the structural properties of the cytochrome c3 superfamily and two sub-groups in this family are proposed.
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resonance raman study of multihemic c type cytochromes from desulfuromonas acetoxidans
FEBS Journal, 2000Co-Authors: Genevia Ve Chottard, Irina Kazanskaya, Mireille BruschiAbstract:Two multihemic cytochromes c from the sulfur reducing Bacteria Desulfuromonas acetoxidans have been studied by optical and resonance Raman spectroscopy: cytochrome c551.5, a trihemic cytochrome and cytochrome c Mr 50 000, a recently isolated high molecular mass cytochrome. The redox and Raman characteristics of cytochrome c551.5 are compared to those of the tetrahemic cytochromes c3 from Desulfovibrio. While the redox behavior, followed by spectroelectrochemistry, is similar to that of cytochrome c3, showing the same conformational change after reduction of the highest potential heme, the Raman data show a contribution from a His− form of the axial ligands and lead to the assignment of a band at 218 cm−1 to the Fe(III)–(His)2 stretching vibration. The Raman data on cytochrome c Mr 50 000 are in favor of an entirely low spin species with two different sets of axial ligands. A partially reduced state is easily accessible by ascorbate addition.
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biochemical and spectroscopic characterization of two new cytochromes isolated from desulfuromonas acetoxidans
Biochemistry, 1997Co-Authors: Mireille Bruschi, Mireille Woudstra, Marcel Asso, Yves Pétillot, Elisabeth Lojou, Bruno Guigliarelli, Chantal AbergelAbstract:: The multimeric cytochromes described to date in sulfate- and Sulfur-Reducing Bacteria are associated with diverse respiratory modes involving the use of elemental sulfur or oxidized sulfur compounds as terminal acceptors. They exhibit no structural similarity with the other cytochrome c classes and are characterized by a bis-histidinyl axial iron coordination and low redox potentials. We have purified two new cytochromes c with markedly different molecular masses (10 000 and 50 000) from the bacterium Desulfuromonas acetoxidans, which uses anaerobic sulfur respiration as its sole energy source. The characterization by electrochemistry and optical and EPR spectroscopies revealed the cytochrome c (Mr = 10 000) to be the first monohemic cytochrome c exhibiting a bis-histidinyl axial coordination and a low redox potential (-220 mV). The cytochrome c (Mr = 50 000) contains four hemes of low potential (-200, -210, -370, and -380 mV) with the same axial coordination. The N-terminal amino acid sequences were compared with that of the trihemic cytochrome c7, previously described in D. acetoxidans and which is related to tetrahemic cytochrome c3 from sulfate reducing Bacteria. Some homology was found between cytochrome c (Mr = 10 000) and cytochrome c7. Both D. acetoxidans cytochromes c are located in the periplasmic space and their biochemical and spectroscopic properties indicate that they belong to the class III cytochromes.
Svitlana O Hnatush - One of the best experts on this subject based on the ideXlab platform.
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light scattering spectra of sulfur reducing Bacteria desulfuromonas acetoxidans under the influence of ions fe metals
Tenth International Conference on Correlation Optics, 2011Co-Authors: Olexsandr I Bilyy, Oresta M Vasyliv, Svitlana O HnatushAbstract:Desulfuromonas acetoxidans are uncoloured gram-negative sulfur Bacteria that inhabit sulfur containing aquatic environments. These are gram-negative obligatory anaerobes that have an ability to reduce S 0 to H 2 S and Fe 3+ to Fe 2+ in the processes of dissimilation Sulfur- and Fe (III)-reduction. Existence of Sulfur and Ferric ions in the anaerobic sediments causes binding of hydrogen sulfide which diffuses from the zone of sulfur reducing. As a result hydrogen sulfide is detoxificated. The ability of these Bacteria to use Sulfur or Ferric ions as acceptors of electrons during organic carbon oxidation causes their special adaptation to the changes of surrounding environment. Interaction between Bacterial Desulfuromonas acetoxidans cells and different concentrations of ferrous Fe 2+ and ferric Fe 3+ ions possibly could cause the changes of cells' light scattering characteristics. The changes of cells relative content and their size distribution during five days of cultivation under the influence of FeSO4 and FeCl 3 ×6H 2 O in concentration from 0.01 to 10 mM was investigated by the new method of measurement. It includes sounding of flow suspended Bacterial cells by monochromatic coherent light, registration of signals of co-operation of sounding radiation with the explored microbiological objects by detects of the changes of amplitudes and durations of scattered light impulses. Under the influence from 0.01 to 10 mM of FeSO4 the maximum of cells' size distribution changed from 0.55 to 0.62 μm and effect of investigated range of FeCl 3 ×6H 2 O concentrations caused it changes from 0.43 to 0.49 μm during five days of sulfurreducing Desulfuromonas acetoxidans Bacteria growth.
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the influence of different metal ions on light scattering properties of pattern microbial fuel cells Bacteria desulfuromonas acetoxidans
Reliability of Photovoltaic Cells Modules Components and Systems IV, 2011Co-Authors: Oresta M Vasyliv, Vasyl B Getman, Olexsandr I Bilyy, Yaroslav P Ferensovyich, Roman Y Yaremyk, Svitlana O HnatushAbstract:Microbial fuel cell (MFC) technologies represent the newest approach for generating electricity - bioelectricity generation from biomass using Bacteria. Desulfuromonas acetoxidans are aquatic obligatory anaerobic Sulfur-Reducing Bacteria that possess an ability to produce electric current in the processes of organic matter oxidation and Fe 3+ - or Mn 4+ - reduction. These are pattern objects for MFC systems. They could be applied as a highly effective and self-sustaining model of wastewater treatment which contains energy in the form of biodegradable organic matter. But wastewaters contain high concentrations of xenobiotics, such as different heavy metals that have a detrimental effect towards all living organisms. The influence of different concentrations of MnCl 2 ×4H 2 O, FeSO 4 CuSO 4 , CdSO 4 , ZnSO 4 and PbNO 3 on light scattering properties of aquatic D. acetoxidans Bacteria on the base of their cells' size distribution and relative content has been investigated by the new method of measurement. The cell distribution curve was in the range of 0.4 - 1.4 μm. The most crucial changes of cell concentration dependences, compared with other investigated metal ions, have been observed under the influence of copper ions. The ability of D. acetoxidans Bacteria to produce electric current upon the specific cultivation conditions and the influence of Fe 2+ and Mn 2+ has been verified.
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the influence of 3d3 type transition metals on light scattering properties of sulfur cycle Bacteria desulfuromonas acetoxidans
Biomedical spectroscopy and imaging, 2011Co-Authors: Oleksandr I Bilyi, Oresta M Vasyliv, Vasyl B Getman, Svitlana O Hnatush, Galyna I KotsyumbasAbstract:Light scattering properties of Bacterial cells mostly depend on their sizes, refractive indexes of their components and surrounding environment. Interaction between Bacterial cells and 3d3 type transition metals causes their optical characteristics' changes. Desulfuromonas acetoxidans are uncolored gram-negative obligatory anaerobic sulfur reducing Bacteria that can be used as microbial fuel cells with high electron recovery from different organic compounds oxidation to electric current as a result of electrons transfer in the processes of sulfur and some 3d3 type transition metals reduction, such as Ferrum and Manganese. In this study size distribution and relative content in the chosen interval of sizes (0.2 ? 2.0 µm) of sulfur reducing D. acetoxidans Bacterial cells under the influence of different concentrations of manganese chloride (II) hexahydrate, ferrous chloride (III) hexahydrate and ferrous sulfate (II) have been investigated by the new method of measuring. A method includes sounding of flow suspended Bacterial cells by monochromatic coherent light, registration of signals of co-operation of sounding radiation with the explored microbiological objects by detects amplitudes and durations of scattered light impulses. Correlation between changes of light-scattering properties and growth of Desulfuromonas acetoxidans cells under these conditions has been shown.
Feng Jiang - One of the best experts on this subject based on the ideXlab platform.
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a pilot scale sulfur based sulfidogenic system for the treatment of cu laden electroplating wastewater using real domestic sewage as electron donor
Water Research, 2021Co-Authors: Zhensheng Liang, Jianliang Sun, Yanying Qiu, Chuyin Qiu, Xiaomin Liang, Yuhang Zhu, Peng Wang, Feng JiangAbstract:Abstract Elemental sulfur (S0) reduction process has been demonstrated as an attractive and cost-efficient approach for metal-laden wastewater treatment in lab-scale studies. However, the system performance and stability have not been evaluated in pilot- or large-scale wastewater treatment. Especially, the sulfide production rate and microbial community structure may significantly vary from lab-scale system to pilot- or large-scale systems using real domestic sewage as carbon source, which brings questions to this novel technology. In this study, therefore, a pilot-scale sulfur-based sulfidogenic treatment system was newly developed and applied for the treatment of Cu-laden electroplating wastewaters using domestic sewage as carbon source. During the 175-d operation, >99.9% of Cu2+ (i.e., 5580 and 1187 mg Cu/L for two types of electroplating wastewaters) was efficiently removed by the biogenic hydrogen sulfide that produced through S0 reduction. Relatively high level of sulfide production (200 mg S/L) can be achieved by utilizing organics in raw domestic sewage, which was easily affected by the organic content and pH value of the domestic sewage. The long-term feeding of domestic sewage significantly re-shaped the microbial community in Sulfur-Reducing bioreactors. Compared to the reported lab-scale bioreactors, higher microbial community diversity was found in our pilot-scale bioreactors. The presence of hydrolytic, fermentative and Sulfur-Reducing Bacteria was the critical factor for system stability. Accordingly, a two-step ecological interaction among fermentative and Sulfur-Reducing Bacteria was newly proposed for sulfide production: biodegradable particulate organic carbon (BPOC) was firstly degraded to dissolved organic carbon (DOC) by the hydrolytic and fermentative Bacteria. Then, Sulfur-Reducing Bacteria utilized the total DOC (both DOC degraded from BPOC and the original DOC present in domestic sewage) as electron donor and reduced the S0 to sulfide. Afterwards, the sulfide precipitated Cu2+ in the post sedimentation tank. Compared with other reported technologies, the sulfur-based treatment system remarkable reduced the total chemical cost by 87.5‒99.6% for the same level of Cu2+ removal. Therefore, this pilot-scale study demonstrated that S0 reduction process can be a sustainable technology to generate sulfide for the co-treatment of Cu-laden electroplating wastewater and domestic sewage, achieving higher Cu2+removal and higher cost-effectiveness than the conventional technologies.
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removal of heavy metals using a novel sulfidogenic amd treatment system with sulfur reduction configuration performance critical parameters and economic analysis
Environment International, 2020Co-Authors: Yu Li, Chunxi Ou, Xiaoyi Wang, Liang Zhang, Feng JiangAbstract:Abstract A novel sulfidogenic acid mine drainage (AMD) treatment system with a sulfur reduction process was developed. During the 220-d operation, >99.9% of 380-mg/L ferric, 150-mg/L aluminum, 110-mg/L zinc, 20-mg/L copper and 2.5-mg/L lead ions, and 42.6–44.4% of 100-mg/L manganese ions in the synthetic AMD were step-by-step removed in the developed system with three pre-posed metal precipitators and a sulfur reduction reactor. Among them, zinc, copper and lead ions were removed by the biogenic hydrogen sulfide that produced through elemental sulfur reduction; while ferric, aluminum and manganese ions were removed by the alkali precipitation. Compared with the reported sulfate reduction reactors, the sulfur reduction reactor significantly reduced the chemical cost by 25.6–78.9% for sulfide production, and maintained a high sulfide production rate (1.12 g S2-/L-d). The pH level in the sulfidogenic reactor driven by Sulfur-Reducing Bacteria posed a significant effect on the sulfide production rate. Under a nearly neutral condition (pH 7.0–7.5), elemental sulfur dissolved into polysulfide to increase the bioavailability of S0. At acidic conditions (pH
T Runge - One of the best experts on this subject based on the ideXlab platform.
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impacts to hydrogen sulfide concentrations in biogas when poplar wood chips steam treated wood chips and biochar are added to manure based anaerobic digestion systems
Bioresource Technology Reports, 2019Co-Authors: Hui Wang, R A Larson, T RungeAbstract:Abstract Hydrogen sulfide (H2S) causes maintenance issues in anaerobic digesters (AD). This study investigates the feasibility of biochar to reduce H2S in biogas produced from manure-based ADs. Two experiments were conducted where (1) biochar, steam treated wood, and raw wood produced from poplar wood chips were added to a respirometer system and the H2S reduction measured, and (2) biochar sulfate (SO42−) adsorption was investigated as a potential mechanism for H2S reduction. Results indicate that poplar wood biochar additions (3 g of biochar per 500 g of manure) reduced the H2S in biogas by 78% per g of TS fed, but did not impact methane (CH4) production. The second experiment indicates biochar sorption of SO42− before conversion to H2S by sulfur reducing Bacteria (SRB) is not the primary removal mechanism, suggesting other mechanisms such as SRB inhibition, direct sorption of H2S, or increased dissociation of H2S to HS− drive the H2S reduction.
Yong Wang - One of the best experts on this subject based on the ideXlab platform.
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microbial ecology of sulfur cycling near the sulfate methane transition of deep sea cold seep sediments
Environmental Microbiology, 2021Co-Authors: Xiyang Dong, Dong Feng, Yingli Zhou, Pengfei Zheng, Yong WangAbstract:Microbial sulfate reduction is largely associated with anaerobic methane oxidation and alkane degradation in sulfate-methane transition zone (SMTZ) of deep-sea cold seeps. How the sulfur cycling is mediated by microbes near SMTZ has not been fully understood. In this study, we detected a shallow SMTZ in three of eight sediment cores sampled from two cold seep areas in the South China Sea. 110 genomes representing sulfur-oxidizing Bacteria (SOB) and Sulfur-Reducing Bacteria (SRB) strains were identified from three SMTZ-bearing cores. In the layers above SMTZ, SOB were mostly constituted by Campylobacterota, GammaproteoBacteria and AlphaproteoBacteria that probably depended on nitrogen oxides and/or oxygen for oxidation of sulfide and thiosulfate in near-surface sediment layers. In the layers below the SMTZ, the deltaproteoBacterial SRB genomes and metatranscriptomes revealed CO2 fixation by Wood-Ljungdahl pathway, sulfate reduction and nitrogen fixation for syntrophic or fermentative lifestyles. 68% of the MAGs were not adjacent to known species in a phylogenomic tree, indicating a high diversity of Bacteria involved in sulfur cycling. With the large number of genomes for SOB and SRB, our study uncovers the microbial populations that potentially mediate sulfur metabolism and associated carbon and nitrogen cycles, which sheds light on complex biogeochemical processes in deep-sea environments. This article is protected by copyright. All rights reserved.
