A5060098954- Microbial Fuel Cells and Bioremediation
- Electrochemical sensors and biosensors
- Electrochemical Analysis and Applications
- Metal Extraction and Bioleaching
- Microbial Community Ecology and Physiology
- Bacterial biofilms and quorum sensing
- Geochemistry and Elemental Analysis
- Corrosion Behavior and Inhibition
- Radioactive element chemistry and processing
- Wastewater Treatment and Nitrogen Removal
- Supercapacitor Materials and Fabrication
- Mine drainage and remediation techniques
- Protist diversity and phylogeny
- Anaerobic Digestion and Biogas Production
- Microbial Metabolic Engineering and Bioproduction
- Photosynthetic Processes and Mechanisms
- Building materials and conservation
- Mining and Gasification Technologies
- Advanced Nanomaterials in Catalysis
- ATP Synthase and ATPases Research
- Genomics and Phylogenetic Studies
- CO2 Reduction Techniques and Catalysts
- Electrocatalysts for Energy Conversion
- Enzyme Structure and Function
- Bacterial Genetics and Biotechnology
University of Minnesota
2015-2024
Biotechnology Institute
2015-2024
Mississippi State University
2022
Twin Cities Orthopedics
2007-2020
Laboratoire de Biochimie
2018
Hunter Cancer Research Alliance
2015
University of Minnesota System
2007-2012
University of Massachusetts Amherst
2002-2009
Parker Hannifin (United States)
2009
Miele (Germany)
2009
ABSTRACT Previous studies have suggested that members of the Geobacteraceae can use electrodes as electron acceptors for anaerobic respiration. In order to better understand this transfer process energy production, Geobacter sulfurreducens was inoculated into chambers in which a graphite electrode served sole acceptor and acetate or hydrogen donor. The electron-accepting were maintained at oxidizing potentials by connecting them similar oxygenated medium (fuel cells) potentiostats poised...
Bacteria able to transfer electrons metals are key agents in biogeochemical metal cycling, subsurface bioremediation, and corrosion processes. More recently, these bacteria have gained attention as the of from cell surface conductive materials can be used multiple applications. In this work, we adapted electrochemical techniques probe intact biofilms Shewanella oneidensis MR-1 sp. MR-4 grown by using a poised electrode an electron acceptor. This approach detected redox-active molecules...
Energy in the form of electricity can be harvested from marine sediments by placing a graphite electrode (the anode) anoxic zone and connecting it to cathode overlying aerobic water. We report specific enrichment microorganisms family Geobacteraceae on energy-harvesting anodes, we show that these conserve energy support their growth oxidizing organic compounds with an serving as sole electron acceptor. This finding not only provides method for extracting matter, but also suggests strategy...
Summary It has been demonstrated previously that Geobacter species can transfer electrons directly to electrodes. In order determine whether electrodes could serve as electron donors for microbial respiration, enrichment cultures were established from a sediment inoculum with potentiostat‐poised graphite electrode the sole donor and nitrate acceptor. Nitrate was reduced nitrite consumption of electrical current. The stoichiometry accumulation consistent serving reduction. Analysis 16 rRNA...
ABSTRACT While electrochemical characterization of enzymes immobilized on electrodes has become common, there is still a need for reliable quantitative methods study electron transfer between living cells and conductive surfaces. This work describes growth thin (<20 μm) Geobacter sulfurreducens biofilms polished glassy carbon electrodes, using stirred three-electrode anaerobic bioreactors controlled by potentiostats nondestructive voltammetry techniques viable biofilms. Routine in vivo...
The Mtr respiratory pathway of Shewanella oneidensis strain MR-1 is required to effectively respire both soluble and insoluble forms oxidized iron. Flavins (riboflavin flavin mononucleotide) recently have been shown be excreted by facilitate the reduction substrates. Other species tested accumulated flavins in supernatants an extent similar that MR-1, suggesting secretion a general trait species. External proposed act as electron shuttle metal chelator; however, at biologically relevant...
Bioelectrochemical systems rely on microorganisms to link complex oxidation/reduction reactions electrodes. For example, in Shewanella oneidensis strain MR-1, an electron transfer conduit consisting of cytochromes and structural proteins, known as the Mtr respiratory pathway, catalyzes flow from cytoplasmic oxidative Reversing this drive microbial reductive metabolism offers a possible route for electrosynthesis high value fuels chemicals. We examined electrodes into determine feasibility...
ABSTRACT Desulfobulbus propionicus was able to grow with Fe(III), the humic acids analog anthraquinone-2,6-disulfonate (AQDS), or a graphite electrode as an electron acceptor. These results provide explanation for enrichment of Desulfobulbaceae species on surface electrodes harvesting electricity from anaerobic marine sediments and further expand diversity microorganisms known have ability use both sulfate Fe(III)
Shewanella oneidensis strain MR-1 can respire using carbon electrodes and metal oxyhydroxides as electron acceptors, requiring mechanisms for transferring electrons from the cell interior to surfaces located beyond cell. Although purified outer membrane cytochromes will reduce both metals, S. also secretes flavins, which accelerate transfer metals electrodes. We developed techniques detecting direct by intact cells, turnover single voltammetry. Metabolically active cells attached graphite...
Abstract The ability of Geobacter sulfurreducens to utilize electrodes as electron acceptors provides a system for monitoring mechanisms transfer beyond the cell surface. This study examined physiology extracellular during many stages growth, and in response short‐ long‐term changes acceptor potential. When G. was grown on planar potentiostat‐controlled electrodes, magnitude early attachment increased with initial density. However, first cells attach did not demonstrate same rates...
ABSTRACT Geobacter sulfurreducens is a well-studied representative of the Geobacteraceae , which play critical role in organic matter oxidation coupled to Fe(III) reduction, bioremediation groundwater contaminated with organics or metals, and electricity production from waste matter. In order investigate G. central metabolism electron transport, metabolic model integrated genome-based predictions available genetic physiological data was developed via constraint-based modeling approach....
In experiments performed using graphite electrodes poised by a potentiostat (+200 mV versus Ag/AgCl) or in microbial fuel cell (with oxygen as the electron acceptor), Fe(III)-reducing organism Geothrix fermentans conserved energy to support growth coupling complete oxidation of acetate reduction electrode. Other organic compounds, such lactate, malate, propionate, and succinate well components peptone yeast extract, were utilized for electricity production. However, electrical...
Summary Five methanogens ( Methanosarcina barkeri MS, Methanosphaera cuniculi 1R7, Methanobacterium palustre F, Methanococcus voltaei A3 and Methanolobus vulcani PL‐12/M) were investigated for their ability to reduce Fe(III) oxide the soluble quinone anthraquinone‐2,6‐disulphonate (AQDS). Two species M. ) reduced significant amounts of using hydrogen as electron donor, 0.1 mM AQDS greatly accelerated reduction by these organisms. Although appeared inhibit growth methanogenesis some strains,...
Transposon insertions in Geobacter sulfurreducens GSU1501, part of an ATP-dependent exporter within operon polysaccharide biosynthesis genes, were previously shown to eliminate insoluble Fe(III) reduction and use electrode as electron acceptor. Replacement GSU1501 with a kanamycin resistance cassette produced similarly defective mutant, which could be partially complemented by expression GSU1500 GSU1505 trans. The Δ1501 mutant demonstrated limited cell-cell agglutination, enhanced attachment...
Abstract Bacteria able to transfer electrons conductive surfaces are of interest as catalysts in microbial fuel cells, well bioprocessing, bioremediation, and corrosion. New procedures for immobilization Geobacter sulfurreducens on graphite electrodes described that allow routine, repeatable electrochemical analysis cell–electrode interactions. Immediately after immobilizing G. electrodes, electrical current was obtained without addition exogenous electron shuttles or electroactive polymers....
ABSTRACT Previous studies have shown that members of the family Geobacteraceae attach to anodes sediment fuel cells are directly involved in harvesting electricity by oxidizing organic compounds carbon dioxide and transferring electrons anode. In order learn more about this process, microorganisms from anode surface a marine cell were enriched isolated with Fe(III) oxide. Two unique isolates recovered, strains A1 T A2. They gram-negative, nonmotile rods, abundant c -type cytochromes....
Abstract Geobacter spp. can form a biofilm that is more than 20 μm thick on an anode surface by utilizing the as terminal respiratory electron acceptor. Just how microbes transport electrons through and across biofilm/anode interface, what determines upper limit to thickness catalytic activity (i.e., current, rate at which are transferred anode), fundamental questions attracting substantial attention. A significant body of experimental evidence suggests from individual cells network...
The multi-heme, outer membrane c-type cytochrome (c-Cyt) OmcB of Geobacter sulfurreducens was previously proposed to mediate electron transfer across the membrane. However, underlying mechanism has remained uncharacterized. In G. sulfurreducens, omcB gene is part two tandem four-gene clusters, each predicted encode a transcriptional factor (OrfR/OrfS), porin-like protein (OmbB/OmbC), periplasmic (OmaB/OmaC) and an c-Cyt (OmcB/OmcC) respectively. Here, we showed that OmbB/OmbC, OmaB/OmaC...
Biofilm synesthesia: A simultaneous spectral and electrochemical analysis reveals the redox status of cytochromes within living electroactive biofilms Geobacter. The results confirm that primary electron reservoirs these are c-type suggest which act as kinetic bottlenecks to transfer.
The respiration of metals by the bacterium Geobacter sulfurreducens requires electrons generated metabolism to pass from interior cell electron acceptors beyond membranes. G. inner membrane multiheme c-type cytochrome ImcH is required for extracellular with redox potentials greater than -0.1 V vs. SHE, but not essential transfer lower potential acceptors. In contrast, deletion cbcL, encoding an protein consisting b-type and domains, severely affected reduction low such as Fe(III)-oxides...
Cellular metabolism is a series of tightly linked oxidations and reductions that must be balanced. Recycling intracellular electron carriers during fermentation often requires substrate conversion to undesired products, while respiration demands constant addition acceptors. The use electrode-based acceptors balance biotransformations may overcome these constraints. To test this hypothesis, the metal-reducing bacterium Shewanella oneidensis was engineered stoichiometrically convert glycerol...
Dissimilatory metal-reducing bacteria, such as Geobacter sulfurreducens, transfer electrons beyond their outer membranes to Fe(III) and Mn(IV) oxides, heavy metals, electrodes in electrochemical devices. In the environment, metal acceptors exist multiple chelated insoluble forms that span a range of redox potentials offer different amounts available energy. Despite this, bacteria have not been shown alter electron strategies take advantage these energy differences. Disruption imcH, encoding...