301
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Holmes DE, Nevin KP, Snoeyenbos-West OL, Woodard TL, Strickland JN, Lovley DR. Protozoan grazing reduces the current output of microbial fuel cells. BIORESOURCE TECHNOLOGY 2015; 193:8-14. [PMID: 26115527 DOI: 10.1016/j.biortech.2015.06.056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/09/2015] [Accepted: 06/12/2015] [Indexed: 06/04/2023]
Abstract
Several experiments were conducted to determine whether protozoan grazing can reduce current output from sediment microbial fuel cells. When marine sediments were amended with eukaryotic inhibitors, the power output from the fuel cells increased 2-5-fold. Quantitative PCR showed that Geobacteraceae sequences were 120 times more abundant on anodes from treated fuel cells compared to untreated fuel cells, and that Spirotrichea sequences in untreated fuel cells were 200 times more abundant on anode surfaces than in the surrounding sediments. Defined studies with current-producing biofilms of Geobacter sulfurreducens and pure cultures of protozoa demonstrated that protozoa that were effective in consuming G. sulfurreducens reduced current production up to 91% when added to G. sulfurreducens fuel cells. These results suggest that anode biofilms are an attractive food source for protozoa and that protozoan grazing can be an important factor limiting the current output of sediment microbial fuel cells.
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Affiliation(s)
- Dawn E Holmes
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States; Department of Physical and Biological Sciences, Western New England University, Springfield, MA, United States.
| | - Kelly P Nevin
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
| | | | - Trevor L Woodard
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
| | - Justin N Strickland
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
| | - Derek R Lovley
- Department of Microbiology, University of Massachusetts, Amherst, MA, United States
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302
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303
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Larom S, Kallmann D, Saper G, Pinhassi R, Rothschild A, Dotan H, Ankonina G, Schuster G, Adir N. The Photosystem II D1-K238E mutation enhances electrical current production using cyanobacterial thylakoid membranes in a bio-photoelectrochemical cell. PHOTOSYNTHESIS RESEARCH 2015; 126:161-9. [PMID: 25588957 DOI: 10.1007/s11120-015-0075-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 01/02/2015] [Indexed: 05/12/2023]
Abstract
The conversion of solar energy (SEC) to storable chemical energy by photosynthesis has been performed by photosynthetic organisms, including oxygenic cyanobacteria for over 3 billion years. We have previously shown that crude thylakoid membranes from the cyanobacterium Synechocytis sp. PCC 6803 can reduce the electron transfer (ET) protein cytochrome c even in the presence of the PSII inhibitor DCMU. Mutation of lysine 238 of the Photosystem II D1 protein to glutamic acid increased the cytochrome reduction rates, indicating the possible position of this unknown ET pathway. In this contribution, we show that D1-K238E is rather unique, as other mutations to K238, or to other residues in the same vicinity, are not as successful in cytochrome c reduction. This observation indicates the sensitivity of ET reactions to minor changes. As the next step in obtaining useful SEC from biological material, we describe the use of crude Synechocystis membranes in a bio-photovoltaic cell containing an N-acetyl cysteine-modified gold electrode. We show the production of significant current for prolonged time durations, in the presence of DCMU. Surprisingly, the presence of cytochrome c was not found to be necessary for ET to the bio-voltaic cell.
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Affiliation(s)
- Shirley Larom
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Dan Kallmann
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Grand Technion Energy Program, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Faculty of Material Science and Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Gadiel Saper
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Grand Technion Energy Program, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Faculty of Material Science and Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Roy Pinhassi
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Grand Technion Energy Program, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Faculty of Material Science and Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Avner Rothschild
- Faculty of Material Science and Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Hen Dotan
- Faculty of Material Science and Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Guy Ankonina
- Photovoltaics Lab, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel
| | - Gadi Schuster
- Faculty of Biology, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel.
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Technion City, 32000, Haifa, Israel.
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304
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Ishii T, Kawaichi S, Nakagawa H, Hashimoto K, Nakamura R. From chemolithoautotrophs to electrolithoautotrophs: CO2 fixation by Fe(II)-oxidizing bacteria coupled with direct uptake of electrons from solid electron sources. Front Microbiol 2015; 6:994. [PMID: 26500609 PMCID: PMC4593280 DOI: 10.3389/fmicb.2015.00994] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 09/07/2015] [Indexed: 11/22/2022] Open
Abstract
At deep-sea vent systems, hydrothermal emissions rich in reductive chemicals replace solar energy as fuels to support microbial carbon assimilation. Until recently, all the microbial components at vent systems have been assumed to be fostered by the primary production of chemolithoautotrophs; however, both the laboratory and on-site studies demonstrated electrical current generation at vent systems and have suggested that a portion of microbial carbon assimilation is stimulated by the direct uptake of electrons from electrically conductive minerals. Here we show that chemolithoautotrophic Fe(II)-oxidizing bacterium, Acidithiobacillus ferrooxidans, switches the electron source for carbon assimilation from diffusible Fe2+ ions to an electrode under the condition that electrical current is the only source of energy and electrons. Site-specific marking of a cytochrome aa3 complex (aa3 complex) and a cytochrome bc1 complex (bc1 complex) in viable cells demonstrated that the electrons taken directly from an electrode are used for O2 reduction via a down-hill pathway, which generates proton motive force that is used for pushing the electrons to NAD+ through a bc1 complex. Activation of carbon dioxide fixation by a direct electron uptake was also confirmed by the clear potential dependency of cell growth. These results reveal a previously unknown bioenergetic versatility of Fe(II)-oxidizing bacteria to use solid electron sources and will help with understanding carbon assimilation of microbial components living in electronically conductive chimney habitats.
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Affiliation(s)
- Takumi Ishii
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Tokyo, Japan
| | - Satoshi Kawaichi
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science Saitama, Japan
| | - Hirotaka Nakagawa
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Tokyo, Japan
| | - Kazuhito Hashimoto
- Department of Applied Chemistry, School of Engineering, The University of Tokyo Tokyo, Japan
| | - Ryuhei Nakamura
- Biofunctional Catalyst Research Team, RIKEN Center for Sustainable Resource Science Saitama, Japan
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305
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McGlynn SE, Chadwick GL, Kempes CP, Orphan VJ. Single cell activity reveals direct electron transfer in methanotrophic consortia. Nature 2015; 526:531-5. [PMID: 26375009 DOI: 10.1038/nature15512] [Citation(s) in RCA: 340] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 08/10/2015] [Indexed: 11/09/2022]
Abstract
Multicellular assemblages of microorganisms are ubiquitous in nature, and the proximity afforded by aggregation is thought to permit intercellular metabolic coupling that can accommodate otherwise unfavourable reactions. Consortia of methane-oxidizing archaea and sulphate-reducing bacteria are a well-known environmental example of microbial co-aggregation; however, the coupling mechanisms between these paired organisms is not well understood, despite the attention given them because of the global significance of anaerobic methane oxidation. Here we examined the influence of interspecies spatial positioning as it relates to biosynthetic activity within structurally diverse uncultured methane-oxidizing consortia by measuring stable isotope incorporation for individual archaeal and bacterial cells to constrain their potential metabolic interactions. In contrast to conventional models of syntrophy based on the passage of molecular intermediates, cellular activities were found to be independent of both species intermixing and distance between syntrophic partners within consortia. A generalized model of electric conductivity between co-associated archaea and bacteria best fit the empirical data. Combined with the detection of large multi-haem cytochromes in the genomes of methanotrophic archaea and the demonstration of redox-dependent staining of the matrix between cells in consortia, these results provide evidence for syntrophic coupling through direct electron transfer.
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Affiliation(s)
- Shawn E McGlynn
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - Grayson L Chadwick
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
| | - Christopher P Kempes
- Exobiology Branch, National Aeronautics and Space Administration Ames Research Center, Moffett Field, California 94035, USA.,Control and Dynamical Systems, California Institute of Technology, Pasadena, California 91125, USA.,SETI Institute, Mountain View, California 94034, USA
| | - Victoria J Orphan
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA
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306
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Lebedev N, Mahmud S, Griva I, Blom A, Tender LM. On the electron transfer through Geobacter sulfurreducens
PilA protein. ACTA ACUST UNITED AC 2015. [DOI: 10.1002/polb.23809] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Nikolai Lebedev
- Center for Bio-Molecular Science and Engineering; Naval Research Laboratory; Washington DC 20375
| | - Syed Mahmud
- Center for Bio-Molecular Science and Engineering; Naval Research Laboratory; Washington DC 20375
| | - Igor Griva
- Department of Mathematical Sciences and Computational Material Science Center George Mason University; Fairfax Virginia 22030
| | - Anders Blom
- QuantumWise A/S; Lersø Parkallé 107 Copenhagen DK-2100 Denmark
| | - Leonard M. Tender
- Center for Bio-Molecular Science and Engineering; Naval Research Laboratory; Washington DC 20375
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307
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A Matter of Timing: Contrasting Effects of Hydrogen Sulfide on Oxidative Stress Response in Shewanella oneidensis. J Bacteriol 2015; 197:3563-72. [PMID: 26324455 DOI: 10.1128/jb.00603-15] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 08/25/2015] [Indexed: 01/29/2023] Open
Abstract
UNLABELLED Hydrogen sulfide (H2S), well known for its toxic properties, has recently become a research focus in bacteria, in part because it has been found to prevent oxidative stress caused by treatment with some antibiotics. H2S has the ability to scavenge reactive oxygen species (ROS), thus preventing oxidative stress, but it is also toxic, leading to conflicting reports of its effects in different organisms. Here, with Shewanella oneidensis as a model, we report that the effects of H2S on the response to oxidative stress are time dependent. When added simultaneously with H2O2, H2S promoted H2O2 toxicity by inactivating catalase, KatB, a heme-containing enzyme involved in H2O2 degradation. Such an inhibitory effect may apply to other heme-containing proteins, such as cytochrome cbb3 oxidase. When H2O2 was supplied 20 min or later after the addition of H2S, the oxidative-stress-responding regulator OxyR was activated, resulting in increased resistance to H2O2. The activation of OxyR was likely triggered by the influx of iron, a response to lowered intracellular iron due to the iron-sequestering property of H2S. Given that Shewanella bacteria thrive in redox-stratified environments that have abundant sulfur and iron species, our results imply that H2S is more important for bacterial survival in such environmental niches than previously believed. IMPORTANCE Previous studies have demonstrated that H2S is either detrimental or beneficial to bacterial cells. While it can act as a growth-inhibiting molecule by damaging DNA and denaturing proteins, it helps cells to combat oxidative stress. Here we report that H2S indeed has these contrasting biological functions and that its effects are time dependent. Immediately after H2S treatment, there is growth inhibition due to damage of heme-containing proteins, at least to catalase and cytochrome c oxidase. In contrast, when added a certain time later, H2S confers an enhanced ability to combat oxidative stress by activating the H2O2-responding regulator OxyR. Our data reconcile conflicting observations about the functions of H2S.
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308
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Development of Electroactive and Anaerobic Ammonium-Oxidizing (Anammox) Biofilms from Digestate in Microbial Fuel Cells. BIOMED RESEARCH INTERNATIONAL 2015; 2015:351014. [PMID: 26273609 PMCID: PMC4530212 DOI: 10.1155/2015/351014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 12/30/2014] [Accepted: 12/31/2014] [Indexed: 01/26/2023]
Abstract
Microbial Fuel cells (MFCs) have been proposed for nutrient removal and energy recovery from different wastes. In this study the anaerobic digestate was used to feed H-type MFC reactors, one with a graphite anode preconditioned with Geobacter sulfurreducens and the other with an unconditioned graphite anode. The data demonstrate that the digestate acts as a carbon source, and even in the absence of anode preconditioning, electroactive bacteria colonise the anodic chamber, producing a maximum power density of 172.2 mW/m2. The carbon content was also reduced by up to 60%, while anaerobic ammonium oxidation (anammox) bacteria, which were found in the anodic compartment of the reactors, contributed to nitrogen removal from the digestate. Overall, these results demonstrate that MFCs can be used to recover anammox bacteria from natural sources, and it may represent a promising bioremediation unit in anaerobic digestor plants for the simultaneous nitrogen removal and electricity generation using digestate as substrate.
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309
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Breuer M, Rosso KM, Blumberger J, Butt JN. Multi-haem cytochromes in Shewanella oneidensis MR-1: structures, functions and opportunities. J R Soc Interface 2015; 12:20141117. [PMID: 25411412 DOI: 10.1098/rsif.2014.1117] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Multi-haem cytochromes are employed by a range of microorganisms to transport electrons over distances of up to tens of nanometres. Perhaps the most spectacular utilization of these proteins is in the reduction of extracellular solid substrates, including electrodes and insoluble mineral oxides of Fe(III) and Mn(III/IV), by species of Shewanella and Geobacter. However, multi-haem cytochromes are found in numerous and phylogenetically diverse prokaryotes where they participate in electron transfer and redox catalysis that contributes to biogeochemical cycling of N, S and Fe on the global scale. These properties of multi-haem cytochromes have attracted much interest and contributed to advances in bioenergy applications and bioremediation of contaminated soils. Looking forward, there are opportunities to engage multi-haem cytochromes for biological photovoltaic cells, microbial electrosynthesis and developing bespoke molecular devices. As a consequence, it is timely to review our present understanding of these proteins and we do this here with a focus on the multitude of functionally diverse multi-haem cytochromes in Shewanella oneidensis MR-1. We draw on findings from experimental and computational approaches which ideally complement each other in the study of these systems: computational methods can interpret experimentally determined properties in terms of molecular structure to cast light on the relation between structure and function. We show how this synergy has contributed to our understanding of multi-haem cytochromes and can be expected to continue to do so for greater insight into natural processes and their informed exploitation in biotechnologies.
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Affiliation(s)
- Marian Breuer
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Kevin M Rosso
- Pacific Northwest National Laboratory, Richland, WA, USA
| | - Jochen Blumberger
- Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
| | - Julea N Butt
- School of Biological Sciences and School of Chemistry, University of East Anglia, Norwich NR4 7TJ, UK
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310
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Direct interspecies electron transfer between Geobacter metallireducens and Methanosarcina barkeri. Appl Environ Microbiol 2015; 80:4599-605. [PMID: 24837373 DOI: 10.1128/aem.00895-14] [Citation(s) in RCA: 460] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Direct interspecies electron transfer (DIET) is potentially an effective form of syntrophy in methanogenic communities, but little is known about the diversity of methanogens capable of DIET. The ability of Methanosarcina barkeri to participate in DIET was evaluated in coculture with Geobacter metallireducens. Cocultures formed aggregates that shared electrons via DIET during the stoichiometric conversion of ethanol to methane. Cocultures could not be initiated with a pilin-deficient G. metallireducens strain, suggesting that long-range electron transfer along pili was important for DIET. Amendments of granular activated carbon permitted the pilin-deficient G. metallireducens isolates to share electrons with M. barkeri, demonstrating that this conductive material could substitute for pili in promoting DIET. When M. barkeri was grown in coculture with the H2-producing Pelobacter carbinolicus, incapable of DIET, M. barkeri utilized H2 as an electron donor but metabolized little of the acetate that P.carbinolicus produced. This suggested that H2, but not electrons derived from DIET, inhibited acetate metabolism. P. carbinolicus-M. barkeri cocultures did not aggregate, demonstrating that, unlike DIET, close physical contact was not necessary for interspecies H2 transfer. M. barkeri is the second methanogen found to accept electrons via DIET and the first methanogen known to be capable of using either H2 or electrons derived from DIET for CO2 reduction. Furthermore, M. barkeri is genetically tractable,making it a model organism for elucidating mechanisms by which methanogens make biological electrical connections with other cells.
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311
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A Post-Genomic View of the Ecophysiology, Catabolism and Biotechnological Relevance of Sulphate-Reducing Prokaryotes. Adv Microb Physiol 2015. [PMID: 26210106 DOI: 10.1016/bs.ampbs.2015.05.002] [Citation(s) in RCA: 174] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Dissimilatory sulphate reduction is the unifying and defining trait of sulphate-reducing prokaryotes (SRP). In their predominant habitats, sulphate-rich marine sediments, SRP have long been recognized to be major players in the carbon and sulphur cycles. Other, more recently appreciated, ecophysiological roles include activity in the deep biosphere, symbiotic relations, syntrophic associations, human microbiome/health and long-distance electron transfer. SRP include a high diversity of organisms, with large nutritional versatility and broad metabolic capacities, including anaerobic degradation of aromatic compounds and hydrocarbons. Elucidation of novel catabolic capacities as well as progress in the understanding of metabolic and regulatory networks, energy metabolism, evolutionary processes and adaptation to changing environmental conditions has greatly benefited from genomics, functional OMICS approaches and advances in genetic accessibility and biochemical studies. Important biotechnological roles of SRP range from (i) wastewater and off gas treatment, (ii) bioremediation of metals and hydrocarbons and (iii) bioelectrochemistry, to undesired impacts such as (iv) souring in oil reservoirs and other environments, and (v) corrosion of iron and concrete. Here we review recent advances in our understanding of SRPs focusing mainly on works published after 2000. The wealth of publications in this period, covering many diverse areas, is a testimony to the large environmental, biogeochemical and technological relevance of these organisms and how much the field has progressed in these years, although many important questions and applications remain to be explored.
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312
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Heterologous expression and purification of a multiheme cytochrome from a Gram-positive bacterium capable of performing extracellular respiration. Protein Expr Purif 2015; 111:48-52. [DOI: 10.1016/j.pep.2015.03.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 03/12/2015] [Accepted: 03/15/2015] [Indexed: 01/16/2023]
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313
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Electrochemical in situ FTIR spectroscopy studies directly extracellular electron transfer of Shewanella oneidensis MR-1. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.04.139] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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314
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Veerubhotla R, Bandopadhyay A, Das D, Chakraborty S. Instant power generation from an air-breathing paper and pencil based bacterial bio-fuel cell. LAB ON A CHIP 2015; 15:2580-2583. [PMID: 25998260 DOI: 10.1039/c5lc00211g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present a low-cost, disposable microbial fuel cell fabricated on a paper based platform, having a start-up time of 10 s. The platform deploys ordinary pencil strokes for graphite electrode deposition. The device uses a membrane-less design in a one-time injection (OTI) mode or a continuous capillary driven flow mode (CPF), where oxygen from the atmosphere is used up at the cathode for water formation, leading to the generation of bioelectricity. The performance of the fuel cell is evaluated using two bacterial strains, namely, Pseudomonas aeruginosa IIT BT SS1 and Shewanella putrefaciens. This flexible device is shown to retain bacteria for a period of at least one hour, resulting in the generation of almost 0.4 V using P. aeruginosa and a maximum current of 18 μA using S. putrefaciens without the use of any additional catalysts.
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Affiliation(s)
- Ramya Veerubhotla
- Dept. of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India.
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315
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Kracke F, Vassilev I, Krömer JO. Microbial electron transport and energy conservation - the foundation for optimizing bioelectrochemical systems. Front Microbiol 2015; 6:575. [PMID: 26124754 PMCID: PMC4463002 DOI: 10.3389/fmicb.2015.00575] [Citation(s) in RCA: 307] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/25/2015] [Indexed: 12/23/2022] Open
Abstract
Microbial electrochemical techniques describe a variety of emerging technologies that use electrode–bacteria interactions for biotechnology applications including the production of electricity, waste and wastewater treatment, bioremediation and the production of valuable products. Central in each application is the ability of the microbial catalyst to interact with external electron acceptors and/or donors and its metabolic properties that enable the combination of electron transport and carbon metabolism. And here also lies the key challenge. A wide range of microbes has been discovered to be able to exchange electrons with solid surfaces or mediators but only a few have been studied in depth. Especially electron transfer mechanisms from cathodes towards the microbial organism are poorly understood but are essential for many applications such as microbial electrosynthesis. We analyze the different electron transport chains that nature offers for organisms such as metal respiring bacteria and acetogens, but also standard biotechnological organisms currently used in bio-production. Special focus lies on the essential connection of redox and energy metabolism, which is often ignored when studying bioelectrochemical systems. The possibility of extracellular electron exchange at different points in each organism is discussed regarding required redox potentials and effect on cellular redox and energy levels. Key compounds such as electron carriers (e.g., cytochromes, ferredoxin, quinones, flavins) are identified and analyzed regarding their possible role in electrode–microbe interactions. This work summarizes our current knowledge on electron transport processes and uses a theoretical approach to predict the impact of different modes of transfer on the energy metabolism. As such it adds an important piece of fundamental understanding of microbial electron transport possibilities to the research community and will help to optimize and advance bioelectrochemical techniques.
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Affiliation(s)
- Frauke Kracke
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
| | - Igor Vassilev
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
| | - Jens O Krömer
- Centre for Microbial Electrochemical Systems, The University of Queensland, Brisbane QLD, Australia ; Advanced Water Management Centre, The University of Queensland, Brisbane QLD, Australia
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316
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Beese-Vasbender PF, Nayak S, Erbe A, Stratmann M, Mayrhofer KJ. Electrochemical characterization of direct electron uptake in electrical microbially influenced corrosion of iron by the lithoautotrophic SRB Desulfopila corrodens strain IS4. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.03.184] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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317
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Liu Z, He Y, Shen R, Zhu Z, Xing XH, Li B, Zhang Y. Performance and microbial community of carbon nanotube fixed-bed microbial fuel cell continuously fed with hydrothermal liquefied cornstalk biomass. BIORESOURCE TECHNOLOGY 2015; 185:294-301. [PMID: 25780905 DOI: 10.1016/j.biortech.2015.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Revised: 02/28/2015] [Accepted: 03/03/2015] [Indexed: 06/04/2023]
Abstract
Hydrothermal liquefaction (HTL) is a green technology for biomass pretreatment with the omission of hazardous chemicals. This study reports a novel integration of HTL and carbon nanotubes (CNTs) fixed-bed microbial fuel cell (FBMFC) for continuous electricity generation from cornstalk biomass. Two FBMFCs in parallel achieved similar performance fed with cornstalk hydrolysate at different organic loading rates (OLRs) (0.82-8.16g/L/d). About 80% of Chemical oxygen demand (COD) and Total organic carbon (TOC) was removed from low-Biochemical oxygen demand (BOD)/COD (0.16) cornstalk hydrolysate at 8.16g/L/d, whereas a maximum power density (680mW/m(3)) was obtained at 2.41g/L/d, and a smallest internal resistance (Rin) (28Ω) at 3.01g/L/d. Illumina MiSeq sequencing reveals the diverse microbial structure induced by the complex composition of cornstalk hydrolysate. Distinguished from Proteobacteria, which a number of exoelectrogens belong to, the identified dominant genus Rhizobium in FBMFC was closely related to degradation of cellulosic biomass.
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Affiliation(s)
- Zhidan Liu
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China.
| | - Yanhong He
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Ruixia Shen
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Zhangbing Zhu
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Xin-Hui Xing
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Baoming Li
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China
| | - Yuanhui Zhang
- Laboratory of Environment-Enhancing Energy (E2E), and Key Laboratory of Agricultural Engineering in Structure and Environment, Ministry of Agriculture, College of Water Resources and Civil Engineering, China Agricultural University, Beijing 100083, China; Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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318
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Shumyantseva VV, Bulko TV, Suprun EV, Kuzikov AV, Agafonova LE, Archakov AI. [Electrochemical methods for biomedical investigations]. BIOMEDIT︠S︡INSKAI︠A︡ KHIMII︠A︡ 2015; 61:188-202. [PMID: 25978386 DOI: 10.18097/pbmc20156102188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the review, authors discussed recently published experimental data concerning highly sensitive electrochemical methods and technologies for biomedical investigations in the postgenomic era. Developments in electrochemical biosensors systems for the analysis of various bio objects are also considered: cytochrome P450s, cardiac markers, bacterial cells, the analysis of proteins based on electro oxidized amino acids as a tool for analysis of conformational events. The electroanalysis of catalytic activity of cytochromes P450 allowed developing system for screening of potential substrates, inhibitors or modulators of catalytic functions of this class of hemoproteins. The highly sensitive quartz crystal microbalance (QCM) immunosensor has been developed for analysis of bio affinity interactions of antibodies with troponin I in plasma. The QCM technique allowed real-time monitoring of the kinetic differences in specific interactions and nonspecific sorption, with out multiple labeling procedures and separation steps. The affinity binding process was characterized by the association (ka) and the dissociation (kd) kinetic constants and the equilibrium association (K) constant, calculated using experimental data. Based on the electroactivity of bacterial cells, the electrochemical system for determination of sensitivity of the microbial cells to antibiotics cefepime, ampicillin, amikacin, and erythromycin was proposed. It was shown that the minimally detectable cell number corresponds to 106 CFU per electrode. The electrochemical method allows estimating the degree of E.coli JM109 cells resistance to antibiotics within 2-5 h. Electrosynthesis of polymeric analogs of antibodies for myoglobin (molecularly imprinted polymer, MIP) on the surface of graphite screen-printed electrodes as sensor elements with o- phenylenediamine as the functional monomer was developed. Molecularly imprinted polymers demonstrate selective complementary binding of a template protein molecule (myoglobin) by the "key-lock" principle.
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Affiliation(s)
- V V Shumyantseva
- Institute of Biomedical Chemistry, Moscow, Russia; IBMC-EcoBioPharm Company, Moscow, Russia
| | - T V Bulko
- Institute of Biomedical Chemistry, Moscow, Russia
| | - E V Suprun
- Institute of Biomedical Chemistry, Moscow, Russia
| | - A V Kuzikov
- Institute of Biomedical Chemistry, Moscow, Russia
| | | | - A I Archakov
- Institute of Biomedical Chemistry, Moscow, Russia
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319
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Kouzuma A, Kato S, Watanabe K. Microbial interspecies interactions: recent findings in syntrophic consortia. Front Microbiol 2015; 6:477. [PMID: 26029201 PMCID: PMC4429618 DOI: 10.3389/fmicb.2015.00477] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/30/2015] [Indexed: 01/12/2023] Open
Abstract
Microbes are ubiquitous in our biosphere, and inevitably live in communities. They excrete a variety of metabolites and support the growth of other microbes in a community. According to the law of chemical equilibrium, the consumption of excreted metabolites by recipient microbes can accelerate the metabolism of donor microbes. This is the concept of syntrophy, which is a type of mutualism and governs the metabolism and growth of diverse microbes in natural and engineered ecosystems. A representative example of syntrophy is found in methanogenic communities, where reducing equivalents, e.g., hydrogen and formate, transfer between syntrophic partners. Studies have revealed that microbes involved in syntrophy have evolved molecular mechanisms to establish specific partnerships and interspecies communication, resulting in efficient metabolic cooperation. In addition, recent studies have provided evidence suggesting that microbial interspecies transfer of reducing equivalents also occurs as electric current via biotic (e.g., pili) and abiotic (e.g., conductive mineral and carbon particles) electric conduits. In this review, we describe these findings as examples of sophisticated cooperative behavior between different microbial species. We suggest that these interactions have fundamental roles in shaping the structure and activity of microbial communities.
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Affiliation(s)
- Atsushi Kouzuma
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Tokyo, Japan
| | - Souichiro Kato
- Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology Sapporo, Japan
| | - Kazuya Watanabe
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences Tokyo, Japan
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320
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Predicting Homogeneous Pilus Structure from Monomeric Data and Sparse Constraints. BIOMED RESEARCH INTERNATIONAL 2015; 2015:817134. [PMID: 26064954 PMCID: PMC4434193 DOI: 10.1155/2015/817134] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Accepted: 01/05/2015] [Indexed: 11/24/2022]
Abstract
Type IV pili (T4P) and T2SS (Type II Secretion System) pseudopili are filaments extending beyond microbial surfaces, comprising homologous subunits called “pilins.” In this paper, we presented a new approach to predict pseudo atomic models of pili combining ambiguous symmetric constraints with sparse distance information obtained from experiments and based neither on electronic microscope (EM) maps nor on accurate a priori symmetric details. The approach was validated by the reconstruction of the gonococcal (GC) pilus from Neisseria gonorrhoeae, the type IVb toxin-coregulated pilus (TCP) from Vibrio cholerae, and pseudopilus of the pullulanase T2SS (the PulG pilus) from Klebsiella oxytoca. In addition, analyses of computational errors showed that subunits should be treated cautiously, as they are slightly flexible and not strictly rigid bodies. A global sampling in a wider range was also implemented and implied that a pilus might have more than one but fewer than many possible intact conformations.
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321
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Yuan H, He Z. Graphene-modified electrodes for enhancing the performance of microbial fuel cells. NANOSCALE 2015; 7:7022-7029. [PMID: 25465393 DOI: 10.1039/c4nr05637j] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Graphene is an emerging material with superior physical and chemical properties, which can benefit the development of microbial fuel cells (MFC) in several aspects. Graphene-based anodes can enhance MFC performance with increased electron transfer efficiency, higher specific surface area and more active microbe-electrode-electrolyte interaction. For cathodic processes, oxygen reduction reaction is effectively catalyzed by graphene-based materials because of a favorable pathway and an increase in active sites and conductivity. Despite challenges, such as complexity in synthesis and property degeneration, graphene-based electrodes will be promising for developing MFCs and other bioelectrochemical systems to achieve sustainable water/wastewater treatment and bioenergy production.
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Affiliation(s)
- Heyang Yuan
- Department of Civil and Environmental Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA.
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322
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Sun D, Cheng S, Wang A, Li F, Logan BE, Cen K. Temporal-spatial changes in viabilities and electrochemical properties of anode biofilms. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:5227-5235. [PMID: 25810405 DOI: 10.1021/acs.est.5b00175] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Sustained current generation by anodic biofilms is a key element for the longevity and success of bioelectrochemical systems. Over time, however, inactive or dead cells can accumulate within the anode biofilm, which can be particularly detrimental to current generation. Mixed and pure culture (Geobacter anodireducens) biofilms were examined here relative to changes in electrochemical properties over time. An analysis of the three-dimensional metabolic structure of the biofilms over time showed that both types of biofilms developed a live outer-layer that covered a dead inner-core. This two-layer structure appeared to be mostly a result of relatively low anodic current densities compared to other studies. During biofilm development, the live layer reached a constant thickness, whereas dead cells continued to accumulate near the electrode surface. This result indicated that only the live outer-layer of biofilm was responsible for current generation and suggested that the dead inner-layer continued to function as an electrically conductive matrix. Analysis of the electrochemical properties and biofilm thickness revealed that the diffusion resistance measured using electrochemical impedance spectroscopy might not be due to acetate or proton diffusion limitations to the live layer, but rather electron-mediator diffusion.
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Affiliation(s)
- Dan Sun
- †State Key Laboratory of Clean Energy Utilization, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, P.R. China
| | - Shaoan Cheng
- †State Key Laboratory of Clean Energy Utilization, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, P.R. China
| | - Aijie Wang
- ‡Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, China Academy of Sciences, Beijing, China
| | - Fujian Li
- †State Key Laboratory of Clean Energy Utilization, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, P.R. China
| | - Bruce E Logan
- §Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kefa Cen
- †State Key Laboratory of Clean Energy Utilization, Department of Energy Engineering, Zhejiang University, Hangzhou 310027, P.R. China
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323
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Dantas JM, Campelo LM, Duke NEC, Salgueiro CA, Pokkuluri PR. The structure of PccH from Geobacter sulfurreducens - a novel low reduction potential monoheme cytochrome essential for accepting electrons from an electrode. FEBS J 2015; 282:2215-31. [PMID: 25786707 DOI: 10.1111/febs.13269] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/09/2015] [Accepted: 03/13/2015] [Indexed: 11/27/2022]
Abstract
The structure of cytochrome c (GSU3274) designated as PccH from Geobacter sulfurreducens was determined at a resolution of 2.0 Å. PccH is a small (15 kDa) cytochrome containing one c-type heme, found to be essential for the growth of G. sulfurreducens with respect to accepting electrons from graphite electrodes poised at -300 mV versus standard hydrogen electrode. with fumarate as the terminal electron acceptor. The structure of PccH is unique among the monoheme cytochromes described to date. The structural fold of PccH can be described as forming two lobes with the heme sandwiched in a cleft between the two lobes. In addition, PccH has a low reduction potential of -24 mV at pH 7, which is unusual for monoheme cytochromes. Based on difference in structure, together with sequence phylogenetic analysis, we propose that PccH can be regarded as a first characterized example of a new subclass of class I monoheme cytochromes. The low reduction potential of PccH may enable the protein to be redox active at the typically negative potential ranges encountered by G. sulfurreducens. Because PccH is predicted to be located in the periplasm of this bacterium, it could not be involved in the first step of accepting electrons from the electrode but is very likely involved in the downstream electron transport events in the periplasm.
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Affiliation(s)
- Joana M Dantas
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Luísa M Campelo
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Norma E C Duke
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
| | - Carlos A Salgueiro
- UCIBIO - REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - P Raj Pokkuluri
- Biosciences Division, Argonne National Laboratory, Lemont, IL, USA
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324
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Selective microbial electrosynthesis of methane by a pure culture of a marine lithoautotrophic archaeon. Bioelectrochemistry 2015; 102:50-5. [DOI: 10.1016/j.bioelechem.2014.11.004] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 11/12/2014] [Accepted: 11/17/2014] [Indexed: 11/22/2022]
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325
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Tremblay PL, Zhang T. Electrifying microbes for the production of chemicals. Front Microbiol 2015; 6:201. [PMID: 25814988 PMCID: PMC4356085 DOI: 10.3389/fmicb.2015.00201] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 02/24/2015] [Indexed: 01/06/2023] Open
Abstract
Powering microbes with electrical energy to produce valuable chemicals such as biofuels has recently gained traction as a biosustainable strategy to reduce our dependence on oil. Microbial electrosynthesis (MES) is one of the bioelectrochemical approaches developed in the last decade that could have critical impact on the current methods of chemical synthesis. MES is a process in which electroautotrophic microbes use electrical current as electron source to reduce CO2 to multicarbon organics. Electricity necessary for MES can be harvested from renewable resources such as solar energy, wind turbine, or wastewater treatment processes. The net outcome is that renewable energy is stored in the covalent bonds of organic compounds synthesized from greenhouse gas. This review will discuss the future of MES and the challenges that lie ahead for its development into a mature technology.
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Affiliation(s)
- Pier-Luc Tremblay
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm Denmark
| | - Tian Zhang
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Hørsholm Denmark
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326
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Microscale microbial fuel cells: Advances and challenges. Biosens Bioelectron 2015; 69:8-25. [PMID: 25703724 DOI: 10.1016/j.bios.2015.02.021] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 12/12/2022]
Abstract
The next generation of sustainable energy could come from microorganisms; evidence that it can be seen with the given rise of Electromicrobiology, the study of microorganisms' electrical properties. Many recent advances in electromicrobiology stem from studying microbial fuel cells (MFCs), which are gaining acceptance as a future alternative "green" energy technology and energy-efficient wastewater treatment method. MFCs are powered by living microorganisms with clean and sustainable features; they efficiently catalyse the degradation of a broad range of organic substrates under natural conditions. There is also increasing interest in photosynthetic MFCs designed to harness Earth's most abundant and promising energy source (solar irradiation). Despite their vast potential and promise, however, MFCs and photosynthetic MFCs have not yet successfully translated into commercial applications because they demonstrate persistent performance limitations and bottlenecks associated with scaling up. Instead, microscale MFCs have received increasing attention as a unique platform for various applications such as powering small portable electronic elements in remote locations, performing fundamental studies of microorganisms, screening bacterial strains, and toxicity detection in water. Furthermore, the stacking of miniaturized MFCs has been demonstrated to offer larger power densities than a single macroscale MFC in terms of scaling up. In this overview, we discuss recent achievements in microscale MFCs as well as their potential applications. Further scientific and technological challenges are also reviewed.
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327
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He Y, Liu Z, Xing XH, Li B, Zhang Y, Shen R, Zhu Z, Duan N. Carbon nanotubes simultaneously as the anode and microbial carrier for up-flow fixed-bed microbial fuel cell. Biochem Eng J 2015. [DOI: 10.1016/j.bej.2014.11.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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328
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Lovley DR, Malvankar NS. Seeing is believing: novel imaging techniques help clarify microbial nanowire structure and function. Environ Microbiol 2015; 17:2209-15. [PMID: 25384844 DOI: 10.1111/1462-2920.12708] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 10/26/2014] [Accepted: 11/06/2014] [Indexed: 11/30/2022]
Abstract
Novel imaging approaches have recently helped to clarify the properties of 'microbial nanowires'. Geobacter sulfurreducens pili are actual wires. They possess metallic-like conductivity, which can be attributed to overlapping pi-pi orbitals of key aromatic amino acids. Electrostatic force microscopy recently confirmed charge propagation along the pili, in a manner similar to carbon nanotubes. The pili are essential for long-range electron transport to insoluble electron acceptors and interspecies electron transfer. Previous claims that Shewanella oneidensis also produce conductive pili have recently been recanted, based on novel live-imaging studies. The putative pili are, in fact, long extensions of the cytochrome-rich outer membrane and periplasm that, when dried, collapse to form filaments with dimensions similar to pili. It has yet to be demonstrated whether the cytochrome-to-cytochrome electron hopping documented in the dried membrane extensions takes place in intact hydrated membrane extensions or whether the membrane extensions enhance electron transport to insoluble electron acceptors such as Fe(III) oxides or electrodes. These findings demonstrate that G. sulfurreducens conductive pili and the outer membrane extensions of S. oneidensis are fundamentally different in composition, mechanism of electron transport and physiological role. New methods for evaluating filament conductivity will facilitate screening the microbial world for nanowires and elucidating their function.
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Affiliation(s)
- Derek R Lovley
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA
| | - Nikhil S Malvankar
- Department of Microbiology, University of Massachusetts, Amherst, MA, USA.,Department of Physics, University of Massachusetts, Amherst, MA, USA
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329
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Tikhonova TV, Popov VO. Structural and functional studies of multiheme cytochromes c involved in extracellular electron transport in bacterial dissimilatory metal reduction. BIOCHEMISTRY (MOSCOW) 2015; 79:1584-601. [DOI: 10.1134/s0006297914130094] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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330
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Microbial Cell Factories for Diol Production. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2015; 155:165-97. [DOI: 10.1007/10_2015_330] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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331
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Daghio M, Gandolfi I, Bestetti G, Franzetti A, Guerrini E, Cristiani P. Anodic and cathodic microbial communities in single chamber microbial fuel cells. N Biotechnol 2015; 32:79-84. [DOI: 10.1016/j.nbt.2014.09.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 09/16/2014] [Accepted: 09/28/2014] [Indexed: 12/26/2022]
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332
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Chen S, Yang F, Li C, Zheng S, Zhang H, Li M, Yao H, Zhao F, Hou H. Encapsulation of a living bioelectrode by a hydrogel for bioelectrochemical systems in alkaline media. J Mater Chem B 2015; 3:4641-4646. [DOI: 10.1039/c5tb00563a] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A hydrogel-bioelectrode was fabricated by encapsulating a living electroactive biofilm with a poly(vinyl alcohol) hydrogel through a freezing/thawing process for bioelectrochemical systems in alkaline media.
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Affiliation(s)
- Shuiliang Chen
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Fangfang Yang
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Chungen Li
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Suqing Zheng
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Hua Zhang
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Ming Li
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
| | - Haimin Yao
- Department of Mechanical Engineering
- The Hong Kong Polytechnic University
- Hong Kong SAR
- China
| | - Feng Zhao
- Institute of Urban Environment
- Chinese Academy of Sciences
- Xiamen
- China
| | - Haoqing Hou
- Department of Chemistry and Chemical Engineering
- Jiangxi Normal University
- Nanchang
- China
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333
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Semenec L, E Franks A. Delving through electrogenic biofilms: from anodes to cathodes to microbes. AIMS BIOENGINEERING 2015. [DOI: 10.3934/bioeng.2015.3.222] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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334
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Choi G, Choi S. Monitoring electron and proton diffusion flux through three-dimensional, paper-based, variable biofilm and liquid media layers. Analyst 2015; 140:5901-7. [DOI: 10.1039/c5an01200g] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
By measuring the current generated from the 3-D paper stack, the electron and proton diffusivity through biofilms were quantitatively investigated.
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Affiliation(s)
- Gihoon Choi
- Bioelectronics & Microsystems Laboratory
- Department of Electrical & Computer Engineering
- State University of New York-Binghamton
- Binghamton
- USA
| | - Seokheun Choi
- Bioelectronics & Microsystems Laboratory
- Department of Electrical & Computer Engineering
- State University of New York-Binghamton
- Binghamton
- USA
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335
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PENG L, ZHANG XT, KAWAICHI S, XIE DT, LI ZL. Using Acetate and Formate as the Substrates for Geobacter sulfurreducens Exoelectrogenesis Resulted in Different Half-saturation Potentials. ELECTROCHEMISTRY 2015. [DOI: 10.5796/electrochemistry.83.600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Luo PENG
- School of Resources & Environment, Southwest University
- Biofunctional Catalysts Research Team, RIKEN Center for Sustainable Resource Science
| | | | - Satoshi KAWAICHI
- Biofunctional Catalysts Research Team, RIKEN Center for Sustainable Resource Science
| | - De-Ti XIE
- School of Resources & Environment, Southwest University
| | - Zhen-Lun LI
- School of Resources & Environment, Southwest University
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336
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Chitosan to Connect Biology to Electronics: Fabricating the Bio-Device Interface and Communicating Across This Interface. Polymers (Basel) 2014. [DOI: 10.3390/polym7010001] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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337
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Xie X, Zhao W, Lee HR, Liu C, Ye M, Xie W, Cui B, Criddle CS, Cui Y. Enhancing the nanomaterial bio-interface by addition of mesoscale secondary features: crinkling of carbon nanotube films to create subcellular ridges. ACS NANO 2014; 8:11958-11965. [PMID: 25415858 DOI: 10.1021/nn504898p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Biological cells often interact with their local environment through subcellular structures at a scale of tens to hundreds of nanometers. This study investigated whether topographic features fabricated at a similar scale would impact cellular functions by promoting the interaction between subcellular structures and nanomaterials. Crinkling of carbon nanotube films by solvent-induced swelling and shrinkage of substrate resulted in the formation of ridge features at the subcellular scale on both flat and three-dimensional substrates. Biological cells grown upon these crinkled CNT films had enhanced activity: neuronal cells grew to higher density and displayed greater cell polarization; exoelectrogenic micro-organisms transferred electrons more efficiently. The results indicate that crinkling of thin CNT films creates secondary mesoscale features that enhance attachment, growth, and electron transfer.
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Affiliation(s)
- Xing Xie
- Department of Civil and Environmental Engineering, Stanford University , 473 Via Ortega, Stanford, California 94305, United States
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338
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Sun D, Call D, Wang A, Cheng S, Logan BE. Geobacter sp. SD-1 with enhanced electrochemical activity in high-salt concentration solutions. ENVIRONMENTAL MICROBIOLOGY REPORTS 2014; 6:723-729. [PMID: 25756125 DOI: 10.1111/1758-2229.12193] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An isolate, designated strain SD-1, was obtained from a biofilm dominated by Geobacter sulfurreducens in a microbial fuel cell. The electrochemical activity of strain SD-1 was compared with type strains, G. sulfurreducens PCA and Geobacter metallireducens GS-15, and a mixed culture in microbial electrolysis cells. SD-1 produced a maximum current density of 290 ± 29 A m−3 in a high-concentration phosphate buffer solution (PBS-H, 200 mM). This current density was significantly higher than that produced by the mixed culture (189 ± 44 A m−3) or the type strains (< 70 A m−3). In a highly saline water (SW; 50 mM PBS and 650 mM NaCl), current by SD-1 (158 ± 4 A m−3) was reduced by 28% compared with 50 mM PBS (220 ± 4 A m−3), but it was still higher than that of the mixed culture (147 ± 19 A m−3), and strains PCA and GS-15 did not produce any current. Electrochemical tests showed that the improved performance of SD-1 was due to its lower charge transfer resistance and more negative potentials produced at higher current densities. These results show that the electrochemical activity of SD-1 was significantly different than other Geobacter strains and mixed cultures in terms of its salt tolerance.
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339
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Aracic S, Semenec L, Franks AE. Investigating microbial activities of electrode-associated microorganisms in real-time. Front Microbiol 2014; 5:663. [PMID: 25506343 PMCID: PMC4246885 DOI: 10.3389/fmicb.2014.00663] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 11/15/2014] [Indexed: 01/28/2023] Open
Abstract
Electrode-associated microbial biofilms are essential to the function of bioelectrochemical systems (BESs). These systems exist in a number of different configurations but all rely on electroactive microorganisms utilizing an electrode as either an electron acceptor or an electron donor to catalyze biological processes. Investigations of the structure and function of electrode-associated biofilms are critical to further the understanding of how microbial communities are able to reduce and oxidize electrodes. The community structure of electrode-reducing biofilms is diverse and often dominated by Geobacter spp. whereas electrode-oxidizing biofilms are often dominated by other microorganisms. The application of a wide range of tools, such as high-throughput sequencing and metagenomic data analyses, provide insight into the structure and possible function of microbial communities on electrode surfaces. However, the development and application of techniques that monitor gene expression profiles in real-time are required for a more definite spatial and temporal understanding of the diversity and biological activities of these dynamic communities. This mini review summarizes the key gene expression techniques used in BESs research, which have led to a better understanding of population dynamics, cell–cell communication and molecule-surface interactions in mixed and pure BES communities.
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Affiliation(s)
- Sanja Aracic
- Applied and Environmental Microbiology Laboratory, Department of Microbiology, La Trobe University , Melbourne, VIC, Australia
| | - Lucie Semenec
- Applied and Environmental Microbiology Laboratory, Department of Microbiology, La Trobe University , Melbourne, VIC, Australia
| | - Ashley E Franks
- Applied and Environmental Microbiology Laboratory, Department of Microbiology, La Trobe University , Melbourne, VIC, Australia
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340
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Shi L, Fredrickson JK, Zachara JM. Genomic analyses of bacterial porin-cytochrome gene clusters. Front Microbiol 2014; 5:657. [PMID: 25505896 PMCID: PMC4245776 DOI: 10.3389/fmicb.2014.00657] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 11/13/2014] [Indexed: 11/13/2022] Open
Abstract
The porin-cytochrome (Pcc) protein complex is responsible for trans-outer membrane electron transfer during extracellular reduction of Fe(III) by the dissimilatory metal-reducing bacterium Geobacter sulfurreducens PCA. The identified and characterized Pcc complex of G. sulfurreducens PCA consists of a porin-like outer-membrane protein, a periplasmic 8-heme c-type cytochrome (c-Cyt) and an outer-membrane 12-heme c-Cyt, and the genes encoding the Pcc proteins are clustered in the same regions of genome (i.e., the pcc gene clusters) of G. sulfurreducens PCA. A survey of additionally microbial genomes has identified the pcc gene clusters in all sequenced Geobacter spp. and other bacteria from six different phyla, including Anaeromyxobacter dehalogenans 2CP-1, A. dehalogenans 2CP-C, Anaeromyxobacter sp. K, Candidatus Kuenenia stuttgartiensis, Denitrovibrio acetiphilus DSM 12809, Desulfurispirillum indicum S5, Desulfurivibrio alkaliphilus AHT2, Desulfurobacterium thermolithotrophum DSM 11699, Desulfuromonas acetoxidans DSM 684, Ignavibacterium album JCM 16511, and Thermovibrio ammonificans HB-1. The numbers of genes in the pcc gene clusters vary, ranging from two to nine. Similar to the metal-reducing (Mtr) gene clusters of other Fe(III)-reducing bacteria, such as Shewanella spp., additional genes that encode putative c-Cyts with predicted cellular localizations at the cytoplasmic membrane, periplasm and outer membrane often associate with the pcc gene clusters. This suggests that the Pcc-associated c-Cyts may be part of the pathways for extracellular electron transfer reactions. The presence of pcc gene clusters in the microorganisms that do not reduce solid-phase Fe(III) and Mn(IV) oxides, such as D. alkaliphilus AHT2 and I. album JCM 16511, also suggests that some of the pcc gene clusters may be involved in extracellular electron transfer reactions with the substrates other than Fe(III) and Mn(IV) oxides.
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Affiliation(s)
- Liang Shi
- Pacific Northwest National Laboratory Richland, WA, USA
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341
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Hol FJH, Dekker C. Zooming in to see the bigger picture: microfluidic and nanofabrication tools to study bacteria. Science 2014; 346:1251821. [PMID: 25342809 DOI: 10.1126/science.1251821] [Citation(s) in RCA: 121] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The spatial structure of natural habitats strongly affects bacterial life, ranging from nanoscale structural features that individual cells exploit for surface attachment, to micro- and millimeter-scale chemical gradients that drive population-level processes. Nanofabrication and microfluidics are ideally suited to manipulate the environment at those scales and have emerged as powerful tools with which to study bacteria. Here, we review the new scientific insights gained by using a diverse set of nanofabrication and microfluidic techniques to study individual bacteria and multispecies communities. This toolbox is beginning to elucidate disparate bacterial phenomena-including aging, electron transport, and quorum sensing-and enables the dissection of environmental communities through single-cell genomics. A more intimate integration of microfluidics, nanofabrication, and microbiology will enable further exploration of bacterial life at the smallest scales.
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Affiliation(s)
- Felix J H Hol
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands
| | - Cees Dekker
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands.
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342
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Choi O, Kim T, Woo HM, Um Y. Electricity-driven metabolic shift through direct electron uptake by electroactive heterotroph Clostridium pasteurianum. Sci Rep 2014; 4:6961. [PMID: 25376371 PMCID: PMC4223642 DOI: 10.1038/srep06961] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 10/22/2014] [Indexed: 01/13/2023] Open
Abstract
Although microbes directly accepting electrons from a cathode have been applied for CO2 reduction to produce multicarbon-compounds, a high electron demand and low product concentration are critical limitations. Alternatively, the utilization of electrons as a co-reducing power during fermentation has been attempted, but there must be exogenous mediators due to the lack of an electroactive heterotroph. Here, we show that Clostridium pasteurianum DSM 525 simultaneously utilizes both cathode and substrate as electron donors through direct electron transfer. In a cathode compartment poised at +0.045 V vs. SHE, a metabolic shift in C. pasteurianum occurs toward NADH-consuming metabolite production such as butanol from glucose (20% shift in terms of NADH consumption) and 1,3-propandiol from glycerol (21% shift in terms of NADH consumption). Notably, a small amount of electron uptake significantly induces NADH-consuming pathways over the stoichiometric contribution of the electrons as reducing equivalents. Our results demonstrate a previously unknown electroactivity and metabolic shift in the biochemical-producing heterotroph, opening up the possibility of efficient and enhanced production of electron-dense metabolites using electricity.
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Affiliation(s)
- Okkyoung Choi
- Clean Energy Research Center, National Agenda Research Division, Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul 136-791, South Korea
| | - Taeyeon Kim
- Clean Energy Research Center, National Agenda Research Division, Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul 136-791, South Korea
| | - Han Min Woo
- Clean Energy Research Center, National Agenda Research Division, Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul 136-791, South Korea
| | - Youngsoon Um
- Clean Energy Research Center, National Agenda Research Division, Korea Institute of Science and Technology (KIST), Seongbuk-gu, Seoul 136-791, South Korea
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343
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Geobacter anodireducens sp. nov., an exoelectrogenic microbe in bioelectrochemical systems. Int J Syst Evol Microbiol 2014; 64:3485-3491. [DOI: 10.1099/ijs.0.061598-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A previously isolated exoelectrogenic bacterium, strain SD-1T, was further characterized and identified as a representative of a novel species of the genus
Geobacter
. Strain SD-1T was Gram-negative, aerotolerant, anaerobic, non-spore-forming, non-fermentative and non-motile. Cells were short, curved rods (0.8–1.3 µm long and 0.3 µm in diameter). Growth of strain SD-1T was observed at 15–42 °C and pH 6.0–8.5, with optimal growth at 30–35 °C and pH 7. Analysis of 16S rRNA gene sequences indicated that the isolate was a member of the genus
Geobacter
, with the closest known relative being
Geobacter sulfurreducens
PCAT (98 % similarity). Similar to other members of the genus
Geobacter
, strain SD-1T used soluble or insoluble Fe(III) as the sole electron acceptor coupled with the oxidation of acetate. However, SD-1T could not reduce fumarate as an electron acceptor with acetate oxidization, which is an important physiological trait for
G. sulfurreducens
. Moreover, SD-1T could grow in media containing as much as 3 % NaCl, while
G. sulfurreducens
PCAT can tolerate just half this concentration, and this difference in salt tolerance was even more obvious when cultivated in bioelectrochemical systems. DNA–DNA hybridization analysis of strain SD-1T and its closest relative,
G. sulfurreducens
ATCC 51573T, showed a relatedness of 61.6 %. The DNA G+C content of strain SD-1T was 58.9 mol%. Thus, on the basis of these characteristics, strain SD-1T was not assigned to
G. sulfurreducens
, and was instead classified in the genus
Geobacter
as a representative of a novel species. The name Geobacter anodireducens sp. nov. is proposed, with the type strain SD-1T ( = CGMCC 1.12536T = KCTC 4672T).
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344
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Kip N, van Veen JA. The dual role of microbes in corrosion. ISME JOURNAL 2014; 9:542-51. [PMID: 25259571 DOI: 10.1038/ismej.2014.169] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/11/2014] [Indexed: 12/16/2022]
Abstract
Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion.
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Affiliation(s)
- Nardy Kip
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
| | - Johannes A van Veen
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, The Netherlands
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345
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Shen HB, Yong XY, Chen YL, Liao ZH, Si RW, Zhou J, Wang SY, Yong YC, OuYang PK, Zheng T. Enhanced bioelectricity generation by improving pyocyanin production and membrane permeability through sophorolipid addition in Pseudomonas aeruginosa-inoculated microbial fuel cells. BIORESOURCE TECHNOLOGY 2014; 167:490-494. [PMID: 25011080 DOI: 10.1016/j.biortech.2014.05.093] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Revised: 05/23/2014] [Accepted: 05/24/2014] [Indexed: 06/03/2023]
Abstract
Improvement on electron shuttle-mediated extracellular electron transfer (EET) is of great potential to enhance the power output of MFCs. In this study, sophorolipid was added to enhance the performance of Pseudomonas aeruginosa-inoculated MFC by improving the electron shuttle-mediated EET. Upon sophorolipid addition, the current density and power density increased ∼ 1.7 times and ∼ 2.6 times, respectively. In accordance, significant enhancement on pyocyanin production (the electron shuttle) and membrane permeability were observed. Furthermore, the conditions for sophorolipid addition were optimized to achieve maximum pyocyanin production (14.47 ± 0.23 μg/mL), and 4 times higher power output was obtained compared to the control. The results substantiated that enhanced membrane permeability and pyocyanin production by sophorolipid, which promoted the electron shuttle-mediated EET, underlies the improvement of the energy output in the P. aeruginosa-inoculated MFC. It suggested that addition of biosurfactant could be a promising way to enhance the energy generation in MFCs.
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Affiliation(s)
- Hai-Bo Shen
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China
| | - Xiao-Yu Yong
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China
| | - Yi-Lu Chen
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China
| | - Zhi-Hong Liao
- Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212013, China
| | - Rong-Wei Si
- Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212013, China
| | - Jun Zhou
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China
| | - Shu-Ya Wang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China
| | - Yang-Chun Yong
- Biofuels Institute, School of the Environment, Jiangsu University, Zhenjiang 212013, China.
| | - Ping-Kai OuYang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China
| | - Tao Zheng
- College of Biotechnology and Pharmaceutical Engineering, Nanjing TECH University, Nanjing 210009, China; Bioenergy Research Institute, Nanjing TECH University, Nanjing 210009, China.
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346
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Wu Y, Liu T, Li X, Li F. Exogenous electron shuttle-mediated extracellular electron transfer of Shewanella putrefaciens 200: electrochemical parameters and thermodynamics. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:9306-9314. [PMID: 25058026 DOI: 10.1021/es5017312] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Despite the importance of exogenous electron shuttles (ESs) in extracellular electron transfer (EET), a lack of understanding of the key properties of ESs is a concern given their different influences on EET processes. Here, the ES-mediated EET capacity of Shewanella putrefaciens 200 (SP200) was evaluated by examining the electricity generated in a microbial fuel cell. The results indicated that all the ESs substantially accelerated the current generation compared to only SP200. The current and polarization parameters were linearly correlated with both the standard redox potential (E(ES)(0)) and the electron accepting capacity (EAC) of the ESs. A thermodynamic analysis of the electron transfer from the electron donor to the electrode suggested that the EET from c-type cytochromes (c-Cyts) to ESs is a crucial step causing the differences in EET capacities among various ESs. Based on the derived equations, both E(ES)(0) and EAC can quantitatively determine potential losses (ΔE) that reflect the potential loss of the ES-mediated EET. In situ spectral kinetic analysis of ES reduction by c-Cyts in a living SP200 suspension was first investigated with the E(ES), E(c-Cyt), and ΔE values being calculated. This study can provide a comprehensive understanding of the role of ESs in EET.
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Affiliation(s)
- Yundang Wu
- Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences , Guangzhou, P. R. China
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347
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Maestro B, Ortiz JM, Schrott G, Busalmen JP, Climent V, Feliu JM. Crystallographic orientation and electrode nature are key factors for electric current generation by Geobacter sulfurreducens. Bioelectrochemistry 2014; 98:11-9. [DOI: 10.1016/j.bioelechem.2014.02.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 02/18/2014] [Accepted: 02/19/2014] [Indexed: 12/20/2022]
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348
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Wen Y, Behiels E, Felix J, Elegheert J, Vergauwen B, Devreese B, Savvides SN. The bacterial antitoxin HipB establishes a ternary complex with operator DNA and phosphorylated toxin HipA to regulate bacterial persistence. Nucleic Acids Res 2014; 42:10134-47. [PMID: 25056321 PMCID: PMC4150777 DOI: 10.1093/nar/gku665] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Nearly all bacteria exhibit a type of phenotypic growth described as persistence that is thought to underlie antibiotic tolerance and recalcitrant chronic infections. The chromosomally encoded high-persistence (Hip) toxin–antitoxin proteins HipASO and HipBSO from Shewanella oneidensis, a proteobacterium with unusual respiratory capacities, constitute a type II toxin–antitoxin protein module. Here we show that phosphorylated HipASO can engage in an unexpected ternary complex with HipBSO and double-stranded operator DNA that is distinct from the prototypical counterpart complex from Escherichia coli. The structure of HipBSO in complex with operator DNA reveals a flexible C-terminus that is sequestered by HipASO in the ternary complex, indicative of its role in binding HipASO to abolish its function in persistence. The structure of HipASO in complex with a non-hydrolyzable ATP analogue shows that HipASO autophosphorylation is coupled to an unusual conformational change of its phosphorylation loop. However, HipASO is unable to phosphorylate the translation factor Elongation factor Tu, contrary to previous reports, but in agreement with more recent findings. Our studies suggest that the phosphorylation state of HipA is an important factor in persistence and that the structural and mechanistic diversity of HipAB modules as regulatory factors in bacterial persistence is broader than previously thought.
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Affiliation(s)
- Yurong Wen
- Unit for Biological Mass Spectrometry and Proteomics, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Ester Behiels
- Unit for Biological Mass Spectrometry and Proteomics, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Jan Felix
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Jonathan Elegheert
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Bjorn Vergauwen
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Bart Devreese
- Unit for Biological Mass Spectrometry and Proteomics, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
| | - Savvas N Savvides
- Unit for Structural Biology, Laboratory for Protein Biochemistry and Biomolecular Engineering (L-ProBE), Ghent University, K.L. Ledeganckstraat 35, 9000 Ghent, Belgium
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349
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Nagarajan H, Embree M, Rotaru AE, Shrestha PM, Feist AM, Palsson BØ, Lovley DR, Zengler K. Characterization and modelling of interspecies electron transfer mechanisms and microbial community dynamics of a syntrophic association. Nat Commun 2014; 4:2809. [PMID: 24264237 DOI: 10.1038/ncomms3809] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 10/23/2013] [Indexed: 12/18/2022] Open
Abstract
Syntrophic associations are central to microbial communities and thus have a fundamental role in the global carbon cycle. Despite biochemical approaches describing the physiological activity of these communities, there has been a lack of a mechanistic understanding of the relationship between complex nutritional and energetic dependencies and their functioning. Here we apply a multi-omic modelling workflow that combines genomic, transcriptomic and physiological data with genome-scale models to investigate dynamics and electron flow mechanisms in the syntrophic association of Geobacter metallireducens and Geobacter sulfurreducens. Genome-scale modelling of direct interspecies electron transfer reveals insights into the energetics of electron transfer mechanisms. While G. sulfurreducens adapts to rapid syntrophic growth by changes at the genomic and transcriptomic level, G. metallireducens responds only at the transcriptomic level. This multi-omic approach enhances our understanding of adaptive responses and factors that shape the evolution of syntrophic communities.
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Affiliation(s)
- Harish Nagarajan
- Department of Bioengineering, University of California San Diego, La Jolla, California 92093-0412, USA
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350
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Song H, Ding MZ, Jia XQ, Ma Q, Yuan YJ. Synthetic microbial consortia: from systematic analysis to construction and applications. Chem Soc Rev 2014; 43:6954-81. [PMID: 25017039 DOI: 10.1039/c4cs00114a] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Synthetic biology is an emerging research field that focuses on using rational engineering strategies to program biological systems, conferring on them new functions and behaviours. By developing genetic parts and devices based on transcriptional, translational, post-translational modules, many genetic circuits and metabolic pathways had been programmed in single cells. Extending engineering capabilities from single-cell behaviours to multicellular microbial consortia represents a new frontier of synthetic biology. Herein, we first reviewed binary interaction modes of microorganisms in microbial consortia and their underlying molecular mechanisms, which lay the foundation of programming cell-cell interactions in synthetic microbial consortia. Systems biology studies on cellular systems enable systematic understanding of diverse physiological processes of cells and their interactions, which in turn offer insights into the optimal design of synthetic consortia. Based on such fundamental understanding, a comprehensive array of synthetic microbial consortia constructed in the last decade were reviewed, including isogenic microbial communities programmed by quorum sensing-based cell-cell communications, sender-receiver microbial communities with one-way communications, and microbial ecosystems wired by two-way (bi-directional) communications. Furthermore, many applications including using synthetic microbial consortia for distributed bio-computations, chemicals and bioenergy production, medicine and human health, and environments were reviewed. Synergistic development of systems and synthetic biology will provide both a thorough understanding of naturally occurring microbial consortia and rational engineering of these complicated consortia for novel applications.
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Affiliation(s)
- Hao Song
- Key Laboratory of Systems Bioengineering, Ministry of Education, School of Chemical Engineering and Technology, and Collaborative Innovation Centre of Chemical Science and Engineering (Tianjin), Tianjin University, Tianjin 300072, P. R. China.
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