DOCSLIB.ORG

Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community Hiroshi Yokoyama, Mitsuyoshi Ishida, and Takahiro Yamashita*

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community Hiroshi Yokoyama, Mitsuyoshi Ishida, and Takahiro Yamashita* J. Microbiol. Biotechnol. (2016), 26(4), 757–762 http://dx.doi.org/10.4014/jmb.1510.10037 Research Article Review jmb Comparison of Anodic Community in Microbial Fuel Cells with Iron Oxide-Reducing Community Hiroshi Yokoyama, Mitsuyoshi Ishida, and Takahiro Yamashita* Animal Waste Management and Environment Division, NARO Institute of Livestock and Grassland Science, Tsukuba 305-0901, Japan Received: October 13, 2015 Revised: December 1, 2015 The group of Fe(III) oxide-reducing bacteria includes exoelectrogenic bacteria, and they Accepted: December 6, 2015 possess similar properties of transferring electrons to extracellular insoluble-electron acceptors. The exoelectrogenic bacteria can use the anode in microbial fuel cells (MFCs) as the terminal electron acceptor in anaerobic acetate oxidation. In the present study, the anodic First published online community was compared with the community using Fe(III) oxide (ferrihydrite) as the January 15, 2016 electron acceptor coupled with acetate oxidation. To precisely analyze the structures, the *Corresponding author community was established by enrichment cultures using the same inoculum used for the Phone: +81-29-838-8676; MFCs. High-throughput sequencing of the 16S rRNA gene revealed considerable differences Fax: +81-29-838-8606; between the structure of the anodic communities and that of the Fe(III) oxide-reducing E-mail: [email protected] community. Geobacter species were predominantly detected (>46%) in the anodic communities. In contrast, Pseudomonas (70%) and Desulfosporosinus (16%) were predominant in the Fe(III) oxide-reducing community. These results demonstrated that Geobacter species are the most specialized among Fe(III)-reducing bacteria for electron transfer to the anode in MFCs. In addition, the present study indicates the presence of a novel lineage of bacteria in the genus Pseudomonas that highly prefers ferrihydrite as the terminal electron acceptor in acetate oxidation. pISSN 1017-7825, eISSN 1738-8872 Copyright© 2016 by Keywords: Acetate oxidation, community structure, dissimilatory Fe(III) reduction, microbial The Korean Society for Microbiology fuel cell, sulfate reduction and Biotechnology Introduction understood. Elucidating this mechanism would provide vital clues to improving the power output of MFCs. Microbial fuel cells (MFCs) are environmentally friendly In anoxic natural environments, bacteria decompose bioreactors that simultaneously perform sustainable acetate to CO2 using soluble and insoluble electron bioenergy production and wastewater treatment [11]. acceptors, such as sulfate, nitrate, and Fe(III) oxides. The Bacteria decompose the organic matter in wastewater to mechanism of electron transfer to the anode is suggested to CO2 through redox reactions under anaerobic conditions in be similar to the transfer to insoluble Fe(III) oxides. In fact, the reactors. The electrons generated in these redox exoelectrogenic bacteria comprise many Fe(III) reducers, reactions are transferred to the anode by bacteria, where such as Geobacter species [2]. Given that the anode acts as a they react with electron acceptors such as O2 and substitute for Fe(III) oxide, it is predicted that the anodic K3[Fe(CN)6] via a circuit in the cathodes. The anode serves community (AC) and Fe(III)-reducing community (FRC) as an insoluble extracellular electron acceptor in these would have similar structures. In the present study, to test redox reactions, called electrode respiration. Many bacteria, this hypothesis, ACs in three MFCs and a FRC were including Geobacter, Shewanella, Desulfuromonas, and established by enrichment cultures, and the structure of the Rhodopseudomonas, can mediate electron transfer to the bacterial communities was analyzed using high-throughput anode [13]. However, the mechanism of formation of an sequencing. For comparison, a sulfate-reducing community electrochemically active biofilm on the anode is not well (SRC) was also analyzed. A 2016 ⎪ Vol. 26⎪ No. 0 758 Yokoyama et al. Materials and Methods 16S rRNA gene fragment was amplified by polymerase chain reaction (PCR) with the 27F and 1492R primers using the KAPA Bacterial Culture HiFi HotStart ReadyMix PCR Kit (Kapa Biosystems, MA, USA). MFC32 was a two-chambered reactor comprising two glass Subsequently, the second round of PCR was conducted using bottles (500 ml) and a Nafion 117 membrane (Dupont Japan, 563F and 802R primers, including the Illumina overhang adapter Tokyo, Japan). The anode and cathode used were a carbon cloth sequences, according to the manufacturer’s instructions. The (5 cm × 5 cm) and a carbon rod (diameter, 0.5 cm; length, 15 cm), libraries were sequenced on a 300PE MiSeq run, and image respectively. The anolyte was a basal medium containing (per liter analysis, base calling, and data quality assessment were performed with the MiSeq Reporter software (Illumina). Paired-end read of distilled water) 0.98 g potassium acetate, 0.6 g NaH2PO4·2H2O, data exported in the FASTQ format were processed with the 2g NaHCO3, 2.9 g NaCl, 0.1 g KCl, 0.2 g NH4Cl, 1 mg resazurin, 41 mg 2-bromoethanesulfonate sodium salt (a methanogenesis Quantitative Insights Into Microbial Ecology (QIIME software ver. 1.8) pipeline [4]. The read sequences were joined, quality- inhibitor), 50 mg Na2S·9H2O, and 10 ml of trace mineral and vitamin checked, and clustered into operational taxonomic units (OTUs) solutions. The catholyte was composed of 16.5 g K3[Fe(CN)6], 0.6 g using the Uclust method [5]. Representative sequences were aligned NaH2PO4·2H2O, 2 g NaHCO3, 2.9 g NaCl, 0.1 g KCl, and 0.2 g using PyNAST [3], and a phylogenetic tree was constructed. After NH4Cl. MFC35 and MFC36 were cubic air-cathode single- chambered reactors (125 ml) fed with the basal medium. The a chimera check, the taxonomic classification and alpha and beta carbon-cloth anode (5 cm × 5 cm) was placed at the opposite side diversities were computed using the QIIME tool. The taxonomic to the carbon-cloth cathode containing 0.5 mg/cm2 of a Pt catalyst assignment of the major OTUs was checked using Classifier [18]. fused with the membrane. Activated sludge collected at the The beta diversity was calculated using an unweighted UniFrac NARO Institute of Livestock and Grassland Science, Tsukuba, distance matrix [15], and the result was visualized using a principal Japan, was inoculated into MFC32 and MFC35 as seed sludge, coordinate (PCo) plot. whereas cattle feces was inoculated into MFC36. The MFCs were The sequencing data were deposited in DDBJ under the accession connected to an external resistor and were operated at 30°C in the numbers LC071702-LC071715 and DRR040632-DRR040636 fed-batch mode. The external resistor was adjusted such that the (Sequence Read Archive). MFCs generated a voltage of 0.5–0.6 V. The FRC and SRC were established by enrichment culture in 15 ml test tubes containing a Results and Discussion gas phase of 100% N2. The test tubes were filled with 10 ml of the basal medium supplemented with poorly crystalline Fe(III) MFC Operation and Enrichment Cultures of FRC and SRC oxyhydroxide (ferrihydrite; 15 mM) or Na2SO4 (20 mM) for the To precisely compare the community structures, all FRC and SRC, respectively. Ferrihydrite was prepared by titrating communities, except MFC36, were cultured using the same a FeCl solution against 10% NaOH [19], and it was stored in a 3 inoculum (activated sludge) and the same medium containing glass bottle with a gas phase of nitrogen until use. Activated acetate as the sole carbon and energy source; cattle feces sludge (1 ml), identical to that used for the MFC, was inoculated were inoculated into MFC36. The MFCs were operated for into the test tubes, and the test tubes were statically incubated at 8 months. The profiles of electricity generation by the MFCs 30°C. The culture medium (1 ml) was transferred into fresh medium at an interval of 1–4 weeks, and the transfer was repeated are shown in Fig. 1. Usually, higher electricity generation is 10 times. Coulombic efficiency was estimated from the amount obtained with the use of K3[Fe(CN)6] than with O2 as an of electron flow and decrease in acetate concentration [14]. The electron acceptor in the cathode. Air-cathode single- Fe(II) concentration was determined photometrically using the chambered MFCs generally exhibit lower Coulombic phenanthroline method [6]. efficiency than double-chambered MFCs because of O2 intrusion from the membrane. Consistent with these High-Throughput Sequencing previous observations, MFC32 (two-chambered MFC with Next-generation sequencing was performed with the MiSeq K3[Fe(CN)6]) generated a higher current (1.0–1.5 mA) than Illumina sequencing platform (Illumina Inc., CA, USA) using the the air-cathode single-chambered MFC35 and MFC36 V4 region of the 16S rRNA gene [10]. The biofilms developed on (0.2–0.3 mA). The Coulombic efficiency of MFC32 was the anodes were extensively washed with distilled water for approximately 71–85%, which was higher than that of removing the bacteria loosely attached to the anodes. The genomes MFC35 (32–33%). The FRC decomposed acetate coupled were extracted from the washed biofilms with an UltraClean Soil DNA Isolation kit (MO BIO Laboratories, Carlsbad, CA, USA). To with reduction of Fe(III) oxide. The stoichiometry was prepare the genomes of the FRC and SRC, the cultured medium acetate:Fe(III) = 1:6.8, which was close to the expected ratio was centrifuged at 12,000 ×g for 15 min. The precipitates were of 1:8. The SRC consumed acetate and sulfate with the washed with distilled water, and the genomes were extracted stoichiometry of acetate:sulfate = 1:1.1. This value was also from the precipitates using the kit. Nearly the full length of the close to the expected ratio of 1:1. These values of stoichiometry J. Microbiol. Biotechnol. Anodic Community in Microbial Fuel Cells 759 Fig. 2. Rarefaction curves (A) and PCo plot (B) showing the relationship between the anodic communities (MFC32, MFC35, and MFC36) and Fe(III)- and sulfate-reducing communities (FRC and SRC, respectively).
Load more

Recommended publications
  • (Pelobacter) and Methanococcoides Are Responsible for Choline-Dependent Methanogenesis in a Coastal Saltmarsh Sediment
    The ISME Journal https://doi.org/10.1038/s41396-018-0269-8 ARTICLE Deltaproteobacteria (Pelobacter) and Methanococcoides are responsible for choline-dependent methanogenesis in a coastal saltmarsh sediment 1 1 1 2 3 1 Eleanor Jameson ● Jason Stephenson ● Helen Jones ● Andrew Millard ● Anne-Kristin Kaster ● Kevin J. Purdy ● 4 5 1 Ruth Airs ● J. Colin Murrell ● Yin Chen Received: 22 January 2018 / Revised: 11 June 2018 / Accepted: 26 July 2018 © The Author(s) 2018. This article is published with open access Abstract Coastal saltmarsh sediments represent an important source of natural methane emissions, much of which originates from quaternary and methylated amines, such as choline and trimethylamine. In this study, we combine DNA stable isotope 13 probing with high throughput sequencing of 16S rRNA genes and C2-choline enriched metagenomes, followed by metagenome data assembly, to identify the key microbes responsible for methanogenesis from choline. Microcosm 13 incubation with C2-choline leads to the formation of trimethylamine and subsequent methane production, suggesting that 1234567890();,: 1234567890();,: choline-dependent methanogenesis is a two-step process involving trimethylamine as the key intermediate. Amplicon sequencing analysis identifies Deltaproteobacteria of the genera Pelobacter as the major choline utilizers. Methanogenic Archaea of the genera Methanococcoides become enriched in choline-amended microcosms, indicating their role in methane formation from trimethylamine. The binning of metagenomic DNA results in the identification of bins classified as Pelobacter and Methanococcoides. Analyses of these bins reveal that Pelobacter have the genetic potential to degrade choline to trimethylamine using the choline-trimethylamine lyase pathway, whereas Methanococcoides are capable of methanogenesis using the pyrrolysine-containing trimethylamine methyltransferase pathway.
    [Show full text]
  • Polyamine Distribution Profiles Among Some Members Within Delta-And Epsilon-Subclasses of Proteobacteria
    Microbiol. Cult. Coll. June. 2004. p. 3 ― 8 Vol. 20, No. 1 Polyamine Distribution Profiles among Some Members within Delta-and Epsilon-Subclasses of Proteobacteria Koei Hamana1）＊, Tomoko Saito1）, Mami Okada1）, and Masaru Niitsu2） 1）Department of Laboratory Sciences, School of Health Sciences, Faculty of Medicine, Gunma University, 39- 15 Showa-machi 3-chome, Maebashi, Gunma 371-8514, Japan 2）Faculty of Pharmaceutical Sciences, Josai University, Keyakidai 1-chome-1, Sakado, Saitama 350-0295, Japan Cellular polyamines of 18 species（13 genera）belonging to the delta and epsilon subclasses of the class Proteobacteria were analyzed by HPLC and GC. In the delta subclass, the four marine myxobacteria（the order Myxococcales）, Enhygromyxa salina, Haliangium ochroceum, Haliangium tepidum and Plesiocystis pacifica contained spermidine. Fe（III）-reducing two Geobacter species and two Pelobacter species belonging to the order Desulfuromonadales con- tained spermidine. Bdellovibrio bacteriovorus was absent in cellular polyamines. Bacteriovorax starrii contained putrescine and spermidine. Bacteriovorax stolpii contained spermidine and homo- spermidine. Spermidine was the major polyamine in the sulfate-reducing delta proteobacteria belonging to the genera Desulfovibrio, Desulfacinum, Desulfobulbus, Desulfococcus and Desulfurella, and some species of them contained cadaverine. Within the epsilon subclass, three Sulfurospirillum species ubiquitously contained spermidine and one of the three contained sper- midine and cadaverine. Thiomicrospora denitrificans contained cadaverine and spermidine as the major polyamine. These data show that cellular polyamine profiles can be used as a chemotaxonomic marker within delta and epsilon subclasses. Key words: polyamine, spermidine, homospermidine, Proteobacteria The class Proteobacteria is a major taxon of the 18, 26）. Fe（Ⅲ）-reducing members belonging to the gen- domain Bacteria and is phylogenetically divided into the era Pelobacter, Geobacter, Desulfuromonas and alpha, beta, gamma, delta and epsilon subclasses.
    [Show full text]
  • Microorganisms
    microorganisms Article Description of Three Novel Members in the Family Geobacteraceae, Oryzomonas japonicum gen. nov., sp. nov., Oryzomonas sagensis sp. nov., and Oryzomonas ruber sp. nov. 1 1, 2 3 4, Zhenxing Xu , Yoko Masuda * , Chie Hayakawa , Natsumi Ushijima , Keisuke Kawano y, Yutaka Shiratori 5, Keishi Senoo 1,6 and Hideomi Itoh 7,* 1 Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan; [email protected] (Z.X.); [email protected] (K.S.) 2 School of Agriculture, Utsunomiya University, Tochigi 321-8505, Japan; [email protected] 3 Support Section for Education and Research, Graduate School of Dental Medicine, Hokkaido University, Hokkaido 060-8586, Japan; [email protected] 4 Department of Marine Biology and Sciences, School of Biological Sciences, Tokai University, Hokkaido 005-8601, Japan; [email protected] 5 Niigata Agricultural Research Institute, Niigata 940-0826, Japan; [email protected] 6 Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan 7 Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology (AIST) Hokkaido, Hokkaido 062-8517, Japan * Correspondence: [email protected] (Y.M.); [email protected] (H.I.) Present address: Division of Agriculture, Graduate School of Agriculture, Hokkaido University, y Hokkaido 060-8589, Japan. Received: 17 March 2020; Accepted: 25 April 2020; Published: 27 April 2020 Abstract: Bacteria of the family Geobacteraceae are particularly common and deeply involved in many biogeochemical processes in terrestrial and freshwater environments. As part of a study to understand biogeochemical cycling in freshwater sediments, three iron-reducing isolates, designated as Red96T, Red100T, and Red88T, were isolated from the soils of two paddy fields and pond sediment located in Japan.
    [Show full text]
  • Appendix 1. New and Emended Taxa Described Since Publication of Volume One, Second Edition of the Systematics
    188 THE REVISED ROAD MAP TO THE MANUAL Appendix 1. New and emended taxa described since publication of Volume One, Second Edition of the Systematics Acrocarpospora corrugata (Williams and Sharples 1976) Tamura et Basonyms and synonyms1 al. 2000a, 1170VP Bacillus thermodenitrificans (ex Klaushofer and Hollaus 1970) Man- Actinocorallia aurantiaca (Lavrova and Preobrazhenskaya 1975) achini et al. 2000, 1336VP Zhang et al. 2001, 381VP Blastomonas ursincola (Yurkov et al. 1997) Hiraishi et al. 2000a, VP 1117VP Actinocorallia glomerata (Itoh et al. 1996) Zhang et al. 2001, 381 Actinocorallia libanotica (Meyer 1981) Zhang et al. 2001, 381VP Cellulophaga uliginosa (ZoBell and Upham 1944) Bowman 2000, VP 1867VP Actinocorallia longicatena (Itoh et al. 1996) Zhang et al. 2001, 381 Dehalospirillum Scholz-Muramatsu et al. 2002, 1915VP (Effective Actinomadura viridilutea (Agre and Guzeva 1975) Zhang et al. VP publication: Scholz-Muramatsu et al., 1995) 2001, 381 Dehalospirillum multivorans Scholz-Muramatsu et al. 2002, 1915VP Agreia pratensis (Behrendt et al. 2002) Schumann et al. 2003, VP (Effective publication: Scholz-Muramatsu et al., 1995) 2043 Desulfotomaculum auripigmentum Newman et al. 2000, 1415VP (Ef- Alcanivorax jadensis (Bruns and Berthe-Corti 1999) Ferna´ndez- VP fective publication: Newman et al., 1997) Martı´nez et al. 2003, 337 Enterococcus porcinusVP Teixeira et al. 2001 pro synon. Enterococcus Alistipes putredinis (Weinberg et al. 1937) Rautio et al. 2003b, VP villorum Vancanneyt et al. 2001b, 1742VP De Graef et al., 2003 1701 (Effective publication: Rautio et al., 2003a) Hongia koreensis Lee et al. 2000d, 197VP Anaerococcus hydrogenalis (Ezaki et al. 1990) Ezaki et al. 2001, VP Mycobacterium bovis subsp. caprae (Aranaz et al.
    [Show full text]
  • The Microbiology and Metal Attenuation in a Natural Wetland Impacted by Acid Mine Drainage
    The microbiology and metal attenuation in a natural wetland impacted by acid mine drainage A thesis submitted to the University of Manchester for the degree of Doctor of Philosophy in the Faculty of Science and Engineering 2018 Oscar E. Aguinaga Vargas School of Earth and Environmental Sciences TABLE OF CONTENTS ABSTRACT ................................................................................ 6 DECLARATION ........................................................................... 7 COPYRIGHT STATEMENT ............................................................. 8 ACKNOWLEDGMENTS ................................................................. 9 Chapter 1: GENERAL INTRODUCTION ..................................... 10 1.1 ACID MINE DRAINAGE ..................................................... 10 1.2 ENVIRONMENTAL IMPLICATIONS OF ACID MINE DRAINAGE ... 13 1.2.1 Presence of trace metals .............................................. 13 1.2.2 Environmental impact .................................................. 14 1.3 ACID MINE DRAINAGE REMEDIATION .................................. 18 1.3.1 Acid mine drainage remediation by wetlands ................... 19 1.3.1.1 Physicochemical processes ...................................... 19 1.3.1.2 Role of plants ........................................................ 21 1.3.1.3 Role of microorganisms ........................................... 23 1.4 CASE STUDIES OF ACID MINE DRAINAGE REMEDIATION BY WETLANDS ...........................................................................
    [Show full text]
  • HEATON-THESIS.Pdf
    BIOGEOCHEMICAL INVESTIGATION OF CENTRIFUGED FINE TAILINGS DEPOSITS AT AN OIL SANDS MINE IN NORTHERN ALBERTA, CANADA A Thesis Submitted to the College of Graduate Studies and Research In Partial Fulfillment of the Requirements For the Degree of Master of Science In the Department of Geological Sciences University of Saskatchewan Saskatoon By KAITLYN KASSANDRA HEATON © Copyright Kaitlyn Kassandra Heaton, September 2015. All rights reserved. PERMISSION TO USE In presenting this thesis in partial fulfillment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for Scholarly purposes may be granted by the professors who supervised my thesis work or, in their absence, by the Head of the Department in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis. Requests for permission to copy or to make other use of material in this thesis in whole or in part should be addressed to: Head of the Department of Geological Sciences University of Saskatchewan 114 Science Place Saskatoon, Saskatchewan, Canada S7N 5E2 i ABSTRACT Centrifuged fine tailings (CFT) technology was developed to reduce volumes of fluid fine tailings (FFT) stored in tailings ponds at oil sands mines.
    [Show full text]
  • Caractérisation Des Communautés Procaryotiques Impliquées Dans La Bioremédiation D'un Sol Pollué Par Des Hydrocarbures
    Caract´erisationdes communaut´esprocaryotiques impliqu´eesdans la biorem´ediationd'un sol pollu´epar des hydrocarbures et d´eveloppement d'outils d'analyse `a haut d´ebit C´ecileMiliton To cite this version: C´ecile Militon. Caract´erisation des communaut´es procaryotiques impliqu´ees dans la biorem´ediationd'un sol pollu´epar des hydrocarbures et d´eveloppement d'outils d'analyse `ahaut d´ebit. Protistologie. Universit´eBlaise Pascal - Clermont-Ferrand II; Universit´ed'Auvergne - Clermont-Ferrand I, 2007. Fran¸cais. <NNT : 2007CLF21810>. <tel-00718551> HAL Id: tel-00718551 https://tel.archives-ouvertes.fr/tel-00718551 Submitted on 17 Jul 2012 HAL is a multi-disciplinary open access L'archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destin´eeau d´ep^otet `ala diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publi´esou non, lished or not. The documents may come from ´emanant des ´etablissements d'enseignement et de teaching and research institutions in France or recherche fran¸caisou ´etrangers,des laboratoires abroad, or from public or private research centers. publics ou priv´es. UNIVERSITE BLAISE PASCAL UNIVERSITE D’AUVERGNE N° D.U. 1810 ANNEE 2007 ECOLE DOCTORALE DES SCIENCES DE LA VIE ET DE LA SANTE N° d’ordre 474 THESE Présentée à l’Université Blaise Pascal pour l’obtention du grade de DOCTEUR D’UNIVERSITE Spécialité : GENOMIQUE ET ECOLOGIE MICROBIENNE Présentée et soutenue publiquement par Cécile MILITON le 17 décembre 2007 CARACTERISATION DES COMMUNAUTES PROCARYOTIQUES IMPLIQUEES DANS LA BIOREMEDIATION D’UN SOL POLLUE PAR DES HYDROCARBURES ET DEVELOPPEMENT D’OUTILS D'ANALYSE A HAUT DEBIT: LES BIOPUCES ADN.
    [Show full text]
  • Cultivating and Characterizing Electroactive Microbial Communities Using Bioelectrochemical Systems and Metagenomics
    Cultivating and Characterizing Electroactive Microbial Communities using Bioelectrochemical Systems and Metagenomics by Tyler Joseph Arbour A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Earth and Planetary Science in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Jillian Banfield, Chair Professor James Bishop Professor Ronald Gronsky Spring 2017 ABSTRACT Cultivating and Characterizing Electroactive Microbial Communities using Bioelectrochemical Systems and Metagenomics by Tyler Joseph Arbour Doctor of Philosophy in Earth and Planetary Science University of California, Berkeley Professor Jillian F. Banfield, Chair Certain microbes have the remarkable ability to form direct electronic connections with their extracellular environment, harnessing existing redox gradients to drive their own life processes. The recognition of extracellular electron transfer (EET) as a widespread microbial phenomenon that plays an important role in biogeochemistry is recent, and is accompanied by new understanding of how this process impacts physical and chemical characteristics of the environment. Our current knowledge of the mechanisms and the microbial physiology behind EET is based largely on studies of two well studied isolates, Geobacter sulfurreducens and Shewanella oneidensis. Nevertheless, nature is not well represented by isolated organisms. Identification of the larger set of “electroactive” microbes from across much of the phylogenetic spectrum is critical for complete understanding of microbial controls on redox chemistry in natural environments. Genomic information for these organisms has the potential to expand our understanding of the mechanisms of growth that rely upon EET. This information should be particularly useful if it is obtained in an experimental setting that enables manipulation of redox potential.
    [Show full text]
  • Biotransformation of Lindane (Γ-Hexachlorocyclohexane) to Non-Toxic End Products by Sequential Treatment with Three Mixed Anaer
    bioRxiv preprint doi: https://doi.org/10.1101/2020.10.25.354597; this version posted October 26, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Biotransformation of lindane (γ-hexachlorocyclohexane) to non-toxic end products by sequential 2 treatment with three mixed anaerobic microbial cultures 3 4 Luz A. Puentes Jácomea, Line Lomheima, Sarra Gaspardb, and Elizabeth A. Edwardsa,c,* 5 aDepartment of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, 6 Ontario, Canada 7 bLaboratory COVACHIMM2E, Université des Antilles, Pointe à Pitre, Guadeloupe, French 8 West-Indies, France 9 cDepartment of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada 10 *Address correspondence to Elizabeth A. Edwards, [email protected] 11 1 bioRxiv preprint doi: https://doi.org/10.1101/2020.10.25.354597; this version posted October 26, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 12 Abstract 13 The γ isomer of hexachlorocyclohexane (HCH), also known as lindane, is a carcinogenic 14 persistent organic pollutant. Lindane was used worldwide as an agricultural insecticide. Legacy 15 soil and groundwater contamination with lindane and other HCH isomers is still a big concern. 16 The biotic reductive dechlorination of HCH to non-desirable and toxic lower chlorinated 17 compounds such as monochlorobenzene (MCB) and benzene, among others, has been broadly 18 documented.
    [Show full text]
  • Phylum “Proteobacteria”: the Deltaproteobacteria and Epsilonproteobacteria George M
    Taxonomic Outline of Bacteria and Archaea, Release 7.7 Taxonomic Outline of the Bacteria and Archaea, Release 7.7 March 6, 2007. Part 6– Phylum “Proteobacteria”: The Deltaproteobacteria and Epsilonproteobacteria George M. Garrity, Timothy G. Lilburn, James R. Cole, Scott H. Harrison, Jean Euzéby, and Brian J. Tindall Class Deltaproteobacteria VP Kuever et al 2006. N4Lid DOI: 10.1601/nm.3456 Order Desulfurellales VP Kuever et al 2006. N4Lid DOI: 10.1601/nm.3457 Family Desulfurellaceae VP Kuever et al 2006. N4Lid DOI: 10.1601/nm.3458 Genus Desulfurella VP Bonch-Osmolovskaya et al. 1993. N4Lid DOI: 10.1601/nm.3459 Desulfurella acetivorans VP Bonch-Osmolovskaya et al. 1993. Source of type material recommended for DOE sponsored genome sequencing by the JGI: ATCC 51451. High-quality 16S rRNA sequence S000008874 (RDP), X72768 (Genbank). N4Lid DOI: 10.1601/nm.3460 Desulfurella kamchatkensis VP Miroshnichenko 1998. Source of type material recommended for DOE sponsored genome sequencing by the JGI: ATCC 700655. High-quality 16S rRNA sequence S000000228 (RDP), Y16941 (Genbank). N4Lid DOI: 10.1601/nm.3461 Desulfurella multipotens VP Miroshnichenko et al. 1996. Source of type material recommended for DOE sponsored genome sequencing by the JGI: DSM 8415. High-quality 16S rRNA sequence S000004736 (RDP), Y16943 (Genbank). N4Lid DOI: 10.1601/nm.3462 Desulfurella propionica VP Miroshnichenko 1998. Source of type material recommended for DOE sponsored genome sequencing by the JGI: ATCC 700656. High-quality 16S rRNA sequence S000007307 (RDP), Y16942 (Genbank). N4Lid DOI: 10.1601/nm.3463 Genus Hippea VP Miroshnichenko et al. 1999. N4Lid DOI: 10.1601/nm.3464 Hippea maritima VP Miroshnichenko et al.
    [Show full text]
  • Dissimilatory Iron-Reducing and Endosporulating Bacteria
    DISSIMILATORY IRON-REDUCING AND ENDOSPORULATING BACTERIA by ROB UCHE ONYENWOKE (Under the Direction of Juergen Wiegel) ABSTRACT This dissertation represents a diversified study of the biochemical, physiological, and genetic traits of members of the low G+C subdivision of the Gram-type positive bacteria, also known as the ‘Firmicutes’. The phylum ‘Firmicutes’ contains a diverse array of taxa that are not easily separated into coherent phylogenetic groups by any one physiological trait, such as endospore-formation or dissimilatory iron reduction. This dissertation considers numerous contemporary, and highly convergent in providing breadth and scope of the subject matter, methods of study. The principle aim was to examine the lineage ‘Firmicutes’ by a) a genomic study of the occurrence or absence of endosporulation genes in numerous members of the lineage, b) classic biochemical studies of the enzymes responsible for biotic iron reduction, and c) culture-dependent studies and isolations of various ‘Firmicutes’ to both identify new iron- reducers and better resolve the taxonomy of the lineage. The work with endosporulation genes has shown there might not be a distinct set of “endosporulation-specific” genes. This raises several new questions about this exceptionally complex process. The work described here on “ferric reductases” suggests there are enzymes capable of iron reduction that also have additional activities. The isolation of novel bacteria presented here have added to the diversity of the ‘Firmicutes’ but have also added to the
    [Show full text]
  • Comparison of Synthetic Medium and Wastewater Used As Dilution Medium to Design Scalable Microbial Anodes: Application to Food Waste Treatment
    Open Archive TOULOUSE Archive Ouverte ( OATAO ) OATAO is an open access repository that collects the work of Toulouse researchers and makes it freely available over the web where possible. This is an author-deposited version published in : http://oatao.univ-toulouse.fr/ Eprints ID : 13879 To link to this article : DOI:10.1016/j.biortech.2015.02.097 URL : http://dx.doi.org/10.1016/j.biortech.2015.02.097 To cite this version : Blanchet, Elise and Desmond-Le Quemener, Elie and Erable, Benjamin and Bridier, Arnaud and Bouchez, Théodore and Bergel, Alain Comparison of synthetic medium and wastewater used as dilution medium to design scalable microbial anodes: Application to food waste treatment. (2015) Bioresource Technology, vol. 185. pp. 106-115. ISSN 0960-8524 Any correspondance concerning this service should be sent to the repository administrator: [email protected] Comparison of synthetic medium and wastewater used as dilution medium to design scalable microbial anodes: Application to food waste treatment ⇑ Elise Blanchet a, , Elie Desmond b, Benjamin Erable a, Arnaud Bridier b, Théodore Bouchez b, Alain Bergel a a Laboratoire de Génie Chimique (LGC), CNRS, Université de Toulouse (INPT), 4 allée Emile Monso, BP 84234, 31432 Toulouse, France b Irstea, UR HBAN, 1 rue Pierre-Gilles de Gennes, 92761 Antony cedex, France highlights Bioanodes were designed by replacing synthetic medium by costless wastewater. Using wastewater ensured 50% of the current density obtained in synthetic medium. Bioanodes differed in biofilm structures and redox charge contents. Current densities were directly correlated to the enrichment in Geob acteraceae . Wastewater is a suitable medium to design bioanodes for food waste treatment.
    [Show full text]