Download or read book Quantitative analysis of the electrochemically active bacteria Geobacter sulfurreducens and Shewanella oneidensis written by Christina Engel and published by Cuvillier Verlag. This book was released on 2020-05-12 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrochemically active bacteria are important biocatalysts in bioelectrochemical systems. This work investigated the long-term behaviour of an electrochemical defined mixed culture of Geobacter sulfurreducens and Shewanella oneidensis, and the influence of the set anode potential on this defined mixed culture. Further, G. sulfurreducens was investigated non-electrochemically in pure culture to elucidate how this bacterium accomplishes oxygen reduction. Planktonic S. oneidensis cells were found to be beneficial for current production and biofilm growth of G. sulfurreducens in a microbial electrolysis cell. However, upon removal of planktonic cells, these benefits could not be maintained as S. oneidensis was not incorporated sufficiently into the G. sulfurreducens-based biofilm. In terms of the applied anode potential, 0.2 VAg/AgCl as well as 0.2 VAg/AgCl were found to be best. At 0.2 VAg/AgCl the highest current density was achieved while at -0.2 VAg/AgCl the highest current production in relation to biofilm thickness was observed. G. sulfurreducens was found to reduce oxygen in non-electrochemical pure cultures at a maximum specific oxygen uptake rate of 95 ± 11 mgO2 gCDW-1 h-1. The expression of the gene for the cytochrome bd menaquinol oxidase was found to be upregulated under microaerobic conditions, indicating this enzyme to be responsible for oxygen reduction.
Download or read book Electrochemically Active Microorganisms written by Yong Xiao and published by Frontiers Media SA. This book was released on 2018-11-14 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial electrochemical systems (MESs, also known as bioelectrochemical systems (BESs) are promising technologies for energy and products recovery coupled with wastewater treatment, and have attracted increasing attention. Many studies have been conducted to expand the application of MESs for contaminants degradation and bioremediation, and increase the efficiency of electricity production by optimizing architectural structure of MESs, developing new electrode materials, etc. However, one of the big challenges for researchers to overcome, before MESs can be used commercially, is to improve the performance of the biofilm on electrodes so that ‘electron transfer’ can be enhanced. This would lead to greater production of electricity, energy or other products. Electrochemically active microorganisms (EAMs) are a group of microorganisms which are able to release electrons from inside their cells to an electrode or accept electrons from an electron donor. The way in which EAMs do this is called ‘extracellular electron transfer’ (EET). So far, two EET mechanisms have been identified: direct electron transfer from microorganisms physically attached to an electrode, and indirect electron transfer from microorganisms that are not physically attached to an electrode. 1) Direct electron transfer between microorganisms and electrode can occur in two ways: a) when there is physical contact between outer membrane structures of the microbial cell and the surface of the electrode, b) when electrons are transferred between the microorganism and the electrode through tiny projections (called pili or nanowires) that extend from the outer membrane of the microorganism and attach themselves to the electrode. 2) Indirect transfer of electrons from the microorganisms to an electrode occurs via long-range electron shuttle compounds that may be naturally present (in wastewater, for example), or may be produced by the microorganisms themselves. The electrochemically active biofilm, which degrades contaminants and produces electricity in MESs, consists of diverse community of EAMs and other microorganisms. However, up to date only a few EAMs have been identified, and most studies on EET have focused on the two model species of Shewanella oneidensis and Geobacter sulfurreducens.
Download or read book Micro and Macroparticle enhanced cultivation of filamentous Lentzea aerocolonigenes for increased rebeccamycin production written by Kathrin Schrinner and published by Cuvillier Verlag. This book was released on 2020-12-28 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: The filamentous actinomycete Lentzea aerocolonigenes produces the antitumor antibiotic rebeccamycin. However, the complex morphology of actinomycetes leads to challenges during the cultivation often accompanied by low product titers. In the recent past, the to date low rebeccamycin titers were increased by particle addition to cultivations of L. aerocolonigenes. In this thesis the addition of micro-, macro- and adsorbent particles to cultivations of L. aerocolonigenes were investigated in more detail. Furthermore, the scale-up to a bubble-free bioreactor was conducted. The addition of glass microparticles (x50 = 7.9 μm, 10 g L-1) to shake flask cultivations increased the rebeccamycin titer up to 3.6-fold compared to an unsupplemented approach. Pellet slices showed the incorporation of microparticles. With different surface modifications of the microparticles, specific incorporation patterns of the microparticles appeared. The incorporation of microparticles causes looser and smaller pellets allowing an increased nutrient and oxygen supply in the pellet core. With addition of larger (glass) macroparticles (ø = 0.2 – 2.1 mm, 100 g L-1) mechanical stress was induced on the biopellets. The additional supplementation of 5 g L-1 soy lecithin and glass beads (ø = 969 μm, 100 g L-1) resulted in a rebeccamycin titer of 388 mg L-1, one of the highest rebeccamycin titers ever achieved. For the scale-up of L. aerocolonigenes cultivations a bubble-free membrane aeration system was developed. The tubular membrane aeration system can additionally be pressurized to increase the oxygen transfer. First cultivations of L. aerocolonigenes successfully provided 18 mg L-1 rebeccamycin, a concentration similar to that of unsupplemented shake flask cultivations. XAD adsorbent particles were added to cultivations to facilitate rebeccamycin recovery. However, the XAD particles additionally increased the rebeccamycin titer which was likely to be caused by the adsorption of the rebeccamycin precursor tryptophan to the resins which in turn directly transferred the tryptophan to the microorganism.
Download or read book Production of labyrinthopeptin A1 with Actinomadura namibiensis written by Sebastian Tesche and published by Cuvillier Verlag. This book was released on 2020-12-21 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: The filamentous actinomycete Actinomadura namibiensis is the only known producer of labyrinthopeptins, a class of ribosomally synthesized and posttranslationally modified peptides (RiPPs) displaying highly attractive bioactive properties. In order to increase the labyrinthopeptin A1 productivity in shaking flask cultivations of A. namibiensis, a new cultivation method called salt-enhanced cultivation was used. Compared to the unsupplemented control, labyrinthopeptin A1 productivity was enhanced the most by addition of 50 mM (NH4)2SO4, reaching a 7-fold higher yield of 325 mg L-1 within 10 cultivation days. Salt-enhanced cultivation affected growth and product formation mechanisms, cell morphology characteristics and rheological characteristics of cultivation broth. An image analysis method was developed to quantify both the macro-morphology (pellet size and shape) and the micro-morphology (hyphal network structure) of the heterogeneous filamentous biomass in detail. Productivity-related morphological parameters were in particular the size and circularity of pellets and the degree of hyphal interweaving (hyphal network spacing). It was shown that the time-dependent change in morphology linked to the rheological properties of the cultivation broth. The results presented in this work provide new insights into the cultivation aspects of A. namibiensis and illustrate the challenges on the way to a comprehensive understanding of the complex relationship between productivity, morphology and rheology in filamentous cultivations.
Download or read book Electrochemically Active Microorganisms written by and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial electrochemical systems (MESs, also known as bioelectrochemical systems (BESs) are promising technologies for energy and products recovery coupled with wastewater treatment, and have attracted increasing attention. Many studies have been conducted to expand the application of MESs for contaminants degradation and bioremediation, and increase the efficiency of electricity production by optimizing architectural structure of MESs, developing new electrode materials, etc. However, one of the big challenges for researchers to overcome, before MESs can be used commercially, is to improve the performance of the biofilm on electrodes so that 'electron transfer' can be enhanced. This would lead to greater production of electricity, energy or other products. Electrochemically active microorganisms (EAMs) are a group of microorganisms which are able to release electrons from inside their cells to an electrode or accept electrons from an electron donor. The way in which EAMs do this is called 'extracellular electron transfer' (EET). So far, two EET mechanisms have been identified: direct electron transfer from microorganisms physically attached to an electrode, and indirect electron transfer from microorganisms that are not physically attached to an electrode. 1) Direct electron transfer between microorganisms and electrode can occur in two ways: a) when there is physical contact between outer membrane structures of the microbial cell and the surface of the electrode, b) when electrons are transferred between the microorganism and the electrode through tiny projections (called pili or nanowires) that extend from the outer membrane of the microorganism and attach themselves to the electrode. 2) Indirect transfer of electrons from the microorganisms to an electrode occurs via long-range electron shuttle compounds that may be naturally present (in wastewater, for example), or may be produced by the microorganisms themselves. The electrochemically active biofilm, which degrades contaminants and produces electricity in MESs, consists of diverse community of EAMs and other microorganisms. However, up to date only a few EAMs have been identified, and most studies on EET have focused on the two model species of Shewanella oneidensis and Geobacter sulfurreducens.
Download or read book Trends in Biosensing Research written by Fred Lisdat and published by Springer Nature. This book was released on with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Biotechnology for Toxicity Remediation and Environmental Sustainability written by K. M. Gothandam and published by CRC Press. This book was released on 2023-03-04 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: Environmental issues such as ozone layer depletion, overpopulation, biodiversity loss, global warming, natural resource depletion, and so on affect every organism on the planet somehow. Environmental biotechnology applications can help to protect and restore the quality of the environment. The goal is to use biotechnology with other technologies and safety procedures to prevent, arrest, and reverse environmental degradation. Environmental biotechnology is one of the most rapidly expanding and practically useful scientific fields. Biochemistry, physiology and genetic research of microorganisms can be converted into commercially available technologies for reversing and preventing further deterioration of the earth's environment. Solid, liquid, and gaseous wastes can be altered either by recycling new by-products or by purifying to make the end product less harmful to the environment. Biotechnology for Toxic Remediation and Environmental Sustainability discusses the removal of pollutants by absorption techniques and recycling wastewater into valuable by-products and biofuels by microorganisms. Moreover, this book also addresses corrosion prevention by green inhibitors, uses electrochemical systems for renewable energy and waste recycling using microbes, and recent food safety and security trends in the food microbiome. On the other hand, this book also discusses therapy and treatments against antibiotic-resistant bacteria, anti-cancer and pharmacological properties of thymoquinone and preventive properties of zinc nanoparticles against stress-mediated apoptosis in epithelial cells. Features Covers all aspects of Biotechnological application in the environment Discusses sustainable technology for the wastewater treatment and value-added products from wastewater Focuses on research activities Green corrosion inhibitors, bio-electrochemical systems, food safety and security, and antimicrobial resistance The book is a valuable resource for the undergrad and graduate students, doctoral and post-doctoral scholars, industrial personnel, academicians, scientists, researchers, and policymakers involved in understanding and implementing applications of biotechnology for environmental toxic remediation.
Download or read book Electrochemically Active Biofilms of Shewanella Oneidensis MR 1 Utilizing Organic Wastes written by Hung Duc Nguyen and published by . This book was released on 2008 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioelectrochemical Systems written by Korneel Rabaey and published by IWA Publishing. This book was released on 2009-12-01 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the context of wastewater treatment, Bioelectrochemical Systems (BESs) have gained considerable interest in the past few years, and several BES processes are on the brink of application to this area. This book, written by a large number of world experts in the different sub-topics, describes the different aspects and processes relevant to their development. Bioelectrochemical Systems (BESs) use micro-organisms to catalyze an oxidation and/or reduction reaction at an anodic and cathodic electrode respectively. Briefly, at an anode oxidation of organic and inorganic electron donors can occur. Prime examples of such electron donors are waste organics and sulfides. At the cathode, an electron acceptor such as oxygen or nitrate can be reduced. The anode and the cathode are connected through an electrical circuit. If electrical power is harvested from this circuit, the system is called a Microbial Fuel Cell; if electrical power is invested, the system is called a Microbial Electrolysis Cell. The overall framework of bio-energy and bio-fuels is discussed. A number of chapters discuss the basics – microbiology, microbial ecology, electrochemistry, technology and materials development. The book continues by highlighting the plurality of processes based on BES technology already in existence, going from wastewater based reactors to sediment based bio-batteries. The integration of BESs into existing water or process lines is discussed. Finally, an outlook is provided of how BES will fit within the emerging biorefinery area.
Download or read book Electrical phenotyping of the Bacterial Envelope Using Microfluidics written by Qianru Wang (Ph. D.) and published by . This book was released on 2018 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bacterial cell envelope is a complex multi-layered covering, crucial for cell viability and physiological capabilities. Phenotypic analysis of bacterial envelopes is challenging due to the small size and low cultivability of microbes. The emerging microfluidic techniques enable quantitative and nondestructive probing of cell envelopes by measuring their physical properties. This thesis demonstrates that phenotypic variations on bacterial envelopes change their surface polarizability–an intrinsic dielectric property–in a manner that can be distinguished by microfluidic dielectrophoresis (DEP). The three-dimensional insulator-based dielectrophoresis (3DiDEP), a microfluidic technique previously reported by our group, was optimized to explore the diverse surface phenotypes of bacterial electrochemical activity and lipopolysaccharide (LPS) biosynthesis. Electrochemically active bacteria transport electrons directly from their interior to external insoluble electron accepters, e.g. metal oxides or electrodes in electrochemical systems, via a process known as extracellular electron transfer (EET), holding an exciting promise in energy conversion and bioremediation. Using 3DiDEP, we demonstrate for the first time the strong correlation between microbial EET and cell surface polarizability, generalizable to three bacterial species with variant electrochemical activities, including Geobacter sulfurreducens, Shewanella oneidensis, and Escherichia coli heterologously expressing Shewanella EET pathways. We also applied 3DiDEP to achieve rapid quantification of LPS, the major component and virulence determinant in Gram-negative bacterial outer membrane. We examined E. coli mutant strains with various LPS components truncated, and show that structural diversity in LPS affects the trapping voltages required for 3DiDEP cell immobilization. Last but not least, we studied the interplay of electrothermal and induced charge electroosmosis (ICEO) flows, which can interfere DEP operations but are often overlooked in the design of iDEP systems. The effects of fluidic ionic strength, applied electric field, and insulating channel geometry on temperature rise and fluid velocities were investigated from a theoretical and experimental viewpoint. Taken together, this thesis introduces surface polarizability as a novel physical property for assessing microbial EET and LPS composition. Dielectrophoretic screening of bacterial envelope polarizability may unlock a vast repertoire of EET- and LPS- related biochemical applications, and will be useful as guidance for further DEP-based phenotypic analysis of a diverse array of cells and organisms.
Download or read book Enzymatic Fuel Cells written by Heather R. Luckarift and published by John Wiley & Sons. This book was released on 2014-05-06 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes research encompassing all of the aspects required to understand, fabricate and integrate enzymatic fuel cells Contributions span the fields of bio-electrochemistry and biological fuel cell research Teaches the reader to optimize fuel cell performance to achieve long-term operation and realize commercial applicability Introduces the reader to the scientific aspects of bioelectrochemistry including electrical wiring of enzymes and charge transfer in enzyme fuel cell electrodes Covers unique engineering problems of enzyme fuel cells such as design and optimization
Download or read book Fundamentals of Biofilm Research Second Edition written by Zbigniew Lewandowski and published by CRC Press. This book was released on 2013-12-16 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: The six years that have passed since the publication of the first edition have brought significant advances in both biofilm research and biofilm engineering, which have matured to the extent that biofilm-based technologies are now being designed and implemented. As a result, many chapters have been updated and expanded with the addition of sections reflecting changes in the status quo in biofilm research and engineering. Emphasizing process analysis, engineering systems, biofilm applications, and mathematical modeling, Fundamentals of Biofilm Research, Second Edition provides the tools to unify and advance biofilm research as a whole. Retaining the goals of the first edition, this second edition serves as: A compendium of knowledge about biofilms and biofilm processes A set of instructions for designing and conducting biofilm experiments A set of instructions for making and using various tools useful in biofilm research A set of computational procedures useful in interpreting results of biofilm research A set of instructions for using the model of stratified biofilms for data interpretation, analysis, and biofilm activity prediction
Download or read book Bacterial Biofilms written by Sadik Dincer and published by BoD – Books on Demand. This book was released on 2020-10-07 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book examines biofilms in nature. Organized into four parts, this book addresses biofilms in wastewater treatment, inhibition of biofilm formation, biofilms and infection, and ecology of biofilms. It is designed for clinicians, researchers, and industry professionals in the fields of microbiology, biotechnology, ecology, and medicine as well as graduate and postgraduate students.
Download or read book Biofilms in Bioelectrochemical Systems written by Haluk Beyenal and published by John Wiley & Sons. This book was released on 2015-09-08 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as a manual of research techniques for electrochemically active biofilm research. Using examples from real biofilm research to illustrate the techniques used for electrochemically active biofilms, this book is of most use to researchers and educators studying microbial fuel cell and bioelectrochemical systems. The book emphasizes the theoretical principles of bioelectrochemistry, experimental procedures and tools useful in quantifying electron transfer processes in biofilms, and mathematical modeling of electron transfer in biofilms. It is divided into three sections: Biofilms: Microbiology and microbioelectrochemistry - Focuses on the microbiologic aspect of electrochemically active biofilms and details the key points of biofilm preparation and electrochemical measurement Electrochemical techniques to study electron transfer processes - Focuses on electrochemical characterization and data interpretation, highlighting key factors in the experimental procedures that affect reproducibility Applications - Focuses on applications of electrochemically active biofilms and development of custom tools to study electrochemically active biofilms. Chapters detail how to build the reactors for applications and measure parameters
Download or read book Electrochemical Systems written by Alanah Fitch and published by Wiley. This book was released on 2015-05-26 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introducing the topic of electrochemistry for non-electrochemists, Electrochemical Systems provides an overview of the fundamentals of electrochemical theory and techniques along with an appreciation for its wide range of applications. Covering both common topics (batteries, corrosion, and fuel cells) along with new topics (membranes and proteins), introductory chapters provide students and practitioners with the skills to be able to "read" cyclic voltammograms, linear sweep voltammetry, and other various fundamental terms. Chapters are arranged in order of ascending complexity of the system.
Download or read book Bioelectrosynthesis written by Falk Harnisch and published by Springer. This book was released on 2019-01-04 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume discusses both the latest experimental research in bioelectrosynthesis and current applications. Beginning with an introduction into the “electrification of biotechnology” as well as the underlying fundamentals, the volume then discusses a wide range of topics based on the interfacing of biotechnological and electrochemical reaction steps. It includes contributions on the different aspects of bioelectrochemical applications for synthesis purposes, i.e. the production of fine and platform chemicals based on enzymatically or microbially catalyzed reactions driven by electric energy. The volume finishes with a summary and outlook chapter which gives an overview of the current status of the field and future perspectives. Edited by experts in the field, and authored by a wide range of international researchers, this volume assesses how research from today’s lab bench can be developed into industrial applications, and is of interest to researchers in academia and industry.
Download or read book Microorganisms and Minerals written by Eugene D. Weinberg and published by . This book was released on 1977 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
