Micro- and Macroparticle enhanced cultivation of filamentous Lentzea aerocolonigenes for increased rebeccamycin production PDF Download

Author: Kathrin Schrinner
Publisher: Cuvillier Verlag
ISBN: 3736963505
Category : Science
Languages : en
Pages : 142

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Book Description
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.

Author: Sebastian Tesche
Publisher: Cuvillier Verlag
ISBN: 3736963432
Category : Technology & Engineering
Languages : en
Pages : 130

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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.

Author: Yong Xiao
Publisher: Frontiers Media SA
ISBN: 288945651X
Category :
Languages : en
Pages : 218

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Book Description
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.

Author: Fred Lisdat
Publisher: Springer Nature
ISBN: 303156913X
Category :
Languages : en
Pages : 448

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Author: K. M. Gothandam
Publisher: CRC Press
ISBN: 100081646X
Category : Science
Languages : en
Pages : 313

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Book Description
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.

Author: Korneel Rabaey
Publisher: IWA Publishing
ISBN: 184339233X
Category : Science
Languages : en
Pages : 525

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Book Description
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.

Author: Sadik Dincer
Publisher: BoD – Books on Demand
ISBN: 1789858992
Category : Science
Languages : en
Pages : 362

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Book Description
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.

Author: Zbigniew Lewandowski
Publisher: CRC Press
ISBN: 1466559594
Category : Medical
Languages : en
Pages : 666

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Book Description
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

Author: Heather R. Luckarift
Publisher: John Wiley & Sons
ISBN: 1118869737
Category : Technology & Engineering
Languages : en
Pages : 540

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Book Description
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

Author: Falk Harnisch
Publisher: Springer
ISBN: 303003299X
Category : Science
Languages : en
Pages : 423

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Book Description
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.