Download or read book Contribution of Oxidative Enzymes to the Degradation of Cellulose by Filamentous Fungi written by William Templeton Beeson and published by . This book was released on 2011 with total page 117 pages. Available in PDF, EPUB and Kindle. Book excerpt: The cost of cellulose degrading enzymes is still a major barrier to the economical production of liquid fuels from lignocellulose. Fungi play a central role in the degradation of plant biomass in terrestrial environments. They use a wide variety of secreted enzymes to break down biopolymers present in the plant cell wall. Here I report on the mechanisms of cellulose degradation used by Neurospora crassa, a model genetic organism, and Myceliopthora thermophila, a thermophilic fungus. Enzymes important for the degradation process were identified using a combination of transcriptomics, proteomics, genetics, and biochemistry. A key result from this work is that, in N. crassa and many other fungi, oxidative enzymes play a critical role in the depolymerization of cellulose. In contrast to the accepted models of oxidative cellulose degradation, via non-specific hydroxyl radical species, I found that in N. crassa, an oxidoreductase and several copper oxidases bind to cellulose and hydroxylate the substrate at specific positions leading to cleavage of the glycosidic bonds. This mode of action is orthogonal to that of traditional hydrolases and if used optimally in conjunction with other cellulases, could reduce the required enzyme loading for lignocellulose saccharification by 2-4 fold.

Download or read book Enzymatic Degradation of Cellulose by the Filamentous Fungus Neurospora Crassa written by Christopher Michael Phillips and published by . This book was released on 2011 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lignocellulosic biomass is an abundant renewable resource that can be used as a feedstock for production of second-generation biofuels. Currently, the bottleneck to generation of such fuels lies in the expensive and technically challenging process for converting biomass to fermentable sugars. Filamentous fungi are efficient at depolymerizing plant biomass. These fungi are also used for the production of industrial enzymes due to their ability to secrete large quantities of enzymes. The filamentous fungus Neurospora crassa is a genetically tractable model organism and a proficient degrader of plant biomass. In this dissertation, the enzymatic depolymerization of cellulose by Neurospora crassa was investigated using a combination of quantitative proteomics, genetics, and biochemistry. Chapter 1 is an introduction to lignocellulosic biomass and the organisms and enzymes that degrade it. In Chapter 2, a quantitative proteomic approach was taken to characterize the secretome of Neurospora crassa during growth on microcrystalline cellulose. Depolymerization of cellulose occurs by endoglucanases that hydrolyze internal glycosidic bonds and cellobiohydrolases that hydrolyze cellobiose from the reducing or non-reducing chain ends of cellulose. In addition to these canonical cellulases, a number of other proteins were quantified including a beta-glucosidase, a cellobiose dehydrogenase (CDH), and glycosyl hydrolase family 61 (GH61) enzymes. The beta-glucosidase and 3 cellulases were purified and biochemically characterized. While these 4 enzymes represent more than 85% of the cellulase in the secretome, they were significantly impaired in their rate of cellulose degradation relative to the complete set of enzymes in the secretome. This result suggested that proteins other than canonical cellulases may be important in cellulose depolymerization by fungi. The deletion of a gene encoding cellobiose dehydrogenase in N. crassa is described in Chapter 3. Cellobiose dehydrogenase (CDH) catalyzes the oxidation of cellobiose to cellobionolactone, but the biological function of this protein was previously unknown. Deletion of cdh-1 reduced cellulase activity 37-49% and addition of purified CDHs to the cdh-1 deletion strain resulted in a 1.6 to 2.0-fold stimulation in cellulase activity. The stimulatory effect of CDH required the presence of molecular oxygen and other secreted metalloproteins. The discovery that cellobiose dehydrogenase plays an integral role in degradation of cellulose marked a significant shift from previous models centered on the degradation of cellulose by mixtures of glycosyl hydrolases. To determine the molecular mechanisms by which CDH can enhance cellulase activity, a fractionation strategy was employed as described in Chapter 4 to identify synergistic metalloproteins in the N. crassa secretome. CDH was shown to enhance cellulose degradation by coupling the oxidation of cellobiose to the reductive activation of copper-dependent polysaccharide monooxygenases (PMOs), previously called GH61 enzymes. These enzymes catalyze the insertion of oxygen into C-H bonds adjacent to the glycosidic linkage and facilitate elimination of the adjacent carbohydrate moiety. A further discussion of the mechanism of copper-dependent PMOs is discussed in Chapter 5. Here, the action of different PMOs was shown to be regiospecific resulting in oxidized products modified at C1 on the reducing end or C4 on the non-reducing end. CDHs and proteins related to the PMOs are found in cellulolytic species throughout the fungal kingdom. When added to mixtures of cellulases, these proteins enhance cellulose depolymerization and could significantly reduce the cost of biofuel production. In chapter 6, the development of N. crassa as a host for recombinant expression of secreted enzymes is described. Expression of the endocellulase GH5-1 is used to complement the phenotype of a gh5-1 deletion strain. Experiments with GH5-1 fused to GFP (green fluorescent protein) were used to visualize the binding of this endocellulase to plant biomass. Additional applications for N. crassa as an expression host for fundamental studies of biomass depolymerizing enzymes are described.

Download or read book Oxidative Enzymes Involved in Fungal Cellulose Degradation Progress Report May 15 1992 May 14 1994 written by and published by . This book was released on 1992 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes progress in understanding of the structure, function, and mechanism, and the role of cellobiose dehydrogenase (CDH) of Phanerochaete chrysosporium in lignocellulose degradation.

Download or read book Handbook of Fungal Biotechnology written by Dilip K. Arora and published by CRC Press. This book was released on 2003-12-17 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Fungal Biotechnology offers the newest developments from the frontiers of fungal biochemical and molecular processes and industrial and semi-industrial applications of fungi. This second edition highlights the need for the integration of a number of scientific disciplines and technologies in modern fungal biotechnology and reigns as

Download or read book Fungal Metabolites written by Jean-Michel Mérillon and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Enzyme Systems for Lignocellulose Degradation written by Michael P. Coughlan and published by Springer. This book was released on 1989-08-23 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plant Litter written by Björn Berg and published by Springer Science & Business Media. This book was released on 2013-11-19 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the publication of the 2nd edition, there have been substantial developments in the field of litter decomposition. This fully revised and updated 3rd edition of Plant Litter reflects and discusses new findings and re-evaluates earlier ones in light of recent research and with regard to current areas of investigation. The availability of several long-term studies allows a more in-depth approach to decomposition patterns and to the later stages of decomposition, as well as to humus formation and accumulation. The latest information focuses on three fields: - the effects of manganese on decomposition and possibly on carbon sequestration, - new findings on decomposition dynamics, and - the new analytical technique using 13C-NMR.

Download or read book Xylanolytic Enzymes written by Pratima Bajpai and published by Academic Press. This book was released on 2014-02-03 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: Xylanolytic Enzymes describes the enzyme structure and its interaction with plant cell walls, the properties and production of different enzymes and their application, and the knowledge gathered on the hydrolysis mechanism of hemicellulose. The knowledge gathered about the hydrolysis mechanism of the hemicelluloses, especially xylans, has greatly promoted the rapid application of these enzymes in new areas. Recently there has been much industrial interest in xylan and its hydrolytic enzymatic complex, as a supplement and for the manufacturing of food, drinks, textiles, pulps and paper, and ethanol; and in xylitol production as a fermentation substrate for the production of enzymes. This book describes xylan as a major component of plant hemicelluloses. - Presents a thorough overview of all aspects of xylanolytic enzymes - Gives up-to-date authoritative information and cites pertinent research - Includes studies on xylanase regulation and synergistic action between multiple forms of xylanase

Download or read book Sustainable Degradation of Lignocellulosic Biomass written by Anuj Chandel and published by BoD – Books on Demand. This book was released on 2013-05-15 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides important aspects of sustainable degradation of lignocellulosic biomass which has a pivotal role for the economic production of several value-added products and biofuels with safe environment. Different pretreatment techniques and enzymatic hydrolysis process along with the characterization of cell wall components have been discussed broadly. The following features of this book attribute its distinctiveness: This book comprehensively covers the improvement in methodologies for the biomass pretreatment, hemicellulose and cellulose breakdown into fermentable sugars, the analytical methods for biomass characterization, and bioconversion of cellulosics into biofuels. In addition, mechanistic analysis of biomass pretreatment and enzymatic hydrolysis have been discussed in details, highlighting key factors influencing these processes at industrial scale.

Download or read book Biotechnology and Biology of Trichoderma written by Vijai G. Gupta and published by Newnes. This book was released on 2014-02-17 with total page 569 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biotechnology and Biology of Trichoderma serves as a comprehensive reference on the chemistry and biochemistry of one of the most important microbial agents, Trichoderma, and its use in an increased number of industrial bioprocesses for the synthesis of many biochemicals such as pharmaceuticals and biofuels. This book provides individuals working in the field of Trichoderma, especially biochemical engineers, biochemists and biotechnologists, important information on how these valuable fungi can contribute to the production of a wide range of products of commercial and ecological interest. - Provides a detailed and comprehensive coverage of the chemistry, biochemistry and biotechnology of Trichoderma, fungi present in soil and plants - Includes most important current and potential applications of Trichoderma in bioengineering, bioprocess technology including bioenergy & biofuels, biopharmaceuticals, secondary metabolites and protein engineering - Includes the most recent research advancements made on Trichoderma applications in plant biotechnology and ecology and environment

Download or read book Green Bio processes written by Binod Parameswaran and published by Springer. This book was released on 2018-11-03 with total page 451 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume discusses recent advancements to the age old practice of using microbial enzymes in the preparation of food. Written by leading experts in the field, it discusses novel enzymes and their applications in the industrial preparation of food to improve taste and texture, while reducing cost and increasing consistency. This book will be of interest to both researchers and students working in food technology.

Download or read book Environmental Research at the Leading Edge written by Alfred B. Gore and published by Nova Publishers. This book was released on 2007 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The environment is considered the surroundings in which an organism operates, including air, water, land, natural resources, flora, fauna, humans and their interrelation. It is this environment which is both so valuable, on the one hand, and so endangered on the other. And it is people who are by and large ruining the environment both for themselves and for all other organisms. This book reviews the latest research in this field which is vital for everyone.

Download or read book Chitin and Chitosan written by Lambertus A. M. van den Broek and published by John Wiley & Sons. This book was released on 2020-01-21 with total page 534 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a comprehensive guide to the isolation, properties and applications of chitin and chitosan Chitin and Chitosan: Properties and Applications presents a comprehensive review of the isolation, properties and applications of chitin and chitosan. These promising biomaterials have the potential to be broadly applied and there is a growing market for these biopolymers in areas such as medical and pharmaceutical, packaging, agricultural, textile, cosmetics, nanoparticles and more. The authors – noted experts in the field – explore the isolation, characterization and the physical and chemical properties of chitin and chitosan. They also examine their properties such as hydrogels, immunomodulation and biotechnology, antimicrobial activity and chemical enzymatic modifications. The book offers an analysis of the myriad medical and pharmaceutical applications as well as a review of applications in other areas. In addition, the authors discuss regulations, markets and perspectives for the use of chitin and chitosan. This important book: Offers a thorough review of the isolation, properties and applications of chitin and chitosan. Contains information on the wide-ranging applications and growing market demand for chitin and chitosan Includes a discussion of current regulations and the outlook for the future Written for Researchers in academia and industry who are working in the fields of chitin and chitosan, Chitin and Chitosan: Properties and Applications offers a review of these promising biomaterials that have great potential due to their material properties and biological functionalities.

Download or read book Methods of Soil Enzymology written by Richard P. Dick and published by John Wiley & Sons. This book was released on 2020-01-22 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods of Soil Enzymology provides the first comprehensive set of vetted methods for studying enzymes in soils. Readers will especially benefit from the step-by-step explanation of the lab procedures, as well as background information for using these methods effectively and analyzing data. Main topics include activity assays, enzyme extraction, and synthetic enzyme complexes. Each method covered includes background informaton, step-by-step descriptions of the procedure, and special comments regarding nuances, pitfalls, and interpretation of the method. Learn the latest research methods, including enzyme extraction methods and procedures for creating synthetic enzyme complexes, as well as the newest ways to use small-scale and high-throughput methods for enzyme activity assays. Written for the researcher, but welcoming to those new to soil enzymology, the introduction includes conceptual information to orient those who are not familiar with these methods but want to use them. In the tradition of SSSA methods books, Methods of Soil Enzymology features a comprehensive approach with a focus on ease of use.

Download or read book Applied Molecular Genetics of Filamentous Fungi written by J.R. Kinghorn and published by Springer Science & Business Media. This book was released on 1992-08-31 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: The filamentous fungi are perhaps unique in the diversity of their metabolic activities. This includes biosynthetic as well as degradative activities, many is to provide an of which are of industrial interest. The objective of this text up-to-date and broad review which emphasizes the genetic and molecular biological contribution in the field of fungal biotechnology. This text begins with an overview of the tools and methodologies involved which, to a large extent, have been developed in the model filamentous fungus Aspergillus nidulans and subsequently have been extended to commercially important fungi. This is followed by a chapter which provides a compilation of genes isolated from commercial fungi and their present status with respect to structure, function and regulation. Chapters 3 and 4 highlight the degradative powers of filamentous fungi. First, a discussion of what is known regarding the molecular genetics of fungi and the genes and enzymes involved in the beverage and food industries. This has an oriental flavour, reflecting the tremendous importance of fungi in traditional Chinese and Japanese food production. An account of lignocellulose degradation by filamentous fungi follows, illustrating the potential of fungi to utilize this substance as a renewable energy source. The ability of fungi to produce high-value foreign proteins is reviewed in chapters 5 and 6. Chymosin production, in particular, represents a good example of high-level yields being obtained, such as to warrant commercial production.

Download or read book Biorefinery of Oil Producing Plants for Value Added Products written by Suraini Abd-Aziz and published by John Wiley & Sons. This book was released on 2021-12-21 with total page 791 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biorefinery of Oil Producing Plants for Value-Added Products An instructive and up-to-date pretreatment and industrial applications of oil producing plants Biorefinery of Oil Producing Plants for Value-Added Products is a two-volume set that delivers a comprehensive exploration of oil producing plants, from their availability to their pretreatment, bioenergy generation, chemical generation, bioproduct generation, and economic impact. The distinguished team of editors has included a wide variety of highly instructive resources written by leading contributors to the field. This set explores the current and future potential of bioenergy production to address the energy and climate crisis, as well as the technologies used to produce materials like biogas, biodiesel, bioethanol, biobutanol, biochar, fuel pellets, and biohydrogen. It also discusses the production of biobased chemicals, including bio-oil, biosurfactants, catanionic surfactants, glycerol, biovanillin, bioplastic, and plant-oil based polyurethanes. Concluding with an insightful analysis of the economic effects of oil producing plants, the set also offers readers: A thorough introduction to the availability of oil producing plants, including palm oil, castor oil, jatropha, nyamplung, and coconut A comprehensive exploration of the pretreatment of oil producing plants, including the physical, chemical and biological pretreatment of lignocellulosic biomass Practical discussion of the generation of bioenergy, including biogas generation in the palm oil mill and biodiesel production techniques using jatropha In-depth examinations of the generation of biobased chemicals, including those produced from the tobacco plant Perfect for researchers and industry practitioners involved with the biorefinery of oil producing plants, Biorefinery of Oil Producing Plants for Value-Added Products also belongs in the libraries of undergraduate and graduate students studying agriculture, chemistry, engineering, and microbiology.

Download or read book Biotechnology of Lignocellulose written by Hongzhang Chen and published by Springer. This book was released on 2014-04-21 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents and summarizes the new thoughts, new methods and new achievements that have emerged in the biotechnology of lignocellulose in recent years. It proposes new concepts including the primary refining, fractionation, multi-level utilization and selective structural separation of lignocellulose, etc. By approaching lignocellulose as a multi-level resource, biotechnology could have a significant effect on ecological agriculture, bio-energy, the chemical and paper making industries, etc., ultimately establishing distinctive eco-industrial parks for lignocellulose. Additionally, this book provides systematic research methods for the biotechnology of lignocellulose including investigation methods for the primary refining of lignocellulose, for microbial degradation and enzymatic hydrolysis, for cellulose fermentation and for lignocellulose conversion processes. It offers an excellent reference work and guide for scientists engaging in research on lignocellulose. Dr. Hongzhang Chen is a Professor at the Institute of Process Engineering of the Chinese Academy of Sciences, Beijing, China.