Download or read book Characterizing the Degradation of Cellulose by Combinations of Cellulolytic Enzymes written by Thomas Starr and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Cellulose is the most abundant biomolecule on Earth and is composed of chains of glucose, but its depolymerization for use in the production of renewable bioenergy and biomaterials is inefficient. To better understand the mechanisms of cellulose degradation by cellobiohydrolases, a class of enzymes that cleave cellulose into cellobiose dimers, we characterized accessory enzymes that act on cellulose in combination with Trichoderma reesei Cel7A, a cellobiohydrolase that targets the reducing ends of glucan chains in cellulose. The accessory enzymes studied include endo-1,4-[beta]-D-glucanase (Cel7B) from Trichoderma longibrachiatum and Cel6A, a cellobiohydrolase II. Cel7B randomly cleaves cellulose to produce additional binding sites for other cellulases, whereas Cel6A cleaves cellobiose units from the nonreducing ends of glucan chains in cellulose. By measuring reducing end production in reactions between cellulose from Acetobacter and these enzymes, we found that although the addition of Cel7B with Cel7A significantly enhances cellulose hydrolysis, the enzyme appears to act in an additive manner rather than a synergistic (multiplicative) one. Conversely, Cel6A appears to act synergistically with Cel7A at varying concentrations, resulting in more cellulose hydrolysis by the enzyme mixture than the sum of the two enzymes alone. Further experiments to test three-enzyme cocktails containing each of the previous enzymes indicate that combining all three cellulases increases synergy above that observed for each two-enzyme combination. These data will be used to develop biochemical models to help explain the single-molecule behaviors of these enzymes as they degrade cellulose alone or in concert, as observed using a newly developed SCATTIRSTORM microscope.
Download or read book Ecology of Saprotrophic Basidiomycetes written by Lynne Boddy and published by Elsevier. This book was released on 2007-12-29 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: The breadth and depth of understanding of many areas concerning basidiomycetes has increased dramatically since the premier publication of Frankland et al., Decomposer Basidiomycetes: their Biology and Ecology. New vistas have opened up with the advent of powerful computing, modeling and molecular approaches helping to greatly increase the general understanding of the ecology of basidiomycetes. This is tantamount to understanding the role of fungi in natural ecosystems because they are major agents of decomposition and nutrient cycling. These remarkable advances have been incorporated into this volume that discusses all aspects of saprotrophic basidiomycete ecology.
Download or read book Biochemistry and Genetics of Cellulose Degradation written by Jean-Paul Aubert and published by . This book was released on 1988 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume reviews basic research into the biochemistry and genetics of lignocellulose biodegradation; the breakdown of cellulose containing products utilizing microorganisms. This topic has received much attention of late because of possibilities for the biotechnology industry and because it is hoped that advances in the field will make a contribution to the energy crisis by utilizing biomass. However, there remains a good deal of basic research still to be done before full exploitation can be achieved.
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 Current Status and Future Scope of Microbial Cellulases written by Deepak K. Tuli and published by Elsevier. This book was released on 2021-04-01 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: Current Status and Future Scope of Microbial Cellulases not only explores the present and future of cellulase production, it also compares solid state fermentation (SSF) and submerged fermentation (SMF) for cellulase production. Chapters explore bioprocess engineering, metabolic engineering and genetic engineering approaches for enhanced cellulase production, including the application of cellulase for biofuel production. This important resource presents current technical status and the future direction of advances in cellulase production, including application of cellulases in different sectors. - Covers the present industrial scenarios and future prospect of cellulase production - Describes the molecular structure of cellulase - Explores genetic engineering, metabolic engineering and other approaches for improved cellulase production - Includes different applications of cellulases, including their application in the bioenergy sector
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 Enzymatic Degradation of Insoluble Carbohydrates written by John N. Saddler and published by . This book was released on 1995 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a review of enzymes used in the conversion of renewable feedstocks such as starch and cellulose. Provides examples of the use of enzymes in the resource sector, specifically addressing their use in agriculture, forest products, and pulp and paper. Explores greater use of agriculture and forestry residues and possible enzymatic modification.
Download or read book Mechanisms and Regulation of Cellulose Degradation by Clostridia Papyrosolvens C7 and Neurospora Crassa written by Veronica Zepeda and published by . This book was released on 2011 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: Microbial degradation of plant biomass plays a central role in the global carbon cycle. However, the turnover of cellulose in plants poses a difficult challenge due to its microcrystalline nature and its protection by other polymers in the plant cell wall. Bacteria and fungi have evolved diverse strategies for breaking down plant biomass, involving suites of cellulolytic enzymes that are produced at appropriate times to degrade the recalcitrant substrate. The work presented here provides an analysis of two cellulolytic organisms and their potential as model systems in the study of cellulose degradation. We probed the cellulolytic system in Clostridium papyrosolvens C7 by sequencing its genome and characterizing the cellulosomal components. Comparisons to other cellulosome producing organisms revealed many unique enzymes and non-catalytic cellulosome components. When grown on different carbon sources, C. papyrosolsovens C7 upregulates enzymes incorporated into cellulosomes with surprisingly little compositional diversity or dynamic range. These results provide a framework for using C. papyrosolvens C7 in the engineering of designer cellulosomes, as well as understanding the regulation and efficiency of these heterogeneous multienzyme complexes. The tools available for studying N. crassa have recently been applied to its cellulolytic system and much has been quickly learned about its degradative capability. However, the processes that produce its strong and specific induction of cellulase genes are not well understood. Through a screen for deletion strains that affect cellulose degradation, a kinase (NCU07399) was identified that seems to affect the transcriptional activation of several cellulase genes. Preliminary characterization of this kinase reveals an unusual domain architecture and in vitro phosphorylation activity that mimic studies on its yeast and human homologs. The screen and subsequent assays used to analyze NCU07399 presented here should provide a basis for dissecting the pathways involved in cellulase upregulation by N. crassa.
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 Mycodegradation of Lignocelluloses written by R. Naraian and published by Springer Nature. This book was released on 2019-10-16 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a knowledge-based view to the dynamic capabilities in an organization. The author integrates two existing views on gaining competitive advantage: the Knowledge View which suggests that the capability of organizations to learn faster than competitors is the only source of competitiveness; and the Dynamic Capability View which speculates that a fi rm’s competitive advantage rests on it’s ability to adapt to changes in the business environment. Using the IT sector in India as a case study, this book provides and tests a new framework—Knowledge-Based Dynamic Capabilities—in the prediction of competitive advantage in organizations.
Download or read book Biofuels Refining and Performance written by Ahindra Nag and published by McGraw Hill Professional. This book was released on 2008-01-07 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: Learn about the ways to economically manufacture biofuels Written by a team of international experts, Biofuels Refining and Performance describes the refining processes and issues involved in producing fuel derived from recently living organisms or their by-products. Each chapter offers detailed discussion of theory as well as the actual experimental procedure used to economically manufacture biofuels on a commercial scale.
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 Green Fuels Technology written by Carlos Ricardo Soccol and published by Springer. This book was released on 2016-08-10 with total page 558 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents key recent developments in biofuel policy, products, processes, patents and innovative technologies. It presents several case studies, which maximize reader insights into how innovative green energy technologies can be implemented on an industrial scale, with illustrations, photos and new approaches. It also analyzes in detail several different technological aspects of the research into and production of green fuels from the first, second and third generation, such as, bioethanol, biogas, biohydrogen, biobutanol, biofuels from pyrolysis, and discusses their economic and environmental impacts. A new source of information for engineers, technicians and students involved in production and research in the biofuels sector, this book also provides a valuable resource for industry, covering the current and future status of biofuels.
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 Comprehensive Natural Products Chemistry written by Derek Barton and published by Newnes. This book was released on 1999-02-18 with total page 11380 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Natural Products Chemistry
Download or read book Cellulose Hydrolysis written by Liang-tseng Fan and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent economic trends, especially the worldwide decline in oil prices, and an altered political climate in the United States have combined to bring about major reductions in research on renewable energy resources. Yet there is no escaping the "facts of life" with regard to these resources. The days of inexpensive fossil energy are clearly numbered, the credibility of nuclear energy has fallen to a new low, and fusion energy stands decades or more from practical realization. Sooner than we may wish ,we will have to turn to renewable raw materials - plant "biomass" and, especially, wood - as significant suppliers of energy for both industry and everyday needs. It is therefore especially important to have a single, comprehensive and current source of information on a key step in any process for the technological exploitation of woody materials, cellulose hydrolysis. Further more, it is essential that any such treatment be unbiased with respect to the two methods - chemical and biochemical - for the breakdown of cellulose to sugars. Researchers on cellulose hydrolysis have frequently been chided by persons from industry, especially those individuals concerned with determining the economic feasibility of various technological alternatives. They tell us that schemes for the utilization of wood and other such resources fly in the face of economic realities.
Download or read book Isolation and Partial Characterization of Four Components of the Multienzyme Cellulase Complex of Trichoderma Reeseii QM9414 written by Bruce Harold Odegaard and published by . This book was released on 1982 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt:
