Enzymes in the Valorization of Waste: Enzymatic Pretreatment of Waste for Development of Enzyme-based Biorefinery

Cover
Half Title
Series Page
Title Page
Copyright Page
Table of Contents
Preface
Acknowledgments
Editor
Contributors
Conflict of Interest
Abbreviations
Chapter 1: Pretreatment Methods for Overcoming Biomass Recalcitrance
	1.1 Introduction
	1.2 Structural Composition of Lignocellulosic Biomass
		1.2.1 Cellulose
		1.2.2 Hemicellulose
		1.2.3 Lignin
	1.3 Chemical Interactions Among the Components of Lignocellulosic Biomass
		1.3.1 Intrapolymer Linkages
		1.3.2 Interpolymer Linkages
	1.4 Pretreatment of Lignocellulosic Biomass
		1.4.1 Physical Pretreatment
			1.4.1.1 Mechanical Grinding
			1.4.1.2 Liquid Hot Water Pretreatment
			1.4.1.3 Pretreatment by Radiation
		1.4.2 Chemical Pretreatment
			1.4.2.1 Dilute Acid Pretreatment
			1.4.2.2 Dilute Alkali Pretreatment
			1.4.2.3 Ionic Liquids
			1.4.2.4 Organosolv Pretreatment
			1.4.2.5 Deep Eutectic Solvent Pretreatment
		1.4.3 Physicochemical Pretreatment
			1.4.3.1 Steam Explosion
			1.4.3.2 Ammonia Fiber Explosion (AFEX)
			1.4.3.3 Oxidative Pretreatment
		1.4.4 Biological Pretreatment
		1.4.5 Combination of Pretreatment Methods
			1.4.5.1 Alkaline Pretreatment Combined with Dilute Acid Pretreatment
			1.4.5.2 Dilute Acid Pretreatment Combined with Steam Explosion Pretreatments
			1.4.5.3 Microwave-assisted Alkali Pretreatment
	1.5 Formation of Inhibitors During Pretreatment of Biomass
		1.5.1 Origin of Inhibitors and Mechanism of Inhibition
	1.6 Conclusion
	Acknowledgments
	References
Chapter 2: Lignocellulosic Biomass for Biofuels Production, an Integrated Approach
	2.1 Introduction
	2.2 Supply Chain Network and Biomass Process Integration
		2.2.1 Supply Chain Network Structures
		2.2.2 Biomass Conversion Processes and Integration of Biological Processes
	2.3 Pretreatment of Lignocellulosic Feedstock Sources for Biological Processes
		2.3.1 Mechanical Pretreatments
			2.3.1.1 High-pressure Homogenization (HPH)
			2.3.1.2 Steam Explosion Pretreatment
			2.3.1.3 Hot Water
			2.3.1.4 Microwave Radiation
		2.3.2 Chemical Pretreatments
			2.3.2.1 Acid-Base Pretreatments
			2.3.2.2 Ammonia-base Pretreatments
			2.3.2.3 Organic Solvents
			2.3.2.4 Organic Solvents Combined with Oxidants
			2.3.2.5 Microwave-assisted Solvolysis
			2.3.2.6 Ionic Liquids
		2.3.3 Lignin Recovery in Pulp Mills
	2.4 Biological Processes for Integration with Biomass Activities or Other Conversion Processes
		2.4.1 Hydrolysis and Fermentation for Ethanol Production
	References
Chapter 3: Laccase-mediated Pretreatment of Lignocellulosic Biomass: Current Status and Future Prospects
	3.1 Introduction
	3.2 Sources of Laccases
		3.2.1 Fungal Laccase
		3.2.2 Bacterial Laccase
		3.2.3 Plant Laccase
		3.2.4 Insect Laccase
	3.3 Structural Characteristics of Laccase
	3.4 The Catalytic Mechanism of Laccase
	3.5 Approaches for Better Biocatalytic Action of Laccase
	3.6 Perspective
	3.7 Conclusion
	Acknowledgments
	References
Chapter 4: Lignin Peroxidases and Their Relevance in Lignin-based Circular Bioeconomy: A Microbial Treasure for Sustainable Development
	4.1 Introduction
	4.2 Structural Components of Lignocellulosic Biomass
	4.3 Enzymatic Systems Involved in the Cessation of the Lignocellulosic Organization
		4.3.1 Cellulolytic Enzymes
		4.3.2 Xylanolytic Enzymes
		4.3.3 Ligninolytic Enzymes
			4.3.3.1 Laccases
			4.3.3.2 Peroxidases
	4.4 Mechanism of Lignin Peroxidase Catalytic Reactions
	4.5 Microbial Production of Lignin Peroxidases
	4.6 Challenges in Lignin Peroxidase Production for Industrial Applications
	4.7 Applications of Lignin Peroxidase
		4.7.1 Biodegradation of Environmental Pollutants
		4.7.2 Cosmetic Industries
		4.7.3 Paper and Pulp Industries
		4.7.4 Valorization of Biomass for Value-Added Products
	4.8 Conclusions
	Acknowledgments
	References
Chapter 5: Structure, Properties, and Functions of Manganese Peroxidase for Enzymatic Pretreatment of Waste Biomass
	5.1 Introduction
	5.2 Enzyme-mediated Pretreatment of Waste Biomass
	5.3 Manganese Peroxidase: A Brief History
	5.4 Structure and Properties of Manganese Peroxidase
		5.4.1 The Overall Crystal Structure
		5.4.2 The Heme Environment and Peroxide Binding Site
		5.4.3 The Manganese Binding Site
		5.4.4 The Role of Calcium Ions
	5.5 Mechanism of Action and Catalytic Pathway
		5.5.1 Mechanism of Action on Phenolic Lignin Substrates
		5.5.2 Mechanism of Action on Non-phenolic Lignin Substrates
	5.6 Factors Affecting Enzyme-assisted Pretreatment
		5.6.1 Fungal Strain
		5.6.2 Moisture Content
		5.6.3 Aeration
		5.6.4 Source of Carbon
		5.6.5 Concentration and Source of Nitrogen
		5.6.6 Temperature
		5.6.7 Acidity
	5.7 Versatile Peroxidase: An Amalgam of MnP and LiP
	5.8 Future Perspective
	5.9 Conclusion
	Acknowledgement
	References
Chapter 6: An Overview of Pretreatment Strategies for the Development of Enzyme-based Biorefinery with Special Emphasis on Pectinases
	6.1 Introduction
	6.2 Pretreatment of Lignocellulosic Biomass
		6.2.1 Different Methods of Pretreatment
			6.2.1.1 Physical Pretreatment
				6.2.1.1.1 Thermal Pretreatment
				6.2.1.1.2 Mechanical Pretreatment
				6.2.1.1.3 Ultrasound Pretreatment
			6.2.1.2 Physicochemical Pretreatment
				6.2.1.2.1 Steam Explosion
				6.2.1.2.2 Liquid Hot Water Pretreatment
				6.2.1.2.3 Radiation Pretreatment
			6.2.1.3 Chemical Pretreatment
				6.2.1.3.1 Acid Pretreatment
				6.2.1.3.2 Alkaline Pretreatment
			6.2.1.4 Biological Pretreatment
				6.2.1.4.1 Enzymatic Pretreatment
				6.2.1.4.2 Fungal and Microbial Consortium Pretreatment
				6.2.1.4.3 Aerobic Digestion
	6.3 Merits and Demerits of Different Pretreatment Methods
	6.4 Pretreatment of Lignocellulose Biomass Using Pectinase Enzyme
		6.4.1 Structure of Pectinase Enzyme
		6.4.2 Mechanism of Pectinase in the Pretreatment of Waste Biomass
	6.5 Future Prospects and Conclusion
	References
Chapter 7: Chitinases: Structure, Function, and Valorization of Marine Shell Waste
	7.1 Introduction
	7.2 Chitin and Its Derivatives: Their Structures and Properties
	7.3 Conventional Methods of Chitin Recovery
		7.3.1 Chemical Conversion of Chitin to Chitosan and Chito- oligosaccharide
	7.4 Classification of Chitinases
		7.4.1 Structural Diversity of Chitinases
		7.4.2 Chitinases: Types and Mechanism of Action
	7.5 Screening, Production, and Purification of Chitinases
		7.5.1 Screening and Isolation of Chitinase Producing Organisms
			7.5.1.1 Screening of Bacteria
			7.5.1.2 Screening of Fungi
		7.5.2 Production of Chitinase
		7.5.3 Extraction and Purification of Chitinases
	7.6 Chitinase Assay Development
	7.7 Role of Chitinases
	7.8 Application of Chitinases
		7.8.1 Enzymatic Valorization of Marine Waste
		7.8.2 Effect of Pretreatment Process
		7.8.3 Chitinase for Hydrolysis
	7.9 Future Perspective
	References
Chapter 8: Pretreatment and Valorization of Textile-Wastewaters by Haloarchaea
	8.1 Textile Factory Effluents
		8.1.1 Various Constituents and Their Harmful Effects
		8.1.2 Characteristics of Textile Effluents
		8.1.3 Characteristics of the Real Effluent Discharged from Textile Factories
	8.2 Conventional Biotreatment Processes
		8.2.1 Biological Methods
		8.2.2 Chemical Methods
		8.2.3 Physical Methods
	8.3 Microbes, Bioreactors Used and Difficulties Encountered
	8.4 Biohydrolysis of Cellulose
		8.4.1 Cellulases
	8.5 Halophiles and Haloarchaea in Treatment of Textile Effluents
	8.6 Predicted Biorefinery, Environmental Clean Technology
	References
Chapter 9: Evolution of Biological Pretreatment Methods for Agricultural Residues and Defatted Microalgae for Overcoming Biomass Recalcitrance in Biofuel Generation
	9.1 Introduction
	9.2 Agricultural Wastes for Biofuel Generation
	9.3 Pretreatment Methods for Agricultural Wastes in Biofuel Generation
		9.3.1 Physical Pretreatment Methods
			9.3.1.1 Milling
			9.3.1.2 Extrusion
			9.3.1.3 Microwave Treatment
			9.3.1.4 Ultrasonication
		9.3.2 Thermochemical Methods
			9.3.2.1 Gasification
			9.3.2.2 Liquefaction
			9.3.2.3 Pyrolysis
	9.4 Microalgae in Biofuel Generation
	9.5 Conventional Biological Pretreatment Methods for Defatted Microalgae for Biofuel Generation
	9.6 Microalgae Potential in the Fuel Industry
	9.7 Methods of Converting Microalgae into Energy
	9.8 Challenges and Prospects for Biofuel Production from Microalgae
	9.9 Pretreatment Methods for Microalgae in Biofuel Generation
		9.9.1 Microwave-assisted Pretreatment Method
		9.9.2 Ultrasonic Pretreatment Method
		9.9.3 Enzymatic Hydrolysis-based Pretreatment Method
		9.9.4 Catalytic Pretreatment Method
	References
Index