Novel Enzymes for Functional Carbohydrates Production : From Scientific Research to Application in Health Food Industry

This book focuses on the latest research and new techniques in the field of functional carbohydrate-related enzymes. Carbohydrates are a key form of energy for most organisms. The “good” carbohydrates generally refer to functional carbohydrates. In addition to the low or moderate energy-supplying function, they have more nutritious value than traditional carbohydrates and some of them also have health-promoting effects especially prebiotic actions. Several enzymatic methods for the synthesis of such carbohydrates have been discovered and developed in the recent decades, providing a new range of application areas for these novel enzymes. This book addresses the classification of functional carbohydrate-related enzymes and the overall development in food enzyme in Chapter 1. Chapters 2-5 describe the isomerases or epimerases involved in the production of rare sugars, such as D-allulose, D-mannose, D-tagatose, and D-allose. While the studies of the enzymes related to fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) dominate the scientific literature in the field of enzymatic production of health-functional oligosaccharides, some enzymes also show promise for the emerging oligosaccharide production, which are introduced in Chapters 6-8. Chapters 9-12 summarize the new enzymatic technologies and applications in fructan- and glycan-related industries. The last Chapter gives an overall prospective on the trends of enzymatic functional carbohydrate production. This book is a valuable resource for researchers and graduate students in the fields of biotechnology, enzyme engineering, and carbohydrate production, as well as the health industry. Preface Contents Chapter 1: Development and Classification of Functional Carbohydrate Processing Enzymes in the Food Industry 1.1 Introduction of Modern Enzymology 1.2 Current Commercial Carbohydrate-Related Enzymes 1.3 Enzymatic Production of Functional Carbohydrate 1.4 Classification of the Functional Carbohydrate-Related Enzymes Based on Catalytic Mechanism 1.4.1 Hydrolases and Transferases Involved in Functional Carbohydrate Production 1.4.1.1 Cyclodextrin Glucanotransferase 1.4.1.2 Sucrose-Utilizing Enzymes 1.4.1.3 Lactose-Utilizing Transglycosidases 1.4.1.4 Transferase Acting on Activated Sugars 1.4.2 Isomerases and Epimerases Involved in Functional Carbohydrate Production 1.4.3 Hydrogenase and Dehydrogenase Involved in Functional Carbohydrate Production 1.5 Conclusion References Chapter 2: Recent Advances in Ketose 3-Epimerase and Its Application for D-Allulose Production 2.1 Rare Sugar 2.2 Introduction of D-Allulose 2.3 Physiological Functions of D-Allulose 2.4 Application of D-Allulose 2.5 Bioproduction of D-Allulose 2.5.1 Microbial Source of KEase 2.5.2 Enzyme Properties of KEase 2.5.3 Crystal Structure and Catalytic Mechanism 2.5.4 Molecular Modification of KEase 2.5.5 Bioproduction of D-Allulose 2.6 Conclusion and Future Scope References Chapter 3: D-Mannose-Producing Isomerases and Epimerases: Properties, Comparisons, and Different Strategies 3.1 Introduction 3.2 Overview of D-mannose 3.2.1 Brief Description of D-mannose 3.2.2 Functions and Health Effects 3.2.3 Determination Methods 3.3 Production of D-mannose 3.3.1 Plant Extraction 3.3.2 Chemical Synthesis 3.3.3 Biological Synthesis 3.3.3.1 D-LIase Sources Temperature and pH Information About Crystal Structure Metal Ions Dependence 3.3.3.2 D-MIase Sources Biochemical Parameters 3.3.3.3 CEase 3.3.3.4 D-MEase 3.3.4 Strategies to Produce D-mannose Using Above Isomerases and Epimerases 3.4 Applications 3.5 Conclusion References Chapter 4: L-Arabinose Isomerase: Sources, Biochemical Properties, and Its Use to Produce D-Tagatose 4.1 Introduction 4.2 Identification of L-Arabinose Isomerase 4.2.1 The Sources 4.2.2 Temperature 4.2.3 pH 4.2.4 Metal Ion 4.2.5 Substrate Specificity and Kinetic Parameters 4.3 Molecular Modification of L-Arabinose Isomerase 4.3.1 Structure of L-AIase 4.3.2 Lowing the Optimal pH 4.3.3 Increasing the Catalytic Activity Toward D-Galactose 4.4 Brief Description of D-Tagatose 4.5 Physiological Function and Benefits 4.6 Production of D-Tagatose Using L-Arabinose Isomerase 4.7 Conclusion References Chapter 5: Various Enzymes for the Biotechnological Production of D-Allose 5.1 Introduction 5.2 Conspectus of D-Allose 5.2.1 Physicochemical Properties 5.2.2 Occurrence in Plants 5.2.3 Metabolism Pathway 5.2.4 Chemical Preparation 5.3 Physiological and Healthy Functions 5.3.1 Anticancer and Antitumor 5.3.2 Antioxidant Properties 5.3.3 Anti-inflammatory Effects 5.3.4 Other Health Benefits 5.4 Applications 5.4.1 Application in the Food Industry 5.4.2 Application in Clinical Medicine 5.4.3 Application in Health Care 5.5 Various Enzymes for D-Allose Production 5.5.1 L-Rhamnose Isomerase 5.5.2 D-Ribose-5-Phosphate Isomerase 5.5.3 Other D-Allose-Producing Enzymes 5.6 Biological Production of D-Allose 5.7 Conclusions and Future Perspectives References Chapter 6: Characteristics of Cellobiose 2-Epimerase and Its Application in Enzymatic Production of Lactulose and Epilactose 6.1 Introduction 6.2 Property of Lactulose and Epilactose 6.2.1 General Physical and Chemical Properties 6.2.2 Physiological Effects of Lactulose and Epilactose 6.3 Property of Cellobiose 2-Epimerase 6.4 Enzymatic Production of Epilactose and Lactulose 6.4.1 Enzymatic Production of Epilactose 6.4.2 Enzymatic Production of Lactulose 6.5 Enzyme Engineering 6.6 Outlook and Perspectives References Chapter 7: Enzymatic Production of Lactosucrose by Levansucrase, β-Fructofuranosidase, and β-Galactosidase 7.1 Introduction 7.2 Physiological Benefits of Lactosucrose 7.2.1 Improve the Intestinal Microflora 7.2.2 Promote the Absorption of Calcium 7.2.3 Inhibit Fat Accumulation and Obesity 7.2.4 Regulate the Immune Response 7.2.5 Other Physiological Effects 7.3 Production of Lactosucrose 7.3.1 Production of Lactosucrose by Levansucrase in Its Cell-Free Form 7.3.2 Production of Lactosucrose by Microorganisms Harboring the Levansucrase Activity 7.3.3 Production of Lactosucrose by β-Fructofuranosidase 7.3.4 Production of Lactosucrose by β-Galactosidase 7.4 Application of Lactosucrose 7.5 Conclusion and Future Perspectives References Chapter 8: Difructose Anhydrides-Producing Fructotransferase: Characteristics, Catalytic Mechanism, and Applications 8.1 Introduction 8.2 Physiological Functions of DFAs 8.2.1 Low-Calorie Sweeteners 8.2.2 Prebiotic Function 8.2.3 Mineral Absorption 8.2.4 Immune System 8.2.5 Adverse Effect 8.3 Enzymatic Synthesis of DFAs 8.3.1 IFTase for DFA III-Forming 8.3.1.1 IFTase (DFA III-Forming) Production from Microorganisms 8.3.1.2 Properties of IFTases (DFA III-Forming) 8.3.2 IFTase for DFA I-Forming 8.3.3 Enzyme for DFA V-Forming 8.3.4 LFTase for DFA IV-Forming 8.4 Structural Analysis and Catalytic Mechanisms 8.4.1 Overall Structures 8.4.2 Catalytic Mechanisms 8.4.3 Molecular Modifications 8.5 Biological Production and Application of DFAs 8.6 Concluding Remarks References Chapter 9: Characteristics of Levansucrase and Its Application for the Preparation of Levan and Levan-Type Oligosaccharides 9.1 Levan and Its Existing Resources 9.2 Chemical Structure of Levan and Its Physicochemical Property 9.2.1 Solubility 9.2.2 Viscosity 9.2.3 Tensile Strength 9.2.4 Thermostability and Safety 9.3 Biological Production of Levan 9.3.1 Biological Production of Levan by Gram-Positive Microorganisms 9.3.2 Biological Production of Levan by Gram-Negative Microorganisms 9.4 Characteristics of Microbial LSase 9.4.1 LSase from Bacillus Species 9.4.2 LSase from Gram-Negative Species 9.4.3 Molecular Weight Distribution of Microbial Levan 9.4.4 Crystal Structures Analysis of LSase 9.4.5 Mutation Studies of LSase in Altering Product Size 9.5 Two Types of Elongation Mechanism for Levan 9.5.1 Effect of Reaction Conditions on the Product Length 9.5.2 Influence of Key Residues on the Product Length 9.6 Application of LSase for the Production of Levan 9.6.1 Biological Production of Levan by Microbial LSase 9.6.2 Immobilization of LSase 9.7 Conclusions and Future Perspective References Chapter 10: Inulosucrase, an Efficient Transfructosylation Tool for the Synthesis of Microbial Inulin 10.1 Introduction 10.2 Resource and Production of Inulin 10.3 Inulin-Forming Enzymes 10.3.1 Inulin-Forming Enzymes from Plants 10.3.2 Inulin-Forming Enzyme from Microorganisms 10.4 Characterization of ISase 10.4.1 Microbial Sources of ISase 10.4.2 Sequence Analysis of ISase 10.4.3 The Effects of pH and Temperature 10.4.4 Thermostability of ISase 10.4.5 The Effect of Sucrose Concentration and Enzyme Dosage 10.4.6 Kinetic Parameters 10.5 Structure and Molecular Modification 10.5.1 Overall Structure 10.5.2 Subsites in the Catalytic Pocket 10.5.3 Ca2+ Binding Sites 10.6 Modulation of Product Chain Length 10.6.1 The Chain-Length Distribution of Microbial Inulin 10.6.2 The Chain-Length Modulation of Microbial Inulin 10.7 Applications of ISase 10.7.1 Production of High-Molecular-Weight Inulin 10.7.2 Production of FOSs 10.7.3 Production of Novel Oligosaccharides 10.7.4 Production of Inulin Nanoparticles 10.8 Conclusions References Chapter 11: Amylosucrase: A Versatile Sucrose-Utilizing Transglucosylase for Glycodiversification 11.1 Introduction 11.2 Characteristics 11.2.1 Catalytic Mechanism 11.2.2 Substrate Specificity 11.2.3 Effect of Reaction Conditions 11.2.4 GRAS-Grade Expression 11.3 Structure-Based Molecular Modification 11.3.1 Structural Features 11.3.2 Enhancing Activity and Thermostability 11.3.3 Altering Substrate and Product Specificity 11.4 Versatile Functions and Its Applications 11.4.1 Reactions with Sucrose As the Sole Substrate 11.4.1.1 Utilization of Amylose-Like Polymer 11.4.1.2 Synergistic Action with Starch-Converting Enzymes 11.4.2 Reactions with Sucrose and Other Carbohydrates 11.4.2.1 Production of Alternative Sweeteners 11.4.2.2 Synthesis of Microbial Cell Surface Oligosaccharides 11.4.2.3 Modification of Starches 11.4.3 Reactions with Sucrose and Bioactive Compounds 11.4.3.1 Glycosylation of Flavonoids 11.4.3.2 Glycosylation of Other Bioactive Compounds 11.5 Conclusion and Perspectives References Chapter 12: Glucansucrases Derived from Lactic Acid Bacteria to Synthesize Multitudinous α-Glucans 12.1 Introduction 12.2 Characterization of Glucansucrases 12.2.1 Dextransucrase 12.2.2 Mutansucrase 12.2.3 Reuteransucrase 12.2.4 Alternansucrase 12.2.5 Branching Sucrases 12.3 Structures of Glucansucrases 12.3.1 Structural and Functional Organization 12.3.2 Catalytic Mechanism 12.4 Product Specificity of Glucansucrases 12.4.1 Elongation of α-Glucans 12.4.2 Branching Specificity 12.4.3 Linkage Specificity 12.5 Conclusions and Outlook References Chapter 13: Trends in Enzymology for Functional Carbohydrate Production 13.1 Enzyme Engineering for Industrial Enzymes 13.1.1 Directed Evolution 13.1.1.1 Pioneering Technologies for Library Generation 13.1.1.2 Selection and Screening Techniques 13.1.2 Rational and Semi-Rational Enzyme Design 13.1.3 De Novo Design 13.2 Enzyme Immobilization 13.2.1 Introduction 13.2.2 Overview of Traditional Immobilization Techniques 13.2.2.1 Adsorption 13.2.2.2 Covalent Binding 13.2.2.3 Entrapment 13.2.2.4 Cross-Linking 13.2.3 New Technology for Enzyme Immobilization 13.2.3.1 New Carrier Materials 13.2.3.2 Synthesis of Single Enzyme Nanoparticles 13.2.3.3 Immobilization Assisted by Microwave Irradiation Enzymatic Immobilization of Enzyme 13.2.4 Application of Enzyme Immobilization in Food Industry 13.3 Prospect of the Enzymatic Production for Functional Carbohydrates References