Fungi and Lignocellulosic Biomass

Harnessing fungi s enzymatic ability to break downlignocellulolytic biomass to produce ethanol more efficiently andcost–effectively has become a significant research and industrialinterest. Fungi and Lignocellulosic Biomass provides readerswith a broad range of information on the uses and untappedpotential of fungi in the production of bio–based fuels.

With information on the molecular biological and genomic aspectsof fungal degradation of plant cell walls to the industrialproduction and application of key fungal enzymes, chapters in thebook cover topics such as enzymology of cellulose, hemicelluloses,and lignin degradation. Edited by a leading researcher in thefield, Fungi and Lignocellulosic Biomass will be a valuabletool in advancing the development and production of biofuels and acomprehensive resource for fungal biologists, enzymologists,protein chemists, biofuels chemical engineers, and other researchand industry professionals in the field of biomass research.

1 The Plant Biomass 1

1.1 The Structure of Plant Cell Wall 1

1.2 Chemical and Physicochemical Properties of the Major Plant Cell Wall Constituents 3

1.3 Abundant Sources of Carbohydrate Polymers and Their Monomer Composition 13

1.4 Biosynthesis of Plant Cell Wall Polymers 16

1.5 Strategies for Manipulating Wall Composition 26

2 The Actors: Plant Biomass Degradation by Fungi 29

2.1 Ecological Perspectives 29

2.2 The Major Three Mechanisms of Lignocellulose Degradation by Fungi 30

2.3 Plant Cell Wall Degradation by Plant Pathogenic Fungi 40

2.4 Anaerobic Fungi 41

3 The Tools–Part 1: Enzymology of Cellulose Degradation 45

3.1 General Properties and Classification of Enzymes That Hydrolyze Polysaccharides 45

3.2 Fungal Cellulolytic Enzymes 49

3.3 Nonenzymatic Proteins Involved in Cellulose Hydrolysis 65

4 The Tools–Part 2: Enzymology of Hemicellulose Degradation 69

4.1 Xyloglucan Hydrolysis 69

4.2 Degradation of the Xylan Backbone 72

4.3 Degradation of the Galactomannan Backbone 78

4.4 Degradation of Pectin 80

4.5 Accessory Glycoside Hydrolases for Hemicelluloses Degradation 84

4.6 Other Accessory Enzymes 92

5 The Tools–Part 3: Enzymology of Lignin Degradation 99

5.1 Lignin Peroxidase 101

5.2 Manganese Peroxidase 105

5.3 Versatile Peroxidase 108

5.4 Dye–Oxidizing Peroxidase 109

5.5 Laccases 110

5.6 Enzymes Generating Hydrogen Peroxide 115

5.7 Cellobiose Dehydrogenase 116

5.8 Enzymes Essential for Oxalic Acid Formation 117

5.9 Glycopeptides 118

6 Catabolic Pathways of Soluble Degradation Products from Plant Biomass 119

6.1 Uptake of Mono– and Oligosaccharides 119

6.2 Metabolism of D–Glucose and D–Mannose 121

6.3 Catabolism of D–Galactose 122

6.4 Catabolism of Pentoses 125

6.5 Catabolism of Hexuronic Acids 127

7 Regulation of Formation of Plant Biomass–Degrading Enzymes in Fungi 129

7.1 The Cellulase Inducer Enigma 129

7.2 Inducers for Hemicellulases 133

7.3 Transcriptional Regulation of Cellulase and Hemicellulase Gene Expression 134

7.4 Regulation of Ligninase Gene Expression 146

8 The Fungal Secretory Pathways and Their Relation to Lignocellulose Degradation 149

8.1 The Fungal Secretory Pathway 149

8.2 Protein Glycosylation 159

8.3 Strategies for Improvement of the Fungal Secretory Pathway 161

9 Production of Cellulases and Hemicellulases by Fungi 165

9.1 Fungal Producer Strains 165

9.2 Strain Improvement 170

9.3 Cellulase Production 180

10 Production of Fermentable Sugars from Lignocelluloses 185

10.1 Pretreatment Technologies 186

10.2 Hydrolysis 195

11 Lignocellulose Biorefinery 201

11.1 Ethanol 202

11.2 n–Butanol 212

11.3 Advanced Biofuel Alcohols 213

11.4 Lactic Acid 215

11.5 Succinic Acid 217

11.6 Xylitol 222

11.7 1,3–Propanediol 222

11.8 Polyhydroxyalkanoate 223

11.9 Other Products 223

11.10 Refinement by Chemical Processes 225

Acknowledgments 229

References 231

Index 285

Christian P. Kubicek is a Professor at the Institute ofChemical Engineering at the Vienna University of Technology, isHead of the Institute s Research Division of Biotechnologyand Microbiology, has authored more than 300 refereed journalarticles and more than 20 book chapters, and has served as aneditor and editorial board member for several international peerreviewed journals.

Written by a leading researcher in the field, this bookis a valuable tool for researchers, engineers, and industryprofessionals interested in advancing the development andproduction of biofuels.   (Redaktion Landtechnik,1 March 2012)