Water Hyacinth: A Potential Lignocellulosic Biomass for Bioethanol (eBook)

Contents 5
Abbreviations 8
1 Introduction 10
1.1 First-Generation Biofuel 11
1.2 Second-Generation Biofuel 11
1.3 Chemical Composition of Lignocelluloses 12
1.3.1 Holocellulose 12
1.3.2 Lignin 14
1.4 Bioethanol and Status Worldwide 16
References 18
2 Water Hyacinth: An Environmental Concern or a Sustainable Lignocellulosic Substrate 20
2.1 Origin 21
2.2 Ecology 21
2.3 Biology 22
2.4 Impacts of Water Hyacinth 22
2.5 Control 23
2.6 Various Utilities of Water Hyacinth 24
References 26
3 Lignocellulolytic Enzymology 29
3.1 Ligninolytic Enzymes 31
3.1.1 Laccase 32
3.1.2 Heme-Peroxidases 34
3.2 Hemicellulases 36
3.2.1 Xylanases and Mannanases 37
3.2.2 Xyloglucanases 38
3.3 Cellulases 38
References 39
4 Pretreatment Strategies: Unlocking of Lignocellulosic Substrate 44
4.1 Pretreatment Technologies for Lignocellulosic Biomass 44
4.1.1 Physical Methods 45
4.1.2 Chemical Method 47
4.1.3 Physico-Chemical Pretreatment 49
4.1.4 Thermo-Chemical Processes 51
4.1.5 Biological Pretreatment 52
4.2 Inhibitory Compounds in Lignocellulosic Hydrolysate and Their Detoxification 52
References 53
5 Biological Pretreatment: Need of the Future 57
5.1 Lignocellulose-Degrading Organisms 57
5.2 Lignin-Degrading Fungi 59
5.3 Lignin-Degrading Bacteria 63
5.4 Methods of Delignification 64
5.4.1 Fungal Delignification 64
5.4.2 Enzymatic Delignification 67
5.4.3 Laccase–Mediator System (LMS) 67
5.4.4 Integrated Fungal Fermentation (IFF) 68
5.5 Factors Affecting Production of Ligninolytic Enzymes and Lignin Degradation 69
5.5.1 Fungal Strain 69
5.5.2 Carbon Source and Concentration 69
5.5.3 Nitrogen Source and Concentration 70
5.5.4 Aeration 70
5.5.5 Initial Moisture Content 71
5.5.6 pH 71
5.5.7 Temperature 72
5.5.8 Substrate Particle Size 72
5.5.9 Incubation Time 73
References 73
6 Strategies for Saccharification of Lignocellulosic Substrate 79
6.1 Enzymatic Saccharification of Lignocellulosic Feedstocks 80
6.2 Solid-State Fermentation (SSF) 82
6.3 Submerged Fermentation 83
6.4 Analytical-Scale Enzymatic Saccharification 84
6.5 Factors Affecting Enzymatic Hydrolysis of Cellulose 85
6.5.1 Substrate Type and Concentration 85
6.5.2 Enzyme Concentration 86
6.5.3 Pretreatment Method 88
6.5.4 Temperature 89
6.5.5 pH 90
6.5.6 Reaction Time 91
References 91
7 Bioethanol Production from Water Hyacinth 96
7.1 Fermentation Strategies 97
7.1.1 Separate Hydrolysis and Fermentation (SHF) 97
7.1.2 Simultaneous Saccharification and Fermentation (SiSF) 98
7.1.3 Simultaneous Saccharification and Co-fermentation (SSCF) 98
7.1.4 Consolidated Bioprocessing (CBP) 99
7.2 Microbes in Fermentation 99
7.3 Pentose Fermentation 101
7.4 Bioethanol Production from Water Hyacinth 102
7.5 Recent Research and Recombinant Fermentative Microbes 104
References 107