Algae Biotechnology (eBook)

Professor Faizal Bux is the Director of the Institute for Water and Wastewater Technology, Durban University of Technology. He has  more than 20 years service at higher Education Institutes and has received numerous  awards. Prof Bux's primary research areas are: wastewater biotechnology, bioremediation, algal biofuels research and biotechnology, constructed wetlands/rhizofiltration and rainwater harvesting. He has acted/current editor for CLEAN  Soil Air Water (John Wiley & sons, Germany), Environmental Science and Health Part A (Taylor Francis, USA) He is a Fellow of the Water Institute of Southern Africa. He has recently edited the following books: (1) Biomass (2) Biotechnological application of microalgae (Taylor Francis, CRC press .) Served on the Scientific program committee/Advisory board/Chair/Invited speaker of various national and  International conferences. He is Member of many professional bodies nationally and internationally. Prof Bux has served as reviewer many international funding agencies. He serves as Scientific advisor for various NGO’s both in South Africa and internationally especially with regards to water quality issues and waste beneficiation. He established an extensive network of collaborators based at Universities both nationally and internationally with active student and staff exchange for team members in the Institute.  Yusuf Chisti is Professor of Biochemical Engineering at Massey University, New Zealand. Professor Chisti holds a MSc (Biochemical Engineering) degree from University of London, England, and a PhD in Chemical Engineering from University of Waterloo, Canada. He is a Chartered Engineer, CEng, and Fellow of the Institution of Chemical Engineers (FIChemE), UK. His previous appointments were with the University of Almería, Spain; Chembiomed Ltd, Edmonton, Canada; University of Waterloo, Canada; and The Polytechnic, Ibadan, Nigeria. Professor Chisti has produced nearly 300 publications including a highly cited book (Airlift Bioreactors, Elsevier, 1989). Thomson Reuters Web of Knowledge records more than 6,000 citations to Professor Chisti’s research publications. He has lectured at nearly 200 international events. He sits is on editorial boards of numerous journals including Biotechnology Advances (Elsevier), Journal of Biotechnology (Elsevier), Journal of Applied Phycology (Springer) and Biofuels, Bioproducts & Biorefining (Wiley). He is a senior editor of Biofuels (Future Science, UK). He received a Doctor Honoris Causa degree from Gheorghe Asachi Technical University, Iasi, Romania, in recognition of his many contributions to chemical and biological engineering. In 2008, he was the United Kingdom’s Royal Academy of Engineering Distinguished Visiting Fellow at Newcastle University, UK. Professor Chisti’s research is focussed on sustainable production of goods and services through biotechnology.

Contents 6
1 Microalgae Cultivation Fundamentals 8
Abstract 8
1 Introduction 8
2 Illumination 9
2.1 Light Absorption 9
2.2 Light Attenuation Through Mutual Shading 9
3 Carbon Supply 10
4 Oxygen Accumulation 12
5 Nutrient Supply 13
5.1 Common Culture Media 13
5.1.1 Bold Basal Medium 13
5.1.2 N8 Medium for Chlorella and Other Green Algae 14
5.1.3 Bristol Medium 15
5.2 Sterilization 15
6 Culture Methods 15
6.1 Cultivation on Solid Media 15
6.2 Cultivation in Liquid Culture Media 16
6.2.1 Batch Culture 16
Mixing and Turbulence 17
Growth Phases 18
6.2.2 Continuous Culture 21
Principles of Continuous Flow Culture 21
6.3 Chemostat 25
6.4 Fedbatch Culture 25
References 26
2 Large-Scale Production of Algal Biomass: Raceway Ponds 27
Abstract 27
1 Introduction 28
2 Raceways 29
2.1 Typical Configuration 29
2.2 Culture Flow in the Raceway Conduit 30
2.3 Power Consumption for Flow and Mixing 31
2.4 The Paddle Wheel 33
2.5 Climatic and Topological Considerations 34
2.6 Temperature and Productivity 34
2.7 The pH and Carbon Supply 35
2.8 Oxygen Inhibition of Production 37
2.9 Culture Contamination 37
2.10 Dependence of Photosynthesis on Culture Depth 38
2.11 Specific Growth Rate 39
2.12 Cost of Construction and Operation 40
3 Biomass Production in Raceways 41
3.1 Biomass Productivity 43
4 Concluding Remarks 44
References 44
3 Large-Scale Production of Algal Biomass: Photobioreactors 47
Abstract 47
1 Cultivation Systems 49
1.1 Requirements for Photosynthetic Growth and Possible Limitations 49
1.2 Open Systems and Closed Photobioreactors 49
1.3 Photobioreactors Principles 50
1.4 Surface and Volumetric Illuminations 52
2 Photobioreactor Engineering and Scaling Rules 53
2.1 Maximizing Biomass Production 53
2.2 Growth Limitations by Nutrient and Inorganic Carbon Sources 53
2.3 The Light-Limited Regime 54
2.4 Role of Light Attenuation Conditions and Absorption Rate 55
2.5 PBR Efficiencies and Intensification Principles 58
3 The Specific Case of Solar Photobioreactor Engineering 60
3.1 The Use of Sunlight 60
3.2 Thermal Regulation Issues 61
3.3 Modeling for Solar PBR Optimization 62
3.3.1 Model-Based Design of Intensified PBR Technologies 63
3.3.2 Prediction of PBR Operating Conditions and Optimization of Biomass Productivity 65
3.3.3 Definition of Optimal Concentration to Maximize PBR Productivity 67
4 Conclusions 69
Acknowledgments 69
References 69
4 Commercial Production of Macroalgae 73
Abstract 73
1 Introduction 73
2 Advances in the Commercial Production of Macroalgae 76
2.1 Enhanced Availability of Seaweed Seedstock and Improvement via Strain Selection and Hybridization 77
2.2 Increased Number of Commercially Cultivated Species 78
2.3 Application of DNA-Marked Systems in Genetic Study and Application 79
2.4 Improvements in Seedling Nursery Systems and Development of New Technologies for Intensive High-Efficiency Seedling Production 79
2.5 Expansion of Cultivation Areas from Shallow Seas to Deep Seas 79
2.6 Polyculture of Commercial Seaweeds and Aquatic Animals 80
2.7 Improvements of Seaweeds Process Technologies and Development of Novel Foods and Drugs 80
3 Concluding Remarks 80
References 81
5 Harvesting of Microalgal Biomass 83
Abstract 83
1 Introduction 84
2 Microalgae Dewatering Technologies 84
2.1 Flocculation 84
2.2 Electrolysis 85
2.2.1 Electrolytic Coagulation 86
2.2.2 Electrolytic Flotation 86
2.2.3 Electrolytic Flocculation 87
2.3 Gravity Sedimentation 88
2.4 Magnetic Separation 88
2.5 Filtration 89
2.6 Evaporation and Drying 89
3 Comparison of Dewatering Techniques 90
4 Conclusion 92
References 92
6 Extraction and Conversion of Microalgal Lipids 96
Abstract 96
1 Introduction 96
2 Microalgal Lipids for Biodiesel Production 98
3 Lipid Extraction Techniques 100
3.1 Conventional Lipid Extraction Techniques 100
3.1.1 Soxhlet Extraction 100
3.1.2 Mechanical Press 101
3.1.3 Solvents for Lipid Extraction 102
3.2 Process Intensification by Cell Disruption 103
3.2.1 Microwave 103
3.2.2 Sonication 104
3.2.3 Autoclaving 104
3.2.4 Bead Beating 104
3.3 Supercritical Lipid Extraction 105
3.4 Effect of Preceding Processing Steps on the Lipid Extraction 105
4 Novel Lipid Extraction Techniques and Recent Advances 106
5 Microalgal Lipids Conversion to Biodiesel 107
5.1 Chemical Catalysis 107
5.2 Biocatalysis 107
5.3 Solvents Used in Conversion 109
6 Influence of Microalgal Lipids on Biodiesel Properties 110
7 Challenges in Lipid Extraction and Conversion 112
References 112
7 Techno-economics of Algal Biodiesel 116
Abstract 116
1 Introduction 117
2 Economic Assessment 119
3 Environmental Impact Assessment 123
4 Key Challenges to Feasibility of Algal Biodiesel 126
4.1 Areal Productivity 126
4.1.1 Insolation 126
4.1.2 Photosynthesis 127
4.1.3 Absorption and Photoinhibition 127
4.1.4 Photorespiration and Respiration 128
4.1.5 Theoretical Areal Productivity 128
4.1.6 Biomass and Lipid Productivity 129
4.2 Nutrient Supply: Carbon, Nitrogen, and Phosphate 131
4.2.1 Availability 132
4.2.2 Carbon Dioxide Mass Transfer 133
4.2.3 Alternative Fertilizer Sources 133
4.3 Nutrient Recycling 134
4.4 Water and Energy Consumption 135
4.4.1 Algal Cultivation 136
4.4.2 Downstream Processing 137
5 Conclusions 139
References 141
8 Fuel Alcohols from Microalgae 147
Abstract 147
1 Introduction 147
2 Utility of Microalgae 149
2.1 Extraction of Microalgal Carbohydrates 149
3 Alcoholic Fermentation 151
3.1 Microalgae to Ethanol 151
3.2 Microalgae to Acetone, Butanol, and Ethanol 152
4 Other Applications/Products of Microalgae 154
5 Concluding Remarks 155
Acknowledgements 155
References 155
9 Microalgae for Aviation Fuels 159
Abstract 159
1 History of the Aviation Industry 159
2 Flying in the Twenty-First Century 160
3 Fuels That Mostly Fly the Sky 160
4 Search for Alternative Jet Fuels 161
5 Jet Fuel from Bio-based Sources 162
6 Microalgae as Alternatives to Jet Fuel 163
7 Bioremediation and Wastewater to Biojet Fuel by Algaetech International, Malaysia 163
8 Global Biofuel Mandatory Requirement 164
9 How Close Are We to Sustainable Biojet Fuels? 165
10 Concluding Remarks 166
References 166
10 Biohydrogen from Microalgae 168
Abstract 168
1 Introduction 168
2 Hydrogen Production Pathways in Chlamydomonas 169
2.1 Photobiological Hydrogen Production Pathways 170
2.1.1 Direct Biophotolysis (PSII-Dependent Pathway) 170
2.1.2 Indirect Hydrogen Production (PSII-Independent Pathway) 171
2.2 Fermentation-Dependent Pathway 172
3 Physiological Strategies to Sustain Hydrogen Production 172
3.1 Nutrient Stress (S, N, P) 173
3.1.1 Sulfur Deprivation 174
3.1.2 Nitrogen Deficiency 175
3.1.3 Phosphorous Deficiency 176
3.1.4 Differences in Hydrogen Production with Different Nutritional Stresses 176
3.2 Supply of Reduced Carbon Source 178
4 Molecular Strategies to Improve Hydrogen Production 181
4.1 Light Saturation 182
4.2 Effect of the Undissipated Proton Gradient on Electron Flow 184
4.3 Competition for Photosynthetic Reductant 184
4.4 Limitations Linked to the Hydrogenases 186
4.4.1 Oxygen Sensitivity of the Hydrogenases 186
4.4.2 Hydrogenases Reversibility and H2 Partial Pressure 187
5 Conclusions 187
Acknowledgments 188
References 188
11 Biogas from Algae via Anaerobic Digestion 197
Abstract 197
1 Introduction 197
2 Anaerobic Digestion 198
2.1 Fundamentals 198
2.2 Factors Influencing Anaerobic Digestion 200
2.2.1 Temperature 200
2.2.2 pH 201
2.2.3 Carbon/Nitrogen Ratio 201
2.2.4 Toxic Compounds 201
3 Algae Anaerobic Digestion 202
3.1 Macroalgae 202
3.2 Microalgae 204
4 Pretreatment of Algal Biomass 205
4.1 Thermal Pretreatments 207
4.2 Mechanical Pretreatments 208
4.3 Chemical Pretreatments 209
4.4 Biological Pretreatments 211
5 Codigestion 212
6 Economic and Environmental Aspects 213
7 Conclusions 214
Acknowledgements 214
References 214
12 Food and Feed Applications of Algae 219
Abstract 219
1 Introduction 219
2 Algae and Their Constituents 220
3 What Drives the Interest in Algae as Food, Food Ingredients and Animal Feed? 222
4 Production of Food from Microalgae and Seaweeds 224
5 Algae as Food 229
5.1 Algal Nutritional Content 229
5.2 Bio-Available Nutrients 232
5.3 Attractiveness—Building on Nutrition 232
6 Algae as Feed 233
6.1 Finfish 234
6.2 Non-finfish Aquatic Species 234
6.3 Terrestrial Livestock 236
7 Algae as Nutraceuticals, Functional Food and Food Ingredients 237
7.1 Bioactivity of Functional Foods 239
8 Algae Food Contaminants 241
Acknowledgements 243
References 243
13 Microalgae Applications in Wastewater Treatment 250
Abstract 250
1 Introduction: Conventional WW Treatment Plants and Limitations 250
2 Phycoremediation 251
2.1 Nutrient Removal 252
2.1.1 Nitrogen Removal 253
2.1.2 Phosphorus Removal 254
3 Phycoremediation of Heavy Metals 254
3.1 Factors Influencing Algal Sequestration of Metallic Ions 256
3.2 Significance of Phycoremediation of Heavy Metals 257
4 High-Rate Algal Ponds 257
5 Advanced Integrated Wastewater Pond Systems 258
5.1 Facultative Pond with Internal Fermentation Pit 258
5.2 High-Rate Algal Pond (HRAP) 259
5.3 Algae Settling Pond 259
5.4 Maturation Pond 260
6 Symbiosis of Algae with Bacteria for Wastewater Treatment 260
7 Utilisation of Wastewater-Grown Microalgae 261
8 Conclusion 264
References 264
14 Major Commercial Products from Micro- and Macroalgae 270
Abstract 270
1 Introduction 271
2 Food and Nutraceuticals 274
2.1 Macroalgae 274
2.1.1 Nori 274
2.1.2 Wakame 275
2.1.3 Kombu 275
2.2 Microalgae 275
2.2.1 Spirulina 276
2.2.2 Chlorella 277
3 Feed 278
3.1 Aquaculture 278
3.2 Pets and Farm Animals 280
4 Hydrocolloids 280
4.1 Alginates 281
4.2 Carrageenans 281
4.3 Agars and Agarose 281
5 Pigments 282
5.1 Carotenoids 282
5.1.1 ?-carotene 282
5.1.2 Astaxanthin 283
5.2 Phycobiliproteins 284
6 Polyunsaturated Fatty Acids (PUFAs) 286
6.1 PUFA Production 287
7 Fertilizers and Soil Conditioners 289
8 Fuels 289
9 Bioactive Compounds 290
9.1 Anticancer Compounds 291
9.2 Antifungal and Antibiotic Compounds 291
9.3 Antiviral Compounds 291
9.4 Toxins 292
10 Cosmetics 293
11 Chemicals 293
11.1 Stable Isotopically Labeled Compounds 294
11.2 Biomanufacturing and Specialty Chemicals 294
11.3 Feedstock for Industrial Bioprocesses 295
12 Environmental Applications 295
12.1 CO2 Sequestration 295
12.2 Wastewater Treatment and Bioremediation 296
13 Conclusions 296
References 298
15 Harmful Algae and Their Commercial Implications 302
Abstract 302
1 Introduction 302
2 Public Health: Direct Impacts of HABs on Microalgae Products 303
3 Impacts of HABs on Aquaculture 304
3.1 Shellfish 304
3.2 Finfish 306
4 Impacts of Coastal HABs on Tourism 309
5 Costs of Managing HABs 310
Acknowledgments 312
References 312
16 Genetic and Metabolic Engineering of Microalgae 317
Abstract 317
1 Introduction 317
2 Microalgal Genomics 318
3 Genetic Engineering of Microalgae 323
3.1 Construction of Transformation and Expression Vectors 324
3.2 Methods of Gene Introduction 326
3.3 Potential Applications of Genetic Transformation in Microalgae 328
4 Metabolic Engineering 329
4.1 Metabolic Engineering of Lipid Metabolism 330
4.2 Metabolic Engineering of Biohydrogen Production 333
5 Limitations and Risks in Genetic and Metabolic Engineering of Microalgae 334
6 Concluding Remarks 335
Acknowledgements 335
References 335