Microalgal Biotechnology: Integration and Economy (eBook)

lt;!doctype html public "-//w3c//dtd html 4.0 transitional//en">

Clemens Posten,Karlsruhe Institute of Technology, Karlsruhe; Christian Walter, Wacker Chemie AG, Burghausen, Germany.

Preface 5
List of contributing authors 15
1 Introduction – Integration in microalgal biotechnology 23
1.1 Integration on the process level 24
1.2 Integration on the metabolic level 26
1.3 Integration into environmental conditions 27
1.4 Adaptation to cultural realities 28
Integrated production processes 33
2 Products from microalgae: An overview 35
2.1 Microalgae: An introduction 35
2.2 Products 37
2.2.1 Use and production of algal biomass 37
2.2.2 Microalgae for human nutrition 40
2.2.2.1 Spirulina (Arthrospira) 41
2.2.2.2 Chlorella 42
2.2.2.3 Dunaliella salina 43
2.2.3 Microalgae for animal feed 43
2.2.4 Microalgae as natural fertilizer 44
2.2.5 Microalgae in cosmetics 44
2.2.6 Fine chemicals 45
2.2.6.1 PUFAs 45
2.2.6.2 Pigments 48
Pigments as antioxidants 48
Pigments as natural colorants 50
2.2.6.3 Polysaccharides 51
2.2.6.4 Recombinant proteins 53
2.2.6.5 Stable isotopes 53
2.2.7 Micro- and nanostructured particles 53
2.2.8 Bulk chemicals 55
2.2.9 Energy production from microalgae 57
2.2.9.1 Biodiesel 57
2.2.9.2 Bio-ethanol 62
2.2.9.3 Bio-hydrogen 63
2.2.9.4 Bio-gas 64
2.2.9.5 Biorefinery of microalgae 65
2.3 Conclusion 66
References 66
3 Spirulina production in volcano lakes: From natural resources to human welfare 73
3.1 Introduction 73
3.2 Natural Spirulina lakes in Myanmar 74
3.3 Environmental parameters of Myanmar Spirulina lakes 76
3.4 Spirulina production from natural lakes 79
3.4.1 Harvesting 79
3.4.2 Washing and dewatering 80
3.4.3 Extrusion and sun drying 81
3.4.4 Lake-side enhancement ponds 83
3.5 Sustainable Spirulina production from volcanic crater lakes 84
3.6 Myanmar Spirulina products 85
3.7 Spirulina as biofertilizer 86
3.8 Spirulina as a biogas enhancer 89
3.9 Spirulina as a source of biofuel 89
3.10 Myanmar and German cooperation in microalgae biotechnology 89
3.11 Discussion 90
3.12 Conclusion 90
Acknowledgments 91
References 91
4 Case study of a temperature-controlled outdoor PBR system in Bremen 95
Acknowledgments 99
References 99
5 Algae for aquaculture and animal feeds 101
5.1 Introduction 101
5.2 Microalgae use in aquaculture hatcheries 101
5.2.1 Microalgal strains used in aquaculture hatcheries 102
5.2.2 Methods of microalgae cultivation for aquaculture 104
5.2.3 Role of microalgae in aquaculture hatcheries 104
5.2.3.1 Microalgae as a feed source for filter-feeding aquaculture species 104
5.2.3.2 Microalgae as a feed source for zooplanktonic live prey 105
5.2.3.3 Benthic microalgae as a feed source for gastropod mollusks and echinoderms 106
5.2.3.4 Addition of microalgae to fish larval rearing tanks 107
5.2.3.5 Use of microalgal concentrates in aquaculture hatcheries 109
5.3 Use of algae in formulated feeds for aquaculture species and terrestrial livestock 110
5.3.1 Algae as a supplement to enhance the nutritional value of formulated feeds 110
5.3.1.1 Vitamins and minerals 110
5.3.1.2 Pigments 111
5.3.1.3 Fatty acids 112
5.3.2 Algae as a potential feed ingredient: source of protein and energy 112
5.4 Outlook 117
References 118
6 Algae as an approach to combat malnutrition in developing countries 123
6.1 Introduction 123
6.2 Algae in human food 123
6.3 Microalgae as a solution against malnutrition: meet Spirulina 124
6.4 Small-scale Spirulina production as a development tool 125
6.5 Spirulina as a business to combat malnutrition 126
6.6 Spirulina and its place in food aid and development policies 128
6.7 Evidence of Spirulina in malnutrition 129
6.8 Conclusion 131
Acknowledgements 131
References 131
7 Hydrogen production by natural and semiartificial systems 133
7.1 Biological hydrogen production of microorganisms 133
7.2 Photobiological hydrogen production by green algae 137
7.3 Photohydrogenproduction by cyanobacterial design cells 139
7.4 Photohydrogen production by a “biobattery” 141
7.5 Photobioreactor design for hydrogen production 142
7.6 Photobioreactor geometry 143
7.7 Process control 144
7.8 Upscaling strategies 145
References 146
8 The carotenoid astaxanthin from Haematococcus pluvialis 151
8.1 Introduction 151
8.2 Characteristics and biosynthesis 152
8.2.1 Chemical forms of astaxanthin 152
8.2.2 Astaxanthin biosynthesis 153
8.2.3 Function of astaxanthin 155
8.3 Haematococcus pluvialis 155
8.3.1 General characteristics 155
8.3.2 Factors responsible for ax accumulation 157
8.3.3 Industrial production of Haematococcus 160
8.4 Conclusions and outlook 162
References 162
9 Screening and development of antiviral compound candidates from phototrophic microorganisms 167
9.1 Introduction 167
9.2 Supply of natural compounds from microalgae 168
9.3 Sterilizable photobioreactors 169
9.4 Antiviral agents from microalgae 172
9.5 Antiviral screening 175
9.5.1 Primary target of screening 175
9.5.2 Smart screening approach 175
9.5.3 Basic process sequence 176
9.5.4 Antiviral activity and immunostimulating effects of Arthrospira platensis 178
9.5.5 Characterization of novel antiviral spirulan-like compounds 179
9.6 Conclusion 183
Acknowledgements 184
References 184
10 Natural product drug discovery from microalgae 191
10.1 Introduction 191
10.1.1 Eukaryotic microalgae 192
10.1.1.1 Dinoflagellates 192
10.1.1.2 Diatoms 194
10.1.2 Cyanobacteria 194
10.1.2.1 Proteinase inhibitors 196
10.1.2.2 Cytotoxic compounds 197
10.1.2.3 Antiviral substances 201
10.1.2.4 Antimicrobial metabolites 201
10.1.2.5 Miscellaneous bioactivities 202
10.1.3 Three examples of current microalgal drug research projects 205
10.1.3.1 Dolastatins as leads for anti-cancer drugs 205
10.1.3.2 Cryptophycins as leads for anti-cancer drugs 208
10.1.3.3 Microcystins as targeted anti-cancer drugs 209
10.1.4 Outlook 209
References 211
Socio-economic and environmental considerations 223
11 Biorefining of microalgae: Production of high-value products, bulk chemicals and biofuels 225
11.1 Introduction 225
11.2. Structural biorefining approach of microalgae 227
11.2.1 Approach 227
11.2.2 Cell disruption, fractionation and mild cell disruption of organelles 230
11.2.3 Extraction and fractionation of high-value components 232
11.2.4 Economically feasible continuous biorefining concept 233
11.3. Conclusions 234
References 235
12 Development of a microalgal pilot plant: A generic approach 237
12.1 Understanding the aims of the pilot plant 237
12.2 Pilot plant location and site selection 238
12.3 Develop the process flow diagram 238
12.4 Know what will be required to conduct experiments and measure the data 239
12.5 Sizing of the units 239
12.6 Plant layout 241
12.7 HAZOP study 243
12.8 Multidisciplinary review of the design 246
12.9 Tender for plant construction 246
12.10 Finalize the design 247
References 247
13 Finding the bottleneck: A research strategy for improved biomass production 249
13.1 Introduction: What do we expect from cell engineering? 249
13.1.1 The need for domestication of microalgae 249
13.1.2 Limitation of traditional approaches to strain improvement 250
13.2 Algal domestication through chloroplast genetic engineering 251
13.2.1 Chloroplast engineering in Chlamydomonas: progress and challenges 251
13.2.2 A synthetic biology approach to chloroplast metabolic engineering 254
13.2.3 Mitigating the risks and concerns of GM algae 256
13.3 Algal domestication through nucleus genetic engineering 257
13.3.1 Improving light to biomass conversion by regulation of the pigment optical density of algal cultures 257
13.4 Models for predicting growth in photobioreactors 259
13.4.1 PAM fluorimetry: a keyhole to look into the photosynthetic machinery 259
13.4.2 Microalgae cultivation in photobioreactors: the fluctuating light effects 262
13.4.3 Standard model for growth under an exponential light gradient 266
13.5 Cells’ response to changing environments: the example of nitrogen limitation 269
Acknowledgments 24
References 271
14 Trends driving microalgae-based fuels into economical production 275
14.1 Introduction 275
14.2 Leading trends 276
14.2.1 Microalgae biorefinery for food, feed, fertilizer and energy production 276
14.2.2 Biofuel production from low-cost microalgae grown in wastewater 277
14.2.3 Biogas upgrading with microalgae production for production of electricity 279
14.2.4 Hydrocarbon milking of modified Botryococcus microalgae strains 279
14.2.5 Hydrogen production combining direct and indirect microalgae biophotolysis 280
14.2.6 Direct ethanol production from autotrophic cyanobacteria 281
14.3 Production platforms 284
14.3.1 Ocean 284
14.3.2 Lakes 285
14.3.3 Raceways 285
14.3.4 Photobioreactors 285
14.3.5 Fermenters 285
14.4 Conclusions 285
References 286
15 Microalgal production systems: Global impact of industry scale-up 289
15.1 Microalgal biotechnology 289
15.2 Global challenges, production and demand 290
15.2.1 Global fuel production and demand 290
15.2.2 Global food production and demand 291
15.2.3 Solar irradiance and areal requirement 292
15.2.4 Global challenges 293
15.3 Potential production and limitations 294
15.3.1 Solar energy and geographic location 294
15.3.2 Potential productivity 296
15.3.3 Land resources 298
15.3.4 Carbon management and associated costs 300
15.3.4.1 CO2 requirements 300
15.3.4.2 CO2 utilization and sequestration 301
15.3.4.3 CO2 delivery 302
15.3.5 Nutrient management and associated costs 303
15.3.5.1 Phosphorus 304
15.3.5.2 Nitrogen 304
15.3.5.3 Nutrient recycling 304
15.3.6 Water management and associated costs 305
15.4 Global impact of scale-up 307
15.4.1 Addressing world production 307
15.4.2 Economics of large-scale microalgal production systems 309
15.4.3 Techno-economic analysis of microalgal production systems 310
15.4.3.1 Cultivation systems 310
15.4.3.2 Impact of capital costs 311
15.4.3.3 Downstream processing 312
15.4.3.4 Harvesting and dewatering 312
15.4.4 Dedicated versus integrated production models 314
15.4.5 Business models 316
15.4.6 Pathways to commercialization 318
15.5 Conclusion 321
References 323
Index 329