Chemicals from Microalgae

by Cohen; Zvi

• ISBN13: 9780748405152
• ISBN10: 0748405151
• Edition: 1st
• Format: Hardcover
• Copyright: 1999-05-27
• Publisher: CRC Press

Summary

The production of chemicals from microalgae is becoming a significant area of biological research. This work seeks to cover the various aspects that relate to the use of microalgae as a source of chemicals. The chapters discuss the occurrence and physiological role of these chemicals and concentrates on the methods aimed at enhancing their content, as well as large-scale algal biomass production and down-stream processing. It describes the major algal chemicals of interest, namely pigments and lipids.

Author Biography

Zvi Cohen is an Associate Professor at the Jacob Blaustein Institute for Desert Research at Ben-Gurion University, Israel.

Table of Contents

Preface	p. xi
Foreword	p. xiii
Contributors	p. xiv
Porphyridium cruentum	p. 1
Fatty acid composition	p. 1
Triacylglycerols	p. 2
Biosynthesis of AA and EPA	p. 3
Feeding with fatty acid precursors	p. 4
Radiolabelling studies	p. 5
Selection of mutants deficient in EPA biosynthesis	p. 9
Environmental factors affecting PUFA content	p. 11
Temperature	p. 11
Light intensity and biomass concentration	p. 14
Nitrogen starvation	p. 15
Strains	p. 16
Outdoor cultivation	p. 17
EPA overproduction	p. 18
EPA purification	p. 20
Feeding with external fatty acids	p. 20
References	p. 21
Monodus subterraneus	p. 25
Fatty acid composition of individual lipids	p. 25
Effects of nutritional and environmental conditions	p. 25
Outdoor cultivation	p. 28
Evaluation of EPA-producing species	p. 30
Production of high purity EPA	p. 32
Biosynthesis	p. 35
Future directions	p. 38
References	p. 39
Production of eicosapentaenoic acid by the marine eustigmatophyte Nannochloropsis	p. 41
Introduction	p. 41
Nannochloropsis and other eustigmatophytes	p. 42
Chemical composition	p. 43
Biosynthesis of lipids and polyunsaturated fatty acids	p. 45
Modulation of fatty acid composition	p. 47
Mass production	p. 49
Commercial applications and feeding experiments	p. 51
Acknowledgements	p. 53
References	p. 53
Production of EPA from Phaeodactylum tricornutum	p. 57
Introduction	p. 57
Criteria for selecting Phaeodactylum tricornutum UTEX 640 as a potential source of EPA	p. 58
Phaeodactylum tricornutum UTEX 640 biomass production in horizontal tubular air-lift photobioreactors	p. 62
EPA production from Phaeodactylum tricornutum UTEX 640	p. 78
Concluding remarks	p. 85
Acknowledgements	p. 86
Nomenclature	p. 86
References	p. 87
Genetic improvement of EPA content in microalgae	p. 93
Introduction	p. 93
The genetic approach to strain improvement	p. 94
Genetic improvement of EPA content in microalgae	p. 96
Conclusions	p. 102
Acknowledgements	p. 103
References	p. 103
Recovery of algal PUFAs	p. 108
Introduction	p. 108
A general overview of lipid and fatty acid extraction	p. 113
PUFA concentration and purification techniques	p. 120
Integrated process for obtaining highly pure PUFA from algae	p. 128
Concluding remarks	p. 138
Acknowledgements	p. 138
References	p. 140
Microalgal carotenoids	p. 145
Introduction	p. 145
Structures of microalgal carotenoids	p. 145
Distribution of microalgal carotenoids	p. 149
Isolation, identification and structure elucidation	p. 161
Biological aspects	p. 165
Summary	p. 168
References	p. 168
Production of astaxanthin by Haematococcus	p. 173
Introduction	p. 173
Astaxanthin-producing microalgae	p. 174
Cell cycle of Haematococcus	p. 174
Pathway of astaxanthin synthesis	p. 177
Regulation of biosynthesis of carotenoids leading to astaxanthin	p. 179
Location of astaxanthin in Haematococcus cells	p. 181
Factors affecting astaxanthin accumulation and cell growth	p. 181
Function of secondary carotenoids including astaxanthin	p. 185
Improvement of cell growth and astaxanthin synthesis	p. 187
Molecular biology of Haematococcus	p. 188
Commercial production and application of astaxanthin from Haematococcus	p. 188
Conclusion and future work	p. 189
References	p. 190
Production of [beta]-carotene from Dunaliella	p. 196
Biology and halotolerance	p. 196
[beta]-carotene and production	p. 197
Biotechnology of [beta]-carotene production by Dunaliella	p. 199
Natural versus synthetic [beta]-carotene	p. 201
Commercial producers	p. 203
References	p. 203
Chemicals of Botryococcus braunii	p. 205
Introduction	p. 205
Isolation and methodology for the study of chemicals from B. braunii	p. 210
Hydrocarbons	p. 211
Usual lipids	p. 223
Non-classical lipids	p. 225
Macromolecular lipids and algaenans	p. 243
Polysaccharides	p. 248
Biotechnological studies	p. 248
Concluding remarks	p. 252
References	p. 253
Phycobiliproteins	p. 261
Introduction	p. 261
Phycobiliproteins from cyanobacteria or red algae	p. 262
Cryptomonad phycobiliproteins	p. 267
Applications of the phycobiliproteins	p. 269
References	p. 276
Polysaccharides of red microalgae	p. 282
Introduction	p. 282
Red microalgae	p. 282
Cell-wall polysaccharides of the red microalgae	p. 283
Cell wall formation	p. 285
Production of new polysaccharides by protoplast fusion	p. 286
Applications of red microalgal polysaccharides	p. 286
References	p. 287
Polyhydroxyalkanoates	p. 292
Introduction	p. 292
Properties of PHAs relevant to their use	p. 293
Biosynthesis of PHAs	p. 297
Occurrence of PHAs in cyanobacteria	p. 298
Functions of PHAs in cyanobacteria	p. 304
Future prospects	p. 306
Acknowledgements	p. 307
References	p. 307
Pharmaceuticals and agrochemicals from microalgae	p. 313
Introduction	p. 313
Antibiotics	p. 314
Antiviral activity	p. 320
Cytotoxic, antitumour and antineoplastic metabolites	p. 320
Toxins	p. 328
Other pharmacologically active compounds	p. 330
Other activities	p. 334
Vitamins, carotenoids and fatty acids	p. 334
Production of biologically active substances by algal culture	p. 335
Culture versus 'wild'	p. 337
Conclusion	p. 338
References	p. 338
Physiological principles and modes of cultivation in mass production of photoautotrophic microalgae	p. 353
Introduction	p. 353
Microalgal nutrition	p. 354
Temperature and light: the major growth limitations outdoors	p. 357
Reactors for mass production of microalgae	p. 365
Maintenance of mass cultures	p. 378
Acknowledgements	p. 382
References	p. 383
Economic evaluation of microalgal processes and products	p. 387
Introduction	p. 387
The algae and algal products	p. 387
Economic modelling	p. 393
The cost of algal production--case studies	p. 401
Conclusions	p. 406
References	p. 406
Index	p. 410
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