Preface xv
Acknowledgements xix
Part I: Culture Methods 1
1 Adaptation of Chitosan-Based Harvesting Methods for Flocculation of Microalgae 3
Mainavi Patel, Hirak Parikh and Gayatri Dave
1.1 Microalgae 4
1.2 Microalgae Cultivation and Challenges 4
1.3 Microalgae Harvesting: Technological Limitations and Needs 6
1.4 Harvesting Methods 7
1.5 Chitosan as Natural Flocculant 9
1.6 Chitosan in Conjunction with Other Physicochemical Methods 12
1.6.1 Electroflotation and Mechanical Stirring 12
1.6.2 Electroflocculation 13
1.6.3 Synergistic Effects of Chitosan and Inorganic Flocculants 14
1.6.4 Integrated Flocculation 14
1.7 Comparison of Different Harvesting Methods 15
1.8 Conclusion 15
References 16
2 Diatoms Cultivation: Trends, Scope and Technoeconomic Prospects 21
Anshuman Rai, Nirmala Sehrawat, Mukesh Yadav, Varruchi Sharma, Vikas Kumar and Anil K. Sharma
2.1 Introduction 22
2.2 Cultivation Strategy and Production 24
2.3 Design and Implementation of a Prototype Algal Reactor 27
2.4 Potential of Diatoms as a Source of Biofuel with Value-Added Products 29
2.4.1 Diatoms in the Biofuels Industry 30
2.4.2 Medical Applications 31
2.5 Industrial Aspects of Diatoms as a Source of Biofuel 31
2.5.1 Biomedical Industrial Aspects 32
2.6 Economic Feasibility Assessment 32
2.7 Biochemical Composition 33
2.8 Feedstock Availability Assessment 37
2.9 Scope of Diatoms in Biorefinery 38
2.10 Conclusions and Future Prospects 39
Acknowledgment 40
Human and Animal Rights and Informed Consent 40
References 40
3 Biochemical Compounds in Phaeodactylum tricornutum 51
Vandana Sirotiya and Vandana Vinayak
3.1 Introduction 52
3.2 Biochemical Compounds 59
3.2.1 Pigments 59
3.2.2 Proteins 61
3.2.2.1 Hydrolysates 61
3.2.2.2 Chlorophyll Proteins: 10-Hydroxy-Phaeophorbide A and Phaeophorbide A 62
3.2.3 Carbohydrates 62
3.2.3.1 Chrysolaminarin 62
3.2.3.2 Exopolysaccharides (EPSs) 62
3.2.3.3 Sulfated Polysaccharides 63
3.2.4 Lipids 63
3.2.5 Fatty Acids 64
3.2.5.1 Omega-3 Fatty Acids 65
3.3 Demand, Valorization and Biotechnological Applications 66
3.4 Conclusion 68
References 69
Part II: High-Value Products 79
4 Diatoms: A Natural Resource of High-Valued Products and their Future Prospective 81
Khushboo Kesharwani, Shruti Sharma, Aanand Kautu, Satyendra Kumar Tripathi, Vikas Kumar and Khashti Ballabh Joshi
4.1 Introduction 82
4.1.1 Diatom Morphology 85
4.1.2 General Features of Oil Bodies in Diatoms 85
4.2 Biosilicification and Silicification as a Crucial Application in Bone Repair 89
4.3 Effect of Metals as a Therapeutic Application on Diatom Frustules 90
4.4 Successful Deposition of Metals on Diatom Frustules 91
4.4.1 Germanium 91
4.4.2 Titanium 91
4.4.3 Calcium 91
4.4.4 Strontium 92
4.5 Biomedical and Environmental Applications 92
4.5.1 Biomedical Applications 92
4.5.2 Environmental Applications 93
4.6 Deposition of Different Metal Nanoparticles for Various Applications 94
4.6.1 Iron Oxide Nanoparticles 95
4.6.2 Silver Nanoparticles 95
4.6.3 Gold Nanoparticles 98
4.6.4 Titanium Nanoparticle 99
4.6.5 Magnetite Nanoparticles 99
4.7 Interaction of Diatoms with Peptides and Their Plausible Applications 100
4.8 Diafuel: A Diatom Application with the Most Potential 101
4.9 Conclusion 102
Acknowledgments 102
References 102
5 Diatom Cell Wall: Nature Engineered Nanostructures 115
Sakshi Phogat, Rashi Tyagi, Abhishek Saxena, Pankaj Kumar Singh and Archana Tiwari
5.1 Introduction 116
5.2 Nature of Diatom Cell Wall 117
5.2.1 Biosilicification 118
5.2.2 Applications 119
5.3 Purification of Diatoms 121
5.3.1 Principle 121
5.3.2 Process 121
5.3.3 Purification of Raw DE Silica 122
5.4 Nutritive and High-End Product 122
5.5 Biofuel Industry 126
5.6 Factors of Diatom for Producing Biofuel 126
5.7 Biomedical Industry 127
5.8 DE Silica for Tissue Engineering 127
5.9 Nanotechnologically Derived Smart Drug Delivery System 128
5.10 Future Perspective 132
5.11 Conclusion 132
References 133
6 Biochemical Engineering of Diatoms for Health Benefits 139
Rishabh Rathore, Pragati Verma, Sonali Raghdale, Avishek Kumar, Mohd Jahir Khan and Vandana Vinayak
6.1 Introduction 140
6.1.1 Diatom Pigments 140
6.1.2 Diatoms' Nutritional Value 141
6.1.3 Diatoms as Bio-Indicators 141
6.1.4 Metal Toxicity 142
6.2 Chemical Composition of Diatom Biomass 142
6.2.1 Carbohydrate 143
6.2.2 Polyunsaturated Fatty Acid (PUFA) 144
6.2.3 Pigments 145
6.3 Microalgae as Hidden Treasure of Novel Drugs for Good Health 146
6.3.1 Drugs from Microalgae 147
6.3.2 As a Feed for Aquaculture 149
6.3.3 Diatoms in Drug Delivery 151
6.4 Microalgal Drugs in Preventing Viral Pandemics 153
6.5 Conclusions 156
References 157
7 Metabolism and Transcriptome Stress in Diatom Phaeodactylum tricornutum for Value-Added Products 167
Urvashi Soni, Sonali Rahangdale, Megha Mourya and Vandana Vinayak
7.1 Introduction 168
7.2 Commercial Market Value 170
7.2.1 Industrial Applications 170
7.2.2 Types of Foods with Health Benefits from Diatoms 172
7.3 Metabolic Pathways and Mechanisms for Synthesis of High Value Added Products in Diatoms 173
7.3.1 Carbon Dioxide Fixation 174
7.3.2 Photorespiration and Glyoxylate Metabolism 176
7.3.3 Reductive/Oxidative Pentose Phosphate Pathway 176
7.3.4 Glycolysis 177
7.3.5 Storage Products Synthesis and Degradation 177
7.3.6 Inositol and Propionate Pathway 178
7.3.7 Biosynthesis Production of Carotenoid in P. tricornutum Diatoms 178
7.4 Light Stress in Diatoms and Fucoxanthin Biosynthesis 179
7.5 Transcriptomics in Diatoms 186
7.5.1 Steps in Transcriptomics Sequencing 187
7.5.2 Transcriptomic Studies in Phaeodactylum tricornutum Under Various Influential Factors 187
7.6 Conclusions 189
References 190
8 Terraforming Mars with Microalgae, Especially Diatoms 203
Ira Rai, Jackson Achankunju, Richard Gordon and Vandana Vinayak
8.1 Introduction 204
8.2 Instrumentation to Artificially Simulate Life on Mars 206
8.2.1 SpaceQ 206
8.2.2 GraviSat Platform 209
8.3 Diatoms for Long-Term Space Missions 211
8.4 Potential Diatoms for the BLSS: Taxa Tolerant to Extreme Conditions 212
8.5 Testing Diatom Growth Under Microgravity Conditions 217
8.5.1 Microgravity and Living Organisms 217
8.6 Life Support Systems for Space Missions 220
8.7 Management of the Culture Vessel and Elements 222
8.8 Conclusions 223
Acknowledgments 223
References 223
9 Diatom: Source of Biofuel and Active Green Anode Material for Advanced Energy Storage Application 231
Vivek Dalvi, Sumit Dhali and Anushree Malik
9.1 Diatoms - Microalgae with Unique Structure and Properties 232
9.2 Biofuel Application 234
9.3 Diatom Silica: Material for Li-Ion Battery Anode 237
9.4 Conclusion 239
Acknowledgment 239
References 240
Part III: Low-Value Products 245
10 Milking of Diatoms: A Realistic Approach to Serve the Biorefinery Concept 247
Mrinal Kashyap
10.1 Introduction 248
10.2 Cell Disruption Methods 250
10.2.1 Ultrasonication of Cells to Extract Value-Added Compounds 250
10.2.2 Microwave-Assisted Cell Wall Disruption Method 251
10.2.3 High-Pressure Homogenization 251
10.2.4 Chemical Methods 252
10.2.5 Pulsed Electric Field 252
10.2.6 Milking of Diatoms 253
10.3 Concept of Milking Cells for Value-Added Compounds 254
10.3.1 Advancements in the Milking Approach 254
10.4 Economic Perspectives of Biofuels and Cell Disruption 257
10.5 Prospects and Challenges of the Milking Process 259
10.6 Conclusions 260
References 260
11 Dissection of Gene Expression Pattern and Metabolic Profile Under Enhanced Oil Production Conditions in Diatoms 267
Geetanjali Kumawat, Pallavi Vyas, Sandhya Deora, Sneha Sabu, Amit Kumar Gupta, Mukesh Meena, Ashwani Kumar, Vandana Vinayak and Harish
Abbreviations 268
11.1 Introduction 269
11.1.1 Why Algae Over Other Sources? 270
11.1.2 Basic Cell Structure of Diatoms 270
11.1.3 Why Diatoms? 271
11.1.4 Percentage Lipid Extraction as Per Dry Cell Weight 274
11.1.5 Aquatic Species Programme (ASP) 275
11.2 Generalized Pathway for Lipid Biosynthesis in Diatoms 276
11.3 Stress Conditions (Metabolites) Helping to Increase Oil Production 278
11.3.1 Salt Stress 284
11.3.2 Urea as a Nitrogen Source 285
11.3.3 Nutrient Stress 285
11.3.4 Light Stress 286
11.3.5 Nanoparticle Stress 286
11.3.6 Nitrogen Stress 287
11.3.7 Phosphorus Stress 288
11.3.8 Silicon Stress 288
11.3.9 Temperature Stress 289
11.3.10 POME-Based Biofuel 289
11.4 Changes in Gene Expression in Diatoms During Stress Conditions 290
11.5 Structural and Functional Aspect of Candidate Genes/ Enzymes of Lipid Biosynthesis Pathway 294
11.6 Role of rDNA Technology in Improving Diatom Strains for Enhanced Lipid Production 297
References 301
12 Implications of Diatoms for Heavy Metal Bioremediation 323
Varad Nagar, Vinay Aseri, Rushikesh Chopade, Pritam P. Pandit, Badal Mavry, Apoorva Singh, Garima Awasthi, Kumud Kant Awasthi and Mahipal Singh Sankhla
12.1 Introduction 324
12.2 Mechanism for Heavy Metal Removal by Diatoms 326
12.3 Bioremediation and Biosorption of Heavy Metals 326
12.4 Challenges 328
12.5 Advantage of Diatoms Over Other Techniques and Algae 329
12.6 Production of Diatoms on a Commercial Scale and Its Application 329
12.7 Future Aspects 333
12.8 Conclusion 334
References 334
13 Optimizing Bioenergy from Diatoms through Biofilms 341
G. Saranya and T.V. Ramachandra
13.1 Introduction 342
13.2 Different Configurations of Biofilm Cultivation Systems 344
13.3 Surface Materials for Biofilm Cultivation 345
13.3.1 Biofilm Bioreactor Design 346
13.3.2 Lab-Scale Biofilm Bioreactor 346
13.3.3 Operating Conditions for Diatom Cultivation 347
13.3.4 Field Biofilm Bioreactor 347
13.3.5 Evaluation of Algal Growth in Biofilms Grown under Field Conditions 348
13.3.6 Growth Dynamics of Lab-Cultivated Diatom and In-Field Bioreactor 349
13.3.7 Isolation and Identification of Bacteria in Biofilm 350
13.3.8 Bacterial Morphology Studies using DAPI 351
13.3.9 Species Interaction during Biofilm Cultivation 352
13.3.10 Biofilm Bacteria Identification through Molecular Sequencing 352
13.3.11 Diatom Sampling and Analysis 353
13.3.12 Biomass Yield and Productivity 354
13.3.13 Statistical Analysis 356
13.3.14 Optimization of Reaction Parameters for Direct Transesterification 357
13.3.15 Direct Transesterification of the Field Harvested Biomass 362
13.3.16 Biodiesel Extraction and Determination of Its Quality 363
13.4 Microalgal Biorefinery 365
13.4.1 Material Balance 365
13.5 Conclusion and Future Perspectives 366
Acknowledgments 367
Funding 367
Research Ethics 367
Animal Ethics 368
References 368
14 Diatoms Characteristics and Mass Processing of Lipids for Biofuel Production 377
Tawaf Ali Shah, Zhihe Li, Zhiyu Li and Andong Zhang
14.1 Diatoms 378
14.2 Reproduction 379
14.3 Ecology and Distribution 379
14.4 Morphology and Identification 381
14.5 Diatom Age, Diversity and Ecological Functions 381
14.6 Biofuel Production and Types of Biofuels 383
14.6.1 First-Generation Biofuels 384
14.6.2 Second-Generation Biofuels 384
14.6.3 Third-Generation Biofuels 384
14.6.4 Diatoms Mass and Lipids for Biofuel 385
14.6.5 Growth, Biomass and Lipid Extraction 388
14.7 Different Methods of Lipid Extraction for Biofuel 390
14.7.1 Plastic Bubble Wrap for Diatom Cultivation 390
14.7.2 Spontaneous Oozing 391
14.7.3 Mechanical Pressure 391
14.7.4 High-Pressure Homogenization 391
14.7.5 Ball Milling 392
14.7.6 Microwave Oven 392
14.7.7 Transesterification 392
14.8 Benefits of Diatoms 393
14.9 Genetic Engineering and Metabolic Pathway Engineering 393
14.10 Future Prospects 394
14.11 Conclusion 395
Acknowledgment and Funding 396
Data Availability 396
References 396
Index 399
