..................................................................................................................................... ii ACKNOWLEDGMENTS ............................................................................................................... iii TABLE OF CONTENTS ................................................................................................................. iv LIST OF FIGURES ........................................................................................................................ vii LIST OF TABLES ......................................................................................................................... viii LIST OF ABBREVIATIONS .......................................................................................................... ix CHAPTER 1 – Introduction.............................................................................................................. 1 1.1 Research Objectives .............................................................................................................................. 3 1.2 Thesis Overview ................................................................................................................................... 3 CHAPTER 2 Background and Literature Review .......................................................................... 4 2.1 Microalgae ............................................................................................................................................ 4 2.1.1 Cultivation ...................................................................................................................................... 5 2.1.2 Applications and Commercial Interest ........................................................................................... 7 2.1.2.1 Whole Foods ........................................................................................................................... 8 2.1.2.2 Nutraceuticals (High Value Products) .................................................................................... 9 2.1.2.3 Cosmetics and Dyes .............................................................................................................. 11 2.1.2.4 Bioremediation (CO2 and Wastewater) ................................................................................. 12 2.1.2.5 Biofuels ................................................................................................................................. 14 2.2 Microalgae Selection for Biodiesel Applications ............................................................................... 16 2.2.1 Selected Microalgae Biomass Productivities, Lipid Content and Lipid Productivities ............. 16 2.2.2 Additional Considerations............................................................................................................ 18 2.2.3 Nannochloropsis oculata .............................................................................................................. 19 2.3 Growth and Products Stimulation ....................................................................................................... 20 2.3.1 Media Changes (N & P) ............................................................................................................... 21 2.3.2 pH and Inorganic Carbon Sources ............................................................................................... 22 2.3.3 Salinity ......................................................................................................................................... 23 2.3.4 Light ............................................................................................................................................. 24 2.3.5 Temperature ................................................................................................................................. 25 2.3.7 Static Magnetic Fields .................................................................................................................. 26 2.3.7.1 Static Magnetic Fields and Microalgae ................................................................................. 28 2.4 Thesis Relationship with the Literature Review ................................................................................. 32 CHAPTER 3 Materials and Methods ........................................................................................... 34 v 3.1 Microalgae Strain and Seed Culture Conditions ................................................................................. 34 3.2 Experimental Set Up and Magnetic Field Exposure ........................................................................... 35 3.3 Analysis............................................................................................................................................... 37 3.3.1 pH Measurements ........................................................................................................................ 37 3.3.2 Growth Curves (Biomass Concentration vs. Time) ..................................................................... 37 3.3.2.1 Growth Models ..................................................................................................................... 38 3.3.3 Final Biomass Concentration ....................................................................................................... 39 3.3.4 Biochemical Analysis .................................................................................................................. 39 3.3.5 Biomass, Lipids and Co-Products Productivity ........................................................................... 41 3.3.6 Cell Size Determination and Cell Ultrastructure ......................................................................... 41 3.3.6.1 Cell Size ................................................................................................................................ 41 3.3.6.2 Effect of 10 mT on Cell Ultrastructure ................................................................................. 42 3.4 Statistical Analysis .............................................................................................................................. 43 CHAPTER 4 – Results.................................................................................................................... 44 4.1 Growth ................................................................................................................................................ 44 4.1.1 pH Levels ..................................................................................................................................... 44 4.1.2 Growth Curves ............................................................................................................................. 44 4.1.3 Final Biomass Concentration ....................................................................................................... 46 4.2 Biochemical Analysis ......................................................................................................................... 46 4.2.1 Biomass and Pigment Composition Control, 5, 10 and 15 mT (30-Day Runs) ......................... 46 4.2.2 Metal Content Control, 5, 10 and 15 mT (30-Day Runs) .......................................................... 47 4.2.3 Time Effect on Biomass and Pigment Composition – Control and 5 mT (10-Day and 30-Day Runs) ..................................................................................................................................................... 48 4.3 Biomass and Product Productivity ...................................................................................................... 49 4.4 Cell Size and Cell Ultrastructure ........................................................................................................ 50 4.4.1 Cell Size ....................................................................................................................................... 50 4.4.2 Cell Ultrastructure – Control vs. 10 mT Cells ......................................................................... 52 CHAPTER 5 – Discussion .............................................................................................................. 54 5.1 Growth ................................................................................................................................................ 54 5.1.1 Seed Culture and Control Culture ................................................................................................ 54 5.1.2 SMF Experiments: Control and SMF Cultures ............................................................................ 55 5.1.2.1 Growth Curves and Final Biomass Yield (30-Day Runs) ..................................................... 55 5.1.2.2 Specific Growth Rates .......................................................................................................... 57 5.1.2.3 Cell Size ................................................................................................................................ 58 5.1.2.4 Media Composition and pH .................................................................................................. 59