Optimization and Lipid Quantitation of Potential Algal Biofuels Feedstocks

Abstract

This research investigates the lipid content and composition of extremophilic and estuarine microalgae for suitability as biofuel feedstocks. These are major considerations in optimizing algal biofuel production, as they affect important fuels characteristics including production yield, melting point, flash point, cetane number, and fuel value. In these studies the known feedstock alga Chlorella saccharophila and potential new feedstocks including Galdieria sulphuraria and cold‐tolerant estuarine algae isolated from the Severn River, MD were grown mixotrophically, under replete conditions and a variety of nutrient‐depleted growth conditions. The lipid content of these organisms was determined by spectroscopic quantitation techniques in comparison with dry‐weight percentage, and acyl content was characterized by GS‐MS of fatty acid‐methyl ester (FAME) derivatives. This work compares lipid yields, fatty acid profiles, and quantitation methods from a variety of organisms under various temperature and nutrient conditions, to examine their suitability as feedstocks and determine optimal feedstock production techniques. Observations include increased relative lipid yield in Galdieria under replete conditions compared to Chlorella and increased presence of unsaturated fatty acids in the lipids of cold‐tolerant estuarine algae.Support or Funding InformationResearch Corporation Cottrell College Science Award, DoD ONR/USNA Midshipman Research Fund, and DoD DTRA Service Academy Research Initiative