Characterization of Microalgal Lipids for Optimization of Biofuels

摘要

This research project investigates the lipid content and composition of extremophilic and estuarine microalgae under different growth conditions for suitability as biofuel feedstocks. Fatty acid content and lipid composition are major considerations in optimizing algae as feedstocks for fuel production. In this project fatty acid-methyl ester analysis (FAME GC-MS) was used to characterize the acyl content of the typical feedstock alga Chlorella saccharophila, the unusual acidothermophilic alga Galdieria sulphuraria, and cold-tolerant primary cultures cultured from the Severn River through winter bioprospecting. The cold tolerant species' acyl content included a greater percentage of C16 and highly unsaturated hydrocarbon chains, while Galdieria had a greater percentage of C18 and less unsaturated hydrocarbon chains, in comparison to Chlorella. In addition, a new, high-recovery method of direct FAME extraction from algal biomass was used to examine fatty acid content and composition from Galdieria and Chlorella cultures grown under a variety of nutrient conditions, including mixotrophic and autotrophic growth. Chlorella demonstrated a typical and expected effect of nutrient variation on algal lipid production. In contrast, Galdieria produced a greater percentage of fatty acids when grown with sugar, even while achieving higher culture density.