Dielectric Measurement Of Algal Lipid Content For Biodiesel Production

Abstract

Algae are a promising feedstock for biodiesel production. Real-time monitoring of algal lipid content will enable increased productivity of algal biofuel feedstocks. Dielectric spectroscopy is well-suited to automated industrial monitoring and is sensitive to cellular properties, making it a promising method for algal lipid monitoring. In the first portion of this dissertation, I developed a method to measure the dielectric properties of algae cell suspensions and verified dielectric sensitivity to lipid accumulation via calibration with Nile red fluorometry. In order to develop an improved calibration method for my dielectric characterization, I then characterized intact algae cells via flow cytometry and quantitative 1 H NMR for development of an NMR-traceable flow cytometry protocol for algal lipid measurement. Flow cytometry provides information on the distribution of lipid content within algae populations, whereas 1 H NMR provides direct, rapid quantification of lipids in living cell suspensions without the need for cellular disruption and lipid extraction. In the final part of this dissertation, I used microfluidic single-cell impedance cytometry to simultaneously measure the impedance and fluorescence of individual algae cells with a range of lipid contents for development of an industrial algal lipid measurement system. This work has demonstrated the potential of dielectric spectroscopy for automated algal lipid monitoring, which will facilitate reliable harvest of algal biofuel feedstocks with high lipid content.