Theses and Dissertations Collection

Yarrowia lipolytica has been identified as a highly productive organism for the biosynthesis of triacyl glycerides (lipids) which can be converted into biofuels. To monitor lipid droplet production in the cell Raman-based methods shows promise when using deuterated probes for detection in the Raman-silent region (1800–2600 cm−1). The study involves the use of deuterated labeled glucose as Raman tag-based assessment of the Y. lipolytica MTYL038 strain cells for the multifold monitoring of glucose uptake, consumption, and lipid biosynthesis. The cells were grown in yeast extract peptone dextrose followed by growth in three different synthetic media with no nitrogen (N) with either glucose in H2O, glucose-D7 in H2O and glucose D7 in D2O. The cells were grown under optimum conditions (96 h) in synthetic media to an optical density >2.5. The changes in biomass and lipid yields were observed. Fourier-transform infrared and Raman spectroscopies showed the incorporation of deuterium with the presence of a C-D bands in the Raman silent region (1800-2600 cm-1) for both the glucose-d7 and glucose-D7 in D2O grown cells. The fatty acid profiles for the extracted cells grown in the three media showed significant differences in lipid profiles. The cells grown on both glucose-D7 media showed deuterium incorporation in the fatty acids as determined by mass spectrometry. This approach of labeling fatty acids can be used to monitor lipogenesis by Raman microscopy.