(462f) An Examination of Lipid Production by Chlorella Protothecoides Using Compartmentalized Metabolic Flux Analysis

With increasing energy demands, many forms of alternative and sustainable energy production are receiving increased attention.  Biodiesel from algae continues to be a promising source of renewable liquid fuel.  C. protothecoides has demonstrated the highest lipid productivity of any strain of algae when it is grown heterotrophically.  However, much still remains to be learned about its primary metabolism.  A deeper understanding of the metabolism of this lipid-producing algal strain will set the stage for further improvements in its lipid production, as well as the lipid production of other algal strains with alternate desirable characteristics.

¹³C metabolic flux analysis is a powerful tool to examine the distribution of metabolic rates within a cell.  An examination of the labeling patterns in intermediary metabolites makes it possible to determine the flux rates of many key reactions in carbon metabolism.  Using subcellular fractionation we are able to deconvolute the labeling patterns of metabolites located in the plastid and the cytosol. Thus we are able to separate the fluxes of identical reactions which occur in both of these locations in the cell.  We have examined these flux rates using both glucose and glycerol to determine the differences in heterotrophic metabolism on each substrate with a focus on determining their impact on lipid metabolism.