Tuesday, April 30, 2013
Exhibit Hall
Developing environmentally sustainable biofuels remains a major research challenge for our society. Oleaginous yeasts, which can accumulate lipids in excess of 70% of their total biomass, are being investigated as potential producers of biodiesel. Metabolic engineering and process optimization efforts may be able to produce an economically competitive biodiesel fuel from these species. Lipomyces starkeyi is a particularly well suited host given its native ability to metabolize xylose, a pentose sugar obtained from agricultural hydrolysate feedstocks.
Oleaginous yeasts are known to accumulate lipids when grown in a nitrogen-deficient or other nutrient-limited medium. Here we report results from several Lipomyces starkeyi batch shake flasks grown in a minimal media with variable nitrogen content. Among defined nitrogen sources, growth and pH control were optimal with a mixture of urea and ammonium chloride. Additionally, we have implemented a persulfate digestion method for measuring media nitrogen levels, to investigate the relationship between nitrogen limitation and lipid production over time.