Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
Our civilization must soon reduce its dependence on non-renewable fossil fuels, and transition towards a more sustainable way of life. Biodiesels fulfill all the requirements of an ideal “next-generation” biofuel: they are liquid, energy dense, compatible with existing infrastructure, and potentially environmentally friendly. Biodiesels are composed of fatty acid esters produced from the transesterification of naturally occurring plant, animal, and microbial triacylglycerols. Oleaginous yeasts, such as Lipomyces starkeyi, are well known for their capacity to accumulate high levels of intracellular lipids. Metabolic engineering and process optimization efforts may be able to produce an economically competitive biodiesel fuel from these species. Lipomyces 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 preliminary results from several Lipomyces starkeyi batch shake flasks using a medium optimized for lipid production. Fatty acid methyl ester analyses were performed to examine the effect of aeration rate, carbon-to-nitrogen ratios, and sugar content on lipid accumulation. The best performing flasks produced lipid yields in excess of 65% of cell dry weight.