(575f) Growth, Harvesting, and Modeling of Lipomyces Starkeyi Lipids On Waste Sweet Potatoes

Authors: 
Dufreche, S., University of Louisiana at Lafayette
Zappi, M. E., University of Louisiana at Lafayette
Bajpai, R., University of Louisiana at Lafayette



The production of fuels from renewable resources has traditionally faced many barriers, with the most common being limited feed stocks for utilization. The growing need for cost effective renewable resources is a driving force in the development of potential feed stocks. The sweet potato has shown in previous research to have a very high starch content. In addition, up to 20% of the annual sweet potato harvest is discarded due to unsuitable use as a food item. The yeast Lipomyces Starkeyi had previously shown the ability to produce lipids from pure starch, but not raw extract from whole sweet potatoes. The soluble starch obtained from this waste was used for the microbial conversion of starch to lipids utilizing a cheap feedstock. The soluble starch was evaluated for methods that would optimize production of the starch for conversion to lipids. Techniques were developed for preparing the sweet potatoes and maximizing extractable soluble starch. The starch obtained was then used as a feedstock for Lipomyces starkeyi to evaluate lipid production. Results to be presented include analysis of yeast growth and lipid accumulation, extraction efficiencies, and an economic analysis of full-scale lipid production from sweet potatoes.