(260c) Cost Effective Lipid Production By Lipomyces Starkeyi Using Different Carbon Sources

Energy demand and environmental concerns are making it essential to find renewable and sustainable alternatives to fossil fuels. Biofuel can supplement diesel fuel in an environmentally friendly and economical way as long as the raw material employed is of low cost and can be derived from sustainable sources. Such an alternative feedstock, from non-vegetable source, could be provided by microbial lipid produced by oleaginous microorganisms which has chemical composition similar to that of vegetable oils. The oleaginous yeast, Lipomyces starkeyi, can be cultivated on different carbohydrates for production of over 75% of cell dry weight as lipids. Over one billion tons of lignocellulosics can be available in the USA annually which could be used for microbial lipid production. Several byproducts are formed during the hydrolysis of lignocellulosics. These products include pentoses and hexoses (furfural, hydroxymethyl furfural), phenolic compounds originating from lignin (hydroxybenzaldehyde, syringaldehyde) and organic acids. The concentration ranges of these byproducts in the hydrolyzates depend on the type of lignocellulosics as well as the method of hydrolysis employed. Out of the byproducts produced, furfural, HMF, and acetic acid are the key components which inhibit the microbial growth. This research work deals with the synthetic hydrolyzate compositions in shake flasks to identify tolerance limit of the byproduct (furfural, hydroxymethyl furfural, acetic acid) concentrations in the medium by Lipomyces starkeyi cells. Response surface methodology will be utilized to design and analyze the experiments. All the experiments will be conducted in 500 mL shake flasks with the working volume of 125 mL. The cell mass and lipid content are analyzed by dry weight and nile-red fluorescence respectively. The glucose concentration is measured by HPLC analysis.