Submitted to: Annual Meeting and Expo of the American Oil Chemists' Society
Publication Type: Abstract Only
Publication Acceptance Date: February 15, 2006
Publication Date: April 30, 2006
Citation: Ashby, R.D., Solaiman, D., Foglia, T.A. 2006. New uses for glycerol: fermentation substrates for value-added product synthesis [abstract]. Annual Meeting and Expo of the American Oil Chemists' Society. p. 72. Technical Abstract: Biodiesel is quickly becoming a more recognized and accepted alternative to petrochemical-based diesel as evidenced by the recent signing of the Federal Excise Tax Credit of 1¢ per % biodiesel in a diesel fuel blend (effective January 1, 2005) and the allowance by certain automakers for its use in their diesel engines (see Jeep's Common Rail Diesel (CRD) engine and Volkswagen's TDI diesel engine) with warranty protection on up to B5 blends. As biodiesel gains more of a foothold in American life, its production will continue to increase and with it result in a growing amount of crude glycerol (in the form of a biodiesel coproduct stream) that will need to find outlets for reduced production costs. One promising possibility is for its use as a fermentation substrate for the production of biodegradable "value-added" materials. Over the past few years we have focused on the synthesis of microbially derived biopolyesters (i.e., polyhydroxyalkanoates; PHAs) and biosurfactants (i.e., sophorolipids; SLs) from low-cost agricultural coproducts including the crude glycerol from biodiesel synthesis. To date, it has been determined that both short-chain (sc-) and medium-chain (mc-) PHA with widely varying properties can be produced from crude glycerol by different strains of Pseudomonas. In addition, the yeast, Candida bombicola, was shown to utilize crude glycerol in the synthesis of sophorolipids, extracellular glycolipids composed of a dissacharide (sophorose; 2-O-beta-D-glucopyranosyl-beta-D-glucopyranose) attached to a hydroxyl fatty acyl moiety at the omega-1 or omega carbon. Success in this arena will lend itself positively to the "biorefinery" concept and provide an additional outlet for crude glycerol thus helping to minimize biodiesel production costs.