Biodiesel fuel produced from vegetable oil or other waste oil resources is advantageous in terms of sustainable resource supply, less emissions, and biodegradability. The widely used biodiesel production process adopts strong base or acid as the catalyst. The main products of the catalytic reaction are methyl ester (ME) or ethyl esters (AE) (the chemical names for biodiesel) and glycerol, which is a waste byproduct.  The problems associated with biodiesel production catalyzed by chemicals include high energy cost, difficulty of glycerol recovery, catalyst removal, and the need for waste water treatment.  Enzymatic conversion by lipase can result in the same products as that catalyzed by strong acid or base and do not have the problems mentioned above. Lipase catalyzed biodiesel production is not utilized in industry, however, because of the high cost of enzymes.

In this poster, we present a new process for enzymatic production of biodiesel in a biphasic system. In this new process, the byproduct from biodiesel production, glycerol, will be utilized as the carbon source to culture yeast cells to produce lipase in the aqueous phase. The lipase produced by yeast in the aqueous phase will catalyze the biodiesel production reaction in the oil phase. The cost of this process is expected to go down because we can utilize a byproduct and avoid exogenous catalyst addition. Results of preliminary lipase screening for the suitability of catalyzing the transesterification reaction in the biphasic system and biodiesel production utilizing fed-batch and continuous operation will be reported.