High enzyme cost is one reason lipases are not used for processing fats and oils. The fungus Rhizopus delemar produces a lipase which has a high degree of specificity for the hydrolysis and resynthesis of the primary ester bonds of triglycerides. However, production of this lipase by the fungus is low, and isolation of the enzyme is difficult. To overcome these problems, the lipase gene has been cloned and transferred into the bacterium E. coli. Production of the lipase by the cloned gene in this strain of E. coli has been optimized and the modified organism has been made to serve as a readily-grown source of enzyme. The lipase shows a high degree of positional selectivity for the primary ester bonds of triglycerides in both hydrolytic and synthetic modes of action. It is active in aqueous and organic solvents and can be used for both the hydrolysis and restructuring of fats and oils and the generation of flavor and essence compounds. Preparations of the lipase from this organism contain no other fungal proteins or lipases.

In subsequent work, the production of the enzyme by the cloned gene has been increased more than 100 fold and a derivative of the enzyme has been produced which is substantially more heat resistant than the original fungal lipase. Current studies are directed at the mutation of the cloned gene to produce variants of the lipase with improved properties.

In working with an industrial partner, we would provide samples of the enzymes for testing in their reaction schemes, collaborate with them on the directed mutagenesis of the gene to produce a modified lipase, provide microbial strains bearing the cloned gene to be used in lipase production within their facilities, assist in lipase isolation/purification, and collaborate on the application of these enzymes as industrial catalysts.

This lipase group is an established multidisciplinary team with ten years of experience in the biochemistry, molecular biology and applied enzymology of lipases. The group has developed specialized skills which maximize the probability of success in the design and development of lipases and lipase-catalyzed reactions.

Patent Status:
U.S. Patent 5,219,753 issued June 15, 1993.

Responsible Scientist/Engineer:
Dr. Michael J. Haas
Eastern Regional Research Center
ARS, USDA
600 East Mermaid Lane
Wyndmoor, PA 19038
(215) 233-6459
e-mail: Michael.Haas@ars.usda.gov

Technology Transfer Contact:
Victor (Vic) Chavez
(215) 233-6610
e-mail: vic.chavez@ars.usda.gov