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Poster Presentation 6-35
Modification of Lipase for the Hydrolysis of Castor Oil
S. R. Kulkarni1 and A. B. Pandit2
1Oak Ridge National Laboratory Life Sciences Division P. O. Box 2008 Oak Ridge, Tennessee 37831-6226
2Chemical Engineering Division Department of Chemical Technology University of Mumbai Mumbai 400 019, India
Telephone: (865) 574-6775; Fax: (865) 574-6442; E-mail: kulkarnisr@ornl.gov
Hydrolysis of castor oil provides a range of commercially significant oleo-chemical intermediates, such as 12-hydroxystearic acid, n-heptaldehyde, and undecylenic acid. These products have been used in the manufacture of specialty greases; nylon-6, 10, 11; and specialty plasticizers. The enzymatic method is the most suitable method for hydrolysis of castor oil as the castor fatty acid (ricinoleic acid) is susceptible to thermal degradation when the hydrolysis is carried out by conventional methods. However, the rate of enzymatic hydrolysis of castor oil decreases with time. A high rate of reaction can be maintained by subjecting the substrate to large quantities of enzyme. Therefore, to balance the economics of the process, a reusable enzyme is desirable. Lipases display interfacial activation; hence, utilization of the enzyme in an insoluble-immobilized form is undesirable. A reversibly soluble-insoluble lipase (pH-responsive solubility) was developed by conjugating the enzyme to Eudragit L-100, which was then used to catalyze the hydrolysis of castor oil in a biphasic system. The parameters affecting the rate of the reaction were found to be the presence of solvent, temperature, product inhibition, concentration of enzyme, and the oil-water interfacial area.
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