Studies on the Lipoprotein Lipases of Microorganisms

Abstract

The production of lipoprotein lipases by Pseudomonas sp. M–12–33 was improved by an increased aeration. Glucose stimulated the growth of the bacterium but reduced the enzyme production in Bouillon medium. Olive oil remarkably increased the production of lipoprotein lipases but the effect was cancelled by calcium carbonate. Stearic and palmitic acids were as effective as olive oil, but capric and caprylic acids inhibited the enzyme production. Urea was proved to be very effective as a, nitrogen source for the production of lipoprotein lipases. The lipoprotein lipase production by Mucor species was tested and Mucor javanicus IAM 6108 was selected as the best producer of the enzyme in shaking culture. Then the effect of culture conditions was examined. Corn steep liquor was a good nitrogen source, while the addition of urea markedly inhibited the enzyme production. Each of glucose, dextrin and soluble starch was equally effective as the carbon source. A high concentration of glucose (3.0%) resulted inhibitory effect. Optimum temperature was 26°C and a good aeration was required. Lipoprotein lipase production was increased remarkably (by 5 to 8 times) by the addition of “soybean yuto” (1.0%), the effective component of which was demonstrated to be phosphatidyl inositol. Lipoprotein lipase activity was assayed by the estimation of free fatty acids according to the method of Dole with some modifications in which “plasma activated” olive oil emulsion was used as substrate.