Isolation of lipase from germinating oilseeds for biotechnological processes

Abstract

AbstractGerminating oilseeds have been explored as a possible source of lipases (glycerol ester hydrolase, EC.3.1.1.3) for the biotechnological processing of oils and fats. Seedlings of rape (Brassica napus) and mustard (Sinapis alba) at day 4 of germination and cotyledons of lupine (Lupinus albus) seedlings at day 3 of germination yield active crude lipase preparations upon homogenization with Tricine buffer (pH 7.5) followed by centrifugation at 23,000 g. The major portion of the lipase activity, determined with an emulsion of sunflower oil as substrate, is recovered in the supernatant fraction. These crude lipase preparations exhibit highest activity between pH 8 and 9, but they are inactive in acidic pH or at pH>10. Each of the crude lipase preparations is highly specific for thesn‐1,3 positions of triacylglycerols. The crude lipase preparations exhibit excellent stability on storage at −10 C, but about 50–60% of their activity is lost upon freeze‐drying. Dialysis of the crude lipase prior to freeze‐drying does not prevent the loss of activity. However, acetone powder obtained from the seedlings exhibits a lipase activity as high as the undialyzed crude lipase preparation.