[Characteristics of lipases in the culture fluid of Penicillium roqueforti].

Lipases were isolated from the cultural broth of Penicillium roqueforti 141, purified and their properties were studied. The lipases differed in their amino acid composition and had a high content of polar amino acids , in particular aspartic and glutamic acids. The lipases contained also carbohydrates (1.4-3.3%): mannose, xylose and glucosamine. The lipases were stable to heating (up to 55 degrees C) and within a wide pH range. The optimal activity of lipases I and III was observed at 40 degrees C and pH 7.0, that of lipase II at 45 degrees C and pH 6.0. The effect of metal ions and various inhibitors on the activity of the lipases was studied. Ca2+, Mg2+ and Fe2+ ions did not activate the lipases. These were inhibited by a broad spectrum of reagents for sulfhydryl groups and by a phosphoorganic compound. This fact suggest that the lipases belong to "serine" enzymes containing sulfhydryl groups.