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A new high-pressure liquid chromatography multidetection quantitative method for the isolation of the products of oleuropein hydrolysis is described. A single analysis yields sufficient amounts of the compounds to test their inhibitory effect on bacterial growth.

Cryptococcus albidus var. albidus produced an extracellular endo-polygalacturonase (poly (1,4-alpha-D-galacturonide) glycanohydrolase EC 3.2.1.15) when grown in a synthetic medium containing one of a variety of pectic substances or galacturonic acid. The highest level of enzyme activity (15.5 VU X ml-1) was obtained after 72 h of growth on 1.0% low-methoxyl pectin. The enzyme, purified by gel filtration (Sephadex G-100) after repeated ammonium sulphate precipitation and dialysis, showed only one band by polyacrylamide gel electrophoresis and had the following properties: mol wt (MWr) 41000 dal; isoelectric point (pI) = 8.10 +/- 0.10; optimum temperature and pH for activity around 37 degrees C and pH 3.75, respectively; pH stability in the pH range 4.0 to 8.0; complete heat inactivation after 10 min at 55 degrees C; Km and Vmax values 5.7 X 10(-1) mg X ml-1 and 5.1 X 10(-1) mmoles X min-1, respectively.

A preliminary study was done on the pectolytic activity of Cryptococcus albidus var. albidus. Cell-free culture broths of six strains of this yeast species were shown to degrade pectin hydrolytically by means of a polygalacturonase-pectinmethylesterase system. Neither pectin nor pectate lyase activities were detected.