Isolation and some properties of beta-1,3-glucanase from the fungus Verticillium dahliae

The strain with the highest beta-1,3-glucanase activity was selected from 14 Verticillium dahliae strains. The highest enzyme accumulation was achieved at day 15 of growth in culture. The presence of two extracellular molecular forms of beta-1,3-glucanase from V. dahliae is demonstrated for the first time. Both molecular forms of beta-1,3-glucanase, with molecular masses of 52 and 49 kD (forms I and II, respectively), were isolated in highly purified state using preparative electrophoresis in polyacrylamide gel. Basic physicochemical properties of both beta-1,3-glucanase forms were studied. Both forms of the enzyme are resistant to heating to 40 degrees C and stable in the 4.0-7.5 pH range. The maximal activities of forms I and II were observed at pH 6.8 and at 45 degrees C and at pH 5.2 and at 55 degrees C, respectively. The isoelectric point for both enzyme forms is 5.8. Both forms of beta-1,3-glucanase showed exo-type activity.