Purification and properties of a 1,3-β-glucanase from Penicillium oxalicum autolysates

High 1,3-beta-glucanase activity was detected during autolysis in a culture medium containing Penicillium oxalicum. It was due to the combined action of four enzymes. The purification process for the major enzyme produced a homogeneous band in the SDS polyacrylamide gel that corresponded to a molecular weight of 79,400 daltons. The enzyme pI was 6.3 and it was only active against 1,3-beta-glucans, with a S0.5 of 0.23 mg ml-1 against laminarin. The enzymatic optima were found at pH 4 and 55 degrees C, and instability was evident when pH and temperature were altered. The enzyme was not active against oxidated laminarin and was barely inhibited by glucono-D-lactone. Hg2+, Ag+ and Fe2+ were effective inhibitors. The enzyme was adsorbed by concanavalin-A-sepharose.