The pectic enzymes of Aspergillus niger. 2. Endopolygalacturonase

PEOTIC ENZYMES 57obtained with an inoculum size which does not give maximum mycelial dry weight.The pectic enzymes show a marked increase during the third day of growth, and this point is marked also by the virtually complete utilization of the sucrose originally present in the culture and by a dis- continuity in the curve of mycelial dry weight.SUMMARY 1.A method is described for the preparation of a mixture of pectic enzymes with cultures of A8pergillu8 niger.2. The cultures were produced in stirred fer- menters with a medium consisting of 005 % of Na%S04, 02 % of NH4NO,, 2 % of sucrose and 2 % of pectin in a boiled extract of groundnut flour.Fermentation was continued for 5-6 days at 30°.The pH of the culture remained between 3 and 4.3. The preparations induced virtually complete hydrolysis of pectin.4. Enzymic preparations obtained from the culture fluid by precipitation with ethanol were more active, on a weight for weight basis, than commercially available materials.We wish to acknowledge the