Abstract
Summary: The production of a rennin-like milk-clotting enzyme by Penicillium citrinum 805 was investigated. Corn-steep water was the best medium for the production of the enzyme. Dephytinization of corn-steep water lowered production of the enzyme. The extent of mycelial sporulation was correlated with the milk-clotting activity. Precipitation with ammonium sulphate and ethanol was unsuitable, but acetone produced active fractions. The enzyme action was optimal at 60° and at pH 6.0 while the stability of the enzyme was maximal at pH 5.37. The enzyme exhibited feeble proteolytic activity.