A lipolytic enzyme which hydrolyzed monoacylglycerols more easily than triacylglycerols was found in the culture broth of Penicillium cyclopium M1. The enzyme was purified to homogeneity and its properties were investigated. Among various substrates used, mono-acylglycerols, especially those of medium chain fatty acids, were hydrolyzed very rapidly. Although the rate was low, the enzyme hydrolyzed methyl esters of fatty acids, Span or tri-acylglycerols of medium chain fatty acids. Based on its substrate specificity, the enzyme was regarded as a partial glyceride hydrolase.
When the partial glyceride hydrolase was used in conjunction with lipase on triacyl-glycerol, the degree of hydrolysis of triacylglycerol became extremely high.