Some properties of an exocellular lipase fromRhizopus arrhizus

Rhizopus arrhizus , a mold of the mucor family, excretes an active lipase when cultured properly. This lipase has a mol wt of 43,000 and a high carbohydrate content, Upon storage at 4C in aqueous solution, lipase I is slowly converted by proteolysis to a more cationic form, lipase II, which has a lower mol wt (32,000) and no carbohydrate. Rhizopus lipase shows the same positional specificity on long chain triglycerides as pancreatic lipase; it has no preferential side chain specificity against oleic vs. palmitic acid. Like pancreatic lipase, Rhizopus lipase acts on micelles of short chain triglycerides and is inhibited by high concentrations of bile acids; however, in the presence of deoxycholate, Rhizopus lipase does not require added Ca ++ for full activity.