The mature lipase of the fungus Rhizopus oryzae (ROL) was functionally expressed and secreted in the methylotrophic yeast Pichia pastoris. In a batch cultivation, where methanol feeding was linked to the dissolved oxygen content in the cultivation solution, a lipase activity of 500,000 units per liter (60 mg active lipase per liter) of culture was achieved after initial glycerol feeding of the culture. Recombinant ROL lipase was purified to homogeneity by a simple two-step purification procedure and had a specific activity of 8571 U mg-1 (triolein, 30 degrees C, pH 8.1) which is comparable with the purified native enzyme. The properties of the recombinant lipase were similar to those reported both for the native lipase and for the enzyme expressed in Escherichia coli and refolded from inactive inclusion bodies.