ENZYMATIC-HYDROLYSIS OF TRIGLYCERIDES BY RHIZOPUS-DELEMAR IMMOBILIZED ON BIOMASS SUPPORT PARTICLES

The best medium composition for production of intracellular lipase by Rhizopus delemar contained oleic acid and no glucose. The technique of cell immobilization using polyurethane foam biomass support particles was studied as a means of further enhancing intracellular lipase activity. Fungal mycelia were found to strongly adhere to the polyurethane foam matrix during growth to form immobilized cell biocatalysts, which, after cell membrane permeabilization and drying, exhibited a lipase activity 3.3 times greater than that of cells grown in a freely suspended state. Lipase within the immobilized cells showed properties similar to purified extracellular Rhizopus delemar lipase but was more thermostable than the free enzyme. The biocatalyst was used for triglyceride hydrolysis in a continuous stirred-tank reactor. In this format it was found that the degree of hydrolysis of olive oil and the flavor profile of lipolyzed milk fat could be easily controlled.