Strategies in lipase production by immobilized Candida rugosa cells

Growing cells of Candida rugosa immobilized in polymethacrylamide-hydrazide and polyurethane foam were employed in fluidized and packed bed reactors, for discontinuous and continuous fermentations to obtain extracellular lipase. In spite of hydrodynamic problems, fermentation cultures using polyurethane foam showed higher lipolytic activity than cultures employing polymethacrylamide-hydrazide beads, which was probably owing to the high immobilized biomass concentration in polyurethane observed by direct microscopy enumeration. Different oleic acid concentrations were assayed. The maximum level of lipase was achieved at 4 g/L of oleic acid. These results reaffirm that lipase production is a direct function of cell-substrate contact and that the organic substrate dispersion is important in this system.