LIPASE PRODUCTION BY PENICILLIUM-RESTRICTUM IN A BENCH-SCALE FERMENTER - EFFECT OF CARBON AND NITROGEN NUTRITION, AGITATION, AND AERATION

A preliminary screening work selected Penicillium restrictum as a prom ising micro-organism for lipase production. The physiological response of the fungus towards cell growth and enzyme production upon variable carbon and nitrogen nutrition, specific air flow rate (Qa) and agitat ion (N) was evaluated in a 5-L bench-scale fermenter. In optimized con ditions for lipase production meat peptone at 2% (w/v) and olive oil a t 1% (w/v) were used in a growth medium with a C/N ratio of 9.9. Highe r C/N ratios favored cell. growth in detriment of enzyme production. L ow extracellular lipase activities were observed using glucose as carb on source suggesting glucose regulation. Final lipase accumulation of 13,000 U/L was obtained, using optimized specific air flow rate (Qa) o f 0.5 vvm and an impeller speed (N) of 200 rpm. Agitation showed to be an important parameter to ensure nutrient availability in a growth me dium having olive oil as carbon source.