Dm. Freire et al., LIPASE PRODUCTION BY PENICILLIUM-RESTRICTUM IN A BENCH-SCALE FERMENTER - EFFECT OF CARBON AND NITROGEN NUTRITION, AGITATION, AND AERATION, Applied biochemistry and biotechnology, 63-5, 1997, pp. 409-421
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.