الفهرس 
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Abstract
The present work led to a number of conclusions, which could be summarized as follows:
A novel mixed substrates from fatty acids residues, soapstock and olive oil were assessed, and the maximum activity was 10 U/ml at 30 oC with aeration rate value of 0.5 vvm and agitation rate of 200 rpm. Consequently they are evaluated as substitute to the olive oil in the function of lipase inducers.
The produced enzyme was directly used in sun flower oil hydrolysis, and the maximum conversion was 39.5 % after 24 h.
The maximum activity of lipase (12 U/ml) was obtained by using 0.5% w/v of olive oil.
Lipase activity obtained by using soapstock was higher than that produced by using fatty acids residues.
Lipase yield obtained by using the mixed substrate was higher than the yield obtained using soapstock and fatty acids residues individually.
The optimum concentration of each soapstock and fatty acids residues as a substrate in the submerged fermentation reaction was 1% (w/v).
Mechanical stirring is recommended to reduce the optimum fermentation time (at the maximum lipase activity) compared to magnetic stirring.
The highest cell mass was obtained from the fermentation of olive oil as a substrate.
In enzymatic oil hydrolysis, the enzyme was active in the first 24h, after that the activity of enzyme dropped to be zero.
The kinetics analysis for oil hydrolysis by lipase produced from the fermentation of 0.5% mixed substrate was determined from Lineweaver-Burk, Hanes and Eadie-Hofstee plots after plotting the Michaelis–Menten model.
The kinetic parameter km were 225.1, 184.7 and 193mg/mL for Lienweaver, Burk, Eadie Hofstee and Hanes plots, respectively. The kinetic parameter V_max was 18.39, 16.18 and 16.62 µmol fatty acids / mL/ min for Lienweaver Burk, Eadie Hofstee and Hanes plots, respectively.
The kinetics calculation for enzyme production from the fermentation of 0.5% mixed substrate,showed that, the specific growth rateμ_g was 0.01 h-1,the specific production rateK_pwas 0.012 h-1 and the specific degradation rate K was 0.051 h.