Abstract
Temperature, agitation and aeration as process parameters have significant influence on lipase production by
Candida cylindracea ATCC 14830 in POME-based medium. The maximum lipase production of 41.46
U/ml was obtained through the statistical method, full factorial design in a stirred tank reactor with a significant reduction in fermentation time. The graphical results obtained appear to be promising taking into account that it was attained using a cheaply and available raw material with significant reduction in COD.
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► Full factorial design was used to optimize the production of
Candida cylindracea lipase in POME-based medium. ► Interactions and dependence of the selected process parameters on the lipase production. ► Optimal working conditions for lipase production in 2-L bioreactor were found to be 35
°C, 1.0
vvm and 400
rpm. ► Two-fold increment as well as reduction in fermentation time was observed based on this methodology.
A two-level full factorial design (FFD) was employed to determine the effects of process parameters on lipase production by
Candida cylindracea ATCC 14830 in palm oil mill effluent (POME)-based medium. Ten experimental runs based on three parameters (temperature, agitation and aeration) as indicated by the FFD were carried out in a stirred-tank bioreactor. On statistical analysis of the results, the optimum temperature, aeration and agitation rates were found to be 30
°C, 1.0
vvm and 400
rpm respectively, with a maximum activity of 41.46
U/ml after 36
h of fermentation. Analysis of variance (ANOVA) showed a high coefficient of determination (
R
2) value of 0.999, indicating a satisfactory fit of the model with the experimental data. All the three parameters were statistically significant at
p
<
0.05. The validation experiment also confirmed that apart from lipase production, there was an increase in chemical oxygen demand (COD) removal throughout the fermentation period.