Optimization of lipase production by Candida cylindracea in palm oil mill effluent based medium using statistical experimental design

Sequential optimization strategy based on statistical experimental design including one-factor-at-a-time (OFAT) method was used to enhance the production of lipase by Candida cylindracea ATCC 14830 using palm oil mill effluent as a basal medium in shake flask cultures. The two-level Plackett-Burman (PB) design was implemented to screen the medium components that significantly influence the production. Following the OFAT method, three significant components influencing lipase production were identified as peptone, Tween-80 and inoculum. The optimum values of these three components were determined by response surface methodology (RSM) based on the face-centered central composite design (FCCCD). The validity of the model developed was verified, and the optimum medium containing 0.45% (w/v) peptone, 0.65% (v/v) Tween-80 and 2.2% (v/v) inoculum led to a maximum lipase production of 20.26 U/ml, which was 5.19-fold higher than the unoptimized medium. The analysis of variance indicated that the established model was significant (P < 0.05). This study innovatively developed a fermentation medium utilizing renewable palm oil mill effluent (POME) to produce lipase at considerable level. © 2010 Elsevier B.V.