Optimization of carotenoid production by Rhodotorula glutinis using statistical experimental design

A two-step optimization strategy of statistical experimental design was employed to enhance carotenoid production from sugar cane molasses (SCM) in the yeast Rhodotorula glutinis. In the first step, a fractional factorial design was used to evaluate the impact of five fermentation factors (pH and concentrations of SCM, urea, KH2PO4, and NaCl). The results revealed that three factors (concentrations of SCM, urea, and KH2PO4) had a significant influence on biomass and carotenoid production. A face-centered central composite design was then used in the second step to optimize the three significant factors to further enhance the biomass yield and carotenoid production. Through this two-step optimization strategy, the carotenoid concentration could be increased from an average of 1.39 mg/l to an average of 3.46 mg/l, representing a 2.5-fold carotenoid production enhancement.