Optimization of canthaxanthin production by Dietzia natronolimnaea HS-1 from cheese whey using statistical experimental methods

Sequential methodology combining a screening test by fractional factorial design and an optimization test by central composite design was applied to enhance canthaxanthin production by Dietzia natronolimnaea HS-1 from cheese whey in shake flask cultures. Six variables (pH, luminous intensity, inoculum percent and concentrations of whey lactose, yeast extract and KH2PO4) were studied with the screening test. The results revealed that three factors of pH, concentrations of whey lactose and yeast extract had greater influence on the canthaxanthin production (P < 0.01). The central composite design was then used to determine the maximum canthaxanthin concentration. The optimum conditions for the highest canthaxanthin production (2871 ± 76 μg/l) were pH 7.66, whey lactose concentration 55.54 g/l and yeast extract concentration 7.36 g/l.