J. Ramirez et al., Optimization of astaxanthin production by Phaffia rhodozyma through factorial design and response surface methodology, J BIOTECH, 88(3), 2001, pp. 259-268
Sequential methodology based on the application of three types of experimen
tal designs was used to optimize the astaxanthin production of the mutant s
train 25-2 of Phaffia rhodozyma in shake flask cultures. The first design e
mployed was a factorial design 2(5), where the factors studied were: pH, te
mperature, percent of inoculum, carbon and nitrogen concentrations, each on
e at two levels. This design was performed in two medium types: rich YM med
ium and minimal medium, based on date juice (Yucca medium). With this first
design the most important factors were determined (carbon concentration an
d temperature) that were used in the second experimental strategy: the meth
od of steepest ascent was applied in order to rapidly approach the optimum.
Finally, a second-order response surface design was applied using temperat
ure and carbon concentration as factors. The optimal conditions stimulating
the highest astaxanthin production were: 19.7 degreesC temperature; 11.25
g l(-1) carbon concentration; 6.0 pH; 5% inoculum and 0.5 g l(-1) nitrogen
concentration. Under these conditions the astaxanthin production was 8100 m
ug l(-1), 92% higher than the production under the initial conditions. (C)
2001 Elsevier Science B.V. All rights reserved.