Growth kinetics and astaxanthin production of Phaffia rhodozyma on glycerol as a carbon source during batch fermentation

Glycerol was studied as a substrate for astaxanthin by Phaffia rhodozyma PR 190. With co-utilisation of yeast extract and peptone, the maximum specifi c growth rate was 0.24 +/- 0.02 h(-1). Astaxanthin percentage in total pigm ent is constant (0.78 mg/g) and its yield from glycerol is always 0.97 mg/g . The yield of biomass from glycerol alone is 0.50 +/- 0.02 g/g. The specif ic rate of astaxanthin production versus the cell growth rate reached a max imum for an optimal specific growth rate of 0.075 h(-1). For this optimal v alue, the maximum specific astaxanthin production rate is 0.09 +/- 0.01 mg/ g.h. The best astaxanthin results were : 33.7 mg/l, 10.2 mg/l.h and 1.8 mg/ g yeast after a fermentation term of 168 hours. Our results suggest a strat egy of astaxanthin production in fed batch culture or chemostat at a growth rate of 0.075 h(-1).