ASTAXANTHIN PRODUCTION BY A PHAFFIA-RHODOZYMA MUTANT ON GRAPE JUICE

During fermenter cultivation of Phaffia rhodozyma on a grape juice med ium, the presence of glucose initially delayed fructose utilization, a lthough fructose was consumed before glucose depletion. Total pigment and astaxanthin production were growth associated and reached maximum values of 15.9 mug/ml and 9.8 mug/ml, respectively, after depletion of the carbon source. The total cellular pigment and astaxanthin content increased during the stationary growth phase due to a decrease in bio mass, reaching final values of 2120 mug/g and 1350 mug/g, respectively , without the volumetric concentration in the culture changing. The fi nal cell yield was 0.33 g/g sugar utilized. High sugar concentrations in shake-flasks as well as O2 limitation decreased the astaxanthin con tent of the cells. Addition of yeast extract to a grape juice minimal medium markedly increased the maximum specific growth rate, total pigm ent and astaxanthin content of the cells. An excess of ammonia decreas ed the intracellular astaxanthin content, which reached a maximal valu e in cultures with no residual glucose or ammonia.