| Abstract: | The potential of peat hydrolysates for the production of astaxanthin from Phaffia rhodozyma yeast biomass in continuous fermentation was studied. Chemostat fermentations of the yeast were performed using peat hydrolysates as substrate. Kinetic parameters were calculated for the growth of the yeast and the biomass productivity was determined using mathematical models. A low maximum specific growth rate (μmax=0·08 h−1) and a high Monod constant (Ks=26·2×103) were obtained for this substrate. The low maintenance energy requirement found, 0·020 g (gh)−1, confirms the aerobic metabolism of the yeast with this substrate. Under selected conditions, a biomass productivity of 0·108 g (lh)−1 and an astaxanthin productivity of 0·046 mg (lh)−1 were obtained. The biomass produced had a high protein and astaxanthin content (490±8 g kg−1 and 0.43±0.07 g kg−1, respectively), indicating that it can be used as a feed additive. © 1998 SCI. |
