Grape skins as a natural support for yeast immobilization

Grape skins were used to immobilize Saccharomyces cerevisiae. In repeated batch fermentations of grape by immobilized and free cells, the maximum specific rate of alcohol production on glucose decreased from 7.98 h−1 at 25 °C to 0.7 h−1 at 5 °C. The rate was approximately twice as high as that on fructose. The rates for free cells were very low. The maximum alcohol yield (0.45 g g−1) was obtained at 5 °C when the immobilized biocatalyst was used.