8-36: Physiological effects on two strains of Saccharomyces cerevisiae during fermentation of lignocellulosic material

Improved cell viability contributes to a sustained high ethanol production rate. Adaptation of the fermenting organism, to a lignocellulosic fermentation media, has previously shown to improve cell viability in fermentations of woody material. In the present investigation, physiological effects in two strain of Saccharomyces cerevisiae fermenting two different lignocellulosic materials were analysed with respect to fermentation capacity and energy balance. The two substrate used were spruce hydrolysate produced with a dilute acid technique and, spent sulphite liquor derived from a sulphite mill, producing Special Cellulose. The two yeast strains used were an industrially harvested Saccharomyces cerevisiae and a Saccharomyces cerevisiae strain (Thermosacc) specially selected to withstand the stress related to fermentation. Nutritional supplementation to the fermentation proved to have a significant impact on the fermentation capacity although the two lignocellulosic materials tested indicated physiological differences between the two strains tested.