Utilization of spent brewer's yeast for supplementation of distillery corn mashes

The aim of the study was to use spent brewer's yeast biomass (SBY) as a nutrient adjunct of distillery type corn mashes to improve the process of ethanol fermentation by yeast Saccharomyces cerevisiae. There were prepared corn mashes with raw material loading at 20% ww. with SBY addition at solids loadings of 0 (control); 0.1; 0.5; 0.7; 1.0; 3.0 and 5.0% ww. The obtained mashes were inoculated with yeast and subjected to batch fermentation for 72 h. It was observed that supplementation of corn mashes with SBY improved the process of fermentation. The consumption of sugars and production of ethanol by yeast in supplemented mashes was accelerated and the overall ethanol yield was improved by 6.5 to 11% depending on the amount of added SBY. It was also observed that the fermentation could be shortened by 24 h in mashes enriched with SBY.