Nutrient-Enhanced Production of Remarkably High Concentrations of Ethanol by Saccharomyces bayanus through Soy Flour Supplementation.

The supplementation of a simple medium with soy flour led to an increase in the specific growth rate and viable cell concentration of Saccharomyces bayanus during fermentation. Increasing the amount of soy flour led to an increase in the maximum number of viable yeast cells and the percentage of glucose fermented. It was possible in 64 h to reach 12.8% (wt/vol) ethanol by adding 4% soy flour (wt/vol) to a simple medium with 300 g of glucose per liter. The aqueous extract from soy flour was nearly as effective as whole-soy flour, whereas the lipidic fraction had no positive effect.