Control of spoilage yeasts in fuel ethanol production

Summary A selective process has been developed to control contaminant wild yeasts in industrial ethanol production. A genetically improved yeast resistant to nystatin is essential and the economic use of this antibiotic is described. The process strain starts at the stage of pure culture development and if necessary, after cycles of continuous cultures or fed batches, with no need of special equipment or operational process modifications. The principle can be adopted in other fermentations.