Optimization of conditions and cell feeding procedures for alcohol fermentation

Alcohol fermentation was studied with an emphasis on the separation of cell growth and alcohol production stages. Experiments were conducted to establish the optimal conditions for alcohol production in batch fermentations and to simulate continuous fermentations with cell feeding at various stages. It was found that the glucose concentration should be kept under 10% (w/v), and the temperature should be between 40 and 42.5 degrees C for maximum specific alcohol productivity. If the cell concentration is increased, a decrease in specific alcohol productivity is observed. Higher cell concentrations are needed for higher final alcohol concentrations. Among the cell feeding procedures into alcohol production stages, a cocurrent design was found to be better than recycle and countercurrent designs.