First, cornstarch or another polymer of glucose is broken down into single sugar (glucose) molecules by enzymes, then yeast ferments the glucose into ethanol and carbon dioxide.

• 不但如此，这些基改酵母菌，也间接的提高了生产乙醇的效能，相较于一般的酵母菌，其生产乙醇的效能整整提高了50%25以上。