Now, there are many different examples of fermentation processes. But the most common fermentation processes are those that produce lactate or ethanol from the pyruvate molecules. So these are known as ethanol fermentation or alcoholic fermentation or in the case of producing lactate which is actually the conjugate base of lactic acid. This is known as lactic acid fermentation. So let's focus on ethanol fermentation. So basically, yeast cells and several other bacterial cells utilize this process of fermentation.