Difference Between Alcohol and Lactic Acid Fermentation

What is Alcohol Fermentation?

Sugar is transformed into ethyl alcohol and carbon dioxide during alcohol fermentation. However, glucose is first converted to pyruvic acid, a process known as glycolysis, and then to ethanol and carbon dioxide, a process known as fermentation. This method is used by alcoholic beverage and bread makers.

Yeasts carry out alcohol fermentation, and oxygen is not required for this process to take place. Ethanol fermentation is another name for alcohol fermentation. An interesting fact is that alcohol fermentation occurs along with lactic acid fermentation in some types of fish and provides energy to them when there is no oxygen.

Alcohol fermentation makes ethanol fuel, alcoholic beverages like wine and beer, and bread dough rise. During alcohol production, yeast such as Saccharomyces cerevisiae and Schizosaccharomyces are utilized. In the absence of oxygen, alcohol fermentation occurs in the cytoplasm of yeasts.

What is Lactic Acid Fermentation?

Animals and certain types of bacteria use this sort of fermentation. Lactic acid bacteria are essential in preserving and producing a wide range of foods. Lactic acid fermentation is a low-cost process. Lactic acid fermentation is an anaerobic respiration process carried out by lactobacillus and other bacteria. In anaerobic conditions, it creates ATP.

Lactic acid fermentation can take place in our muscle cells as well. When we engage in strenuous activity or run a marathon, our bodies manufacture lactic acid through lactic acid fermentation. As fermentation progresses, we experience muscle tiredness and soreness as lactic acid accumulates in muscle cells. This is because, during strenuous activity, our respiratory and cardiovascular systems cannot carry oxygen to the muscle cells. As a result, lactic acid fermentation occurs to allow the continued generation of ATP.

Lactic acid is a byproduct of lactic acid fermentation. The fermentation of lactic acid is also used to make yogurt and cheese.

Difference Between Alcohol and Lactic Acid Fermentation

  1. Glucose is transformed into ethanol and carbon dioxide during alcohol fermentation, but glucose is converted to lactic acid during lactic acid fermentation.
  2. Alcohol fermentation happens in yeasts and microorganisms, while, Lactic acid fermentation happens in muscle cells, yeasts, and some bacteria.
  3. Wine, beer, and bread dough are all made by alcohol fermentation, but yogurt and cheese are made through lactic acid fermentation.
  4. Lactobacillus is the most frequent microbe in alcohol fermentation, while yeast is the most common bacterium in lactic acid fermentation.
  5. Alcohol fermentation enzymes include pyruvate decarboxylase and alcohol dehydrogenase, while lactic acid fermentation enzymes include lactate dehydrogenase.

Comparison Between Alcohol and Lactic Acid Fermentation

Parameters of ComparisonAlcohol FermentationLactic acid Fermentation
Products Glucose is transformed into ethanol and carbon dioxide during alcohol fermentation.Glucose is transformed into lactate and cellular energy during lactic acid fermentation.
Use The fermentation of alcohol is utilized in producing bread, wine, and beer.Yogurt and cheese are both made via lactic acid fermentation.
Enzymes In alcohol fermentation, two enzymes are involved: pyruvate decarboxylase and alcohol dehydrogenase.Lactate dehydrogenase and pyruvate decarboxylase are the enzymes involved in this type of fermentation.
OccurrenceYeast and other microbes undergo alcoholic fermentation.Lactic acid fermentation occurs in lactobacillus, yeast, and muscle cells.
ProcessGlycolysis, decarboxylation, and reduction are all involved in alcohol fermentation.Hydrolysis, glycolysis, and reduction are all involved in lactic acid fermentation.


  1. https://scielo.conicyt.cl/scielo.php?pid=S0717-34582004000200008&script=sci_arttext&tlng=e
  2. https://onlinelibrary.wiley.com/doi/abs/10.1002/jctb.449