What is the difference between Homolactic and Heterolactic Fermentation?

Homolactic and heterolactic fermentations are two types of microbial metabolic processes that occur in different organisms and produce different end products. Here's the difference between the two:

Homolactic Fermentation:

Definition: Homolactic fermentation is a type of fermentation where microorganisms, such as certain species of bacteria, convert glucose or other sugars into lactic acid.
Microorganisms involved: Examples of bacteria that undergo homolactic fermentation include Lactobacillus species and Streptococcus species.
End product: The main end product of homolactic fermentation is lactic acid. This process is characterized by the conversion of glucose into two molecules of lactic acid through the metabolic pathway known as Embden-Meyerhof-Parnas (EMP) pathway. No other byproducts, such as carbon dioxide or ethanol, are produced.
Heterolactic Fermentation:

Definition: Heterolactic fermentation is a type of fermentation where microorganisms, such as certain species of bacteria and yeasts, convert sugars into a combination of lactic acid, ethanol, carbon dioxide, and/or other metabolic products.
Microorganisms involved: Examples of bacteria that can perform heterolactic fermentation include some species of Lactobacillus, Leuconostoc, and Enterococcus. Some yeast species, such as Candida milleri, can also undergo heterolactic fermentation.
End products: Unlike homolactic fermentation, heterolactic fermentation produces a mixture of products. The primary end products include lactic acid, ethanol, and carbon dioxide. The fermentation pathway involves the conversion of glucose into lactic acid, carbon dioxide, and ethanol, with lactic acid being the major end product.
In summary, the key difference between homolactic and heterolactic fermentation lies in the end products produced. Homolactic fermentation produces lactic acid exclusively, while heterolactic fermentation results in a combination of lactic acid, ethanol, carbon dioxide, and possibly other metabolites.