Lactic acid: an in-depth examination of its characteristics, physiological functions, and the role of lactic acid bacteria in both biological systems and industrial applications
Tim Klein
2026-03-24
4 min. read
29
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Lactic acid, generated both as a byproduct of anaerobic metabolic pathways within the human body—particularly during strenuous physical exertion—and through the fermentative activity of specialized bacterial strains, exhibits a broad range of applications. Its distinctive preservative, pH-modulating, and bioactive properties render it indispensable in the food industry—spanning dairy production to fermented vegetable products—as well as in chemical and pharmaceutical sectors, where it serves as a raw material or functional additive. Yet does its presence within the body confer tangible health benefits, or is it merely a metabolic byproduct without additional physiological value?
Milk acids
From a chemical point of view, lactic acid is a carboxylic acid CH 3 CHOHCOOH. It is a colourless substance. It has a mild, slightly acidic taste and a distinctive odor. It's produced in humans and animals during exercise. When the body is unable to meet tissues' needs for oxygen, it starts drawing energy from oxygen-free breathing as a result of glycolysis.
Bacteria of lactic acid
If they additionally produce other substances such as Bifidobacteriaceae and Bacillales and Lactobacillales from the Firmicutes group, they are a very large group of microorganisms. They are most commonly used by bacteria of the genus Lacto Bacillus, Lactococcus and Streptococcius. Bacteria that produce mainly lactic acid are called homofermentative bacteria. If they also produce other materials such as human acetic acid, human ant and ethanol are also called heterofermentatives.
Milk acid properties
Due to its broad properties, lactic acid is used in the food, pharmaceutical, chemical and cosmetic industries. However, in household products it can partially replace acetic acid, e.g. salt. In the food industry it is used as a food additive E270..