A yellowish or clear, syrupy organic acid, CH3CHOHCOOH, produced by the fermentation of lactose when milk sours or from sucrose and some other carbohydrates by the action of certain microorganisms: used in tanning leather, as a preservative, in the formation of plasticizers, etc.
Webster's New World
Lactic Acid Sentence Examples
Lister for isolating a pure culture of lactic acid bacterium.
The Bacterium acidi lacti described by Pasteur decomposes milk sugar into lactic acid.
Glucose also undergoes fermentation into lactic acid in the presence of the lactic acid bacillus, and into butyric acid if the action of the preceding ferment be continued, or by other bacilli.
Massart and Bordet, Leber, Metchnikoff and others have studied the phenomenon in leucocytes, with the result that while there is evidence of their being positively chemiotactic to the toxins of many pathogenic microbes, it is also apparent that they are negatively influenced by such substances as lactic acid.
It is difficultly fermented by yeast, but readily by the lactic acid bacillus.