... sticky liquid, no smell, slightly taste sour, wet admittance Lactic acid (IUPAC systematic name: 2-hydroxypropanoic acid), also known ... the other, its mirror image, is D-(-)-lactic acid or (R)-lactic acid. L-(+)-Lactic acid is the biologically important isomer. In ... to over 20 mmol/L during intense exertion. Industrially, lactic acid fermentation is performed by Lactobacillus bacteria, among others. ...