Evaluation of Lactic Acid As an Antibacterial Agent.

Fifty strains each of Staphylococcus aureus, beta haemolytic Streptococci, Proteus species, Esch coli and Pseudomonas aeruginosa were subjected to 2%, 1 % and 0. 1 % lactic acid in peptorie water. Minimum inhibitory concentration of lactic acid for all the strains of each of these organisms was 0.1% or 1%. Depending upon its concentration, lactic acid added to peptone water brings down the PH to 2.5-4 which by itself has some inhibitory effect on the microorganisms. Lactic acid however, retains its inhibitory effect even if the Ph of the peptone water is brought back to 7.3. Lactic acid is a nontoxic and non-sensitizing agent because it is a normal metabolite of the body. Thus, it can be used as a safe and effective antibacterial agent for local application.