Acid Production and Tolerance of Lactobacilli from Dental Caries and other Sources as Measured by the Glass Electrode

Publisher Website
Google Scholar
Abstract
19 strains of lactobacilli, including human dental and intestinal forms and strains from normal rat mouths, were tested for acid production limits in a 2% glucose, dilute (1-6) veal broth, titrated to pH 2.8-6.6, and for acid tolerance in a stock veal broth titrated to pH 2.2-4.8. All pH determinations were made with a glass electrode-vacuum tube potentiometer. Results indicate that the most strongly acidogenic lactobacilli, including members from dental and intestinal groups, are able to attain a pH slightly above 3 as the initial pH of the medium is progressively reduced; the weakest strains, including chiefly rat forms, do not reduce the pH of the medium below 4. and are in this respect similar to Bacterium coli and Staphylococcus aureus. A correlation between growth strength and acid production is indicated. Tests for acid-tolerance limits, thus far incomplete, indicate that this property parallels acid production for a given strain.

This publication has 8 references indexed in Scilit: