Hydrogen Peroxide Formation by Lactobacilli and Its Effect on Staphylococcus aureus

Abstract

Culture filtrates of Lactobacillus lactis and Lactobacillus bulgaricus were observed to contain material inhibitory against Staphylococcus aureus. The concentration of inhibitor increased on storage of the lactobacilli at 5 C, and the maximum was attained after five days. A carbohydrate source was necessary for the formation of this inhibitory activity by resting cell suspensions. The inhibitory factor was identified as hydrogen peroxide. Storage of lactobacilli in dextrose at neutral pH and at 5 C resulted in maximum accumulation of hydrogen peroxide.