Antibacterial Activity of Lactobacillus acidophilus in MRS Broth and Skim Milk

摘要

The production of antibacterial activity of Lactobacillus acidophilus strains 1899, 111, 1748 and LAR in milk and MRS broth was studied against Escherichia coli, Staphylococcus aureus and Salmonella paratyphi using the agar diffusion technique. All the four stains of Lactobacillus acidophilus produced highest activity in MRS broth. In milk, the only strain of Lactobacillus acidophilus that produced antibacterial activity was LAR, while the remaining strains failed to produce any activity. Addition ofsodium acetate with peptone and yeast extract into milk caused the remaining three strains also to produce antibacterial activity. The antibacterial activity present in milk and broth culture filtrates remained stable when they were heated in the temperature range 60° to 121°C for 10 minutes.'