|Murry, A. - UGA|
|Hinton, Jr, Arthur|
|Morrison Iii, Wiley|
Submitted to: International Journal of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2004
Publication Date: September 16, 2004
Citation: Murry, A.C., Hinton Jr, A., Morrison Iii, W.H. 2004. Inhibition of growth of escherichia coli, salmonella typhimurium, and clostridia perfringens on chicken feed media by lactobacillus salivarius and lactobacillus plantarum. International Journal of Poultry Science. Interpretive Summary: Beneficial bacteria may be added to chicken feed to reduce the number of harmful bacteria in the digestive tract of poultry. Several mechanisms have been proposed to explain how beneficial bacteria inhibit the growth of harmful bacteria. In this experiment, 2 lactic acid producing bacteria were isolated from a mixture of beneficial bacteria that can be fed to chickens. The ability of these bacteria to inhibit the growth of three bacteria that can be spread by chicken feces was determined. Both lactic acid bacteria were grown for 2 days on a bacteriological media made from feed. Growth of the lactic bacteria was covered with fresh media, and the 3 fecal bacteria were added to separate plates containing the lactic bacteria. Plates were incubated for 1 day, and then observed for zones of inhibition of the growth of fecal bacteria around the area where the lactic bacteria had grown. Results indicated that the lactic bacteria inhibited growth of the fecal bacteria. Analysis of media inoculated with the lactic bacteria indicated that these bacteria produced high amounts of acid in the media. These acids have been associated with inhibition of the growth of other bacteria. Findings indicate that mixtures of beneficial bacteria containing these 2 lactic bacteria may be useful in reducing the number of undesirable fecal bacteria in chickens.
Technical Abstract: The two predominant strains of lactobacilli isolated from a botanical probiotic were identified and evaluated to determine their ability to inhibit the in vitro growth of Escherichia coli, Salmonella typhimurium, and Clostridium perfringens on a medium that simulated a normal starter and grower diet for broiler chickens. The two strains identified were Lactobacillus salivarius and Lactobacillus plantarum. In the inhibition assay in vitro, both strains of Lactobacillus from the probiotic produced significant (P < 0.001) inhibition of the growth of E. coli, S. typhimurium, and C. perfringens on agar media prepared using starter or grower broiler feed. Both strains of Lactobacillus produced significant (P < 0.001) concentrations of acetic and lactic acid and caused significant (P < 0.001) reductions in the pH of the media when cultured in bacteriological media prepared from starter and grower broiler feed. These results indicate that L. salivarius and L. plantarum contained in the botanical probiotic can ferment carbohydrates in poultry feed to produce pH levels and concentrations of lactic and acetic acid that inhibit the growth of E. coli, S. typhimurium, and C. perfringens in vitro.