Development of a Competitive Exclusion Culture from Local Strains of Lactic Acid Bacteria

Virginia  P. Obsioma,; Edwin  S. Luis,; Marcela  R. Batungbacal,; Ninfa  P. Roxas,; Erlinda  I. Dizon,; Susan  A. Sedano,

Development of a Competitive Exclusion Culture from Local Strains of Lactic Acid Bacteria

Abstract:

Competitive exclusion (CE) culture intended for use as probiotics for animals, consisting of Lactobacillus plantarum 42, L. acidophilus 38 and Lactococcus lactis 66 was developed. The CE culture was prepared by separately growing individual strains in de Man, Rogosa and Sharpe (MRS) broth and then mixing them together in equal proportion. Viability of the lactic acid bacteria (LAB) in the CE culture was evaluated by determining their LAB count in various dilutions of the CE culture every four hours for a period of 20 hours. Mathematical relationship between turbidity of the suspension and LAB count was established through simple regression analysis and the formula derived was used to determine the appropriate turbidity that will provide a load of 109 cells/ml. Results showed no significant (P>0.05) change in the LAB count over a period of 20 hours, indicating that the viability of the organisms remained the same regardless of dilution used. Using the equation derived from the regression analysis, a CE culture with a turbidity value of 8.83% contained about 10⁹ cells/ml.