가금류 생균제 개발을 위한 Lactobacillus fermentum YL-3의 분리 및 생리 특성

This study was per-formed to screen lactic acid bacteria poultry for the probiotic use. Among the previously obtained acid tolerant, 139 strains, 111 strains were selected with MRS medium containing 0.3% oxgall. 34 strains of 111 was re-selected by Gram-staining and acid producing ability. These strains was identified by MIDI Sherlock Microbial Identification System. Among the identified 34 strains Lactobacillus fermenum YL-3 was selected for the final pro-biotic use because of the good growth and high survival rate at pH 2.0. 60%, 50% and 40% cells of Lactobacillus fermentum YL-3 survived at pH 3.0, 2.5 and 2.0, respectively. More than $10^{7}$ / CFU/ml survived when exposed with the number of $10^{8}$ CFU/ml at pH 2.0 after 12 hr. L.fermenum YL-3 maintained growth in MRS broth containing 0.3, 0.5, 1.0 and 2.0% oxgall for 24 hr. L.fermenum YL-3 showed an inhibitory effect against pathogenic strains of Sal. enteritidis and E. coli O157:H7. In mixed culture with L.fermenum YL-3 Sal. enteritidis lost ability com-pletely in 15 hrs and E. coil O157:H7 in 16 hrs.