Isolation of Enterococcus faecium with Antibacterial Activity and Characterization of Its Bacteriocin

Abstract

Enterococcus faecium-100, screened from 120 strains of lactic acid bacteria, produced an antibacterial substance. From the narrow inhibitory spectrum, proteineous nature, and bactericidal mode of action, this antibacterial substance was concluded to be a bacteriocin and designated enterocin-100. E. faecium-100 produced bacteriocin during its log phase and in a narrow pH range of the culture broth around pH 6.3. Enterocin-100 was most active at neutral pH between 6 and 8, and was stable below pH 5.0. From the scanning electron microscopic observation, enterocin-100 caused morphorogical changes especially in highly sensitive bacteria at log and stationary phase.