食肉より分離した乳酸球菌が生産するバクテリオシンの抗菌特性

To control the growth of foodborne spoilage bacteria in fermentes meat produncts, 732 strains of lactic acid bacteria were isolated from commercial meats, and their inhibitory activities were investigated by paper disc assay using Staphylococcus aureus IAM 1011 and Listeria monocytogenes VTU 206 as indicator starins. Four starins produced antibacterial substances and one of them showed greater activity against two indicator strains. It was identified as Enterococcus faecium, and it was designed as strain C210. Antibacterial activity was high between the late-logarithmic growth phase and early-stationary growth phase in broth media. Activity in the antibacterial substance was not detectable after treatments with proteolysis enzymes such as pepsin, carboxypeptidase, aminopeptidase, pronase E and proteinase K. The bacteiocin was heat-stable and showed greater antibacterial activity at low pH. The substance showed antibacterial activity against 5 species of lactic acid bacteria in addition to Staphylococcus aureus and Listeria monocytogenes, although it was not active against Gram-negative bacteria. It exhibited bacteriostatic action at pH 4.5, and bactericidal action at pH 6.5 against Listeira monocytogenes as an indicator strain.