Salmonella균과 대장균에 대하여 길항작용을 나타내는 bacillus species의 분리

Isolation of bacillus species displaying antagonistic activity towards salmonella species and escherichia coli

Bacillus spp. displaying antagonistic activity against Salmonella enteritidis, S. typhimurium, S. gallinarum, S. pullorum and Escherichia coli that cause diarrhea and sepsis in animals were isolated. Antagonistic properties of Bacillus spp. towards Salmonella spp. and E. coli were demonstrated by the inhibition zone (mm) around giant colony of spot-overlay co-culture. Of 11 Bacillus species tested, two species, B. circulans and B. subtilis, displayed antagonistic properties. Of 4 strains of B. circulans tested, two strains, HD 7320 and 7321 isolated from soybeans (referred to as B. circulans singokriensis) displayed antagonistic activities towards S. enteritidis (6.4mm/6.0mm), S. gallinarum (11.3mm /11.5mm), S. pullorum (5.5mm /6.0mm) and E. coli (1.6mm/1.8mm) but not towards S. typhimurium. Of 8 strains of B. subtilis examined, five strains displayed antagonistic properties: product I 97806-7 strain displayed antagonistic activity towards S. enteritidis (4.3mm) and S. gallinarum (10.0mm), product K 971202-2 strain towards S. typhimurium (2.0mm), S. gallinarum (10.7mm) and S. pullorum (2.0mm), and product G 971113-4 and product J 971120-4 strains towards S. gallinarum (11.0/6.2mm) and E. coli (1.0mm/1.0mm), and HD 7921 isolated from swine stomach contents towards S. gallinarum, respectively. B. circulans singokriensis HD 7321 would be preferable to B. subtilis for the production of anti-diarrheal feed additive probiotics.