Screenings of Antibiotic Substance F 16-2-Resistant Mutants of Lactobacillus sake and Saccharomyces sake Kyokai No. 7

Abstract

Antibiotic substance F 16-2 was produced by Bacillus subtilis 16-2 isolated from rice-koji in sake breweries. The F 16-2 inhibited the growth of Lactobacillus sake and Saccharomyces sake. In the classic moto, kimoto, infected with F 16-2, acid formation by L. sake and growth of S. sake were significantly depressed. In the moromi sake mash infected with F 16-2, fermentation was suppressed and ceased at an alcohol concentration of 12 to 13%. F 16-2-resistant mutants of L. sake and S. sake were isolated as natural mutants from their respective cultures. A F 16-2-resistant mutant No. 7-2, selected from the culture of S. sake Kyokai No. 7, showed the same property with that of the parent. Even in sake mash infected with F 16-2, mutant No. 7-2 indicated normal growth, and fermentation proceeded to an alcohol concentration of 20%.