Development of Lactobacillus casei Resistant to Rifampicin, an Antituberculosis Agent

항 결핵제, 리팜피신에 내성인 유산균의 개발

Lactobacillus casei was treated with N-methyl-N'-nitro-N-nitrosoguanidine(NTG) to obtain resistant mutants to rifampicin. Freshly grown cells of the strain suspended in tris-maleic acid buffer were exposed to NTG of $50{\mu}g/ml$ for 30min. Five colonies of the NTG-induced mutants showed distinct resistance to rifampicin. They also exhibited identical characteristics with the original Lactobacillus casei when they were tested for growth, titrable acidity and sugar fermentation. It is suggested that they can be utilized as efficieient starter cultures for fermented milk.