| 摘要 |
PURPOSE:To provide the titled mutant belonging to Bifidobacterium longum, having high hydrogen peroxide resistance, and capable of keeping the number of bifidus cells even in the storage of a food under aerobic condition or acidic condition. CONSTITUTION:Bifidobacterium longum ATCC-15708 is applied to a blood liver agar (BL agar) plate or Brigg's liver agar plate, irradiated with ultraviolet radiation to an extent to give a survival rate of <=0.1%, and cultured at 37 deg.C for 48hr under anaerobic condition. The strain is streaked to a BL agar plate, cultured under anaerobic condition, subjected to pure culture, and sub-cultured for several generations. A strain resistant to H2O2 having high concentration as far as possible is selected by the H2O2 resistant test. A number of H2O2 resistant strains were sub-cultured for 10 generations, and a strain [Bifidobacterium longum No.1022 (FERM-P No.8033)] having H2O2 resistance and high stability was separated. The strain has improved oxygen resistance and acid resistance. |
