A method for producing bacteria belonging to thegenus Bifidobacterium having excellent viability evenunder various conditions with different environmentalfactors, novel bacteria belonging to the genusBifidobacterium obtained by the method, and a method fordetecting the bacteria are provided. By subculturing andstoring bacteria belonging to the genus Bifidobacteriumalternately in systems under conditions with differentenvironmental factors, the bacteria belonging to thegenus Bifidobacterium exhibiting excellent viabilityunder all the conditions used for the alternatesubculturing and storing can be produced.
