A method for producing bacteria belonging to the genusBifidobacteriumhaving excellent viability even under various conditions with different environmental factors, novel bacteria belonging to the genusBifidobacteriumobtained by the method, and a method for detecting the bacteria are provided. By subculturing and storing bacteria belonging to the genusBifidobacteriumalternately in systems under conditions with different environmental factors, the bacteria belonging to the genusBifidobacteriumexhibiting excellent viability under all the conditions used for the alternate subculturing and storing can be produced.本發明提供一種即便於環境因素不同之條件下存活性仍優異之雙叉桿菌屬細菌之製作方法、藉由本製作方法而獲得之新穎雙叉桿菌屬細菌、及該細菌之檢測方法。本發明藉由在將環境因素設為不同條件之系統中交替進行繼代培養保存，而製作交替繼代培養保存中所使用之所有條件下之存活性優異之雙叉桿菌屬細菌。
