MIZKAN HOLDINGS CO LTD;株式会社Ｍｉｚｋａｎ Ｈｏｌｄｉｎｇｓ;株式会社Mizkan Holdings
发明人:
ISHIKAWA ATSUSHI,石川 篤志
申请号：
JP2017036652
公开号：
JP2018139550A
申请日:
2017.02.28
申请国别(地区):
JP
年份:
2018
代理人:
摘要：
PROBLEM TO BE SOLVED: To provide a temperature sensitive strain of Bacillus natto (Bacillus subtilis var. natto) that has a spore forming ability in a temperature zone used for liquid culture to obtain a starter for inoculation, but has a lower spore forming ability in a temperature zone used for natto fermentation, and to provide a natto product with a low spore content.SOLUTION: The invention provides a variant of Bacillus natto (Bacillus subtilis var. natto) having the following properties (A) to (C), that is, (A) when the variant is cultured for 48 hours on a solid selection medium supplemented with biotin at a gas phase temperature of 49°C, the color specification of a single colony formed is such that an area having yellow hue, brightness of 9 or more, and chroma not more than 2 in the Munsell color system is not more than 20% of the total surface area of the single colony； (B) a property to form spores at a level of 1×10spores/ml or more when cultured in a spore formation medium at a temperature of 37°C； and (C) a property to produce a natto with excellent stringiness, specific natto flavor, and a spore number not more than 5×10/g natto when cooked or steamed soybean is inoculated with the variant Bacillus natto at a concentration of 5×10spores/g cooked or steamed soybean and kept at a temperature of 40-53°C.SELECTED DRAWING: Figure 2【課題】植菌用の納豆菌スターター取得のための液体培養での温度帯では胞子形成能を有するが、納豆発酵での温度帯では胞子形成能の低下した温度感受性の納豆菌、及び納豆菌胞子の含有量が少ない納豆の提供。【解決手段】(Ａ)ビオチンを含有する選択固体培地において、気相温度４９℃で４８時間培養して生育した納豆菌変異株のシングルコロニーの表色が、シングルコロニーの表面の全面積を１００％としたときに、マンセル表色系の色相が黄系、明度が９以上、彩度が２以下である領域の面積が２０％以下、(Ｂ)胞子形成培地で３７℃で培養した際に胞子数が１×１０７個／ｍｌ以上、（Ｃ）煮大豆又は蒸煮大豆に１ｇあたり納豆菌胞子数５×１０３個となるように植菌し、豆の品温を４０～５３℃の範囲に維持した際に、糸引き、納豆特有の香りが良好で、且つ納豆１ｇあたり納豆菌胞子数が５×１０５個以下の納豆を製造できる性質、である納豆菌変異株。【選択図】図２
