Patent ID: 11879122
Assignee: MIZKAN HOLDINGS CO., LTD.
Field: Biotechnology (Chemistry)
Classification: CPC C  A  G | IPC A  C

Claim 11:
12. A method of producing natto, comprising the following steps (i) to (iii):
(i) a step of preparing a mutant strain of Bacillus subtilis var. natto strain having the following properties:
a single colony of the mutant strain cultured in a selective solid medium supplemented with biotin at a gas phase temperature of 49° C. for 48 hours has a region having a hue of yellow (Y), a value of 9 or more, and a chroma of 2 or less, as defined by the Munsell Color System, wherein a surface area of the region is 20% or less of a total surface area of the single colony;

(ii) a step of culturing the mutant strain obtained in (i) in a liquid medium for spore formation at a liquid temperature of 37° C. so that a number of mutant strain spores is 1×107 spores/ml or more; and
(iii) a step of fermenting soybeans inoculated with the mutant strain by maintaining a temperature of the soybeans at 40° C. to 53° C., wherein the number of the mutant strain spores after fermenting the soybeans is 5×105 or less spores per gram of the fermented soybeans.