Selection of Carrier for Dried Bacillus natto

Preparation of a dried Bacillus natto product was studied. The carrier material, mixing ratio, and drying temperature for the making were evaluated according to the survival rate of B. natto in the dried product. The optimal process was determined to be stirring the bacterial solution with quartz monzonite as the adsorbent carrier in a mixing ratio of 1:1 at 150 r·min^-1 and 37℃ for 60 min in a container prior to dehydration at 40℃. The dried product had a bacterial count of 1.09×10⁹ CFU·g^-1. After 6-month storage at 25℃, the count decreased by 20.2% to 2.9×10⁸ CFU·g^-1. Inclusion of wheat bran, soymeal and/or corn meal in the mix would provide nutrients for B. natto resulting in aprolonged shelf life of the dried product.