Other bacteria tested in this study were B.
subtilis (natto) ATCC 7058, B. subtilis (natto) ATCC 7059, B. subtilis
(natto) IFO 13169, B. subtilis (natto) IFO 3335, which were obtained
from the Culture Collection and Research Center (CCRC) Taiwan.
Reagents for cultivation such as nutrient agar (NA) and nutrient
broth (NB) were purchased from DIFCO Laboratories Michigan, USA