In contrast, thua nao production is still practiced
locally with little information regarding microbial
population and fermentation process. Our aim was
to examine the microorganisms responsible for such
fermentation. In this study, several B. subtilis isolates
were screened from thua nao and investigated for
their proteolytic activity. It was found that B. subtilis
strain 38 showed the highest protease activity. Some
fundamental characteristics of the proteases were
also determined. In addition, we attempted to develop
a laboratory scale process for making fermented
soybeans using B. subtilis strain 38 as a pure starter
culture