Thua-nao was fermented with 5% (v/w)
pure inoculum of Bacillus sp. B4 or Klebsiella
sp.KB2. Figure1 showed that the vitamin B12
content of Thua-nao fermented with pure culture
of Klebsiella sp.KB2 was 10.15 mg/100gdw at 36
h and no vitamin B12 was detected from Bacillus
sp. B4 fermentation. Even though monoculture of
Bacillus sp. B4 was unable to produce vitamin B12
in the product, the Bacillus sp. B4 reached a
population of 5.8¥1010cell/gdw within 36 h
incubation earlier than Klebsiella sp. KB2 which
reached its maximum growth at 2.1¥1010cell/gdw
after 48 h incubation. Thua-nao fermented with
Bacillus sp. B4 showed high proteolytic activity
826.40 units/gdw and good characteristics in the
release of soluble protein when compared
withsoybean fermented by Klebsiella sp. KB2.