抄録
Cultures of bakers' yeast, Rhodotorula flava (Saito) Lodder No. 0407,R. rubra (Demme) Lodder No. 0382,or Neurospora crassa incubated hours 48 hours with 10-20mg% dihydrothiamine showed destruction of dihydrothiamine to the extent of 90-100%, and formation of thiamine to 4-10%. The similar destruction of dihydrothiamine and formation of thiamine were observed with an extract of boiled bakers' yeast. Dihydrothiamine was readily decomposed in contact with the cultures of these microorganisms and formation of thiamine from it was not enzymatic ; it was a mere oxidation of dihydrothiamine by aeration or dissolved oxygen.
