Studies on the Enzymatic Synthesis of Thiamine by Staphylococcus Aureus

Studies on the enzymatic synthesis of thiamine by Staphylococcus aureus FDA 209-P were carried out and following results were obtained. 1) The active form of pyrimidine was OMP-PP. 2) Free Th as well as its phosphorylated derivatives was sctive as a substrate for the acetone-dried powder of the organisms and the crude enzyme preparation extracted from the powder. 3) Th-P was the most active form of Th for the enzyme preparation with had been purified by the treatment with ammonium sulfate and chromatography on DEAE-cellulose. The activity of free Th for the partially purefied enzyme was negligible. 4) The reaction products from OMP-PP and Th-P of the purified enzyme preparation were TDP and TMP as examined by paper chromatographic and bioautographic method. 5) The activity of the enzyme was increased by the addition of Mn¨ Mg¨or Cd¨. 6) The rhiamine-synthesizing enzyme was comparatively thermostable.