Abstract
In the accumulation process of thiamine by Staphylococcus aureus FDA 209P cells, phosphorylation of thiamine (B_1) could be separated and distinguished from uptake process. The cell used in this experiment was presaturated with B_1 phosphates as follows : The cell, which had been shaken at 37℃ with free B_1 for 180 minutes in the presence of glucose, was collected by centrifuge, resuspended in three times the volume of 0.9% NaCl and shaken at 37℃ for 60 minutes. Normally more than 95% of the accumulated B_1 in the cell thus obtained was phosphorylated forms. The ^<14>C-B_1 taken up by the B_1 phosphates-presaturated cell accumulated as free B_1 during 3 to 5 minutes of incubation, but in longer period of incubation ^<14>C-B_1 phosphates started to accumulate. The free B_1 accumulation reaction depended on the presence of glucose and temperature. The Km for free B_1 accumulation was 3.9×10^<-7> M. Small amount of B_1 phosphates accumulated in the cell leaked out in a process which needed glucose and an incubation at 37℃.
