Abstract
The growth inhibitory effects of 2-methyl-4-amino-5-aminomethylpyrimidine (AMPm) and some pyrimidine compounds for thiamine requiring L.fermenti and Kl. apiculata decreased with increasing amount of thiamine and were almost compensated by the presence of 1/2500 and 1/25000 equimolecular amounts of thiamine, respectively and no effects were seen for such microorganisms requiring no thiamine, as L.arabinosus 17-5,L.casei, Streptococcus faecalis and Sacch. carlsbergensis. From these results, the inhibitory effect of the pyrimidine compounds seems to be specifically antagonistic with thiamine. As shown in Fig.1 and 2,for the growth of L.fermenti AMPm inhibited the utilization of thiamine diphosphate (TDP) 3 to 6 times more than that of thiamine, while for Kl.apiculata no difference of inhibitory effect of AMPm was observed between thiamine and TDP.
