[Effect of methylation antagonists on biosynthesis of tetrapyrrole compounds by Propionibacterium shermanii].

The effect of methylation antagonists (DL-ethionine, S-adenosyl homocysteine and folic acid analogs-aminopterine, ametopterine and tomisine) on vitamin B12 and porphyrin biosynthesis of P. shermanii resting cells was studied. DL-ethionine proved the most active inhibitor. Inhibition of vitamin B12 biosynthesis induced by DL-ethionine was accompanied by increase in porphyrin formation. DL-methionine reversed the inhibitory effect of DL-ethionine on the vitamin synthesis. Other compounds tested showed a less marked effect.