The effect of folic acid upon the urinary excretion of the growth factor required by Leuconostoc citrovorum.

In a previous study it was observed that Leuconostoc citrovorum 8081 failed to grow on a synthetic medium adequate for the growth of Leuconostoc mesenteroides P-60 and other common assay organisms (1). However, the addition to the medium of certain extracts from liver permitted excellent growth of L. citrovorum. Similarly, folic acid stimulated growth of the organism but the amounts necessary were very high (l).’ The present paper is concerned with the effects of folic acid upon the urinary excretion of the L. citrovorum factor by the rat.