Synthesis of a compound with folic acid activity by Lactobacillus arabinosus 17-5

Summary A compound with folic acid activity is synthesized by growing as well as respiring cells of Lactobacillus arabinosus in the presence of p-aminobenzoic acid. The essentiality of glutamic acid is seen in studies with respiring cells.The free folic acid activity elaborated by Lactobacillus arabinosus reaches its maximum in about 48 hrs. and is present mainly in the culture filtrate.Additions of Tween 80, or biotin and of xanthine show marked stimulation of the synthesis of folic acid activity.With the organisms Streptococcus faecalis R and Lactobacillus casei, requiring exogenous folic acid for growth, it is seen that the entire folic acid activity resides in the cells and as citrovorum factor.Sulphanilamide inhibits the synthesis of folic acid activity by Lactobacillus arabinosus.     

Synthesis of a substance exhibiting citrovorum factor activity by Lactobacillus arabinosus 17-5

Summary Growing and respiring cells of Lactobacillus arabinosus elaborate citrovorum factor activity from p-aminobenzoic acid. Pteroylglutamic acid is a step in this conversion.That the activity synthesized is apparently different from the citrovorum factor is inferable from observations on inhibition analysis, differential distribution between immiscible solvents at various p_H and bioautographic studies.Ascorbic acid aids in the synthesis of citrovorum factor active substance. Formate and formyl precursors have stimulatory effect on this synthesis but only in presence of ascorbic acid.