STUDIES OF THE EFFECT OF PARA-AMINOBENZOIC ACID, FOLIC ACID, AND SULFANILAMIDE ON DEXTRAN SYNTHESIS BY LEUCONOSTOC

Abstract
Two folic acid-dependent strains, L. mesenteroides 683 and L. dextranicum 8086, and 2 folic acid-independent strains, L. mesenteroides 535 and L. dextranicum elai, were employed. Low levels of p-aminobenzoic acid failed to stimulate dextran synthesis, while higher concns. retarded growth and polysaccharide formation. With folic acid-independent strains, sulfanilamide produced a greater inhibition of acid production than of dextran synthesis. With added folic acid, sulfanilamide in high concn. did not retard dextran formation by strains dependent on this vitamin. Thus p-aminobenzoic acid is not involved in dextran synthesis by these strains of Leuconostoc.