P-Aminobenzoic Acid Prevents the Growth-Inhibitory Action of Sulfanilamide

Abstract

The addition of sulfanilamide in 1:1000 conc. to an agar medium caused complete inhibition of mat growth of a strain of the fungus Tnchophyton purpureum although germination of spores occurred. The inhibition was nullified by the addition of p-amino-benzoic acid in conc. as low as 1:500,000 but the addition of the acid alone to the culture media did not increase the rate of growth.