The influence of various metabolites upon the p-aminobenzoate-pantothenate interaction in Bacterium linens.

The nutritional equivalence of pantothenate and p-aminobenzoate for the growth of Bacterium linens and the reversal of growth inhibition by sulfanilamide and salicylate has indicated a biochemical relationship between pantothenate and p-aminobenzoate (Purko et al., 1953). Recently, Pomper (1952) observed that the pantothenate, as well as the methionine, histidine, and adenine requirements of a mutant of Saccharomyces cerevisiae, could be replaced by high p-aminobenzoate concentrations and also has suggested that an interaction between p-aminobenzoate and pantothenate exists. Other evidence supports the postulate that p-aminobenzoate is involved in the synthesis of purine and pyrimidine bases (Cutts and Rainbow, 1949), methionine (Woods, 1950), folic acid (Lampen and Jones, 1947), and other metabolites (Lampen and Jones, 1946; Winkler and DeHaan, 1948). Inasmuch as p-aminobenzoate may function in the formation of other metabolites in addition to pantothenate, the observed pantothenate-paminobenzoate equivalence for the growth of B. linens may reflect a role of p-aminobenzoate or pantothenate in the formation of other metabolites which are required for growth. A study of vitamins and related compounds has been presented by Purko et al. (1953). It is the purpose of this paper to report the effect of various nonvitamin components of the basal medium on the pantothenate-p-aminobenzoate interaction. The evidence indicates that no requirement for specific metabolites, either in the presence of pantothenate or p-aminobenzoate, exists and that the nutritional equivalence of pantothenate and p-aminobenzoate was not altered by the presence or absence of the individual amino acids, purines, pyrimidines, or other compounds with microbiological activity. Thus, these metabolites appear not to be directly involved in this pantothenate-p-aminobenzoate interaction. METHODS