Under conditions of
iron deficiency, strains of Bacillus subtilis produced
2,3-dihydroxybenzoic acid (DHB), 2,3-dihydroxybenzolyglycine (
DHBG), or both of these compounds. DHB(G) production [production of DHB(G) refers to the production of DHB, or
DHBG, or both] was proportional to the amount of
iron present and occurred logarithmically, paralleling growth. Supplementation of media with more than 150 mug of
iron per liter at zero-time inhibited DHB accumulation completely. In the presence of DHB, lower levels of
iron inhibited DHB(G) production, so that the actual inhibitor of synthesis may involve the Fe(3+):[DHB(G)](3) complex. The strains producing
DHBG also produced
coproporphyrin III during
iron-deficient growth, whereas a strain producing DHB did not produce
coproporphyrin III under these conditions. Accumulation of DHB(G) was influenced by the levels of
aromatic amino acids and
anthranilic acid in the medium. In vivo experiments with strain B-1471 demonstrated that DHB was coupled to added
glycine to form
DHBG. Metabolism of DHB(G) was observed in two of the strains studied.