The synthesis of indole from anthranilic acid by Escherichia coli

Abstract

Anthranilate, indol and a compound (BDC) that gives a blue color in the test for anthranilate were detected in the growth media of some E. coli mutants blocked at various stages in the biosynthesis of tryptophan. Washed cells of 2 mutants blocked between indol and tryptophan synthesize indole or BDC or both when incubated with glucose and anthranilate. An enzyme system converting anthranilate into indol was extracted from E. coli. The reaction requires adenosine triphosphate (ATP), inorganic phosphate, pyridoxal phosphate, Mg2+ or Mn2+ and a C-donor. Pyruvate and alpha-oxoglutarate are the most effective of the donors studied. The implication of these results for the problem of tryptophan biosynthesis is discussed.