Date of this Version
The work of Snell on lactic acid bacteria provided the first evidence that anthranilic acid may act as a precursor to tryptophane in vivo. Since the strains of bacteria which utilize anthranilic acid in the place of tryptophane also use indole, it was not possible to establish the order in which these two precursors occurred. In 1943 Tatum, Bonner and Beadle found that anthranilic acid was accumulated in the culture medium by a Neurospora crassa mutant, strain 10575, which required either tryptophane or indole for growth. It was therefore indicated that anthranilic acid is a precursor to indole in Neurospora.