The production of indole by suspensions of Bact. coli

Abstract

Suspensions of B. c. grown in media of known composition in absence of tryptophane (I) were always capable of oxidising I to indole; grown in presence of I the activity of suspensions was 25 times greater. The presence of glucose during growth entirely inhibited the production of the "excess" activity ordinarily produced by the presence of I, but did not affect the normal ("constitutive") ability to oxidise I. The activity of suspensions was inhibited by indole, but growth in presence of indole or indole acrylic acid (II) increased the activity of suspensions (like I); other indole derivatives were ineffective. During growth in presence of II, indole is produced. Possibly I is synthesised from II in growth in presence of the latter.