Abstract
The fecal tryptophanase activities were $0.267{\pm}0.10$ for rats and $0.185{\pm}0.01{\;}{\mu}mole/min/g$ wet feces for humans. The activities of indole pyruvate degradation to indole, indole pyruvate lyase, of these feces were $0.051{\pm}0.02$ and $0.046{\pm}0.01{\;}{\mu}mole/min/g$ wet feces, respectively. The optimal pH values of tryptophanase and indole pyruvate lyase were 5.5-7.5 and 5.5-6.5, respectively. When the intestinal flora or E. coli HGU-3 was cultured in GAM broth having six different pH values (5 to 10), the activities of tryptophanase and indole pyruvate IYilse in the medium adjusted at pH 6 were dramatically induced by elevating the pH to 9. However, when intestinal microflora were inoculated in the medium containing lactulose, the pro¬ductions of these enzymes were dramatically inhibited and the pH of the medium was lower than that of the control.
