Influence of Various Sugars on the Indol Rroduction of E. Coli and It' s Drug-Resistant Strains

Abstract

Among various sugars, glucose demonstrated the strongest indol-production inhibiting activity. Galactose added with minimal amounts of glucose also demonstrated almost the same degree of activity. The inhibition of indol-production was quantitatively investigated with the sulfamine-and streptomycin-resistant strains in comparison with their original strains, in order to study the influence of these drugs on the sugar metabolism of the latter.
The degree of inhibiting activity was measured from the turbidity of both culture fluids added with sugar and not added with it in which a certain amount of each strain was cultivated for 24 hours.
Indol was spectrophotometrically estimated by adding Ehrlich's reagent to the culture fluids and heating them for 30min. at 30°C and using the some fluid previously added with formalin as the blanc. The results were as follows:
Sulfamine-resistant strains demonstrated almost the same degree of the indol-production inhibiting activity as the original strain, while majority of the streptomycin-resistant ones showed a great deviation, hindering from slightly to strongly the activity and only 2 of the 43 strains tested demonstrated the same degree of activity as the original one.
It was concluded by the author that sulfamine hardly influenced the sugar metabolism of E. coli, whereas streptomycin greatly hindered its metabolism.