Radiorespirometric studies in genus Neisserai. I. The catabolism of glucose.

The catabolism of glucose in selected Neisseria species was studied by radiorespirometry. The Entner-Doudoroff and pentose phosphate pathways were operating in all species, the greater part of the substrate being routed through the former, somewhat dependent on the medium used. Acetate was oxidized via the tricarboxylic acid cycle. In all species, a fraction of the triose was recycled through fructose phosphates to glucose 6-phosphate. Phosphate inhibited the oxidation of acetate. In media devoid of phosphate and sodium (N. meningitidis and N. gonorrhoeae) or of phosphate and potassium (other saccharolytic Neisseria), the conversion of triose to pyruvate was inhibited. In these media the catabolism of glucose proceeded slowly, and no substrate was used for biosynthetic purposes. The results point to a difference in the regulation of glucose metabolism in pathogenic and non-pathogenic Neisseria.