Catabolic Activities of Neisseria meningitidis: Utilization of Succinate

When resting cells of Neisseria meningitidis group B were incubated with either succinate, fumarate, or malate, respiration and CO(2) production were not significantly stimulated. These dicarboxylic acids were readily utilized, however, when they were added in association with a combination of alpha-ketoglutarate and aspartate or with glucose or with glutamate. The amounts of these substrates required for exogenous succinate utilization were relatively large. Both the alpha-ketoglutarate-aspartate combination and glutamate greatly stimulated succinate uptake into the cells, but glutamate was far more effective than the alpha-ketoglutarate-aspartate combination in eliciting exogenous succinate utilization. This difference is explained on the basis of evidence reported in another article that succinate derived from the alpha-ketoglutarate-aspartate mixture is metabolized more rapidly-and thus more rapidly dilutes the specific activity of added succinate-than the succinate derived from glutamate.