Catabolic activities of Neisseria meningitidis: utilization of glutamate

Glutamate was catabolized at a rapid rate by Neisseria meningitidis, group B. Surprisingly, there was a lag of 5 to 30 min in respiration, but not in CO(2) production from C(1), and an appreciable amount of succinate accumulated. The eventual rapid rate of respiration was not prevented by the addition of chloramphenicol. The lag period was eliminated by combinations of substrates that favored the activity of a glutamate-oxaloacetate transaminase. It is suggested that with glutamate as the sole substrate, the reaction terminated at succinate, required only moderate O(2) uptake, and did not result in the transport of succinate to enzymatic sites. The lag period represented the time required for the accumulation of succinate and its transport to enzymatic sites by energy provided by the metabolism of the remaining glutamate. When the transaminase was operative, on the other hand, successive products of the reaction were immediately placed in contact with enzymatic sites.