Effect of Glutamate on Exogenous Citrate Catabolism of Neisseria meningitidis and of Other Species of Neisseria

Abstract

Resting cell suspensions of Neisseria meningitidis group B (strain 2091) do not catabolize citrate as the sole substrate to an appreciable degree. When another substrate, such as glutamate, is also present to furnish energy for transport, citrate metabolism is greatly stimulated. Within limits, the amount of CO2 produced from citrate is proportional to the amount of glutamate added. When the cells are disrupted, citrate is degraded at a rapid rate and the stimulatory effect of glutamate is completely eliminated. Pronounced stimulation of citrate metabolism by glutamate was demonstrated in 12 of 13 strains of N. meningitidis tested and only I of 6 strains of N. lactamicus. The remaining strains of N. lactamicus and one each of N. gonorrhoeae, N. flavescens, and N. flava did not utilize significant amounts of citrate in the absence or presence of glutamate. N. catarrhalis shared with Mima polymorpha and Moraxella glucidolytica a capability to catabolize citrate at a rapid rate without added glutamate. It is concluded that tests of glutamate-stimulated citrate metabolism may contribute to species characterization in the genus Neisseria.

Growth and physiology of rickettsiae.

“…In fact,, as discussed in a previous section, it was shown that for protein and lipid syntheses exogenous ATP must also be supplied (11,18,20). Although a requirement for exogenous ATP is rare among bacteria, it is not uncommon to find that separate energy-yielding reactions take place for transport and for synthetic activity (47,69,119). It is therefore conceivable that rickettsiae are capable of meeting their endogenous ATP requirements but depend on the host for energy for the transport of key metabolites.…”

Physiology and metabolism of pathogenic neisseria: tricarboxylic acid cycle activity in Neisseria gonorrhoeae

“…gonorrhoeae may explain the failure of Tonhazy and Pelczar (41) to observe oxidation of citrate by resting-cell suspensions. However, the permeability of citrate may also be an important factor (15). Except for citrate synthase, growth on glucose-containing medium repressed the synthesis of other tricarboxylic acid cycle enzymes.…”

“…The cell suspension was disrupted by sonic treatment (Biosonik IV; Bronwill, Rochester, N.Y.) for a total of 3 min in 30-s pulses (40% maximum output with 1-min intervals for cooling). The resulting suspension was centrifuged at low speed (23,000 x g, for 15 min) to remove cell walls and unbroken cells. The supernatant fluid was centrifuged at 100,000 x g for 1 h (type 30 rotor, Spinco model L5-65 ultracentrifuge).…”

Protein Fraction with Immunogenic Potential and Low Toxicity Isolated from the Cell Wall of Neisseria meningitidis Group B

“…In a survey of the electrophoretic patterns of CE of various gram-negative bacteria, Schnaitman (21) found that Neisseria catarrhalis and Pseudomonas aeruginosa, unlike E. coli and the other gram-negative organisms studied, showed two major protein components. It is not surprising to find a difference between N. catarrhalis and N. meningitidis in view of the evidence indicating that N. catarrhalis is not closely related to the other members of the genus Neisseria (2,9,12,13), leading to the proposal that it be transferred to a new genus, Branhamella (2).…”