Effects of Bicarbonate on Growth of Neisseria gonorrhoeae: Replacement of Gaseous CO2 Atmosphere

Talley, Richard S.; Baugh, Clarence L.

doi:10.1128/aem.29.4.469-471.1975

Cited by 12 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The industrially important Gram-positive C. glutamicum possesses the biotin-dependent PCx and the PEP carboxylase, both with Michaelis–Menten constants ( K M ) for

of about 3 mM (Hanke et al, 2005 ; Chen et al, 2013 ) which is about 30-fold higher compared to the K M (0.1 mM i.e., 4.4 mg/L) of PEP carboxylase from Escherichia coli as single anaplerotic enzyme (Kai et al, 1999 ). These differences already point to organism-specific aeration needs to install proper metabolic activity by maintaining sufficient

availability at fermentation start when biomass concentrations are still low (Repaske et al, 1974 ; Talley and Baugh, 1975 ) or for products requiring a high anaplerotic flux (e.g., succinate, l -lysine, and derived products).…”

Section: Metabolic Release and Incorporationmentioning

confidence: 99%

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

Blombach

Takors

2015

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

Carbon dioxide formation mirrors the final carbon oxidation steps of aerobic metabolism in microbial and mammalian cells. As a consequence, CO2/HCO3− dissociation equilibria arise in fermenters by the growing culture. Anaplerotic reactions make use of the abundant CO2/HCO3− levels for refueling citric acid cycle demands and for enabling oxaloacetate-derived products. At the same time, CO2 is released manifold in metabolic reactions via decarboxylation activity. The levels of extracellular CO2/HCO3− depend on cellular activities and physical constraints such as hydrostatic pressures, aeration, and the efficiency of mixing in large-scale bioreactors. Besides, local CO2/HCO3− levels might also act as metabolic inhibitors or transcriptional effectors triggering regulatory events inside the cells. This review gives an overview about fundamental physicochemical properties of CO2/HCO3− in microbial and mammalian cultures effecting cellular physiology, production processes, metabolic activity, and transcriptional regulation.

show abstract

“…The industrially important Gram-positive C. glutamicum possesses the biotin-dependent PCx and the PEP carboxylase, both with Michaelis–Menten constants ( K M ) for

Section: Metabolic Release and Incorporationmentioning

confidence: 99%

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

Blombach

Takors

2015

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

show abstract

“…The proposal by Talley and Baugh (21) that N. gonorrhoeae was utilizing bicarbonate and not carbon dioxide is supported by the findings of Maruyama et al (15) that bicarbonate and not carbon dioxide was the reactive substrate of PEPC. The Km of the enzyme for bicarbonate would have to be low if the carboxylation of PEP is to be accomplished during the fermentation of glucose at 370C when the acids of fermentation would decrease the pH of the environment and cause disfavorable conditions for the maintenance of bicarbonate in solution.…”

Section: Resultsmentioning

confidence: 79%

“…It is generally considered that an increased carbon dioxide tension is necessary for the growth of Neisseria gonorrhoeae on primary isolation. However, recent studies in our laboratory (21) have demonstrated that the gaseous carbon dioxide requirement can be replaced by the addition of sodium bicarbonate at a concentration that is too low to significantly increase the atmospheric carbon dioxide level, even if a 100% bicarbonate conversion to carbon dioxide was obtained. Also, in this study, it was shown that the majority of the radioactive bicarbonate assimilated by growing cells was incorporated into nucleic acid and protein fractions.…”

mentioning

confidence: 96%

Carboxylation of phosphoenolpyruvate by extracts of Neisseria gonorrhoeae

Cox¹,

Baugh²

1977

J Bacteriol

View full text Add to dashboard Cite

The enzymatic carboxylation of phosphoenolpyruvate by cell-free extracts of Neisseria gonorrhoeae was examined and determined to be similar to the reaction catalyzed by phosphoenolpyruvate carboxylase (PEPC). This was shown by the irreversibility of the reaction and nucleotide independency. The enzyme was found to have some characteristics different from the other bacterial PEPCs reported. The enzyme showed catalytic activity in the presence of cobalt ions as well as magnesium and manganese ions, was not inhibited by succinate in fresh extracts, and displayed a low Michaelis constant for bicarbonate (0.27 mM), as compared with other PEPCs. The significance of this low Michaelis constant is discussed with respect to the growth of the organism and the importance of this enzyme to protein and nucleic acid synthesis.

show abstract

“…Several studies revealed the inhibitory effect of low p CO2 on microbial growth (2, 26, 27). In the case of C. glutamicum , low p CO2 pressures led to a significant drop in growth rate in turbidostatic continuous cultures (28) as well as batch cultures (29).…”

Section: Introductionmentioning

confidence: 99%

The impact of CO₂/HCO₃^-availability on anaplerotic flux in PDHC-deficientCorynebacterium glutamicumstrains

Krüger

Wiechert

Gätgens

et al. 2019

Preprint

View full text Add to dashboard Cite

18The pyruvate dehydrogenase complex (PDHC) catalyzes the oxidative 19 decarboxylation of pyruvate yielding acetyl-CoA and CO 2 . The PDHC-deficient 20 Corynebacterium glutamicum strain ΔaceE is therefore lacking an important 21 decarboxylation step in central metabolism. Additional inactivation of pyc, encoding 22 pyruvate carboxylase, resulted in a >15 hour lag phase in the presence of glucose, 23 while no growth defect was observed on gluconeogenetic substrates like acetate. 24 Growth was successfully restored by deletion of ptsG encoding the glucose-specific 25 permease of the PTS system, thereby linking the observed phenotype to the 26 increased sensitivity of strain ΔaceE Δpyc to glucose catabolism. In the following, 27 strain ΔaceE Δpyc was used to systematically study the impact of perturbations of 28 the intracellular CO 2 /HCO 3 pool on growth and anaplerotic flux. Remarkably, all 29 measures leading to enhanced CO 2 /HCO 3 levels, such as external addition of HCO 3 -30 , increasing the pH, or rerouting metabolic flux via pentose phosphate pathway, at 31 least partially eliminated the lag phase of strain ΔaceE Δpyc on glucose medium. In 32 accordance, inactivation of the urease enzyme, lowering the intracellular CO 2 /HCO 3 -33 pool, led to an even longer lag phase accompanied with the excretion of L-valine and 34 L-alanine. Transcriptome analysis as well as an adaptive laboratory evolution 35 experiment of strain ΔaceE Δpyc revealed the reduction of glucose uptake as a key 36adaptive measure to enhance growth on glucose/acetate mixtures. Altogether, our 37 results highlight the significant impact of the intracellular CO 2 /HCO 3 pool on 38 metabolic flux distribution, which becomes especially evident in engineered strains 39 suffering from low endogenous CO 2 production rates as exemplified by PDHC-40 deficient strains. 41 42 3 Importance: CO 2 is a ubiquitous product of cellular metabolism and an essential 43 substrate for carboxylation reactions. The pyruvate dehydrogenase complex (PDHC) 44 catalyzes a central metabolic reaction contributing to the intracellular CO 2 /HCO 3 pool 45 in many organisms. In this study, we used a PDHC-deficient strain of 46 Corynebacterium glutamicum, which was additionally lacking pyruvate carboxylase 47 52 metabolic flux especially in strains suffering from low endogenous CO 2 production 53 rates. 54 55 56 2-, which is influenced 59 by the pH of the medium (1). As a product of decarboxylating reactions and substrate 60 for carboxylations, CO 2 and bicarbonate (HCO 3 -) are involved in various metabolic 61 processes. Consequently, the intracellular CO 2 /HCO 3 pool has a significant impact 62 on metabolic fluxes like e.g. anaplerosis, especially in the early phase of cultivations 63 when cell density is low (2). 64 During aerobic growth, the pyruvate dehydrogenase complex (PDHC), which is 65 conserved in various microbial species, catalyzes an important reaction contributing 66 to the intracellular CO 2 /HCO 3 pool (3, 4). The PDHC is a multienzyme complex 67 be...

show abstract

Effects of Bicarbonate on Growth of Neisseria gonorrhoeae: Replacement of Gaseous CO2 Atmosphere

Cited by 12 publications

References 0 publications

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

Carboxylation of phosphoenolpyruvate by extracts of Neisseria gonorrhoeae

The impact of CO₂/HCO₃^-availability on anaplerotic flux in PDHC-deficientCorynebacterium glutamicumstrains

Contact Info

Product

Resources

About

Effects of Bicarbonate on Growth of Neisseria gonorrhoeae: Replacement of Gaseous CO2 Atmosphere

Cited by 12 publications

References 0 publications

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

CO2 – Intrinsic Product, Essential Substrate, and Regulatory Trigger of Microbial and Mammalian Production Processes

Carboxylation of phosphoenolpyruvate by extracts of Neisseria gonorrhoeae

The impact of CO2/HCO3-availability on anaplerotic flux in PDHC-deficientCorynebacterium glutamicumstrains

Contact Info

Product

Resources

About

The impact of CO₂/HCO₃^-availability on anaplerotic flux in PDHC-deficientCorynebacterium glutamicumstrains