Effect of ascorbate on oxygen uptake and growth of Escherichia coli B

1988 ◽  
Vol 34 (6) ◽  
pp. 822-824 ◽  
Author(s):  
Holly E. Richter ◽  
Jacek Switala ◽  
Peter C. Loewen
Keyword(s):  
Escherichia Coli ◽  
Oxygen Uptake ◽  
Electron Acceptor ◽  
Minimal Medium ◽  
Anaerobic Growth ◽  
Rich Medium ◽  
Terminal Electron Acceptor ◽  
Subsequent Change ◽  
Escherichia Coli B

The addition of ascorbate to aerobically growing cultures of Escherichia coli B caused only a short pause in growth and no subsequent change in the rate or extent of growth. The effect of ascorbate on oxygen uptake varied from inhibition in minimal medium to stimulation in rich medium. Cyanide-resistant growth and oxygen uptake were stimulated by ascorbate. Both the rate and extent of anaerobic growth were stimulated in proportion to the amount of ascorbate added when fumarate was the terminal electron acceptor. Ascorbate had no effect on any aspect of anaerobic growth in the absence of a terminal electron acceptor or in the presence of nitrate.

Magnetovibrio blakemorei gen. nov., sp. nov., a magnetotactic bacterium ( Alphaproteobacteria : Rhodospirillaceae ) isolated from a salt marsh

2013 ◽  
Vol 63 (Pt_5) ◽  
pp. 1824-1833 ◽  
Author(s):  
Dennis A. Bazylinski ◽  
Timothy J. Williams ◽  
Christopher T. Lefèvre ◽  
Denis Trubitsyn ◽  
Jiasong Fang ◽  
...  
Keyword(s):  
Salt Marsh ◽  
Electron Acceptor ◽  
Anaerobic Growth ◽  
Rrna Gene ◽  
Magnetotactic Bacterium ◽  
Single Chain ◽  
Circular Chromosome ◽  
Terminal Electron Acceptor ◽  
Content Type ◽  
Link Type

A magnetotactic bacterium, designated strain MV-1T, was isolated from sulfide-rich sediments in a salt marsh near Boston, MA, USA. Cells of strain MV-1T were Gram-negative, and vibrioid to helicoid in morphology. Cells were motile by means of a single polar flagellum. The cells appeared to display a transitional state between axial and polar magnetotaxis: cells swam in both directions, but generally had longer excursions in one direction than the other. Cells possessed a single chain of magnetosomes containing truncated hexaoctahedral crystals of magnetite, positioned along the long axis of the cell. Strain MV-1T was a microaerophile that was also capable of anaerobic growth on some nitrogen oxides. Salinities greater than 10 % seawater were required for growth. Strain MV-1T exhibited chemolithoautotrophic growth on thiosulfate and sulfide with oxygen as the terminal electron acceptor (microaerobic growth) and on thiosulfate using nitrous oxide (N2O) as the terminal electron acceptor (anaerobic growth). Chemo-organoautotrophic and methylotrophic growth was supported by formate under microaerobic conditions. Autotrophic growth occurred via the Calvin–Benson–Bassham cycle. Chemo-organoheterotrophic growth was supported by various organic acids and amino acids, under microaerobic and anaerobic conditions. Optimal growth occurred at pH 7.0 and 26–28 °C. The genome of strain MV-1T consisted of a single, circular chromosome, about 3.7 Mb in size, with a G+C content of 52.9–53.5 mol%.Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain MV-1T belongs to the family Rhodospirillaceae within the Alphaproteobacteria , but is not closely related to the genus Magnetospirillum . The name Magnetovibrio blakemorei gen. nov., sp. nov. is proposed for strain MV-1T. The type strain of Magnetovibrio blakemorei is MV-1T ( = ATCC BAA-1436T  = DSM 18854T).

scholarly journals Modification by an R determinant for streptomycin of hissd phenotype in a mutant strain of Escherichia coli B

1968 ◽  
Vol 12 (2) ◽  
pp. 109-116 ◽  
Author(s):  
A. M. Molina ◽  
L. Calegari ◽  
G. Conte
Keyword(s):  
Escherichia Coli ◽  
Cell Membrane ◽  
Mutant Strain ◽  
Minimal Medium ◽  
Specific Requirement ◽  
Resistance Level ◽  
E Coli ◽  
Level Characteristic ◽  
Escherichia Coli B

When an R determinant for streptomycin is transferred into a conditionally streptomycin-dependent E. coli B mutant—which requires in minimal medium either histidine or streptomycin—the latter behaves like a histidineless strain. This phenotype modification shows that the repairing action of streptomycin is prevented. The specific requirement of the strain is not now replaced even by streptomycin concentrations up to 10000 µg/ml at which the conditionally streptomycin-dependent mutant could originally grow, and which are well beyond the resistance level characteristic of the R determinant itself. These data seem to suggest that a reduction in permeability of the cell membrane cannot be held responsible for the phenomenon observed.

scholarly journals Pyruvate Formate Lyase and Acetate Kinase Are Essential for Anaerobic Growth of Escherichia coli on Xylose

2004 ◽  
Vol 186 (22) ◽  
pp. 7593-7600 ◽  
Author(s):  
Adnan Hasona ◽  
Youngnyun Kim ◽  
F. G. Healy ◽  
L. O. Ingram ◽  
K. T. Shanmugam
Keyword(s):  
Escherichia Coli ◽  
Minimal Medium ◽  
High Capacity ◽  
Redox Balance ◽  
Anaerobic Growth ◽  
Acetate Kinase ◽  
Anaerobic Conditions ◽  
Pyruvate Formate Lyase ◽  
E Coli ◽  
Xylose Transport

ABSTRACT During anaerobic growth of bacteria, organic intermediates of metabolism, such as pyruvate or its derivatives, serve as electron acceptors to maintain the overall redox balance. Under these conditions, the ATP needed for cell growth is derived from substrate-level phosphorylation. In Escherichia coli, conversion of glucose to pyruvate yields 2 net ATPs, while metabolism of a pentose, such as xylose, to pyruvate only yields 0.67 net ATP per xylose due to the need for one (each) ATP for xylose transport and xylulose phosphorylation. During fermentative growth, E. coli produces equimolar amounts of acetate and ethanol from two pyruvates, and these reactions generate one additional ATP from two pyruvates (one hexose equivalent) while still maintaining the overall redox balance. Conversion of xylose to acetate and ethanol increases the net ATP yield from 0.67 to 1.5 per xylose. An E. coli pfl mutant lacking pyruvate formate lyase cannot convert pyruvate to acetyl coenzyme A, the required precursor for acetate and ethanol production, and could not produce this additional ATP. E. coli pfl mutants failed to grow under anaerobic conditions in xylose minimal medium without any negative effect on their survival or aerobic growth. An ackA mutant, lacking the ability to generate ATP from acetyl phosphate, also failed to grow in xylose minimal medium under anaerobic conditions, confirming the need for the ATP produced by acetate kinase for anaerobic growth on xylose. Since arabinose transport by AraE, the low-affinity, high-capacity, arabinose/H+ symport, conserves the ATP expended in pentose transport by the ABC transporter, both pfl and ackA mutants grew anaerobically with arabinose. AraE-based xylose transport, achieved after constitutively expressing araE, also supported the growth of the pfl mutant in xylose minimal medium. These results suggest that a net ATP yield of 0.67 per pentose is only enough to provide for maintenance energy but not enough to support growth of E. coli in minimal medium. Thus, pyruvate formate lyase and acetate kinase are essential for anaerobic growth of E. coli on xylose due to energetic constraints.

scholarly journals The fixA and fixB Genes Are Necessary for Anaerobic Carnitine Reduction in Escherichia coli

2002 ◽  
Vol 184 (14) ◽  
pp. 4044-4047 ◽  
Author(s):  
Angelique Walt ◽  
Michael L. Kahn
Keyword(s):  
Escherichia Coli ◽  
Electron Acceptor ◽  
Anaerobic Conditions ◽  
Terminal Electron Acceptor ◽  
E Coli ◽  
Carnitine Metabolism

ABSTRACT In Escherichia coli, the use of carnitine as a terminal electron acceptor depends on a functional caiTABCDE operon. It had been suggested that the adjacent but divergent fixABCX operon is also required for carnitine metabolism, perhaps to provide electrons for carnitine reduction. We have constructed E. coli fixA and fixB mutants and find that they are unable to reduce carnitine to γ-butyrobetaine under anaerobic conditions.

scholarly journals Medium Plays a Role in Determining Expression of acrB, marA, and soxS in Escherichia coli

2006 ◽  
Vol 50 (3) ◽  
pp. 1071-1074 ◽  
Author(s):  
Andrew M. Bailey ◽  
Mark A. Webber ◽  
Laura J. V. Piddock
Keyword(s):  
Escherichia Coli ◽  
Minimal Medium ◽  
Rich Medium ◽  
Growth Phases ◽  
Minimal Media ◽  
Logarithmic Growth

ABSTRACT Analysis of expression of acrB, marA, and soxS in rich and minimal media, at early and late logarithmic growth phases, showed that acrB had increased expression in minimal medium compared to rich medium, but expression decreased dose dependently upon exposure to ciprofloxacin.

The Escherichia coli CcmG protein fulfils a specific role in cytochrome c assembly

2001 ◽  
Vol 355 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Eleanor REID ◽  
Jeff COLE ◽  
Deborah J. EAVES
Keyword(s):  
Escherichia Coli ◽  
Cytochrome C ◽  
Redox State ◽  
Disulphide Bond ◽  
Anaerobic Growth ◽  
Terminal Electron Acceptor ◽  
Bond Forming ◽  
Disulphide Bonds ◽  
Low Concentrations ◽  
K 12

In Escherichia coli K-12, c-type cytochromes are synthesized only during anaerobic growth with trimethylamine-N-oxide, nitrite or low concentrations of nitrate as the terminal electron acceptor. A thioredoxin-like protein, CcmG, is one of 12 proteins required for their assembly in the periplasm. Its postulated function is to reduce disulphide bonds formed between correctly paired cysteine residues in the cytochrome c apoproteins prior to haem attachment by CcmF and CcmH. We report that loss of CcmG synthesis by mutation was not compensated by a second mutation in disulphide-bond-forming proteins, DsbA or DsbB, or by the chemical reductant, 2-mercaptoethanesulphonic acid. An anti-CcmG polyclonal antibody was used in Western-blot analysis to probe the redox state of CcmG in mutants defective in the synthesis of other proteins essential for cytochrome c assembly. The oxidized form of CcmG accumulated not only in trxA or dipZ mutants defective in the transfer of electrons from the cytoplasm for disulphide isomerization and reduction reactions in the periplasm, but also in ccmF and ccmH mutants. The requirement of both CcmF and CcmH for the reduction of the disulphide bond in CcmG indicates that CcmG functions later than CcmF and CcmH in cytochrome c assembly, rather than in electron transfer from the membrane-associated DipZ (also known as DsbD) to CcmH. The data support a model proposed by others in which CcmG catalyses one of the last reactions specific to cytochrome c assembly.

scholarly journals Anaerobic Expression of Escherichia coli Succinate Dehydrogenase: Functional Replacement of Fumarate Reductase in the Respiratory Chain during Anaerobic Growth

1998 ◽  
Vol 180 (22) ◽  
pp. 5989-5996 ◽  
Author(s):  
Elena Maklashina ◽  
Deborah A. Berthold ◽  
Gary Cecchini
Keyword(s):  
Escherichia Coli ◽  
Tricarboxylic Acid Cycle ◽  
Anaerobic Respiration ◽  
Growth Conditions ◽  
Fumarate Reductase ◽  
Anaerobic Growth ◽  
Enzyme Complex ◽  
Succinate Oxidation ◽  
Terminal Electron Acceptor ◽  
E Coli

ABSTRACT Succinate-ubiquinone oxidoreductase (SQR) from Escherichia coli is expressed maximally during aerobic growth, when it catalyzes the oxidation of succinate to fumarate in the tricarboxylic acid cycle and reduces ubiquinone in the membrane. The enzyme is similar in structure and function to fumarate reductase (menaquinol-fumarate oxidoreductase [QFR]), which participates in anaerobic respiration by E. coli. Fumarate reductase, which is proficient in succinate oxidation, is able to functionally replace SQR in aerobic respiration when conditions are used to allow the expression of the frdABCD operon aerobically. SQR has not previously been shown to be capable of supporting anaerobic growth ofE. coli because expression of the enzyme complex is largely repressed by anaerobic conditions. In order to obtain expression of SQR anaerobically, plasmids which utilize the PFRD promoter of the frdABCD operon fused to the sdhCDAB genes to drive expression were constructed. It was found that, under anaerobic growth conditions where fumarate is utilized as the terminal electron acceptor, SQR would function to support anaerobic growth ofE. coli. The levels of amplification of SQR and QFR were similar under anaerobic growth conditions. The catalytic properties of SQR isolated from anaerobically grown cells were measured and found to be identical to those of enzyme produced aerobically. The anaerobic expression of SQR gave a greater yield of enzyme complex than was found in the membrane from aerobically grown cells under the conditions tested. In addition, it was found that anaerobic expression of SQR could saturate the capacity of the membrane for incorporation of enzyme complex. As has been seen with the amplified QFR complex, E. coli accommodates the excess SQR produced by increasing the amount of membrane. The excess membrane was found in tubular structures that could be seen in thin-section electron micrographs.

scholarly journals Functional anaerobic electron transport linked to the reduction of nitrate and fumarate in membranes from Escherichia coli as demonstrated by quenching of atebrin fluorescence

1975 ◽  
Vol 152 (3) ◽  
pp. 655-659 ◽  
Author(s):  
B A Haddock ◽  
M W Kendall-Tobias
Keyword(s):  
Escherichia Coli ◽  
Electron Transport ◽  
Carbon Source ◽  
Electron Acceptor ◽  
Functional Organization ◽  
Terminal Electron Acceptor ◽  
Membrane Particles ◽  
Electron Transport Chains ◽  
Anaerobic Electron Transport ◽  
Energy Dependent

Measurements were made of energy-dependent quenching of atebrin fluorescence in membrane particles prepared from Escherichia coli grown anaerobically with glycerol as carbon source in the presence of either nitrate or fumarate. It is concluded that this technique can be used to study the functional organization of the anaerobic proton-translocating electron-transport chains that use nitrate or fumarate as terminal electron acceptor.

scholarly journals The role of the membrane-bound hydrogenase in the energy-conserving oxidation of molecular hydrogen by Escherichia coli

1980 ◽  
Vol 188 (2) ◽  
pp. 345-350 ◽  
Author(s):  
R W Jones
Keyword(s):  
Escherichia Coli ◽  
Electron Acceptor ◽  
Cytoplasmic Membrane ◽  
Proton Translocation ◽  
Terminal Electron Acceptor ◽  
Benzyl Viologen ◽  
Carbonyl Cyanide ◽  
Energy Conserving ◽  
Membrane Bound ◽  
Hydroxy Quinoline

H2-dependent reduction of fumarate and nitrate by spheroplasts from Escherichia coli is coupled to the translocation of protons across the cytoplasmic membrane. The leads to H+/2e- stoicheiometry (g-ions of H+ translocated divided by mol of H2 added) is approx. 2 with fumarate and approx. 4 with nitrate as electron acceptor. This proton translocation is dependent on H2 and a terminal electron acceptor and is not observed in the presence of the protonophore carbonyl cyanide m-chlorophenylhydrazone and the respiratory inhibitor 2-n-heptyl-4-hydroxyquinoline N-oxide. H2-dependent reduction of menadione and ubiquinone-1 is coupled to a protonophore-sensitive, but 2-n-heptyl-4-hydroxy-quinoline N-oxide-insensitive, proton translocation with leads to H+/2e- stoicheiometry of approx. 2. H2-dependent reduction of Benzyl Viologen (BV++) to its radical (BV+) liberates protons at the periplasmic aspect of the cytoplasmic membrane according to the reaction: H2 + 2BV++ leads to 2H+ + 2BV+. It is concluded that the effective proton translocation observed in the H2-oxidizing segment of the anaerobic respiratory chain of Escherichia coli arises as a direct and inevitable consequence of transmembranous electron transfer between protolytic reactions that are spatially separated by a membrane of low proton-permeability.

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