Pyruvate:ferredoxin oxidoreductase in Campylobacter species

1995 ◽  
Vol 41 (2) ◽  
pp. 198-201 ◽  
Author(s):  
James A. Daucher ◽  
Noel R. Krieg
Keyword(s):  
Clostridium Pasteurianum ◽  
Benzyl Viologen ◽  
Minimal Inhibitory Concentrations ◽  
Ferredoxin Oxidoreductase ◽  
Crude Extracts ◽  
Reducing Activity ◽  
Pyruvate Ferredoxin Oxidoreductase ◽  
Pyruvate:Ferredoxin Oxidoreductase ◽  
Campylobacter Species

Twelve strains representing 11 Campylobacter species were tested by two methods to see whether pyruvate:ferredoxin oxidoreductase, which occurs mainly in anaerobes, was also present in these oxygen-respiring microaerophiles. Crude extracts exhibited a pyruvate-dependent reduction of benzyl viologen and, to a lesser extent, metronidazole. Addition of Clostridium pasteurianum ferredoxin enhanced the metronidazole-reducing activity. All strains were inhibited by metronidazole, with minimal inhibitory concentrations ranging from 3 to 25 μg/mL. The results suggest that pyruvate: ferredoxin oxidoreductase is characteristic of the genus.Key words: Campylobacter, microaerophilic, metronidazole, pyruvate.

Pyruvate oxidation by the Reiter strain of Treponema phagedenis

1982 ◽  
Vol 152 (3) ◽  
pp. 1060-1065
Author(s):  
H A George ◽  
R M Smibert
Keyword(s):  
Gel Filtration ◽  
Deae Cellulose ◽  
Treponema Denticola ◽  
Benzyl Viologen ◽  
Iron Chelate ◽  
Electron Carrier ◽  
Pyruvate Oxidation ◽  
Crude Extracts ◽  
Pyruvate:Ferredoxin Oxidoreductase ◽  
Triton X

Spectrophotometric assays of pyruvate oxidation catalyzed by extracts of the Reiter strain of Treponema phagedenis indicated that viologen dyes, flavin nucleotides, and a ferric iron chelate, but not pyridine nucleotides, were utilized as electron acceptors. Benzyl viologen-linked activity partially sedimented during ultracentrifugation and appeared similar to clostridial pyruvate:ferredoxin oxidoreductase with respect to the spectral properties of the enzyme chromophore. Electron carrier activity in treponemal extracts was quantitated by a metronidazole-linked assay in which the oxidation of pyruvate by carrier-depleted extracts led to the reduction of electron carrier in the crude extracts which then reduced metronidazole. The rate of metronidazole reduction was proportional to the amount of electron carrier present in the assay. Electron carrier activity in Triton X-100-solubilized, crude extracts partially purified by DEAE-cellulose chromatography and gel filtration was attributed to a protein possessing the spectral and physical properties of a ferredoxin. A similar protein appeared to be present in extracts of Treponema denticola ST10.

scholarly journals Pyruvate-Ferredoxin Oxidoreductase

1971 ◽  
Vol 246 (10) ◽  
pp. 3120-3125
Author(s):  
Kosaku Uyeda ◽  
Jesse C. Rabinowitz
Keyword(s):  
Ferredoxin Oxidoreductase ◽  
Pyruvate Ferredoxin Oxidoreductase

Aerobic resistance of Trichomonas vaginalis to metronidazole induced in vitro

Parasitology ◽  
1993 ◽  
Vol 106 (1) ◽  
pp. 31-37 ◽  
Author(s):  
J. Tachezy ◽  
J. Kulda ◽  
E. Tomková
Keyword(s):  
Parent Strain ◽  
Trichomonas Vaginalis ◽  
Drug Resistant ◽  
Ferredoxin Oxidoreductase ◽  
Low Concentrations ◽  
Percent Concentration ◽  
Resistant Strains ◽  
Pyruvate Ferredoxin Oxidoreductase

SUMMARYAerobic resistance of Trichomonas vaginalis to metronidazole was induced in vitro by anaerobic cultivation of drug-susceptible trichomonads with low concentrations of the drug (2–3 μg/ml) for 50 days. Minimal lethal concentrations (MLC) for metronidazole of the resistant derivatives were high in aerobic susceptibility assays (MLC = 216–261.5 μg/ml) but low in anaerobic assays (MLC = 4.2–6.3 μg/ml), surpassing MLC values of their parent strain approximately 50-fold and 3-fold under aerobiosis and anaerobiosis, respectively. Sensitivity to metronidazole under anaerobic conditions and activity of the hydrogenosomal enzyme pyruvate: ferredoxin oxidoreductase indicated that the resistance was of the aerobic type. Dependence of the resistance manifestation on O2 was further confirmed by susceptibility assays in vitro performed in defined gas mixtures of different oxygen content (1–20%). Five percent concentration of O2 proved to be the threshold required for resistance demonstration and the MLC values further increased with increasing O2 concentrations. The in vitro-induced resistance was also demonstrated in vivo by subcutaneous mouse assay. The dose of metronidazole needed to cure 50% of infected mice (DC50) was 223 mg/kg × 3 for resistant derivative MR-3a but 6.6 mg/kg × 3 only for its drug-susceptible parent strain. The metronidazole – resistant strains developed in this study correspond by their properties to drug-resistant T. vaginalis strains isolated from patients refractory to treatment, and promise to be a useful tool in the study of 5-nitroimidazole aerobic resistance.

The effects of differing concentrations of CO2 and O2 on the fermentative metabolism of the rumen fungi Neocallimastix patriciarum and Neocallimastix frontalis L2

1998 ◽  
Vol 44 (9) ◽  
pp. 819-824 ◽  
Author(s):  
Elizabeth MR Rees ◽  
David Lloyd ◽  
Alan G Williams
Keyword(s):  
Gas Phase ◽  
Glucose Utilization ◽  
Relative Proportion ◽  
Gas Production ◽  
Ferredoxin Oxidoreductase ◽  
Fermentative Metabolism ◽  
Fungal Isolates ◽  
Neocallimastix Patriciarum ◽  
Neocallimastix Frontalis ◽  
Pyruvate Ferredoxin Oxidoreductase

The effects of decreasing the concentration of CO2 and introducing up to 10% O2 into the headspace gases on the fermentative metabolism of the rumen fungi Neocallimastix patriciarum and Neocallimastix frontalis L2 were investigated. The relative proportion of metabolites produced by both fungi depended on the concentration of CO2 in the headspace. Under lowered CO2 levels, both fungi produced increased acetate, lactate, and H2, whereas the production of ethanol, formate, and (in the case of N. frontalis L2) succinate decreased. Lowered CO2 concentrations also decreased the rate of glucose utilization and cumulative gas production by both fungal isolates. In addition, decreased CO2 levels resulted in decreases in NAD(P)H ferredoxin oxidoreductase and hydrogenase activities, whereas malate dehydrogenase and pyruvate ferredoxin oxidoreductase activities were increased. Both N. patriciarum and N. frontalis L2 required at least 7% CO2 in the gas phase for growth. Both isolates also showed a degree of aerotolerance as they grew when exposed to 5% O2; they also grew in media lacking a reducing agent, providing that O2 was initially <1% of the total headspace concentration.Key words: rumen fungi, Neocallimastix, metabolism, carbon dioxide, oxygen.

Octomeric pyruvate-ferredoxin oxidoreductase from Desulfovibrio vulgaris

2007 ◽  
Vol 159 (1) ◽  
pp. 9-18 ◽  
Author(s):  
F GARCZAREK ◽  
M DONG ◽  
D TYPKE ◽  
H WITKOWSKA ◽  
T HAZEN ◽  
...  
Keyword(s):  
Desulfovibrio Vulgaris ◽  
Ferredoxin Oxidoreductase ◽  
Pyruvate Ferredoxin Oxidoreductase
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