Exemplar Abstract for Paracoccus pantotrophus (Robertson and Kuenen 1984) Rainey et al. 1999 emend. Hördt et al. 2020 and Thiosphaera pantotropha Robertson and Kuenen 1984.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Thiosphaera Pantotropha ◽  
Paracoccus Pantotrophus

Nomenclature Abstract for Thiosphaera pantotropha Robertson and Kuenen 1984.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Thiosphaera Pantotropha

Voltammetric characterization of the aerobic energy-dissipating nitrate reductase of Paracoccus pantotrophus: exploring the activity of a redox-balancing enzyme as a function of electrochemical potential

2007 ◽  
Vol 409 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Andrew J. Gates ◽  
David J. Richardson ◽  
Julea N. Butt
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Reduction ◽  
Reductase Activity ◽  
Electrochemical Potential ◽  
Intact Cells ◽  
Protein Film ◽  
Protein Film Voltammetry ◽  
Voltammetric Studies ◽  
Paracoccus Pantotrophus

Paracoccus pantotrophus expresses two nitrate reductases associated with respiratory electron transport, termed NapABC and NarGHI. Both enzymes derive electrons from ubiquinol to reduce nitrate to nitrite. However, while NarGHI harnesses the energy of the quinol/nitrate couple to generate a transmembrane proton gradient, NapABC dissipates the energy associated with these reducing equivalents. In the present paper we explore the nitrate reductase activity of purified NapAB as a function of electrochemical potential, substrate concentration and pH using protein film voltammetry. Nitrate reduction by NapAB is shown to occur at potentials below approx. 0.1 V at pH 7. These are lower potentials than required for NarGH nitrate reduction. The potentials required for Nap nitrate reduction are also likely to require ubiquinol/ubiquinone ratios higher than are needed to activate the H+-pumping oxidases expressed during aerobic growth where Nap levels are maximal. Thus the operational potentials of P. pantotrophus NapAB are consistent with a productive role in redox balancing. A Michaelis constant (KM) of approx. 45 μM was determined for NapAB nitrate reduction at pH 7. This is in line with studies on intact cells where nitrate reduction by Nap was described by a Monod constant (KS) of less than 15 μM. The voltammetric studies also disclosed maximal NapAB activity in a narrow window of potential. This behaviour is resistant to change of pH, nitrate concentration and inhibitor concentration and its possible mechanistic origins are discussed.

scholarly journals Identification of the DNA region responsible for sulfur-oxidizing ability of Thiosphaera pantotropha.

1991 ◽  
Vol 173 (22) ◽  
pp. 7340-7344 ◽  
Author(s):  
G Mittenhuber ◽  
K Sonomoto ◽  
M Egert ◽  
C G Friedrich
Keyword(s):  
Thiosphaera Pantotropha ◽  
Sulfur Oxidizing

scholarly journals Urea production by Thiosphaera pantotropha and by anaerobic enrichment cultures from marine sediments

1993 ◽  
Vol 13 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Henning Pedersen ◽  
Bente Aa. Lomstein ◽  
Mai F. Isaksen ◽  
T. Henry Blackburn
Keyword(s):  
Marine Sediments ◽  
Thiosphaera Pantotropha ◽  
Enrichment Cultures ◽  
Urea Production
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