Oxygen increases the steady-state level of nitrate in denitrifying cells of,<i>Paracoccus denitrificans</i>

Kučera, Igor; Zeman, A.

doi:10.1111/j.1574-6968.1996.tb08572.x

Cited by 5 publications

(3 citation statements)

References 12 publications

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“…The possibility that the control of nitrogen oxyanion transport by oxygen is exerted at the level of nitrite transport (i.e. type II NarK) is lent support by the findings of Kucera and co-workers [9] that in the presence of oxygen intracellular nitrate concentration is higher than under anaerobic conditions. A working model for nitrate and nitrite transport via type I and type II NarK, the effect of mutation of the type II transporter and the impact of oxidising conditions on nitrite accumulation and hence inhibition of nitrate uptake via the type I transporter is presented in figure 5.…”

Section: Multi-author Review Articlesupporting

confidence: 54%

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Nitrate and nitrite transport in bacteria

Moir¹,

Wood²

2001

CMLS, Cell. Mol. Life Sci.

158

121

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The topological arrangements of nitrate and nitrite reductases in bacteria necessitate the synthesis of transporter proteins that carry the nitrogen oxyanions across the cytoplasmic membrane. For assimilation of nitrate (and nitrite) there are two types of uptake system known: ABC transporters that are driven by ATP hydrolysis, and secondary transporters reliant on a proton motive force. Proteins homologous to the latter type of transporter are also involved in nitrate and nitrite transport in dissimilatory processes such as denitrification. These proteins belong to the NarK family, which is a branch of the Major Facilitator Superfamily. The mechanism and substrate specificity of transport via these proteins is unknown, but is discussed in the light of sequence analysis of members of the NarK family. A hypothesis for nitrate and nitrite transport is proposed based on the finding that there are two distinct types of NarK.

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Section: Multi-author Review Articlesupporting

confidence: 54%

“…Kucera and co-workers [9] measured internally accumulated nitrate in whole cells of P. denitrificans. Provision of oxygen (via the catalytic action of catalase on hydrogen peroxide) actually led to an increase in the steadystate nitrate pool inside the cell.…”

Section: Multi-author Review Articlementioning

confidence: 99%

Nitrate and nitrite transport in bacteria

Moir¹,

Wood²

2001

CMLS, Cell. Mol. Life Sci.

158

121

View full text Add to dashboard Cite

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“…For many years, denitrification was considered an anaerobic respiratory process in which the first step was catalyzed by the classical membranebound nitrate reductase (Ferguson 1994;Zumft 1997;Zumft and Körner 1997). Correspondingly, synthesis and activity of this enzyme are repressed by oxygen (Alefounder and Ferguson 1980;Alefounder et al 1983;Baumann et al 1996;Kucera et al 1996). However, in Pseudomonas sp.…”

Section: Introductionmentioning

confidence: 97%

Identification and characterization of a periplasmic nitrate reductase in Azospirillum brasilense Sp245

Steenhoudt

Keijers

Okon

et al. 2001

Archives of Microbiology

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The Azospirillum brasilense Sp245 napABC genes, encoding nitrate reductase activity, were isolated and sequenced. The derived protein sequences are very similar throughout the whole Nap segment to the NapABC protein sequences of Escherichia coli, Pseudomonas sp. G-179, Ralstonia eutropha, Rhodobacter sphaeroides, and Paracoccus denitrificans. Based on whole-cell nitrate reductase assays with the artificial electron donors benzyl viologen and methyl viologen, and assays with periplasmic cell-free extracts, it was concluded that the napABC-encoded enzyme activity in Azospirillum brasilense Sp245 corresponds to a periplasmic dissimilatory nitrate reductase, which was expressed under anoxic conditions and oxic conditions. A kanamycin-resistant Azospirillum brasilense Sp245 napA insertion mutant was constructed. The mutant still expressed assimilatory nitrate reductase activity, but was devoid of its periplasmic dissimilatory nitrate reductase activity.

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Competition between oxygen and nitrate respirations in continuous culture of Pseudomonas aeruginosa performing aerobic denitrification

Chen

Xia

2006

Biotech & Bioengineering

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Continuous culture of P. aeruginosa was conducted with nitrate-containing media under the dilution rates (D) of 0.026, 0.06, and 0.13/h and the dissolved oxygen concentrations (DO) of 0-2.2 mg/L. The bacterium performed simultaneous O(2) and nitrate respiration in all of the systems studied. For each D, the (apparent) cell yield from glucose (Y(X/S)) was lower at zero DO, but did not change substantially with non-zero DO. In non-zero DO systems, Y(X/S) increased with increasing D, and when fit with a model considering cell death, gave the following parameters: maximum cell yield Y(X/S) (m) = 0.49, maintenance coefficient M(S) = 0.029 (/h), and cell decay constant k(d) = 0.014/h. The same model failed to describe the behaviors of zero-DO systems, where neither glucose nor nitrate was limiting and the limiting factor(s) remained unknown. The cell yield from accepted electron (Y(X/e)) was however relatively constant in all systems, and the energy yield per electron accepted via denitrification was estimated at approximately 69% of that via O(2) respiration. A closer examination revealed that increasing DO enhanced O(2) respiration only at extremely low DO ( <0.05 mg/L), beyond which the increasing DO only slightly increased its weak inhibition on denitrification. While O(2) was the preferred electron acceptor, the fraction of electrons accepted via denitrification increased with increasing D.

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Oxygen increases the steady-state level of nitrate in denitrifying cells of,Paracoccus denitrificans

Cited by 5 publications

References 12 publications

Nitrate and nitrite transport in bacteria

Nitrate and nitrite transport in bacteria

Identification and characterization of a periplasmic nitrate reductase in Azospirillum brasilense Sp245

Competition between oxygen and nitrate respirations in continuous culture of Pseudomonas aeruginosa performing aerobic denitrification

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