Microaerobic denitrification in Neisseria meningitidis

The major aetiological agent of human bacterial meningitis is Neisseria meningitidis. During the course of disease and host colonization, the bacterium has to withstand limited oxygen availability. Nitrogen oxide and nitrogen oxyanions are thought to be present, which may constitute an alternative sink for electrons from the N. meningitidis respiratory chain. A partial denitrification pathway is encoded by the aniA nitrite reductase gene and the norB nitric oxide reductase gene. Analysis of the completed genome sequences of two N. meningitidis strains is used to generate a model for the membrane-associated respiratory chain of this organism. Analysis of aniA expression indicates it to be controlled primarily by oxygen and secondarily by nitrite. The ability of N. meningitidis to denitrify relies on microaerobic growth conditions. Here we show that under microaerobic conditions nitrite supplements oxygen as an alternative respiratory substrate.

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Organization of the respiratory chain of Neisseria meningitidis

Biochemical Society Transactions ◽

10.1042/bst0340139 ◽

2006 ◽

Vol 34 (1) ◽

pp. 139-142 ◽

Cited By ~ 10

Author(s):

M. Deeudom ◽

J. Rock ◽

J. Moir

Keyword(s):

Nitric Oxide ◽

Neisseria Meningitidis ◽

Cytochrome Oxidase ◽

Nitrite Reductase ◽

Electron Flow ◽

Bc1 Complex ◽

Nitric Oxide Reductase ◽

Intact Cells ◽

Nitrite Reductase Gene ◽

Reductase Gene

The ability of Neisseria meningitidis to utilize both oxygen and nitrogen oxides as respiratory substrates allows it to thrive in the diverse environment of the human host. Genome analysis highlighted genes encoding a cbb3 cytochrome oxidase, the aniA nitrite reductase gene and the norB nitric oxide reductase gene. In the present study, we used myxothiazol as an inhibitor of the bc1 complex in intact cells and demonstrated that electron flow to nitrite reductase and the cytochrome oxidase, but not NO reductase, passes via the cytochrome bc1 complex. UV–visible spectrophotometry of intact cells demonstrated that oxygen oxidizes c-type and b-type cytochromes. Oxidation of cytochromes by nitrite was only seen in microaerobically precultured whole cells, and the predominant oxidizable cytochromes were b-type. These are likely to be associated with the oxidation of a b-haem-containing nitric oxide reductase. Nitrite inhibits the oxidation of cytochromes by oxygen in a nitrite reductase-independent manner, indicating that nitrite may inhibit oxidase activity directly, as well as via the intermediate of denitrification, nitric oxide.

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The nitrite reductase gene of Pseudomonas aeruginosa: Effect of growth conditions on the expression and construction of a mutant by gene disruption

FEMS Microbiology Letters ◽

10.1111/j.1574-6968.1993.tb06175.x ◽

1993 ◽

Vol 109 (2-3) ◽

pp. 243-250 ◽

Cited By ~ 17

Author(s):

Elisabetta Zennaro ◽

Ilaria Ciabatti ◽

Francesca Cutruzzola ◽

Rosanna D'Alessandro ◽

Maria Chiara Silvestrini

Keyword(s):

Pseudomonas Aeruginosa ◽

Nitrite Reductase ◽

Gene Disruption ◽

Growth Conditions ◽

Nitrite Reductase Gene ◽

Reductase Gene

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Genomic Characterization of Urethritis-Associated Neisseria meningitidis Shows that a Wide Range of N. meningitidis Strains Can Cause Urethritis

Journal of Clinical Microbiology ◽

10.1128/jcm.01018-17 ◽

2017 ◽

Vol 55 (12) ◽

pp. 3374-3383 ◽

Cited By ~ 14

Author(s):

Kevin C. Ma ◽

Magnus Unemo ◽

Samo Jeverica ◽

Robert D. Kirkcaldy ◽

Hideyuki Takahashi ◽

...

Keyword(s):

Neisseria Meningitidis ◽

Etiologic Agent ◽

Factor H ◽

Urogenital Tract ◽

Genetic Characteristics ◽

Content Type ◽

Nitrite Reductase Gene ◽

Reductase Gene ◽

Wide Range ◽

Genomic Characterization

ABSTRACTNeisseria meningitidis, typically a resident of the oro- or nasopharynx and the causative agent of meningococcal meningitis and meningococcemia, is capable of invading and colonizing the urogenital tract. This can result in urethritis, akin to the syndrome caused by its sister species,N. gonorrhoeae, the etiologic agent of gonorrhea. Recently, meningococcal strains associated with outbreaks of urethritis were reported to share genetic characteristics with the gonococcus, raising the question of the extent to which these strains contain features that promote adaptation to the genitourinary niche, making them gonococcus-like and distinguishing them from otherN. meningitidisstrains. Here, we analyzed the genomes of 39 diverseN. meningitidisisolates associated with urethritis, collected independently over a decade and across three continents. In particular, we characterized the diversity of the nitrite reductase gene (aniA), the factor H-binding protein gene (fHbp), and the capsule biosynthetic locus, all of which are loci previously suggested to be associated with urogenital colonization. We observed notable diversity, including frameshift variants, inaniAandfHbpand the presence of intact, disrupted, and absent capsule biosynthetic genes, indicating that urogenital colonization and urethritis caused byN. meningitidisare possible across a range of meningococcal genotypes. Previously identified allelic patterns in urethritis-associatedN. meningitidisstrains may reflect genetic diversity in the underlying meningococcal population rather than novel adaptation to the urogenital tract.

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Molecular Cloning and Characterization of Nitrite Reductase Gene from Sugarbeet

ACTA AGRONOMICA SINICA ◽

10.3724/sp.j.1006.2011.01406 ◽

2011 ◽

Vol 37 (8) ◽

pp. 1406-1414

Author(s):

Xiao-Yan SHI ◽

Yan-Da ZENG ◽

Shi-Long LI ◽

Yu-Bo WANG ◽

Feng-Ming MA ◽

...

Keyword(s):

Molecular Cloning ◽

Nitrite Reductase ◽

Nitrite Reductase Gene ◽

Reductase Gene

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Coaction of light, nitrate and a plastidic factor in controlling nitrite-reductase gene expression in spinach

Planta ◽

10.1007/bf00208239 ◽

1991 ◽

Vol 184 (1) ◽

Cited By ~ 19

Author(s):

B. Seith ◽

C. Schuster ◽

H. Mohr

Keyword(s):

Gene Expression ◽

Nitrite Reductase ◽

Nitrite Reductase Gene ◽

Reductase Gene ◽

Plastidic Factor

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Photocontrol of nitrite reductase gene expression in the barley seedling (Hordeum vulgare L.)

Planta ◽

10.1007/bf00198700 ◽

1993 ◽

Vol 192 (1) ◽

Author(s):

B. Seith ◽

A. Sherman ◽

J.L. Wray ◽

H. Mohr

Keyword(s):

Gene Expression ◽

Hordeum Vulgare ◽

Nitrite Reductase ◽

Barley Seedling ◽

Hordeum Vulgare L ◽

Nitrite Reductase Gene ◽

Reductase Gene

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Bacterial Life and Dinitrogen Fixation at a Gypsum Rock

Applied and Environmental Microbiology ◽

10.1128/aem.70.12.7070-7077.2004 ◽

2004 ◽

Vol 70 (12) ◽

pp. 7070-7077 ◽

Cited By ~ 55

Author(s):

Gudrun Boison ◽

Alexander Mergel ◽

Helena Jolkver ◽

Hermann Bothe

Keyword(s):

Nitrogenase Activity ◽

Dinitrogen Fixation ◽

Molecular Techniques ◽

Low Light ◽

Light Intensities ◽

Bluish Green ◽

Reductase Gene ◽

Gypsum Rock ◽

Microaerobic Conditions ◽

Reduced Light

ABSTRACT The organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. The cyanobacterial consortium consisted almost exclusively of Chroococcidiopsis spp. The organisms of the shards expressed nitrogenase activity (C2H2 reduction) aerobically and in light. After a prolonged period of drought at the rock, the cells were inactive, but they resumed nitrogenase activity 2 to 3 days after the addition of water. In a suspension culture of Chroococcidiopsis sp. strain PCC7203, C2H2 reduction required microaerobic conditions and was strictly dependent on low light intensities. Sequencing of a segment of the nitrogenase reductase gene (nifH) indicated that Chroococcidiopsis possesses the alternative molybdenum nitrogenase 2, expressed in Anabaena variabilis only under reduced O2 tensions, rather than the widespread, common molybdenum nitrogenase. The shards apparently provide microsites with reduced light intensities and reduced O2 tension that allow N2 fixation to proceed in the unicellular Chroococcidiopsis at the gypsum rock, unless the activity is due to minute amounts of other, very active cyanobacteria. Phylogenetic analysis of nifH sequences tends to suggest that molybdenum nitrogenase 2 is characteristic of those unicellular or filamentous, nonheterocystous cyanobacteria fixing N2 under microaerobic conditions only.

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Comparative analysis of the bioenergetics of human adenocarcinoma Caco-2 cell line and postoperative tissue samples from colorectal cancer patients

Biochemistry and Cell Biology ◽

10.1139/bcb-2018-0076 ◽

2018 ◽

Vol 96 (6) ◽

pp. 808-817 ◽

Cited By ~ 3

Author(s):

Lyudmila Ounpuu ◽

Laura Truu ◽

Igor Shevchuk ◽

Vladimir Chekulayev ◽

Aleksandr Klepinin ◽

...

Keyword(s):

Colorectal Cancer ◽

Cell Line ◽

Respiratory Chain ◽

Growth Conditions ◽

Control Analysis ◽

Respiratory Chain Complexes ◽

Colon Tissue ◽

Tissue Samples

The aim of this work was to explore the key bioenergetic properties for mitochondrial respiration in the widely-used Caco-2 cell line and in human colorectal cancer (HCC) postoperational tissue samples. Oxygraphy and metabolic control analysis (MCA) were applied to estimate the function of oxidative phosphorylation in cultured Caco-2 cells and HCC tissue samples. The mitochondria of Caco-2 cells and HCC tissues displayed larger functional activity of respiratory complex (C)II compared with CI, whereas in normal colon tissue an inverse pattern in the ratio of CI to CII activity was observed. MCA showed that the respiration in Caco-2 and HCC tissue cells is regulated by different parts of electron transport chain. In HCC tissues, this control is performed essentially at the level of respiratory chain complexes I–IV, whereas in Caco-2 cells at the level of CIV (cytochrome c oxidase) and the ATP synthasome. The differences we found in the regulation of respiratory chain activity and glycose index could represent an adaptive response to distinct growth conditions; this highlights the importance of proper validation of results obtained from in-vitro models before their extrapolation to the more complex in-vivo systems.

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