scholarly journals Involvement of the cbb3-Type Terminal Oxidase in Growth Competition of Bacteria, Biofilm Formation, and in Switching between Denitrification and Aerobic Respiration

2020 ◽  
Vol 8 (8) ◽  
pp. 1230
Author(s):  
Igor Kučera ◽  
Vojtěch Sedláček
Keyword(s):  
Paracoccus Denitrificans ◽  
Aerobic Denitrification ◽  
Wild Type ◽  
Bacterial Strains ◽  
Aerobic Growth ◽  
Limited Growth ◽  
Terminal Oxidases ◽  
Ubiquinol Oxidase ◽  
Fitness Advantage ◽  
Transport Chain

Paracoccus denitrificans has a branched electron transport chain with three terminal oxidases transferring electrons to molecular oxygen, namely aa3-type and cbb3-type cytochrome c oxidases and ba3-type ubiquinol oxidase. In the present study, we focused on strains expressing only one of these enzymes. The competition experiments showed that possession of cbb3-type oxidase confers significant fitness advantage during oxygen-limited growth and supports the biofilm lifestyle. The aa3-type oxidase was shown to allow rapid aerobic growth at a high oxygen supply. Activity of the denitrification pathway that had been expressed in cells grown anaerobically with nitrate was fully inhibitable by oxygen only in wild-type and cbb3 strains, while in strains aa3 and ba3 dinitrogen production from nitrate and oxygen consumption occurred simultaneously. Together, the results highlight the importance of the cbb3-type oxidase for the denitrification phenotype and suggest a way of obtaining novel bacterial strains capable of aerobic denitrification.

scholarly journals Impact of either Elevated or Decreased Levels of Cytochrome bd Expression on Shigella flexneri Virulence

1999 ◽  
Vol 181 (4) ◽  
pp. 1229-1237 ◽  
Author(s):  
Sing Sing Way ◽  
Sandra Sallustio ◽  
Richard S. Magliozzo ◽  
Marcia B. Goldberg
Keyword(s):  
Shigella Flexneri ◽  
Lethal Dose ◽  
Fold Increase ◽  
Intracellular Survival ◽  
Bacterial Invasion ◽  
Wild Type ◽  
Terminal Oxidases ◽  
Cytochrome Bd ◽  
Transport Chain ◽  
Pathogenic Process

ABSTRACT Shigella spp. are the major cause of bacillary dysentery worldwide. The pathogenic process involves bacterial invasion and lysis of the phagocytic vacuole, followed by replication and movement within the cell cytoplasm and, ultimately, spread directly into adjacent cells. This study demonstrates that S. flexneri cytochrome bd expression is necessary for normal intracellular survival and virulence. Cytochrome bdis one of two terminal oxidases in the bacterial respiratory chain that reduce molecular oxygen to water, utilizing intermediates shuttled through the electron transport chain. S. flexneri mutants that contain a disruption in the cydC locus, which leads to defective cytochrome bd expression, or in the riboflavin (ribE) or ubiquinol-8 (ubiH) biosynthetic pathway, which leads to elevated cytochrome bd expression, were evaluated in intracellular survival and virulence assays. ThecydC mutant formed significantly smaller plaques, had significantly decreased intracellular survival, and had a 100-fold increase in lethal dose for mice compared with the wild type. TheribE and ubiH mutants each formed significantly larger plaques and had a 10-fold decrease in lethal dose for mice compared with the wild type. The data indicate that expression of cytochrome bd is required for S. flexneriintracellular survival and virulence.

Proton translocation coupled to ubiquinol oxidation in Paracoccus denitrificans

1979 ◽  
Vol 57 (2) ◽  
pp. 172-177 ◽  
Author(s):  
Hugh G. Lawford
Keyword(s):  
Respiratory Chain ◽  
Oxidase Activity ◽  
Paracoccus Denitrificans ◽  
Electron Flow ◽  
Proton Translocation ◽  
Energy Coupling ◽  
Ubiquinol Oxidase ◽  
Transport Chain ◽  
Flow Through ◽  
Chemiosmotic Coupling

Measurements were made of the stoichiometry of proton translocation associated with electron flow through the cytochrome-dependent region of the aerobically induced respiratory chain of Paracoccus denitrificans using the pulse oxidant method and rotenone to inhibit NADH dehydrogenase activity. Paracoccus denitrificans (ATCC 13543) was grown aerobically in carbon-limited continuous culture D = 0.27 h−1D, dilution rate per hour) with succinate as sole carbon and energy source. Oxidation of exogenous ubiquinol1 by starved cells was significantly accelerated by treatment of the cells with lysozyme. Spectrophotometric assay of ubiquinol1 oxidase activity in rotenone-poisoned spheroplasts revealed an apparent Km of 25 μM and a Vmax of 217 nmol/min per milligram protein. In site 1 poisoned spheroplasts proton translocation was dependent on the presence of added respiratory substrate, either succinate or ubiquinol1, where the observed ratios of protons ejected from the membrane per atom of oxygen consumed (← H+: O) were 5.3 and 5.2 respectively. The rate of proton translocation associated with succinate and ubiquinol1 oxidation was significantly decreased in the presence of antimycin A and completely abolished with cyanide. Net proton translocation was not observed after the addition of uncoupler (CCCP). Assuming there are two potential sites of energy conservation associated with the region of the respiratory chain from ubiquinone to cytochrome oxidase (i.e., ubiquinol oxidase activity), then the number of protons ejected during the transfer of one pair of reducing equivalents along a region of the electron transport chain equivalent to a single energy-coupling or conservation site (← H+: site) ratio in P. denitrificans is closer to 3 than 2 as predicted by Mitchell's chemiosmotic coupling hypothesis.

Ferrous iron oxidation in moderately thermophilic acidophile Sulfobacillus sibiricus N1T

2010 ◽  
Vol 56 (10) ◽  
pp. 803-808 ◽  
Author(s):  
Tatiana Y. Dinarieva ◽  
Anna E. Zhuravleva ◽  
Oksana A. Pavlenko ◽  
Iraida A. Tsaplina ◽  
Alexander I. Netrusov
Keyword(s):  
Ferrous Iron ◽  
High Performance ◽  
Iron Oxidation ◽  
Early Exponential Phase ◽  
Moderately Thermophilic ◽  
Terminal Oxidases ◽  
Cytochrome Bo ◽  
Ferrous Iron Oxidation ◽  
Transport Chain ◽  
Membrane Bound

The iron-oxidizing system of a moderately thermophilic, extremely acidophilic, gram-positive mixotroph, Sulfobacillus sibiricus N1T, was studied by spectroscopic, high-performance liquid chromatography and inhibitory analyses. Hemes B, A, and O were detected in membranes of S. sibiricus N1T. It is proposed that the electron transport chain from Fe2+ to O2 is terminated by 2 physiological oxidases: aa3-type cytochrome, which dominates in the early-exponential phase of growth, and bo3-type cytochrome, whose role in iron oxidation becomes more prominent upon growth of the culture. Both oxidases were sensitive to cyanide and azide. Cytochrome aa3 was more sensitive to cyanide and azide, with Ki values of 4.1 and 2.5 µmol·L–1, respectively, compared with Ki values for cytochrome bo3, which were 9.5 µmol·L–1 for cyanide and 7.0 µmol·L–1 for azide. This is the first evidence for the participation of a bo3-type oxidase in ferrous iron oxidation. The respiratory chain of the mixotroph contains, in addition to the 2 terminal oxidases, a membrane-bound cytochrome b573.

scholarly journals Somatic production of reactive oxygen species does not predict its production in sperm cells across Drosophila melanogaster lines

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Biz R. Turnell ◽  
Luisa Kumpitsch ◽  
Anne-Cécile Ribou ◽  
Klaus Reinhardt
Keyword(s):  
Reactive Oxygen Species ◽  
Drosophila Melanogaster ◽  
Reactive Oxygen ◽  
Future Research ◽  
Ros Production ◽  
Oxygen Species ◽  
Loss Of Function ◽  
Wild Type ◽  
Ros Scavenging ◽  
Transport Chain

Abstract Objective Sperm ageing has major evolutionary implications but has received comparatively little attention. Ageing in sperm and other cells is driven largely by oxidative damage from reactive oxygen species (ROS) generated by the mitochondria. Rates of organismal ageing differ across species and are theorized to be linked to somatic ROS levels. However, it is unknown whether sperm ageing rates are correlated with organismal ageing rates. Here, we investigate this question by comparing sperm ROS production in four lines of Drosophila melanogaster that have previously been shown to differ in somatic mitochondrial ROS production, including two commonly used wild-type lines and two lines with genetic modifications standardly used in ageing research. Results Somatic ROS production was previously shown to be lower in wild-type Oregon-R than in wild-type Dahomey flies; decreased by the expression of alternative oxidase (AOX), a protein that shortens the electron transport chain; and increased by a loss-of-function mutation in dj-1β, a gene involved in ROS scavenging. Contrary to predictions, we found no differences among these four lines in the rate of sperm ROS production. We discuss the implications of our results, the limitations of our study, and possible directions for future research.

Design and analysis of experiments on double substrate-limited growth of Paracoccus denitrificans

1984 ◽  
Vol 50 (1) ◽  
pp. 102-102
Author(s):  
E. D. Schoen ◽  
M. A. E. van der Heijden ◽  
H. W. van Verseveld ◽  
A. H. Stouthamer ◽  
J. C. Jager
Keyword(s):  
Paracoccus Denitrificans ◽  
Limited Growth ◽  
Double Substrate

scholarly journals The oxidation of nicotinic acid by Pseudomonas ovalis Chester. The terminal oxidase

1972 ◽  
Vol 129 (3) ◽  
pp. 755-761 ◽  
Author(s):  
M. V. Jones ◽  
D. E. Hughes
Keyword(s):  
Electron Transport ◽  
Nicotinic Acid ◽  
Electron Transport Chain ◽  
Acid Oxidase ◽  
Terminal Oxidase ◽  
Difference Spectra ◽  
Terminal Oxidases ◽  
Cytochrome O ◽  
Transport Chain ◽  
Terminal Oxidation

In cell-free extracts of Pseudomonas ovalis nicotinic acid oxidase is confined to the wallmembrane fraction. It is associated with an electron-transport chain comprising b- and c-type cytochromes only, differing proportions of which are reduced by nicotinate and NADH. CO difference-spectra show two CO-binding pigments, cytochrome o (absorption maximum at 417nm) and another component absorbing maximally at 425nm. Cytochrome o is not reduced by NADH or by succinate but is by nicotinate, which can also reduce the ‘425’ CO-binding pigment. The effects of inhibitors of terminal oxidation support the idea of two terminal oxidases and a scheme involving the ‘425’ CO-binding pigment and the other components of the electron-transport chain is proposed.

scholarly journals An intestinally secreted host factor promotes microsporidia invasion of C. elegans

eLife ◽  
2022 ◽  
Vol 11 ◽  
Author(s):  
Hala Tamim El Jarkass ◽  
Calvin Mok ◽  
Michael R Schertzberg ◽  
Andrew G Fraser ◽  
Emily R Troemel ◽  
...  
Keyword(s):  
Bacterial Pathogen ◽  
Oral Route ◽  
Intestinal Lumen ◽  
Wild Type ◽  
Parasite Invasion ◽  
Competitive Fitness ◽  
Obligate Intracellular ◽  
C Elegans ◽  
Fitness Advantage ◽  
Trade Offs

Microsporidia are ubiquitous obligate intracellular pathogens of animals. These parasites often infect hosts through an oral route, but little is known about the function of host intestinal proteins that facilitate microsporidia invasion. To identify such factors necessary for infection by Nematocida parisii, a natural microsporidian pathogen of Caenorhabditis elegans, we performed a forward genetic screen to identify mutant animals that have a Fitness Advantage with Nematocida (Fawn). We isolated four fawn mutants that are resistant to Nematocida infection and contain mutations in T14E8.4, which we renamed aaim-1 (Antibacterial and Aids invasion by Microsporidia). Expression of AAIM-1 in the intestine of aaim-1 animals restores N. parisii infectivity and this rescue of infectivity is dependent upon AAIM-1 secretion. N. parisii spores in aaim-1 animals are improperly oriented in the intestinal lumen, leading to reduced levels of parasite invasion. Conversely, aaim-1 mutants display both increased colonization and susceptibility to the bacterial pathogen Pseudomonas aeruginosa and overexpression of AAIM-1 reduces P. aeruginosa colonization. Competitive fitness assays show that aaim-1 mutants are favoured in the presence of N. parisii but disadvantaged on P. aeruginosa compared to wild type animals. Together, this work demonstrates how microsporidia exploits a secreted protein to promote host invasion. Our results also suggest evolutionary trade-offs may exist to optimizing host defense against multiple classes of pathogens.

scholarly journals Pathway Choice in Glutamate Synthesis inEscherichia coli

1998 ◽  
Vol 180 (17) ◽  
pp. 4571-4575 ◽  
Author(s):  
Robert B. Helling
Keyword(s):  
Glutamate Synthase ◽  
Substantial Effect ◽  
Ammonium Concentration ◽  
Inescherichia Coli ◽  
Deficient Mutant ◽  
Substrate Availability ◽  
Wild Type ◽  
Limited Growth ◽  
Pathway Choice ◽  
Glutamate Synthesis

ABSTRACT Escherichia coli has two primary pathways for glutamate synthesis. The glutamine synthetase-glutamate synthase (GOGAT) pathway is essential for synthesis at low ammonium concentration and for regulation of the glutamine pool. The glutamate dehydrogenase (GDH) pathway is important during glucose-limited growth. It has been hypothesized that GDH is favored when the organism is stressed for energy, because the enzyme does not use ATP as does the GOGAT pathway. The results of competition experiments between the wild-type and a GDH-deficient mutant during glucose-limited growth in the presence of the nonmetabolizable glucose analog α-methylglucoside were consistent with the hypothesis. Enzyme measurements showed that levels of the enzymes of the glutamate pathways dropped as the organism passed from unrestricted to glucose-restricted growth. However, other conditions influencing pathway choice had no substantial effect on enzyme levels. Therefore, substrate availability and/or modulation of enzyme activity are likely to be major determinants of pathway choice in glutamate synthesis.

scholarly journals Role of Campylobacter jejuni Respiratory Oxidases and Reductases in Host Colonization

2008 ◽  
Vol 74 (5) ◽  
pp. 1367-1375 ◽  
Author(s):  
Rebecca A. Weingarten ◽  
Jesse L. Grimes ◽  
Jonathan W. Olson
Keyword(s):  
Campylobacter Jejuni ◽  
Anaerobic Respiration ◽  
Wild Type ◽  
Respiratory Enzymes ◽  
Host Colonization ◽  
Enzymatic Function ◽  
Food Borne ◽  
Transport Chain ◽  
Respiratory Oxidases

ABSTRACT Campylobacter jejuni is the leading cause of human food-borne bacterial gastroenteritis. The C. jejuni genome sequence predicts a branched electron transport chain capable of utilizing multiple electron acceptors. Mutants were constructed by disrupting the coding regions of the respiratory enzymes nitrate reductase (napA::Cm), nitrite reductase (nrfA::Cm), dimethyl sulfoxide, and trimethylamine N-oxide reductase (termed Cj0264::Cm) and the two terminal oxidases, a cyanide-insensitive oxidase (cydA::Cm) and cbb3-type oxidase (ccoN::Cm). Each strain was characterized for the loss of the associated enzymatic function in vitro. The strains were then inoculated into 1-week-old chicks, and the cecal contents were assayed for the presence of C. jejuni 2 weeks postinoculation. cydA::Cm and Cj0264c::Cm strains colonized as well as the wild type; napA::Cm and nrfA::Cm strains colonized at levels significantly lower than the wild type. The ccoN::Cm strain was unable to colonize the chicken; no colonies were recovered at the end of the experiment. While there appears to be a role for anaerobic respiration in host colonization, oxygen is the most important respiratory acceptor for C. jejuni in the chicken cecum.

Sign in / Sign up

Export Citation Format

Share Document