scholarly journals Growth of Campylobacter jejuni Supported by Respiration of Fumarate, Nitrate, Nitrite, Trimethylamine-N-Oxide, or Dimethyl Sulfoxide Requires Oxygen

2002 ◽  
Vol 184 (15) ◽  
pp. 4187-4196 ◽  
Author(s):  
Michael J. Sellars ◽  
Stephen J. Hall ◽  
David J. Kelly
Keyword(s):  
Energy Conservation ◽  
Dimethyl Sulfoxide ◽  
Campylobacter Jejuni ◽  
Electron Acceptor ◽  
Electron Acceptors ◽  
Anaerobic Growth ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Single Class ◽  
Wide Range

ABSTRACT The human gastrointestinal pathogen Campylobacter jejuni is a microaerophilic bacterium with a respiratory metabolism. The genome sequence of C. jejuni strain 11168 reveals the presence of genes that encode terminal reductases that are predicted to allow the use of a wide range of alternative electron acceptors to oxygen, including fumarate, nitrate, nitrite, and N- or S-oxides. All of these reductase activities were present in cells of strain 11168, and the molybdoenzyme encoded by Cj0264c was shown by mutagenesis to be responsible for both trimethylamine-N-oxide (TMAO) and dimethyl sulfoxide (DMSO) reduction. Nevertheless, growth of C. jejuni under strictly anaerobic conditions (with hydrogen or formate as electron donor) in the presence of any of the electron acceptors tested was insignificant. However, when fumarate, nitrate, nitrite, TMAO, or DMSO was added to microaerobic cultures in which the rate of oxygen transfer was severely restricted, clear increases in both the growth rate and final cell density compared to what was seen with the control were obtained, indicative of electron acceptor-dependent energy conservation. The C. jejuni genome encodes a single class I-type ribonucleotide reductase (RNR) which requires oxygen to generate a tyrosyl radical for catalysis. Electron microscopy of cells that had been incubated under strictly anaerobic conditions with an electron acceptor showed filamentation due to an inhibition of cell division similar to that induced by the RNR inhibitor hydroxyurea. An oxygen requirement for DNA synthesis can thus explain the lack of anaerobic growth of C. jejuni. The results indicate that strict anaerobiosis is a stress condition for C. jejuni but that alternative respiratory pathways can contribute significantly to energy conservation under oxygen-limited conditions, as might be found in vivo.

scholarly journals A Conserved Histidine in Cytochrome c Maturation Permease CcmB of Shewanella putrefaciens Is Required for Anaerobic Growth below a Threshold Standard Redox Potential

2006 ◽  
Vol 189 (3) ◽  
pp. 1036-1043 ◽  
Author(s):  
Jason R. Dale ◽  
Roy Wade ◽  
Thomas J. DiChristina
Keyword(s):  
Electron Acceptor ◽  
Type Strain ◽  
Wild Type Strain ◽  
Shewanella Putrefaciens ◽  
Electron Acceptors ◽  
Anaerobic Growth ◽  
Histidine Residue ◽  
Wild Type ◽  
Standard Redox Potential ◽  
Wide Range

ABSTRACT Shewanella putrefaciens strain 200 respires a wide range of compounds as terminal electron acceptor. The respiratory versatility of Shewanella is attributed in part to a set of c-type cytochromes with widely varying midpoint redox potentials (E′0). A point mutant of S. putrefaciens, originally designated Urr14 and here renamed CCMB1, was found to grow at wild-type rates on electron acceptors with high E′0 [O2, NO3 −, Fe(III) citrate, MnO2, and Mn(III) pyrophosphate] yet was severely impaired for growth on electron acceptors with low E′0 [NO2 −, U(VI), dimethyl sulfoxide, TMAO (trimethylamine N-oxide), fumarate, γ-FeOOH, SO3 2−, and S2O3 2−]. Genetic complementation and nucleotide sequence analyses indicated that the CCMB1 respiratory mutant phenotype was due to mutation of a conserved histidine residue (H108Y) in a protein that displayed high homology to Escherichia coli CcmB, the permease subunit of an ABC transporter involved in cytochrome c maturation. Although CCMB1 retained the ability to grow on electron acceptors with high E′0, the cytochrome content of CCMB1 was <10% of that of the wild-type strain. Periplasmic extracts of CCMB1 contained slightly greater concentrations of the thiol functional group (-SH) than did the wild-type strain, an indication that the Eh of the CCMB1 periplasm was abnormally low. A ccmB deletion mutant was unable to respire anaerobically on any electron acceptor, yet retained aerobic respiratory capability. These results suggest that the mutation of a conserved histidine residue (H108) in CCMB1 alters the redox homeostasis of the periplasm during anaerobic growth on electron acceptors with low (but not high) E′0. This is the first report of the effects of Ccm deficiencies on bacterial respiration of electron acceptors whose E′0 nearly span the entire redox continuum.

scholarly journals Substrate-Level Phosphorylation Is the Primary Source of Energy Conservation during Anaerobic Respiration of Shewanella oneidensis Strain MR-1

2010 ◽  
Vol 192 (13) ◽  
pp. 3345-3351 ◽  
Author(s):  
Kristopher A. Hunt ◽  
Jeffrey M. Flynn ◽  
Belén Naranjo ◽  
Indraneel D. Shikhare ◽  
Jeffrey A. Gralnick
Keyword(s):  
Energy Conservation ◽  
Atp Synthase ◽  
Electron Acceptor ◽  
Shewanella Oneidensis ◽  
Proton Motive Force ◽  
Electron Acceptors ◽  
Anaerobic Conditions ◽  
Substrate Level Phosphorylation ◽  
Substrate Level ◽  
Mutant Strains

ABSTRACT It is well established that respiratory organisms use proton motive force to produce ATP via F-type ATP synthase aerobically and that this process may reverse during anaerobiosis to produce proton motive force. Here, we show that Shewanella oneidensis strain MR-1, a nonfermentative, facultative anaerobe known to respire exogenous electron acceptors, generates ATP primarily from substrate-level phosphorylation under anaerobic conditions. Mutant strains lacking ackA (SO2915) and pta (SO2916), genes required for acetate production and a significant portion of substrate-level ATP produced anaerobically, were tested for growth. These mutant strains were unable to grow anaerobically with lactate and fumarate as the electron acceptor, consistent with substrate-level phosphorylation yielding a significant amount of ATP. Mutant strains lacking ackA and pta were also shown to grow slowly using N-acetylglucosamine as the carbon source and fumarate as the electron acceptor, consistent with some ATP generation deriving from the Entner-Doudoroff pathway with this substrate. A deletion strain lacking the sole F-type ATP synthase (SO4746 to SO4754) demonstrated enhanced growth on N-acetylglucosamine and a minor defect with lactate under anaerobic conditions. ATP synthase mutants grown anaerobically on lactate while expressing proteorhodopsin, a light-dependent proton pump, exhibited restored growth when exposed to light, consistent with a proton-pumping role for ATP synthase under anaerobic conditions. Although S. oneidensis requires external electron acceptors to balance redox reactions and is not fermentative, we find that substrate-level phosphorylation is its primary anaerobic energy conservation strategy. Phenotypic characterization of an ackA deletion in Shewanella sp. strain MR-4 and genomic analysis of other sequenced strains suggest that this strategy is a common feature of Shewanella.

scholarly journals Redesigning Escherichia coli Metabolism for Anaerobic Production of Isobutanol

2011 ◽  
Vol 77 (14) ◽  
pp. 4894-4904 ◽  
Author(s):  
Cong T. Trinh ◽  
Johnny Li ◽  
Harvey W. Blanch ◽  
Douglas S. Clark
Keyword(s):  
Escherichia Coli ◽  
Anaerobic Growth ◽  
Mode Analysis ◽  
Glycolytic Flux ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Content Type ◽  
E Coli ◽  
Model Predictions ◽  
Chromosomal Genes

ABSTRACTFermentation enables the production of reduced metabolites, such as the biofuels ethanol and butanol, from fermentable sugars. This work demonstrates a general approach for designing and constructing a production host that uses a heterologous pathway as an obligately fermentative pathway to produce reduced metabolites, specifically, the biofuel isobutanol. Elementary mode analysis was applied to design anEscherichia colistrain optimized for isobutanol production under strictly anaerobic conditions. The central metabolism ofE. coliwas decomposed into 38,219 functional, unique, and elementary modes (EMs). The model predictions revealed that during anaerobic growthE. colicannot produce isobutanol as the sole fermentative product. By deleting 7 chromosomal genes, the total 38,219 EMs were constrained to 12 EMs, 6 of which can produce high yields of isobutanol in a range from 0.29 to 0.41 g isobutanol/g glucose under anaerobic conditions. The remaining 6 EMs rely primarily on the pyruvate dehydrogenase enzyme complex (PDHC) and are typically inhibited under anaerobic conditions. The redesignedE. colistrain was constrained to employ the anaerobic isobutanol pathways through deletion of 7 chromosomal genes, addition of 2 heterologous genes, and overexpression of 5 genes. Here we present the design, construction, and characterization of an isobutanol-producingE. colistrain to illustrate the approach. The model predictions are evaluated in relation to experimental data and strategies proposed to improve anaerobic isobutanol production. We also show that the endogenous alcohol/aldehyde dehydrogenase AdhE is the key enzyme responsible for the production of isobutanol and ethanol under anaerobic conditions. The glycolytic flux can be controlled to regulate the ratio of isobutanol to ethanol production.

scholarly journals The Disulfide Bond Formation Pathway Is Essential for Anaerobic Growth of Escherichia coli

2017 ◽  
Vol 199 (16) ◽  
Author(s):  
Brian M. Meehan ◽  
Cristina Landeta ◽  
Dana Boyd ◽  
Jonathan Beckwith
Keyword(s):  
Escherichia Coli ◽  
Disulfide Bond ◽  
Bond Formation ◽  
Anaerobic Growth ◽  
Strictly Anaerobic ◽  
Disulfide Bond Formation ◽  
Anaerobic Conditions ◽  
Content Type ◽  
E Coli ◽  
Laboratory Conditions

ABSTRACT Disulfide bonds are critical to the stability and function of many bacterial proteins. In the periplasm of Escherichia coli, intramolecular disulfide bond formation is catalyzed by the two-component disulfide bond forming (DSB) system. Inactivation of the DSB pathway has been shown to lead to a number of pleotropic effects, although cells remain viable under standard laboratory conditions. However, we show here that dsb strains of E. coli reversibly filament under aerobic conditions and fail to grow anaerobically unless a strong oxidant is provided in the growth medium. These findings demonstrate that the background disulfide bond formation necessary to maintain the viability of dsb strains is oxygen dependent. LptD, a key component of the lipopolysaccharide transport system, fails to fold properly in dsb strains exposed to anaerobic conditions, suggesting that these mutants may have defects in outer membrane assembly. We also show that anaerobic growth of dsb mutants can be restored by suppressor mutations in the disulfide bond isomerization system. Overall, our results underscore the importance of proper disulfide bond formation to pathways critical to E. coli viability under conditions where oxygen is limited. IMPORTANCE While the disulfide bond formation (DSB) system of E. coli has been studied for decades and has been shown to play an important role in the proper folding of many proteins, including some associated with virulence, it was considered dispensable for growth under most laboratory conditions. This work represents the first attempt to study the effects of the DSB system under strictly anaerobic conditions, simulating the environment encountered by pathogenic E. coli strains in the human intestinal tract. By demonstrating that the DSB system is essential for growth under such conditions, this work suggests that compounds inhibiting Dsb enzymes might act not only as antivirulents but also as true antibiotics.

Influence of Different Electron Donors and Acceptors on Dehalorespiration of Tetrachloroethene byDesulfitobacterium frappieri TCE1

1999 ◽  
Vol 65 (12) ◽  
pp. 5212-5221 ◽  
Author(s):  
Jan Gerritse ◽  
Oliver Drzyzga ◽  
Geert Kloetstra ◽  
Mischa Keijmel ◽  
Luit P. Wiersum ◽  
...  
Keyword(s):  
Electron Acceptor ◽  
Reductive Dechlorination ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Strictly Anaerobic ◽  
16S Rrna Sequence ◽  
Selective Enrichment ◽  
Chemostat Cultures ◽  
16S Rrna Sequence Analysis ◽  
Desulfitobacterium Hafniense

ABSTRACT Strain TCE1, a strictly anaerobic bacterium that can grow by reductive dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE), was isolated by selective enrichment from a PCE-dechlorinating chemostat mixed culture. Strain TCE1 is a gram-positive, motile, curved rod-shaped organism that is 2 to 4 by 0.6 to 0.8 μm and has approximately six lateral flagella. The pH and temperature optima for growth are 7.2 and 35°C, respectively. On the basis of a comparative 16S rRNA sequence analysis, this bacterium was identified as a new strain of Desulfitobacterium frappieri, because it exhibited 99.7% relatedness to the D. frappieri type strain, strain PCP-1. Growth with H2, formate,l-lactate, butyrate, crotonate, or ethanol as the electron donor depends on the availability of an external electron acceptor. Pyruvate and serine can also be used fermentatively. Electron donors (except formate and H2) are oxidized to acetate and CO2. When l-lactate is the growth substrate, strain TCE1 can use the following electron acceptors: PCE and TCE (to produce cis-1,2-dichloroethene), sulfite and thiosulfate (to produce sulfide), nitrate (to produce nitrite), and fumarate (to produce succinate). Strain TCE1 is not able to reductively dechlorinate 3-chloro-4-hydroxyphenylacetate. The growth yields of the newly isolated bacterium when PCE is the electron acceptor are similar to those obtained for other dehalorespiring anaerobes (e.g.,Desulfitobacterium sp. strain PCE1 andDesulfitobacterium hafniense) and the maximum specific reductive dechlorination rates are 4 to 16 times higher (up to 1.4 μmol of chloride released · min−1 · mg of protein−1). Dechlorination of PCE and TCE is an inducible process. In PCE-limited chemostat cultures of strain TCE1, dechlorination is strongly inhibited by sulfite but not by other alternative electron acceptors, such as fumarate or nitrate.

scholarly journals Anaerobic α-Amylase Production and Secretion with Fumarate as the Final Electron Acceptor in Saccharomyces cerevisiae

2013 ◽  
Vol 79 (9) ◽  
pp. 2962-2967 ◽  
Author(s):  
Zihe Liu ◽  
Tobias Österlund ◽  
Jin Hou ◽  
Dina Petranovic ◽  
Jens Nielsen
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Folding ◽  
Protein Secretion ◽  
Electron Acceptor ◽  
Anaerobic Growth ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Content Type ◽  
Final Electron ◽  
Final Electron Acceptor

ABSTRACTIn this study, we focus on production of heterologous α-amylase in the yeastSaccharomyces cerevisiaeunder anaerobic conditions. We compare the metabolic fluxes and transcriptional regulation under aerobic and anaerobic conditions, with the objective of identifying the final electron acceptor for protein folding under anaerobic conditions. We find that yeast produces more amylase under anaerobic conditions than under aerobic conditions, and we propose a model for electron transfer under anaerobic conditions. According to our model, during protein folding the electrons from the endoplasmic reticulum are transferred to fumarate as the final electron acceptor. This model is supported by findings that the addition of fumarate under anaerobic (but not aerobic) conditions improves cell growth, specifically in the α-amylase-producing strain, in which it is not used as a carbon source. Our results provide a model for the molecular mechanism of anaerobic protein secretion using fumarate as the final electron acceptor, which may allow for further engineering of yeast for improved protein secretion under anaerobic growth conditions.

Sulfate as a terminal electron acceptor in toluene oxidation in anaerobic conditions

2020 ◽  
Vol 22 (4) ◽  
pp. 157-167
Author(s):  
I. I. Ivanenkо ◽  
E. Y. Lapatina
Keyword(s):  
Electron Acceptor ◽  
Waste Water Treatment ◽  
Process Intensification ◽  
Petroleum Products ◽  
Electron Acceptors ◽  
Laboratory Research ◽  
Anaerobic Conditions ◽  
Active Sludge ◽  
Toluene Oxidation ◽  
Terminal Electron Acceptor

In aerobic conditions, many of microorganisms cause decomposition of saturated hydrocarbons. Little publications are available relative to anaerobic transformation of these compounds, which provides substantial сapiltal saving for waste water treatment. At the same time, cultures found among aerobic decomposers of petroleum products are characterized by the ability to use elements with variable valence as terminal electron acceptors in oxidation of organic substances. Their ability to decompose aliphatic hydrocarbons helps to identify some of them.Purpose: studying the ability of a selected association of immobilized bacteria on a fibrous carrier to utilize sulfate as a terminal electron acceptor for toluene oxidation.Methodology/approach: Analytical summarizing of results, literature review, laboratory research based on standard and modern up-to-date methodologies with the use of modern analytical equipment.Findings: The availability of using microorganism selection is shown for expanding the range of polluting strippants in biological purification; the main directions are determined for the process intensification by immobilization of active sludge on a fibrous carrier. The ability of microorganisms to oxidize toluene under oxygen-free (anaerobic) conditions is studied in the laboratory conditions.Research implications: monoaromatic hydrocarbons, toluene, in particular, can be changed by selected associations of decomposers using terminal electron acceptors in oxidation of nitrates and sulfates.

scholarly journals Identification of Dimethyl Sulfoxide Reductase in Actinobacillus pleuropneumoniae and Its Role in Infection

2003 ◽  
Vol 71 (12) ◽  
pp. 6784-6792 ◽  
Author(s):  
Nina Baltes ◽  
Isabel Hennig-Pauka ◽  
Ilse Jacobsen ◽  
Achim D. Gruber ◽  
Gerald F. Gerlach
Keyword(s):  
Dimethyl Sulfoxide ◽  
Actinobacillus Pleuropneumoniae ◽  
Growth Conditions ◽  
Open Reading Frames ◽  
Anaerobic Growth ◽  
Infection Model ◽  
Anaerobic Conditions ◽  
Common Strategy ◽  
Dimethyl Sulfoxide Reductase

ABSTRACT Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is capable of persisting in oxygen-deprived surroundings, namely, tonsils and sequestered necrotic lung tissue. Utilization of alternative terminal electron acceptors in the absence of oxygen is a common strategy in bacteria under anaerobic growth conditions. In an experiment aimed at identification of genes expressed in vivo, the putative catalytic subunit DmsA of anaerobic dimethyl sulfoxide reductase was identified in an A. pleuropneumoniae serotype 7 strain. The 90-kDa protein exhibits 85% identity to the putative DmsA protein of Haemophilus influenzae, and its expression was found to be upregulated under anaerobic conditions. Analysis of the unfinished A. pleuropneumoniae genome sequence revealed putative open reading frames (ORFs) encoding DmsB and DmsC proteins situated downstream of the dmsA ORF. In order to investigate the role of the A. pleuropneumoniae DmsA protein in virulence, an isogenic deletion mutant, A. pleuropneumoniae ΔdmsA, was constructed and examined in an aerosol infection model. A. pleuropneumoniae ΔdmsA was attenuated in acute disease, which suggests that genes involved in oxidative metabolism under anaerobic conditions might contribute significantly to A. pleuropneumoniae virulence.

scholarly journals Roles of D-Lactate Dehydrogenases in the Anaerobic Growth ofShewanella oneidensisMR-1 on Sugars

2018 ◽  
Vol 85 (3) ◽  
Author(s):  
Takuya Kasai ◽  
Yusuke Suzuki ◽  
Atsushi Kouzuma ◽  
Kazuya Watanabe
Keyword(s):  
Electron Acceptor ◽  
Deletion Mutant ◽  
Shewanella Oneidensis ◽  
Electron Acceptors ◽  
Anaerobic Growth ◽  
Receptor Protein ◽  
Acid Fermentation ◽  
Respiratory Quinone ◽  
Content Type ◽  
Electron Sink

ABSTRACTShewanella oneidensisMR-1 is a facultative anaerobe that respires using a variety of electron acceptors. Although this organism is incapable of fermentative growth in the absence of electron acceptors, its genome encodes LdhA (a putative fermentative NADH-dependentd-lactate dehydrogenase [d-LDH]) and Dld (a respiratory quinone-dependentd-LDH). However, the physiological roles of LdhA in MR-1 are unclear. Here, we examined the activity, transcriptional regulation, and traits of deletion mutants to gain insight into the roles of LdhA in the anaerobic growth of MR-1. Analyses ofd-LDH activity in MR-1 and theldhAdeletion mutant confirmed that LdhA functions as an NADH-dependentd-LDH that catalyzes the reduction of pyruvate tod-lactate.In vivoandin vitroassays revealed thatldhAexpression was positively regulated by the cyclic-AMP receptor protein, a global transcription factor that regulates anaerobic respiratory pathways in MR-1, suggesting that LdhA functions in coordination with anaerobic respiration. Notably, we found that a deletion mutant of all four NADH dehydrogenases (NDHs) in MR-1 (ΔNDH mutant) retained the ability to grow onN-acetylglucosamine under fumarate-respiring conditions, while an additional deletion ofldhAordlddeprived the ΔNDH mutant of this growth ability. These results indicate that LdhA-Dld serves as a bypass of NDH in electron transfer from NADH to quinones. Our findings suggest that the LdhA-Dld system manages intracellular redox balance by utilizingd-lactate as a temporal electron sink under electron acceptor-limited conditions.IMPORTANCENADH-dependent LDHs are conserved among diverse organisms and contribute to NAD+regeneration in lactic acid fermentation. However, this type of LDH is also present in nonfermentative bacteria, including members of the genusShewanella, while their physiological roles in these bacteria remain unknown. Here, we show that LdhA (an NADH-dependentd-LDH) works in concert with Dld (a quinone-dependentd-LDH) to transfer electrons from NADH to quinones during sugar catabolism inS. oneidensisMR-1. Our results indicate thatd-lactate acts as an intracellular electron mediator to transfer electrons from NADH to membrane quinones. In addition,d-lactate serves as a temporal electron sink when respiratory electron acceptors are not available. Our study suggests novel physiological roles ford-LDHs in providing nonfermentative bacteria with catabolic flexibility under electron acceptor-limited conditions.

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