scholarly journals Physiological and Metabolic Effects of Carbon Monoxide Oxidation in the Model Marine Bacterioplankton Ruegeria pomeroyi DSS-3

2012 ◽  
Vol 79 (2) ◽  
pp. 738-740 ◽  
Author(s):  
Michael Cunliffe
Keyword(s):  
Carbon Monoxide ◽  
Nmr Spectra ◽  
Metabolic Effects ◽  
Co Dehydrogenase ◽  
Ecosystem Models ◽  
Content Type ◽  
Marine Bacterioplankton ◽  
Metabolite Profiles ◽  
Ruegeria Pomeroyi ◽  
Cellular Metabolite

ABSTRACTRuegeria pomeroyiexpresses carbon monoxide (CO) dehydrogenase and oxidizes CO; however, CO has no effect on growth. Nuclear magnetic resonance (NMR) spectra showed that CO has no effect on cellular metabolite profiles. These data support ecosystem models proposing that, even though bacterioplankton CO oxidation is biogeochemically significant, it has an insignificant effect on bacterioplankton productivity.

scholarly journals Energy Conservation Model Based on Genomic and Experimental Analyses of a Carbon Monoxide-Utilizing, Butyrate-Forming Acetogen, Eubacterium limosum KIST612

2015 ◽  
Vol 81 (14) ◽  
pp. 4782-4790 ◽  
Author(s):  
Jiyeong Jeong ◽  
Johannes Bertsch ◽  
Verena Hess ◽  
Sunju Choi ◽  
In-Geol Choi ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Atp Synthesis ◽  
Binding Motif ◽  
Oxidation Of Co ◽  
Co Dehydrogenase ◽  
Content Type ◽  
A Genome ◽  
Eubacterium Limosum ◽  
The One ◽  
Conservation Model

ABSTRACTEubacterium limosumKIST612 is one of the few acetogens that can produce butyrate from carbon monoxide. We have used a genome-guided analysis to delineate the path of butyrate formation, the enzymes involved, and the potential coupling to ATP synthesis. Oxidation of CO is catalyzed by the acetyl-coenzyme A (CoA) synthase/CO dehydrogenase and coupled to the reduction of ferredoxin. Oxidation of reduced ferredoxin is catalyzed by the Rnf complex and Na+dependent. Consistent with the finding of a Na+-dependent Rnf complex is the presence of a conserved Na+-binding motif in thecsubunit of the ATP synthase. Butyrate formation is from acetyl-CoA via acetoacetyl-CoA, hydroxybutyryl-CoA, crotonyl-CoA, and butyryl-CoA and is consistent with the finding of a gene cluster that encodes the enzymes for this pathway. The activity of the butyryl-CoA dehydrogenase was demonstrated. Reduction of crotonyl-CoA to butyryl-CoA with NADH as the reductant was coupled to reduction of ferredoxin. We postulate that the butyryl-CoA dehydrogenase uses flavin-based electron bifurcation to reduce ferredoxin, which is consistent with the finding ofetfAandetfBgenes next to it. The overall ATP yield was calculated and is significantly higher than the one obtained with H2+ CO2. The energetic benefit may be one reason that butyrate is formed only from CO but not from H2+ CO2.

scholarly journals Insight into Energy Conservation via Alternative Carbon Monoxide Metabolism inCarboxydothermus pertinaxRevealed by Comparative Genome Analysis

2018 ◽  
Vol 84 (14) ◽  
Author(s):  
Yuto Fukuyama ◽  
Kimiho Omae ◽  
Yasuko Yoneda ◽  
Takashi Yoshida ◽  
Yoshihiko Sako
Keyword(s):  
Carbon Monoxide ◽  
Co Oxidation ◽  
Gene Cluster ◽  
Genome Analysis ◽  
Transcriptional Analysis ◽  
Comparative Genome Analysis ◽  
Co Dehydrogenase ◽  
Comparative Genome ◽  
Content Type ◽  
Energy Converting

ABSTRACTCarboxydothermusspecies are some of the most studied thermophilic carboxydotrophs. Their varied carboxydotrophic growth properties suggest distinct strategies for energy conservation via carbon monoxide (CO) metabolism. In this study, we used comparative genome analysis of the genusCarboxydothermusto show variations in the CO dehydrogenase-energy-converting hydrogenase gene cluster, which is responsible for CO metabolism with H2production (hydrogenogenic CO metabolism). Indeed, the ability or inability to produce H2with CO oxidation is explained by the presence or absence of this gene cluster inCarboxydothermus hydrogenoformans,Carboxydothermus islandicus, andCarboxydothermus ferrireducens. Interestingly, despite its hydrogenogenic CO metabolism,Carboxydothermus pertinaxlacks the Ni-CO dehydrogenase catalytic subunit (CooS-I) and its transcriptional regulator-encoding genes in this gene cluster, probably due to inversion. Transcriptional analysis inC. pertinaxshowed that the Ni-CO dehydrogenase gene (cooS-II) and distantly encoded energy-converting-hydrogenase-related genes were remarkably upregulated with 100% CO. In addition, when thiosulfate was available as a terminal electron acceptor in 100% CO, the maximum cell density and maximum specific growth rate ofC. pertinaxwere 3.1-fold and 1.5-fold higher, respectively, than when thiosulfate was absent. The amount of H2produced was only 62% of the amount of CO consumed, less than expected according to hydrogenogenic CO oxidation (CO + H2O → CO2+ H2). Accordingly,C. pertinaxwould couple CO oxidation by Ni-CO dehydrogenase II with simultaneous reduction of not only H2O but also thiosulfate when grown in 100% CO.IMPORTANCEAnaerobic hydrogenogenic carboxydotrophs are thought to fill a vital niche by scavenging potentially toxic CO and producing H2as an available energy source for thermophilic microbes. This hydrogenogenic carboxydotrophy relies on a Ni-CO dehydrogenase-energy-converting hydrogenase gene cluster. This feature is thought to be common to these organisms. However, the hydrogenogenic carboxydotrophCarboxydothermus pertinaxlacks the gene for the Ni-CO dehydrogenase catalytic subunit encoded in the gene cluster. Here, we performed a comparative genome analysis of the genusCarboxydothermus, a transcriptional analysis, and a cultivation study in 100% CO to prove the hydrogenogenic CO metabolism. Results revealed thatC. pertinaxcould couple Ni-CO dehydrogenase II alternatively to the distal energy-converting hydrogenase. Furthermore,C. pertinaxrepresents an example of the functioning of Ni-CO dehydrogenase that does not always correspond to its genomic context, owing to the versatility of CO metabolism and the low redox potential of CO.

The use of moderate therapeutic hypothermia for patients with severe head injuries: a preliminary report

1993 ◽  
Vol 79 (3) ◽  
pp. 354-362 ◽  
Author(s):  
Donald W. Marion ◽  
Walter D. Obrist ◽  
Patricia M. Earlier ◽  
Louis E. Penrod ◽  
Joseph M. Darby
Keyword(s):  
Head Injury ◽  
Therapeutic Hypothermia ◽  
Closed Head Injury ◽  
Metabolic Effects ◽  
Secondary Brain Injury ◽  
Content Type ◽  
Closed Head ◽  
Hypothermia Group ◽  
Rebound Increase ◽  
Fine Print

✓ Animal research suggests that moderate therapeutic hypothermia may improve outcome after a severe head injury, but its efficacy has not been established in humans. The authors randomly assigned 40 consecutively treated patients with a severe closed head injury (Glasgow Coma Scale score 3 to 7) to either a hypothermia or a normothermia group. Using cooling blankets and cold saline gastric lavage, patients in the hypothermia group were cooled to 32° to 33°C (brain temperature) within a mean of 10 hours after injury, maintained at that temperature for 24 hours, and rewarmed to 37° to 38°C over 12 hours. Patients in the normothermia group were maintained at 37° to 38°C during this time. Deep-brain temperatures were monitored directly and used for all temperature determinations. Intracranial pressure (ICP), cerebral blood flow (CBF), and cerebral metabolic rate for oxygen (CMRO2) were measured serially for all patients. Hypothermia significantly reduced ICP (40%) and CBF (26%) during the cooling period, and neither parameter showed a significant rebound increase after patients were rewarmed. Compared to the normothermia group, the mean CMRO2 in the hypothermia group was lower during cooling and higher 5 days after injury. Three months after injury, 12 of the 20 patients in the hypothermia group had moderate, mild, or no disabilities; eight of the 20 patients in the normothermia group had improved to the same degree. Both groups had a similar incidence of systemic complications, including cardiac arrhythmias, coagulopathies, and pulmonary complications. It is concluded that therapeutic moderate hypothermia is safe and has sustained favorable effects on acute derangements of cerebral physiology and metabolism caused by severe closed head injury. The trend toward better outcome with hypothermia may indicate that its beneficial physiological and metabolic effects limit secondary brain injury.

scholarly journals Potential of temperature- and salinity-driven shifts in diatom compatible solute concentrations to impact biogeochemical cycling within sea ice

Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Hannah M. Dawson ◽  
Katherine R. Heal ◽  
Angela K. Boysen ◽  
Laura T. Carlson ◽  
Anitra E. Ingalls ◽  
...  
Keyword(s):  
Sea Ice ◽  
Compatible Solutes ◽  
Biogeochemical Cycling ◽  
Compatible Solute ◽  
Arctic Sea Ice ◽  
Polar Regions ◽  
Antarctic Sea Ice ◽  
Metabolite Profiles ◽  
Metabolite Pool ◽  
Cellular Metabolite

Sea-ice algae are an important source of primary production in polar regions, yet we have limited understanding of their responses to the seasonal cycling of temperature and salinity. Using a targeted liquid chromatography-mass spectrometry-based metabolomics approach, we found that axenic cultures of the Antarctic sea-ice diatom, Nitzschia lecointei, displayed large differences in their metabolomes when grown in a matrix of conditions that included temperatures of –1 and 4°C, and salinities of 32 and 41, despite relatively small changes in growth rate. Temperature exerted a greater effect than salinity on cellular metabolite pool sizes, though the N- or S-containing compatible solutes, 2, 3-dihydroxypropane-1-sulfonate (DHPS), glycine betaine (GBT), dimethylsulfoniopropionate (DMSP), and proline responded strongly to both temperature and salinity, suggesting complexity in their control. We saw the largest (> 4-fold) response to salinity for proline. DHPS, a rarely studied but potential compatible solute, had the highest intracellular concentrations among all compatible solutes of ~85 mM. When comparing the culture findings to natural Arctic sea-ice diatom communities, we found extensive overlap in metabolite profiles, highlighting the relevance of culture-based studies to probe environmental questions. Large changes in sea-ice diatom metabolomes and compatible solutes over a seasonal cycle could be significant components of biogeochemical cycling within sea ice.

scholarly journals A Novel Carbon Monoxide-Releasing Molecule Fully Protects Mice from Severe Malaria

2011 ◽  
Vol 56 (3) ◽  
pp. 1281-1290 ◽  
Author(s):  
Ana C. Pena ◽  
Nuno Penacho ◽  
Liliana Mancio-Silva ◽  
Rita Neres ◽  
João D. Seixas ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Severe Malaria ◽  
Adjuvant Treatment ◽  
Malaria Infection ◽  
Severe Disease ◽  
Inhalation Therapy ◽  
Heme Oxygenase 1 ◽  
Primary Therapy ◽  
Content Type

ABSTRACTSevere forms of malaria infection, such as cerebral malaria (CM) and acute lung injury (ALI), are mainly caused by the apicomplexan parasitePlasmodium falciparum. Primary therapy with quinine or artemisinin derivatives is generally effective in controllingP. falciparumparasitemia, but mortality from CM and other forms of severe malaria remains unacceptably high. Herein, we report the design and synthesis of a novel carbon monoxide-releasing molecule (CO-RM; ALF492) that fully protects mice against experimental CM (ECM) and ALI. ALF492 enables controlled CO deliveryin vivowithout affecting oxygen transport by hemoglobin, the major limitation in CO inhalation therapy. The protective effect is CO dependent and induces the expression of heme oxygenase-1, which contributes to the observed protection. Importantly, when used in combination with the antimalarial drug artesunate, ALF492 is an effective adjunctive and adjuvant treatment for ECM, conferring protection after the onset of severe disease. This study paves the way for the potential use of CO-RMs, such as ALF492, as adjunctive/adjuvant treatment in severe forms of malaria infection.

scholarly journals Primary and Secondary Metabolic Effects of a Key Gene Deletion (ΔYPL062W) in Metabolically Engineered Terpenoid-ProducingSaccharomyces cerevisiae

2019 ◽  
Vol 85 (7) ◽  
Author(s):  
Yan Chen ◽  
Ying Wang ◽  
Ming Liu ◽  
Junze Qu ◽  
Mingdong Yao ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Gene Deletion ◽  
Core Promoter ◽  
Strain Improvement ◽  
Genetic Alterations ◽  
Metabolic Effects ◽  
Industrial Biotechnology ◽  
Cell Factory ◽  
Content Type ◽  
Genetic Function

ABSTRACTSaccharomyces cerevisiaeis an established cell factory for production of terpenoid pharmaceuticals and chemicals. Numerous studies have demonstrated that deletion or overexpression of off-pathway genes in yeast can improve terpenoid production. The deletion ofYPL062WinS. cerevisiae, in particular, has benefitted carotenoid production by channeling carbon toward carotenoid precursors acetyl coenzyme A (acetyl-CoA) and mevalonate. The genetic function ofYPL062Wand the molecular mechanisms for these benefits are unknown. In this study, we systematically examined this gene deletion to uncover the gene function and its molecular mechanism. RNA sequencing (RNA-seq) analysis uncovered thatYPL062Wdeletion upregulated the pyruvate dehydrogenase bypass, the mevalonate pathway, heterologous expression of galactose (GAL) promoter-regulated genes, energy metabolism, and membrane composition synthesis. Bioinformatics analysis and serial promoter deletion assay revealed thatYPL062Wfunctions as a core promoter forALD6and that the expression level ofALD6is negatively correlated to terpenoid productivity. We demonstrate that ΔYPL062Wincreases the production of all major terpenoid classes (C10, C15, C20, C30, and C40). Our study not only elucidated the biological function ofYPL062Wbut also provided a detailed methodology for understanding the mechanistic aspects of strain improvement.IMPORTANCEAlthough computational and reverse metabolic engineering approaches often lead to improved gene deletion mutants for cell factory engineering, the systems level effects of such gene deletions on the production phenotypes have not been extensively studied. Understanding the genetic and molecular function of such gene alterations on production strains will minimize the risk inherent in the development of large-scale fermentation processes, which is a daunting challenge in the field of industrial biotechnology. Therefore, we established a detailed experimental and systems biology approach to uncover the molecular mechanisms ofYPL062Wdeletion inS. cerevisiae, which is shown to improve the production of all terpenoid classes. This study redefines the genetic function ofYPL062W, demonstrates a strong correlation betweenYPL062Wand terpenoid production, and provides a useful modification for the creation of terpenoid production platform strains. Further, this study underscores the benefits of detailed and systematic characterization of the metabolic effects of genetic alterations on engineered biosynthetic factories.

scholarly journals Metabolomics of Escherichia coli Treated with the Antimicrobial Carbon Monoxide-Releasing Molecule CORM-3 Reveals Tricarboxylic Acid Cycle as Major Target

2019 ◽  
Vol 63 (10) ◽  
Author(s):  
Sandra M. Carvalho ◽  
Joana Marques ◽  
Carlos C. Romão ◽  
Lígia M. Saraiva
Keyword(s):  
Escherichia Coli ◽  
Carbon Monoxide ◽  
Tricarboxylic Acid Cycle ◽  
Redox Homeostasis ◽  
Glutamate Synthase ◽  
Tca Cycle ◽  
Tricarboxylic Acid ◽  
Bacterial Cells ◽  
Content Type ◽  
Iron Sulfur

ABSTRACT In the last decade, carbon monoxide-releasing molecules (CORMs) have been shown to act against several pathogens and to be promising antimicrobials. However, the understanding of the mode of action and reactivity of these compounds on bacterial cells is still deficient. In this work, we used a metabolomics approach to probe the toxicity of the ruthenium(II) complex Ru(CO)3Cl(glycinate) (CORM-3) on Escherichia coli. By resorting to 1H nuclear magnetic resonance, mass spectrometry, and enzymatic activities, we show that CORM-3-treated E. coli accumulates larger amounts of glycolytic intermediates, independently of the oxygen growth conditions. The work provides several evidences that CORM-3 inhibits glutamate synthesis and the iron-sulfur enzymes of the tricarboxylic acid (TCA) cycle and that the glycolysis pathway is triggered in order to establish an energy and redox homeostasis balance. Accordingly, supplementation of the growth medium with fumarate, α-ketoglutarate, glutamate, and amino acids cancels the toxicity of CORM-3. Importantly, inhibition of the iron-sulfur enzymes glutamate synthase, aconitase, and fumarase is only observed for compounds that liberate carbon monoxide. Altogether, this work reveals that the antimicrobial action of CORM-3 results from intracellular glutamate deficiency and inhibition of nitrogen and TCA cycles.

scholarly journals Draft Genome Sequence of the Hydrogenogenic Carboxydotroph Moorella stamsii DSM 26271

2018 ◽  
Vol 6 (18) ◽  
Author(s):  
Anja Poehlein ◽  
Tim Böer ◽  
Kerrin Steensen ◽  
Rolf Daniel
Keyword(s):  
Carbon Monoxide ◽  
Genome Sequence ◽  
Anaerobic Bacterium ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Content Type ◽  
Obligate Anaerobic ◽  
Protein Encoding ◽  
Encoding Genes

ABSTRACT The spore-forming, thermophilic, and obligate anaerobic bacterium Moorella stamsii was isolated from digester sludge. Apart from its ability to use carbon monoxide for growth, M. stamsii harbors several enzymes for the use of different sugars. The draft genome has a size of 3,329 Mb and contains 3,306 predicted protein-encoding genes.

scholarly journals 2,4,6-Trinitrotoluene Reduction by Carbon Monoxide Dehydrogenase from Clostridium thermoaceticum

2000 ◽  
Vol 66 (4) ◽  
pp. 1474-1478 ◽  
Author(s):  
Shouqin Huang ◽  
Paul A. Lindahl ◽  
Chuanyue Wang ◽  
George N. Bennett ◽  
Frederick B. Rudolph ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Carbon Monoxide Dehydrogenase ◽  
Clostridium Thermoaceticum ◽  
Co Dehydrogenase ◽  
Rearrangement Product ◽  
Reduction Activity ◽  
Oxidation Reduction ◽  
Reduced Products ◽  
Degradation Activity ◽  
Dominant Isomer

ABSTRACT Purified CO dehydrogenase (CODH) from Clostridium thermoaceticum catalyzed the transformation of 2,4,6-trinitrotoluene (TNT). The intermediates and reduced products of TNT transformation were separated and appear to be identical to the compounds formed by C. acetobutylicum, namely, 2-hydroxylamino-4,6-dinitrotoluene (2HA46DNT), 4-hydroxylamino-2,6-dinitrotoluene (4HA26DNT), 2,4-dihydroxylamino-6-nitrotoluene (24DHANT), and the Bamberger rearrangement product of 2,4-dihydroxylamino-6-nitrotoluene. In the presence of saturating CO, CODH catalyzed the conversion of TNT to two monohydroxylamino derivatives (2HA46DNT and 4HA26DNT), with 4HA26DNT as the dominant isomer. These derivatives were then converted to 24DHANT, which slowly converted to the Bamberger rearrangement product. ApparentKm and k cat values of TNT reduction were 165 ± 43 μM for TNT and 400 ± 94 s−1, respectively. Cyanide, an inhibitor for the CO/CO2 oxidation/reduction activity of CODH, inhibited the TNT degradation activity of CODH.

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