Anaerobiosis: The complete absence, or (loosely) the paucity, of gaseous or dissolved elemental oxygen in a given place or environment. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Aerobiosis: Life or metabolic reactions occurring in an environment containing oxygen.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Oxygen: An element with atomic symbol O, atomic number 8, and atomic weight [15.99903; 15.99977]. It is the most abundant element on earth and essential for respiration.Dinitrophenols: Organic compounds that contain two nitro groups attached to a phenol.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Nitrate Reductase: An enzyme that catalyzes the oxidation of nitrite to nitrate. It is a cytochrome protein that contains IRON and MOLYBDENUM.Nitrates: Inorganic or organic salts and esters of nitric acid. These compounds contain the NO3- radical.Iron-Sulfur Proteins: A group of proteins possessing only the iron-sulfur complex as the prosthetic group. These proteins participate in all major pathways of electron transport: photosynthesis, respiration, hydroxylation and bacterial hydrogen and nitrogen fixation.Nitrate Reductases: Oxidoreductases that are specific for the reduction of NITRATES.Bacterial Proteins: Proteins found in any species of bacterium.Formates: Derivatives of formic acids. Included under this heading are a broad variety of acid forms, salts, esters, and amides that are formed with a single carbon carboxy group.Culture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Cyanides: Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.Fermentation: Anaerobic degradation of GLUCOSE or other organic nutrients to gain energy in the form of ATP. End products vary depending on organisms, substrates, and enzymatic pathways. Common fermentation products include ETHANOL and LACTIC ACID.Pyruvate Synthase: A ferredoxin-containing enzyme that catalyzes the COENZYME A-dependent oxidative decarboxylation of PYRUVATE to acetyl-COENZYME A and CARBON DIOXIDE.Genes, Bacterial: The functional hereditary units of BACTERIA.Formate Dehydrogenases: Flavoproteins that catalyze reversibly the reduction of carbon dioxide to formate. Many compounds can act as acceptors, but the only physiologically active acceptor is NAD. The enzymes are active in the fermentation of sugars and other compounds to carbon dioxide and are the key enzymes in obtaining energy when bacteria are grown on formate as the main carbon source. They have been purified from bovine blood. EC 1.2.1.2.Chlamydomonas reinhardtii: A species of GREEN ALGAE. Delicate, hairlike appendages arise from the flagellar surface in these organisms.Hydrogenase: An enzyme found in bacteria. It catalyzes the reduction of FERREDOXIN and other substances in the presence of molecular hydrogen and is involved in the electron transport of bacterial photosynthesis.Operon: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Lac Operon: The genetic unit consisting of three structural genes, an operator and a regulatory gene. The regulatory gene controls the synthesis of the three structural genes: BETA-GALACTOSIDASE and beta-galactoside permease (involved with the metabolism of lactose), and beta-thiogalactoside acetyltransferase.2,4-Dinitrophenol: A toxic dye, chemically related to trinitrophenol (picric acid), used in biochemical studies of oxidative processes where it uncouples oxidative phosphorylation. It is also used as a metabolic stimulant. (Stedman, 26th ed)beta-Galactosidase: A group of enzymes that catalyzes the hydrolysis of terminal, non-reducing beta-D-galactose residues in beta-galactosides. Deficiency of beta-Galactosidase A1 may cause GANGLIOSIDOSIS, GM1.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Electron Transport: The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.NAD: A coenzyme composed of ribosylnicotinamide 5'-diphosphate coupled to adenosine 5'-phosphate by pyrophosphate linkage. It is found widely in nature and is involved in numerous enzymatic reactions in which it serves as an electron carrier by being alternately oxidized (NAD+) and reduced (NADH). (Dorland, 27th ed)Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Oxygen Consumption: The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)Salmonella typhimurium: A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.Antimycin A: An antibiotic substance produced by Streptomyces species. It inhibits mitochondrial respiration and may deplete cellular levels of ATP. Antimycin A1 has been used as a fungicide, insecticide, and miticide. (From Merck Index, 12th ed)Bacillus cereus: A species of rod-shaped bacteria that is a common soil saprophyte. Its spores are widespread and multiplication has been observed chiefly in foods. Contamination may lead to food poisoning.Metabolism: The chemical reactions that occur within the cells, tissues, or an organism. These processes include both the biosynthesis (ANABOLISM) and the breakdown (CATABOLISM) of organic materials utilized by the living organism.Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Carbonyl Cyanide m-Chlorophenyl Hydrazone: A proton ionophore. It is commonly used as an uncoupling agent and inhibitor of photosynthesis because of its effects on mitochondrial and chloroplast membranes.Genes, Regulator: Genes which regulate or circumscribe the activity of other genes; specifically, genes which code for PROTEINS or RNAs which have GENE EXPRESSION REGULATION functions.Molybdenum: A metallic element with the atomic symbol Mo, atomic number 42, and atomic weight 95.94. It is an essential trace element, being a component of the enzymes xanthine oxidase, aldehyde oxidase, and nitrate reductase. (From Dorland, 27th ed)Succinate Dehydrogenase: A flavoprotein containing oxidoreductase that catalyzes the dehydrogenation of SUCCINATE to fumarate. In most eukaryotic organisms this enzyme is a component of mitochondrial electron transport complex II.Oxidoreductases: The class of all enzymes catalyzing oxidoreduction reactions. The substrate that is oxidized is regarded as a hydrogen donor. The systematic name is based on donor:acceptor oxidoreductase. The recommended name will be dehydrogenase, wherever this is possible; as an alternative, reductase can be used. Oxidase is only used in cases where O2 is the acceptor. (Enzyme Nomenclature, 1992, p9)Kinetics: The rate dynamics in chemical or physical systems.Bioreactors: Tools or devices for generating products using the synthetic or chemical conversion capacity of a biological system. They can be classical fermentors, cell culture perfusion systems, or enzyme bioreactors. For production of proteins or enzymes, recombinant microorganisms such as bacteria, mammalian cells, or insect or plant cells are usually chosen.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Glucose: A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.Gene Expression Regulation, Enzymologic: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in enzyme synthesis.Gene Expression Regulation, Fungal: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in fungi.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.Lactates: Salts or esters of LACTIC ACID containing the general formula CH3CHOHCOOR.Biomass: Total mass of all the organisms of a given type and/or in a given area. (From Concise Dictionary of Biology, 1990) It includes the yield of vegetative mass produced from any given crop.Glycolysis: A metabolic process that converts GLUCOSE into two molecules of PYRUVIC ACID through a series of enzymatic reactions. Energy generated by this process is conserved in two molecules of ATP. Glycolysis is the universal catabolic pathway for glucose, free glucose, or glucose derived from complex CARBOHYDRATES, such as GLYCOGEN and STARCH.Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Acetyltransferases: Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.Ethanol: A clear, colorless liquid rapidly absorbed from the gastrointestinal tract and distributed throughout the body. It has bactericidal activity and is used often as a topical disinfectant. It is widely used as a solvent and preservative in pharmaceutical preparations as well as serving as the primary ingredient in ALCOHOLIC BEVERAGES.Energy Metabolism: The chemical reactions involved in the production and utilization of various forms of energy in cells.Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Bacteriological Techniques: Techniques used in studying bacteria.Carbon Dioxide: A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.Gene Deletion: A genetic rearrangement through loss of segments of DNA or RNA, bringing sequences which are normally separated into close proximity. This deletion may be detected using cytogenetic techniques and can also be inferred from the phenotype, indicating a deletion at one specific locus.Saccharomyces cerevisiae: A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Spectrophotometry: The art or process of comparing photometrically the relative intensities of the light in different parts of the spectrum.Pseudomonas aeruginosa: A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. aeruginosa is a major agent of nosocomial infection.Transcription Factors: Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.Spectrophotometry, Infrared: Spectrophotometry in the infrared region, usually for the purpose of chemical analysis through measurement of absorption spectra associated with rotational and vibrational energy levels of molecules. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Phosphates: Inorganic salts of phosphoric acid.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Restriction Mapping: Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

Denitrifying Pseudomonas aeruginosa: some parameters of growth and active transport. (1/4712)

Optimal cell yield of Pseudomonas aeruginosa grown under denitrifying conditions was obtained with 100 mM nitrate as the terminal electron acceptor, irrespective of the medium used. Nitrite as the terminal electron acceptor supported poor denitrifying growth when concentrations of less than 15 mM, but not higher, were used, apparently owing to toxicity exerted by nitrite. Nitrite accumulated in the medium during early exponential phase when nitrate was the terminal electron acceptor and then decreased to extinction before midexponential phase. The maximal rate of glucose and gluconate transport was supported by 1 mM nitrate or nitrite as the terminal electron acceptor under anaerobic conditions. The transport rate was greater with nitrate than with nitrite as the terminal electron acceptor, but the greatest transport rate was observed under aerobic conditions with oxygen as the terminal electron acceptor. When P. aeruginosa was inoculated into a denitrifying environment, nitrate reductase was detected after 3 h of incubation, nitrite reductase was detected after another 4 h of incubation, and maximal nitrate and nitrite reductase activities peaked together during midexponential phase. The latter coincided with maximal glucose transport activity.  (+info)

Molecular characterization of the nitrite-reducing system of Staphylococcus carnosus. (2/4712)

Characterization of a nitrite reductase-negative Staphylococcus carnosus Tn917 mutant led to the identification of the nir operon, which encodes NirBD, the dissimilatory NADH-dependent nitrite reductase; SirA, the putative oxidase and chelatase, and SirB, the uroporphyrinogen III methylase, both of which are necessary for biosynthesis of the siroheme prosthetic group; and NirR, which revealed no convincing similarity to proteins with known functions. We suggest that NirR is essential for nir promoter activity. In the absence of NirR, a weak promoter upstream of sirA seems to drive transcription of sirA, nirB, nirD, and sirB in the stationary-growth phase. In primer extension experiments one predominant and several weaker transcription start sites were identified in the nir promoter region. Northern blot analyses indicated that anaerobiosis and nitrite are induction factors of the nir operon: cells grown aerobically with nitrite revealed small amounts of full-length transcript whereas cells grown anaerobically with or without nitrite showed large amounts of full-length transcript. Although a transcript is detectable, no nitrite reduction occurs in cells grown aerobically with nitrite, indicating an additional oxygen-controlled step at the level of translation, enzyme folding, assembly, or insertion of prosthetic groups. The nitrite-reducing activity expressed during anaerobiosis is switched off reversibly when the oxygen tension increases, most likely due to competition for electrons with the aerobic respiratory chain. Another gene, nirC, is located upstream of the nir operon. nirC encodes a putative integral membrane-spanning protein of unknown function. A nirC mutant showed no distinct phenotype.  (+info)

Unusual ribulose 1,5-bisphosphate carboxylase/oxygenase of anoxic Archaea. (3/4712)

The predominant pool of organic matter on earth is derived from the biological reduction and assimilation of carbon dioxide gas, catalyzed primarily by the enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO). By virtue of its capacity to use molecular oxygen as an alternative and competing gaseous substrate, the catalytic efficiency of RubisCO and the enzyme's ability to assimilate CO2 may be severely limited, with consequent environmental and agricultural effects. Recent genomic sequencing projects, however, have identified putative RubisCO genes from anoxic Archaea. In the present study, these potential RubisCO sequences, from Methanococcus jannaschii and Archaeoglobus fulgidus, were analyzed in order to ascertain whether such sequences might encode functional proteins. We also report the isolation and properties of recombinant RubisCO using sequences obtained from the obligately anaerobic hyperthermophilic methanogen M. jannaschii. This is the first description of an archaeal RubisCO sequence; this study also represents the initial characterization of a RubisCO molecule that has evolved in the absence of molecular oxygen. The enzyme was shown to be a homodimer whose deduced sequence, along with other recently obtained archaeal RubisCO sequences, differs substantially from those of known RubisCO molecules. The recombinant M. jannaschii enzyme has a somewhat low, but reasonable kcat, however, unlike previously isolated RubisCO molecules, this enzyme is very oxygen sensitive yet it is stable to hyperthermal temperatures and catalyzes the formation of the expected carboxylation product. Despite inhibition by oxygen, this unusual RubisCO still catalyzes a weak yet demonstrable oxygenase activity, with perhaps the lowest capacity for CO2/O2 discrimination ever encountered for any RubisCO.  (+info)

Metal-catalyzed oxidation of phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase from Escherichia coli: inactivation and destabilization by oxidation of active-site cysteines. (4/4712)

The in vitro instability of the phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase [DAHPS(Phe)] from Escherichia coli has been found to be due to a metal-catalyzed oxidation mechanism. DAHPS(Phe) is one of three differentially feedback-regulated isoforms of the enzyme which catalyzes the first step of aromatic biosynthesis, the formation of DAHP from phosphoenolpyruvate and D-erythrose-4-phosphate. The activity of the apoenzyme decayed exponentially, with a half-life of about 1 day at room temperature, and the heterotetramer slowly dissociated to the monomeric state. The enzyme was stabilized by the presence of phosphoenolpyruvate or EDTA, indicating that in the absence of substrate, a trace metal(s) was the inactivating agent. Cu2+ and Fe2+, but none of the other divalent metals that activate the enzyme, greatly accelerated the rate of inactivation and subunit dissociation. Both anaerobiosis and the addition of catalase significantly reduced Cu2+-catalyzed inactivation. In the spontaneously inactivated enzyme, there was a net loss of two of the seven thiols per subunit; this value increased with increasing concentrations of added Cu2+. Dithiothreitol completely restored the enzymatic activity and the two lost thiols in the spontaneously inactivated enzyme but was only partially effective in reactivation of the Cu2+-inactivated enzyme. Mutant enzymes with conservative replacements at either of the two active-site cysteines, Cys61 or Cys328, were insensitive to the metal attack. Peptide mapping of the Cu2+-inactivated enzyme revealed a disulfide linkage between these two cysteine residues. All results indicate that DAHPS(Phe) is a metal-catalyzed oxidation system wherein bound substrate protects active-site residues from oxidative attack catalyzed by bound redox metal cofactor. A mechanism of inactivation of DAHPS is proposed that features a metal redox cycle that requires the sequential oxidation of its two active-site cysteines.  (+info)

Anaerobic oxidation of o-xylene, m-xylene, and homologous alkylbenzenes by new types of sulfate-reducing bacteria. (5/4712)

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the delta subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide.  (+info)

Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors. (6/4712)

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fed upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing M. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only M. mazeii S-6 immobilized, while the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (Ks and mumax) of immobilized M. concilii GP-6 or M. mazeii S-6 compared with suspended cultures, indicating that immobilization does not affect the growth kinetics of these methanogens. An enzyme-linked immunosorbent assay using polyclonal antibodies against either M. concilii GP-6 or M. mazeii S-6 showed significant variations in the two methanogenic populations in the different reactors. Polyclonal antibodies were further used to study the spatial distribution of the two methanogens. M. concilii GP-6 was immobilized only on existing support material without any specific pattern. M. mazeii S-6, however, showed a different immobilization pattern: large clumps were formed when the concentration of acetate was high, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps. The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor.  (+info)

Anaerobic degradation of phthalate isomers by methanogenic consortia. (7/4712)

Three methanogenic enrichment cultures, grown on ortho-phthalate, iso-phthalate, or terephthalate were obtained from digested sewage sludge or methanogenic granular sludge. Cultures grown on one of the phthalate isomers were not capable of degrading the other phthalate isomers. All three cultures had the ability to degrade benzoate. Maximum specific growth rates (microseconds max) and biomass yields (YXtotS) of the mixed cultures were determined by using both the phthalate isomers and benzoate as substrates. Comparable values for these parameters were found for all three cultures. Values for microseconds max and YXtotS were higher for growth on benzoate compared to the phthalate isomers. Based on measured and estimated values for the microbial yield of the methanogens in the mixed culture, specific yields for the phthalate and benzoate fermenting organisms were calculated. A kinetic model, involving three microbial species, was developed to predict intermediate acetate and hydrogen accumulation and the final production of methane. Values for the ratio of the concentrations of methanogenic organisms, versus the phthalate isomer and benzoate fermenting organisms, and apparent half-saturation constants (KS) for the methanogens were calculated. By using this combination of measured and estimated parameter values, a reasonable description of intermediate accumulation and methane formation was obtained, with the initial concentration of phthalate fermenting organisms being the only variable. The energetic efficiency for growth of the fermenting organisms on the phthalate isomers was calculated to be significantly smaller than for growth on benzoate.  (+info)

The role of benzoate in anaerobic degradation of terephthalate. (8/4712)

The effects of acetate, benzoate, and periods without substrate on the anaerobic degradation of terephthalate (1, 4-benzene-dicarboxylate) by a syntrophic methanogenic culture were studied. The culture had been enriched on terephthalate and was capable of benzoate degradation without a lag phase. When incubated with a mixture of benzoate and terephthalate, subsequent degradation with preference for benzoate was observed. Both benzoate and acetate inhibited the anaerobic degradation of terephthalate. The observed inhibition is partially irreversible, resulting in a decrease (or even a complete loss) of the terephthalate-degrading activity after complete degradation of benzoate or acetate. Irreversible inhibition was characteristic for terephthalate degradation only because the inhibition of benzoate degradation by acetate could well be described by reversible noncompetitive product inhibition. Terephthalate degradation was furthermore irreversibly inhibited by periods without substrate of only a few hours. The inhibition of terephthalate degradation due to periods without substrate could be overcome through incubation of the culture with a mixture of benzoate and terephthalate. In this case no influence of a period without substrate was observed. Based on these observations it is postulated that decarboxylation of terephthalate, resulting in the formation of benzoate, is strictly dependent on the concomitant fermentation of benzoate. In the presence of higher concentrations of benzoate, however, benzoate is the favored substrate over terephthalate, and the culture loses its ability to degrade terephthalate. In order to overcome the inhibition of terephthalate degradation by benzoate and acetate, a two-stage reactor system is suggested for the treatment of wastewater generated during terephthalic acid production.  (+info)

Anoxic environments are those where oxygen is completely absent. Surprisingly, certain critters have evolved to live in these conditions. This...
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. In contrast, an anaerobic organism (anaerobe) is any organism that does not require oxygen for growth. Some anaerobes react negatively or even die if oxygen is present. Obligate aerobes need oxygen to grow. In a process known as cellular respiration, these organisms use oxygen to oxidize substrates (for example sugars and fats) and generate energy. Facultative anaerobes use oxygen if it is available, but also have anaerobic methods of energy production. Microaerophiles require oxygen for energy production, but are harmed by atmospheric concentrations of oxygen (21% O2). Aerotolerant anaerobes do not use oxygen but are not harmed by it. When an organism is able to survive in both oxygen and anaerobic environments, the use of the Pasteur effect can distinguish between facultative anaerobes and aerotolerant organisms. If the organism is using fermentation in an anaerobic environment, the addition of ...
Now, when we think of weight lifting we think of the anaerobic system working, and when we think of "cardio" or aerobics we think of the aerobic system being the primary energy-production system. But this is in fact not the case. Both systems are working all the time. The difference between high intensity training and typical "cardio" training is the degree to which each system is stressed. During bouts of "cardio" the anaerobic system is not being greatly stressed and there is always enough oxygen to allow for the aerobic metabolism to take place. However, during high intensity training where a lot of energy needs to be produced in a short period of time, the anaerobic system is running so fast that it produces more end product (pyruvate) than the aerobic system can cycle. Pyruvate builds up in the cells and converts into lactic acid and this creates that muscle burn. Because the aerobic system (which produces 34 ATP) cannot work any faster, and the anaerobic system (which can only produce 4 ...
Now, when we think of weight lifting we think of the anaerobic system working, and when we think of "cardio" or aerobics we think of the aerobic system being the primary energy-production system. But this is in fact not the case. Both systems are working all the time. The difference between high intensity training and typical "cardio" training is the degree to which each system is stressed. During bouts of "cardio" the anaerobic system is not being greatly stressed and there is always enough oxygen to allow for the aerobic metabolism to take place. However, during high intensity training where a lot of energy needs to be produced in a short period of time, the anaerobic system is running so fast that it produces more end product (pyruvate) than the aerobic system can cycle. Pyruvate builds up in the cells and converts into lactic acid and this creates that muscle burn. Because the aerobic system (which produces 34 ATP) cannot work any faster, and the anaerobic system (which can only produce 4 ...
The contribution of protein induction and repression to the adaptation of cells to changes in oxygen supply is only poorly understood. We assessed this contribution by measuring the levels of 170 individual polypeptides produced by Escherichia coli K-12 in cells growing aerobically or anaerobically with and without nitrate. Eighteen reached their highest levels during anaerobic growth. These 18 polypeptides include at least 4 glycolytic enzymes and pyruvate formate-lyase (beta-subunit). Most of these proteins were found at significant levels during aerobic growth and appeared to undergo metabolic regulation by stimuli other than anaerobiosis. Anaerobic induction ratios ranged from 1.8- to 11-fold, and nitrate antagonized the anaerobic induction of all of the proteins except one. The time course of synthesis of the proteins after shifts in oxygen supply revealed at least three distinct temporal patterns. These results are discussed in light of known physiological alterations associated with ...
I have a question about anaerobic cultures. I am biochem/biophys grad student at the University of Pennsylvania. I need to grow up wild type ecoli anaerobically. What constitutes an anaerobic culture? How much media should I put into Fernbach flasks to make it an anaerobic culture and is it necessary to degas any flasks or bottles that I choose to grow my bacteria in? Any help in this matter would be appreciated. my email address is ehopper at mail.med.upenn.edu. Thank you Elizabeth Hopper ...
In 2007, biologists from MIT uncovered a mystery surrounding cobalamin.[3] They found bacteria in an ecosystem that did not seem to have any synergistic relationship (involving the production of B-12) with other organisms in their environment. Dr. Graham Walker points out that there are over 30 genes required to synthesize cobalamin, and "thats a lot to carry around if you dont need to make it."[4] So, what is the reason for this biologically expensive process? In the last decade, biologists have been trying to answer this question, and cobalamin has some effect on flagella function (a tail-like structure that bacteria use for propulsion)[5]. So, there could be a synergistic relationship with this nutrient in a larger bacterial colony, especially in an anaerobic environment (lacking oxygen).. Most of the gut is an anaerobic environment, so there may be more answers to be found in the human intestines. In 2014, a group of scientists published a revolutionary paper on Cell Metabolism.[6] The ...
Your metabolism is how your body converts the nutrients you consume in your diet to adenosine triphosphate (ATP), the fuel your body uses for muscular activity. ATP is produced either with oxygen using the aerobic pathways or without oxygen relying on the anaerobic pathways. When you first start to exercise, your body uses the anaerobic energy pathways and stored ATP to fuel that activity. A proper warm-up is important because it can take about five to eight minutes to be able to efficiently use aerobic metabolism to produce the ATP necessary to sustain physical activity. Once a steady-state of oxygen consumption is achieved, the aerobic energy pathways are able to provide most of the ATP needed for the workout. Exercise that places a greater demand on the anaerobic energy pathways during the workout can increase the need for oxygen after the workout, thereby enhancing the EPOC effect ...
I know there is alot of technical stuff in there, so now im going to give practical examples of how this works and how to improve. One last complicated thing before I start though; thresholds. There are alot of complicated and differently names thresholds like lactic threshold or aerobic threshold. Basically however they mostly mean the same thing. before the threshold you can work for a long time, above it you get tired quickly. This is due to how much the anaerobic system is being relied on. practically this very complicated thing is actually very simple. When you are moving around the ring you will mostly be using your aerobic system. When you are moving quickly like stepping back to avoid a kick, dodging to the side or attacking you will be using the anaerobic system, because your body will need more energy than just the aerobic system can provide. By increasing the aerobic systems capability you can take more work off of your anaerobic system leaving you with more energy. More importantly ...
This post was most recently updated on October 17th, 2018. Specimens for anaerobic culture should be properly collected and transported. Indigenous anaerobes are often present in large numbers as normal flora on mucosal surfaces (e.g. mouth). So the sample from sites known to have anaerobes as part of the normal flora is unacceptable for anaerobic culture. ...
Ive become a SysMO DB PAL for MOSES project in 2007 being a post-doc in lab of Prof. Matthias Reuss at University of Stuttgart. In the MOSES project, our major efforts were in the experimental data acquisition for dynamic model of primary carbon and anaerobic energy metabolism in yeast. The model implements prediction of perturbations of two types: glucose pulse and temperature jump. We implement "stimulus-response" methodology for the unraveling the dynamic structure of the network and to parameterize the model. Currently I am a member of FAIRDOM PALs team and PAL for ExtremoPharm project ...
Ive become a SysMO DB PAL for MOSES project in 2007 being a post-doc in lab of Prof. Matthias Reuss at University of Stuttgart. In the MOSES project, our major efforts were in the experimental data acquisition for dynamic model of primary carbon and anaerobic energy metabolism in yeast. The model implements prediction of perturbations of two types: glucose pulse and temperature jump. We implement "stimulus-response" methodology for the unraveling the dynamic structure of the network and to ...
Ive become a SysMO DB PAL for MOSES project in 2007 being a post-doc in lab of Prof. Matthias Reuss at University of Stuttgart. In the MOSES project, our major efforts were in the experimental data acquisition for dynamic model of primary carbon and anaerobic energy metabolism in yeast. The model implements prediction of perturbations of two types: glucose pulse and temperature jump. We implement "stimulus-response" methodology for the unraveling the dynamic structure of the network and to ...
Ive become a SysMO DB PAL for MOSES project in 2007 being a post-doc in lab of Prof. Matthias Reuss at University of Stuttgart. In the MOSES project, our major efforts were in the experimental data acquisition for dynamic model of primary carbon and anaerobic energy metabolism in yeast. The model implements prediction of perturbations of two types: glucose pulse and temperature jump. We implement "stimulus-response" methodology for the unraveling the dynamic structure of the network and to ...
What is the difference between Obligate and Facultative Anaerobe? Obligate anaerobe cannot survive in oxygen while facultative anaerobe can survive in oxygen...
Abattoirs are well suited targets to low-rate, anaerobic process because of the usually low COD and high O&G levels. It may be also possible to design as competitive, higher rate systems. As with most every anaerobic approach, process temperature is key. One will want to avoid seeing an anaerobic treatment plant for wastewaters that contain grease, such as meat processing, milk, cheese, etc., operate at less than 32C. If client or engineers insist, they have to deal with the consequences of designing and operating at lower temperatures. First , a larger reactors. Second, most of the grease will float to the top and form a scum layer that in some cases with meat slaughtering operations has approached six ft (2 m) in depth. This scum layer is very difficult to breakup especially if the reactor is covered with a membrane type material. These problems may occur at 32C, but to a much lesser extent. Therefore stick to and maintain the higher temperature range. Below 20°C removals are simply settling, ...
The International Society for Plant Anaerobiosis welcomes members with an interest in low oxygen responses in plants as caused by flooding of soils or during partial or complete submergence.
Well, I suppose there are a couple of different ways. There are so-called dissimilatory processes, by which the toxic metals, for example, would be sequestered into by-products of the bacteriums natural metabolism, that are not incorporated into the cell. An example of that would be an anoxic environment - bacteria that have adapted to breathing sulphate in the way that we breathe oxygen produce a metabolic waste product called sulphide, which is actually extremely reactive with heavy metals, a number of metals, and the sulphide can precipitate those metals from waste streams or groundwater. Precipitation is the process whereby metals that are in solution are removed from solution - by solution, I mean natural waters, groundwater, surface waters - by the process of forming a new mineral. So, something that is dissolved becomes something that is solid, and the density of those solids, in many cases, tends to cause them to sink or precipitate out from that fluid. So, the sulphide can precipitate ...
General Information: This organism is associated with severe and chronic periodontal (tissues surrounding and supporting the tooth) diseases. Progression of the disease is caused by colonization by this organism in an anaerobic environment in host tissues and severe progression results in loss of the tissues supporting the tooth and eventually loss of the tooth itself. The black pigmentation characteristic of this bacterium comes from iron acquisition that does not use the typical siderophore system of other bacteria but accumulates hemin. Peptides appear to be the predominant carbon and energy source of this organism, perhaps in keeping with its ability to destroy host tissue. Oxygen tolerance systems play a part in establishment of the organism in the oral cavity, including a superoxide dismutase. Pathogenic factors include extracellular adhesins that mediate interactions with other bacteria as well as the extracellular matrix, and a host of degradative enzymes that are responsible for tissue ...
... by Nova Q LTD. AquaClean - Anaerobic Digestion - Microbial Products to enhance Anaerobic Digester Performance. ...
The two-component signal transduction system (TCS) BarA/UvrY activates transcription of CsrB and CsrC noncoding RNAs, which act by sequestering the RNA-binding global regulatory protein CsrA. Here, we show that the metabolic end products formate and acetate provide a physiological stimulus for this TCS and thus link posttranscriptional regulation by the Csr system to the metabolic state of the cell. ...
... ; Anaerobic respiration in muscles. Both of the processes releases energy ...
As a layer of pigmented cells the RPE absorbs the light energy focused by the lens on the retina (72, 86). The RPE transports ions, water, and metabolic end products from the subretinal space to the blood (144, 236, 369, 402, 558). The RPE takes up nutrients such as glucose, retinol, and fatty acids from the blood and delivers these nutrients to photoreceptors. Importantly, retinal is constantly exchanged between photoreceptors and the RPE (30, 58, 596). Photoreceptors are unable to reisomerize all-trans-retinal, formed after photon absorption, back into 11-cis-retinal. To maintain the photoreceptor excitability, retinal is transported to the RPE reisomerized to 11-cis-retinal and transported back to photoreceptors. This process is known as the visual cycle of retinal. Furthermore, the voltage-dependent ion conductance of the apical membrane enables the RPE to stabilize ion composition in the subretinal space, which is essential for the maintenance of photoreceptor excitability (144, 558, 559). ...
As a layer of pigmented cells the RPE absorbs the light energy focused by the lens on the retina (72, 86). The RPE transports ions, water, and metabolic end products from the subretinal space to the blood (144, 236, 369, 402, 558). The RPE takes up nutrients such as glucose, retinol, and fatty acids from the blood and delivers these nutrients to photoreceptors. Importantly, retinal is constantly exchanged between photoreceptors and the RPE (30, 58, 596). Photoreceptors are unable to reisomerize all-trans-retinal, formed after photon absorption, back into 11-cis-retinal. To maintain the photoreceptor excitability, retinal is transported to the RPE reisomerized to 11-cis-retinal and transported back to photoreceptors. This process is known as the visual cycle of retinal. Furthermore, the voltage-dependent ion conductance of the apical membrane enables the RPE to stabilize ion composition in the subretinal space, which is essential for the maintenance of photoreceptor excitability (144, 558, 559). ...
Aerobic respiration and anaerobic respiration both are involve chemical reactions which take place in the cell to produce energy, which is needed for
3. Replace the standard Petri dish lid with a sterile Brewer anaerobic Petri dish cover. The cover should not rest on the Petri dish bottom. The inner glass ridge should seal against the uninoculated periphery of the agar. It is essential that the sealing ring inside the cover is in contact with the medium. This seal must not be broken before the end of the incubation period. A small amount of air is caught over the surface of the medium; however, the oxygen in this space reacts with reducing agents in the medium to form an anaerobic environment ...
It would seem that Henneguya salminicola has undergone an incredible evolution in order to live in a wholly anaerobic environment.
... - This means that the monosaccharide glucose requires only zymase to be broken down into ethanol and CO2 whilst the disaccharide maltose requires both
Individuals should be able to breathe through workout without gasping.. Gasping indicates intensity may be too high and anaerobic system is stressed. This is ok of intention was to train anerobic system, but intensity should be reduced if goal was training the aerobic system.. ...
View Notes - Monera6 from BIOLOGY BSC1005 at Broward College. the cell membrane and move in a back and forth motion. Facultative anaerobes - Organisms that do not require oxygen to carry out
To get faster, youll need to work the aerobic and anaerobic systems. Heres how you can incorporate a variety of workouts so you can avoid a performance pla...
Lactic acid is transported to the liver so that it can be converted into a compund used to produce ATP.. You can continue to breathe heavily after exercise as the additional oxygen is needed to oxidise the lactic acid formed.. ATP was on credit and the oxygen is needed to pay back the debt. ...
Eventually, I do at 4°C when I dont want to stay late in the lab, and continue the experiment the day after. but there is no additional benefit for this kind of incubation. At 4°C you have less dissociation, but its no more true when you incubate then the next steps at RT.. ...
Iron, Proteins, Biogenesis, Sulfur, Escherichia, Escherichia Coli, Gene, Eukaryotes, Bacteria, Growth, Superoxide, Oxygen, Anaerobiosis, DNA, Photosynthesis, Role, Enzymes, Cells, Genes, Regulation
TY - JOUR. T1 - Stepwise metabolic adaption from pure metabolization to balanced anaerobic growth on xylose explored for recombinant Saccharomyces cerevisiae. AU - Klimacek, Mario. AU - Kirl, Elisabeth. AU - Krahulec, Stefan. AU - Longus, Karin. AU - Novy, Vera. AU - Nidetzky, Bernd. PY - 2014. Y1 - 2014. UR - http://www.microbialcellfactories.com/content/13/1/37/abstract. U2 - 10.1186/1475-2859-13-37. DO - 10.1186/1475-2859-13-37. M3 - Article. VL - 13. SP - 1. EP - 12. JO - Microbial cell factories JF - Microbial cell factories SN - 1475-2859. IS - 37. ER - ...
Background. Under hypoxic conditions, plant mitochondria preserve the capacity to oxidize external NADH, NADPH and tricarboxylic acid cycle substrates. Nitrite serves as an alternative electron acceptor at the level of cytochrome oxidase, with possibly complex III and the alternative oxidase also being involved. Nitric oxide is a significant product of the reaction, which has a high affinity for cytochrome c oxidase, inhibiting it. The excess NO is scavenged by hypoxically induced class 1 haemoglobin in the reaction involving ascorbate.. Scope. By using nitrite, mitochondria retain a limited capacity for ATP synthesis. NADH, produced from glycolysis during anaerobiosis and oxidized in the mitochondrial electron transport chain, should shift the composition of metabolites formed during anaerobiosis with increased conversion of pyruvate to alanine and greater involvement of other transamination reactions, such as those involving γ-aminobutyric acid formation.. Conclusions. Anaerobic mitochondrial ...
Anabaena cylindrica was immobilized in calcium alginate beads and was placed in a batch reactor in the presence of a glutamine synthetase inhibitor (methionine sulfoximide). Ammonia was released in the medium during two days with a rate of 0.35 μ moles h−1mgChl−1. Addition of nitrite to the medium increased the ammonia production as cells used the nitrite reductase pathway to form ammonia. When reactors were placed in anaerobiosis by N2 bubbling, ammonia production was sustained several days and the total ammonia formed was about two fold higher than in aerobiosis. Long term effects of MSX, nitrite and anaerobiosis are discussed.
Abstract: The article deals with the analysis of results of verification of a one-stage anaerobic digestion at mesophile and thermophile conditions in two series differing in retention time (26 and 37 days). Substrates consisting of various proportions of poultry crushed bones, pork ligaments, and slurry of beef-cattle and pigs (1:1) were used. Stabilized non-drained remainder of an anaerobic digestion was used as inoculum. Results of verification showed effectiveness of slaughter waste processing in biogas stations. However, slaughter waste processing requires installation of equipment for a thermal modification of the feed-in substrate (warming up to 70°C for the duration of 1 hour)
McIntosh and Fildes anaerobic jar is an instrument used in the production of an anaerobic environment. This method of anaerobiosis as others is used to culture bacteria which die or fail to grow in presence of oxygen (anaerobes). The jar, about 20″×12.5″ is made up of a metal. Its parts are as follows: The body made up of metal (airtight) The lid, also metal can be placed in an airtight fashion A screw going through a curved metal strip to secure and hold the lid in place A thermometer to measuring the internal temperature A pressure gauge to measuring the internal pressure (or a side tube is attached to a manometer) Another side tube for evacuation and introduction of gases (to a gas cylinder or a vacuum pump) A wire cage hanging from the lid to hold a catalyst that makes hydrogen react to oxygen without the need of any ignition source First: The culture: The culture media are placed inside the jar, stacked up one on the other, and Indicator system: Pseudomonas aeruginosa, inoculated on ...
Hydrated encysted embryos of the brine shrimp Artemia franciscana have the ability to withstand years in anaerobic sea water using metabolic strategies that enable them to inactivate all cell metabolic activities and then to resume development when placed in aerobic sea water. However, this unique characteristic of Artemia franciscana embryos is lost during a very short period, at the embryonic­larval transition period of development, coincident with the appearance of prenauplius larvae. Thus, while encysted embryos show complete inhibition of proteolysis over at least 4 years under anoxia, control of this activity, together with resistance to anoxia, is lost in newly hatched nauplius larvae after only a few days in anaerobic sea water. In contrast to encysted embryos, young larvae in anaerobic sea water produce large amounts of lactic acid, which reaches a concentration of nearly 50 mmol l-1 within 12 h of incubation. The accumulated lactic acid is believed to reduce the intracellular pH ...
Three metabolic engineering strategies were successfully designed and applied in this work, including: activation of E. coli native cryptic pathway, multi enzymes to enhance efficiency of one reaction in a pathway, and construction of a novel anaerobic pathway with balanced ox-reduction status and adequate energy production.. All biological systems are capable of short term response to environmental changes and, on longer time scales, to evolutionary adaptation. It was suggested that cryptic or latent pathways are consequences of such adaption. By inactivate once active pathways, microbes are able to save materials and energy associated with expression of the genes, and to change metabolic network for adaption of new environment [36, 37]. Cryptic or latent pathway activation is a classic subject in metabolic engineering, mainly for production of therapeutic natural products in microorganisms such as Aspergillus, Streptomyces, or Pseudomonas [38]. However, only a few examples can be found with ...
Hlavním cílem této bakalářské práce je seznámení se se zpracováním odpadů v České republice a jeho následným využitím v bioplynových stanicích. V následujících kapitolách je postupně popsáno zpracování a procentuální ...
Inoculate Actinomyces cultures into tubes containing broth, semisolid or solid media. The semisolid medium should be stabinoculated and the slanted medium should be inoculated over its entire surface. Incubate cultures at 35 ± 2°C in an anaerobic atmosphere (BD GasPak™ EZ anaerobic system, or alternative system for the cultivation of anaerobic microorganisms).. ...
As a clarification of the above, molecular oxygen, as I understand it, is necessary for the post-transcriptional hydroxylation of proline to hydroxyproline - ie the oxygen in the hydroxyproline does not come from water, but is added from an O2 molecule by an oxygenase enzyme.. The hydroxyprolines are critical for collagen strength. Thus in the complete absence of O2, animals bodies simply would not be able to hold together beyond a certain size (hence my first question about whether or not the small size gets around the problem).. The level of O2 needed is actually much lower than current atmospheric O2 in aerobic environments, and may be low enough that it could be found even in environments that would be considered to be hypoxic. But the post seemed to suggest that these animals lived in a completely anoxic environment - there is no O2 at all? If which case, how do these animals synthesize collagen?. ...
Of the creatures Thauer has analyzed from the bottom of the Black Sea, perhaps the most fascinating are the archaea that metabolize methane to harness its energy. For their metabolic process, these microbes must oxidize-or remove electrons from-methane under anaerobic (no oxygen) conditions. Scientists previously thought biological systems werent capable of oxidizing methane in anaerobic environments because of the strength of the CH bond in methane-cleaving it requires 440 kilojoules per mole of energy-and usually oxygen would be required as a terminal electron acceptor in the metabolic process.. Thauers Black Sea super-microbes manage this feat by using a nickel (Ni(III))-containing protein to catalyze the dehydrogenation of methane to create a one-carbon unit at the same oxidation level as methanol. Since oxygen is not available, the Black Sea microbes typically use sulfate as the terminal electron acceptor to grab the extra electron that is expelled during this reaction. The resulting ...
Anaerobic respiration is the formation of ATP without the presence of oxygen. This method uses the electron transport chain without the presence of oxygen as the electron acceptor. Although oxygen is highly oxidizing, it is only used during aerobic processes. In anaerobic repiration, less oxidizing molecules such as sulfate (SO42-), nitrate (NO3-), or sulfur (S) are used as electron acceptors. Thus, less energy is formed per molecule of glucose during anaerobic respiration. Most prokaryotes that live under environmental conditions that lack oxygen uses aerobic respiration, although humans too, use it sometimes as well (Lactic Acid Fermentation).. In this process, specifically with the absence of Oxygen during respiration process, organisms have evolved with mechanisms to recycle Nicotinamide Adenine Dinucleotide (NAD+) for glycolysis to continue in order to synthesize Adenosine Triphosphate (ATP) molecules, known as "energy currency" of cells. This process evolves into two different mechanisms, ...
... : respiration (anaerobic respiration and rqs, aerobic respiration , Mitochondria structure , need for cellular respiration , respiromoter )
Anaerobic bacteria can live with out oxygen, while animals and humans cant. Anaerobic bacteria can sustain itself without the presence of oxygen. Almost all animals and humans are obligate aerobes that require oxygen for respiration, whereas anaerobic yeast is an example of facilitative anaerobe bacteria. Individual human cells are also facilitative anaerobes: They switch to lactic acid fermentation if oxygen is not available.
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When in an anaerobic environment, some cells can use glycolysis and fermentation to keep producing ATP. Lactic acid fermentation happens in our...
Smith, Alison Mary (1978). Effect of anaerobiosis on plant metabolism (PhD thesis). University of Cambridge. OCLC 500566304. ... was educated at the University of Cambridge where she was awarded a PhD in 1978 for research into the effect of anaerobiosis on ...
ISBN 978-3-540-74334-7. Shcherbakova, V. (2010-12-01). "Growth of the fungus Geomyces pannorum under anaerobiosis". ...
Hechler, Torsten; Pfeifer, Felicitas (2009-01-01). "Anaerobiosis inhibits gas vesicle formation in halophilic Archaea". ...
Lindeman, RL (1942). "Experimental simulation of winter anaerobiosis in a senescent lake". Ecology. 23: 1-13. doi:10.2307/ ...
ethanol under anaerobiosis acetate under respiratory and respirofermentative growth. ethyl acetate from glucose under oxygen ...
"How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the ...
Keeley, Jon E. (1988). "Anaerobiosis as a stimulus to germination in two vernal pool grasses" (PDF). American Journal of Botany ...
Smalla, Pamela LC; Watermanb, Scott R (June 1998). "Acid stress, anaerobiosis and gadCB: lessons from Lactococcus lactis and ...
One's threshold is said to reflect levels of anaerobiosis and lactate accumulation. As the intensity level of the activity ...
2014). "Microbial Ecology of Anaerobic Digesters: The Key Players of Anaerobiosis" ScientificWorldJournal. 3852369 (1). doi: ...
Vagino-rectal culture 18h incubation 36°C anaerobiosis. Streptococcus agalactiae colonies in chromogenic medium (ChromID CPS ...
In anaerobiosis an additional completely Fnr-dependent transcript starting at Pa, is present. Both of these genes then ... Active FNR protein activates and represses target genes in response to anaerobiosis. It also represses the aerobic genes, ...
This important link between QS and anaerobiosis has a significant impact on production of virulence factors of this organism. ... Recent studies have discovered anaerobiosis can significantly impact the major regulatory circuit of QS. ...
This method of anaerobiosis as others is used to culture bacteria which die or fail to grow in presence of oxygen (anaerobes). ... A growth free culture plate at the end of the process indicates a successful anaerobiosis. However, P. aeruginosa possesses a ...
This important link between quorum sensing and anaerobiosis has a significant impact on production of virulence factors of this ... Recent studies have discovered that anaerobiosis can significantly impact the major regulatory circuit of quorum sensing. ...
2007). "Role in anaerobiosis of the isoenzymes for Saccharomyces cerevisiae fumarate reductase encoded by OSM1 and FRDS1". ...
This does not necissarily exclude that species can catabolize other sugars or have anaerobiosis like fermenting bacteria. The ...
... dry heat and anaerobiosis conditions. Plant Ecophysiology 2, 121-26. Mucina, L. and D. Brandes. (1985). Communities of Berteroa ...
... during anaerobiosis". Thermochimica Acta. 373: 23-30. doi:10.1016/S0040-6031(01)00463-4. Regan, MD; Gill, IS; Richards, JG ( ... during anaerobiosis". Thermochimica Acta. 373: 23-30. doi:10.1016/S0040-6031(01)00463-4. Regan, MD; Gill, IS; Richards, JG ( ...
... that is able to respire on nitrate and nitrite in anaerobiosis. Halomonas nitroreducens's closest relatives are Halomonas ...
Non-methylotrophic methanogegenesis is carried out by methanogenic archaebacteria, which use CO2 and H2 in anaerobiosis to give ...
... and pyridoxal phosphate in the enzymatic formation of hydrogen sulfide from cysteine by the rat liver under anaerobiosis.]". ...
Ivanovic Z. and Vlaski-Lafarge M.: Anaerobiosis and stemness, an evolutionary paradigm. p. 190-191.. ...
In this speech, Warburg presented additional evidence supporting his theory that the elevated anaerobiosis seen in cancer cells ...
Leblová, Sylva; Sinecká, Eva; Vaníčková, Věra (1974). "Pyruvate metabolism in germinating seeds during natural anaerobiosis". ...
Proteins induced by anaerobiosis in Escherichia coli. Message Subject (Your Name) has forwarded a page to you from Journal of ... Proteins induced by anaerobiosis in Escherichia coli.. M W Smith, F C Neidhardt ... at significant levels during aerobic growth and appeared to undergo metabolic regulation by stimuli other than anaerobiosis. ...
In the last few years our interest has been devoted to the energy metabolism of the eggs of the common toad Bufo arenarum Hensel which, like some other amphibian eggs, can cleave at a normal rate in the absence of oxygen or in the presence of cyanide (Barbieri & Legname, 1957). Under anaerobic conditions a rapid accumulation of lactic acid gives evidence of an intense glycolytic activity, which is inhibited when the eggs are returned to oxygen (Pasteur effect) (Barbieri & Salomón, 1963). Furthermore, an increase in oxygen uptake during the first 2 h of recovery has been observed (payment of the oxygen debt) (Legname, 1966). Taking into account the low value of the respiratory quotient (r.q. = 0·5-0·7) during this period it can be assumed that most of the oxygen is not involved in the oxidation of lactate (Legname, 1966).. ...
Anaerobiosis and Stemness: An Evolutionary Paradigm for Therapeutic Applications (9780128005408) by Zoran Ivanovic; Marija ... Anaerobiosis and Stemness: An evolutionary paradigm provides a context for understanding the many complexities and evolutionary ... Anaerobiosis and Stemness is an important resource for stem cell and developmental biologists alike, as well as oncologists, ... 1. Anaerobiosis and Stemness: An Evolutionary Paradigm for Therapeutic Applications (Hardback) Zoran Ivanovic, Marija Vlaski- ...
Effect of anaerobiosis on cysteine protease regulation during the embryonic-larval transition in ... Effect of anaerobiosis on cysteine protease regulation during the embryonic-larval transition in ... Effect of anaerobiosis on cysteine protease regulation during the embryonic-larval transition in ... Effect of anaerobiosis on cysteine protease regulation during the embryonic-larval transition in ...
Glycogen Degradation and the Accumulation of Compounds During Anaerobiosis in the Fresh Water Snail Lymnaea Stagnalis. in ... Glycogen Degradation and the Accumulation of Compounds During Anaerobiosis in the Fresh Water Snail Lymnaea Stagnalis. in ...
NADH, produced from glycolysis during anaerobiosis and oxidized in the mitochondrial electron transport chain, should shift the ... composition of metabolites formed during anaerobiosis with increased conversion of pyruvate to alanine and greater involvement ...
Anaerobiosis promotes survival and adaption strategies of Shigella, while modulating virulence plasmid genes involved in T3SS- ... These genes, located on the large Shigella virulence plasmid, were down regulated in anaerobiosis in an FNR-dependent manner. ... To define the influence of anaerobiosis on the virulence of Shigella, we performed deep RNA sequencing to identify ... transcriptomic differences that are induced by anaerobiosis and modulated by the anaerobic Fumarate and Nitrate Reduction ...
Pörtner, H. O. , Grieshaber, M. K. and Heisler, N. (1984): Anaerobiosis and acid-base status in marine invertebrates: effect of ... Anaerobiosis and acid-base status in marine invertebrates: effect of environmental hypoxia on extracellular and intracellular ...
The International Society for Plant Anaerobiosis welcomes members with an interest in low oxygen responses in plants as caused ...
Article: Restoration of GABA production machinery in Lactobacillus brevis by accessible carbohydrates, anaerobiosis and early ... Restoration of GABA production machinery in Lactobacillus brevis by accessible carbohydrates, anaerobiosis and early ... Restoration of GABA production machinery in Lactobacillus brevis by accessible carbohydrates, anaerobiosis and early ...
Effect of TAT on Anaerobiosis and Osmotolerance.. Another intriguing phenotype of tat mutants was related to growth under ...
In this work, light-induced photosynthetic electron transfer after a prolonged dark-anaerobiosis period was studied by ... Light-induced photosynthetic electron transfer upon anaerobiosis in Chlamydomonas : kinetics, electron sinks and setup of a ... In Chlamydomonas reinhardtii, prolonged anaerobiosis leads to the expression of various fermentative pathways. Among them, ... on the basis of the fluorescence induction kinetics upon a shift from dark-anaerobiosis to light. Five mutants display the ...
Integration of pDN0117 was obtained by increasing the temperature to 40 °C (2 µg/mL erythromycin; anaerobiosis). The result was ... Selection was performed under anaerobiosis at 30 °C on medium containing 2 µg/mL erythromycin. ...
Global anaerobic transcriptional regulators FNR and ArcA induced c5038 expression in anaerobiosis, and C5038 played a major ... Global anaerobic transcriptional regulators FNR and ArcA induced c5038 expression in anaerobiosis, and C5038 played a major ... FIGURE 2. c5038 transcription was induced whereas kgtP repressed in anaerobiosis. (A) Promoter region of kgtP. (B) Promoter ... Anaerobiosis Induced c5038 but Repressed kgtP Expression. Given that kgtP and c5038 contributed differentially to growth on KG ...
Costs of life - Dynamics of the protein inventory of Staphylococcus aureus during anaerobiosis *Daniela Zühlke ... during anaerobiosis . Opens in a new window. ...
When reactors were placed in anaerobiosis by N2 bubbling, ammonia production was sustained several days and the total ammonia ... Long term effects of MSX, nitrite and anaerobiosis are discussed. ... When reactors were placed in anaerobiosis by N2 bubbling, ... Effect of nitrite and anaerobiosis}, author={Joseph Jeanfils and Roland Loudeche}, journal={Biotechnology Letters}, year={2005 ...
3 H2 photoproduction in C. reinhardtii cultures requires anaerobiosis. (A) Accumulation of H2 under a train of light pulses ... In a low O2 environment, such pulse-illuminated algae can spontaneously establish anaerobiosis and produce H2 for up to three ... H2ase activation, however, requires strong anaerobiosis, which contradicts the suggestion of Liran and co-authors28 about the ... 3) occur only after the establishment of anaerobiosis in the culture. As shown in Fig. 3A, the photoautotrophic C. reinhardtii ...
A Mutant in the ADH1 Gene of Chlamydomonas reinhardtii Elicits Metabolic Restructuring during Anaerobiosis Publication Type:. ... Title: A Mutant in the ADH1 Gene of Chlamydomonas reinhardtii Elicits Metabolic Restructuring during Anaerobiosis. Date: Fri, ... Home » A Mutant in the ADH1 Gene of Chlamydomonas reinhardtii Elicits Metabolic Restructuring during Anaerobiosis ...
Metabolic rate depression and biochemical adaptation in anaerobiosis, hibernation and estivation. Publication. Publication. ... Facultative metabolic rate depression is the common adaptive strategy of anaerobiosis, hibernation, and estivation, as well as ... Storey, K, & Storey, J. (1990). Metabolic rate depression and biochemical adaptation in anaerobiosis, hibernation and ...
Anaerobiosis and Stemness Product Type: Book. Edition: 1. First Published: 2015. Hardcover: 978-0-12-800540-8 ...
Anaerobiosis * Archaea / growth & development* * Archaea / metabolism * Geologic Sediments / microbiology * Methane / ...
NAD-dependent butanediol dehydrogenase (Bdh1p) from Saccharomyces cerevisiae reversibly transforms acetoin to 2,3-butanediol in a stereospecific manner. Deletion of BDH1 resulted in an accumulation of acetoin and a diminution of 2,3-butanediol in two S. cerevisiae strains under two different growth …
"How to define obligatory anaerobiosis? An evolutionary view on the antioxidant response system and the early stages of the ...

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