Succinate production positively correlates with the affinity of the global transcription factor Cra for its effector FBP in Escherichia coli.

Science.gov (United States)

Wei, Li-Na; Zhu, Li-Wen; Tang, Ya-Jie

2016-01-01

Effector binding is important for transcription factors, affecting both the pattern and function of transcriptional regulation to alter cell phenotype. Our previous work suggested that the affinity of the global transcription factor catabolite repressor/activator (Cra) for its effector fructose-1,6-bisphosphate (FBP) may contribute to succinate biosynthesis. To support this hypothesis, single-point and three-point mutations were proposed through the semi-rational design of Cra to improve its affinity for FBP. For the first time, a positive correlation between succinate production and the affinity of Cra for FBP was revealed in Escherichia coli . Using the best-fit regression function, a cubic equation was used to examine and describe the relationship between succinate production and the affinity of Cra for FBP, demonstrating a significant positive correlation between the two factors (coefficient of determination R 2  = 0.894, P  = 0.000 Cra and DNA showed that Cra bound to the promoter regions of pck and aceB to activate the corresponding genes. Normally, Cra-regulated operons under positive control are deactivated in the presence of FBP. Therefore, theoretically, the enhanced affinity of Cra for FBP will inhibit the activation of pck and aceB . However, the activation of genes involved in CO 2 fixation and the glyoxylate pathway was further improved by the Cra mutant, ultimately contributing to succinate biosynthesis. Enhanced binding of Cra to FBP or active site mutations may eliminate the repressive effect caused by FBP, thus leading to increased activation of genes associated with succinate biosynthesis in the Cra mutant. This work demonstrates an important transcriptional regulation strategy in the metabolic engineering of succinate production and provides useful information for better understanding of the regulatory mechanisms of transcription factors.

De Novo Biosynthesis of Glutarate via α-Keto Acid Carbon Chain Extension and Decarboxylation Pathway in Escherichia coli.

Science.gov (United States)

Wang, Jian; Wu, Yifei; Sun, Xinxiao; Yuan, Qipeng; Yan, Yajun

2017-10-20

Microbial based bioplastics are promising alternatives to petroleum based synthetic plastics due to their renewability and economic feasibility. Glutarate is one of the most potential building blocks for bioplastics. The recent biosynthetic routes for glutarate were mostly based on the l-lysine degradation pathway from Pseudomonas putida that required lysine either by feeding or lysine overproduction via genetic manipulations. Herein, we established a novel glutarate biosynthetic pathway by incorporation of a "+1" carbon chain extension pathway from α-ketoglutarate (α-KG) in combination with α-keto acid decarboxylation pathway in Escherichia coli. Introduction of homocitrate synthase (HCS), homoaconitase (HA) and homoisocitrate dehydrogenase (HICDH) from Saccharomyces cerevisiae into E. coli enabled "+1" carbon extension from α-KG to α-ketoadipate (α-KA), which was subsequently converted into glutarate by a promiscuous α-keto acid decarboxylase (KivD) and a succinate semialdehyde dehydrogenase (GabD). The recombinant E. coli coexpressing all five genes produced 0.3 g/L glutarate from glucose. To further improve the titers, α-KG was rechanneled into carbon chain extension pathway via the clustered regularly interspersed palindromic repeats system mediated interference (CRISPRi) of essential genes sucA and sucB in tricarboxylic acid (TCA) cycle. The final strain could produce 0.42 g/L glutarate, which was increased by 40% compared with the parental strain.

X-Ray crystal structure of GarR—tartronate semialdehyde reductase from Salmonella typhimurium

OpenAIRE

Osipiuk, J.; Zhou, M.; Moy, S.; Collart, F.; Joachimiak, A.

2009-01-01

Tartronate semialdehyde reductases (TSRs), also known as 2-hydroxy-3-oxopropionate reductases, catalyze the reduction of tartronate semialdehyde using NAD as cofactor in the final stage of D-glycerate biosynthesis. These enzymes belong to family of structurally and mechanically related β-hydroxyacid dehydrogenases which differ in substrate specificity and catalyze reactions in specific metabolic pathways. Here, we present the crystal structure of GarR a TSR from Salmonella typhimurium determi...

Crystallization and preliminary X-ray analysis of AAMS amidohydrolase, the final enzyme in degradation pathway I of pyridoxine

International Nuclear Information System (INIS)

Kobayashi, Jun; Yoshida, Hiromi; Chu, Huy Nhat; Yoshikane, Yu; Kamitori, Shigehiro; Yagi, Toshiharu

2009-01-01

Recombinant α-(N-acetylaminomethylene)succinic acid amidohydrolase from M. loti MAFF303099 was crystallized and diffraction data were collected at 2.7 Å resolution. α-(N-Acetylaminomethylene)succinic acid (AAMS) amidohydrolase from Mesorhizobium loti MAFF303099, which is involved in a degradation pathway of vitamin B 6 and catalyzes the degradation of AAMS to acetic acid, ammonia, carbon dioxide and succinic semialdehyde, has been overexpressed in Escherichia coli. To elucidate the reaction mechanism based on the tertiary structure, the recombinant enzyme was purified and crystallized by the sitting-drop vapour-diffusion method using PEG 8000 as precipitant. A crystal of the enzyme belonged to the monoclinic space group C2, with unit-cell parameters a = 393.2, b = 58.3, c = 98.9 Å, β = 103.4°, and diffraction data were collected to 2.7 Å resolution. The V M value and calculation of the self-rotation function suggested that three dimers with a threefold symmetry were possibly present in the asymmetric unit

Short-Term Pretreatment of Sub-Inhibitory Concentrations of Gentamycin Inhibits the Swarming Motility of Escherichia Coli by Down-Regulating the Succinate Dehydrogenase Gene

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Yijing Zhuang

2016-09-01

Full Text Available Background/Aims: Motility is a feature of many pathogens that contributes to the migration and dispersion of the infectious agent. Whether gentamycin has a post-antibiotic effect (PAE on the swarming and swimming motility of Escherichia coli (E. coli remains unknown. In this study, we aimed to examine whether short-term pretreatment of sub-inhibitory concentrations of gentamycin alter motility of E. coli and the mechanisms involved therein. Methods: After exposure to sub-inhibitory concentrations (0.8 μg/ml of gentamicin, the swarming and swimming motility of E. coli was tested in semi-solid media. Real-time PCR was used to detect the gene expression of succinate dehydrogenase (SDH. The production of SDH and fumarate by E. coli pretreated with or without gentamycin was measured. Fumarate was added to swarming agar to determine whether fumarate could restore the swarming motility of E. coli. Results: After pretreatment of E. coli with sub-inhibitory concentrations of gentamycin, swarming motility was repressed in the absence of growth inhibition. The expression of all four subunits of SDH was down-regulated, and the intracellular concentration of SDH and fumarate, produced by E. coli, were both decreased. Supplementary fumarate could restore the swarming motility inhibited by gentamycin. A selective inhibitor of SDH (propanedioic acid could strongly repress the swarming motility. Conclusion: Sub-inhibitory concentrations of gentamycin inhibits the swarming motility of E. coli. This effect is mediated by a reduction in cellular fumarate caused by down-regulation of SDH. Gentamycin may be advantageous for treatment of E. coli infections.

Succinate overproduction: A case study of computational strain design using a comprehensive Escherichia coli kinetic model

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Ali eKhodayari

2015-01-01

Full Text Available Computational strain design prediction accuracy has been the focus for many recent efforts through the selective integration of kinetic information into metabolic models. In general, kinetic model prediction quality is determined by the range and scope of genetic and/or environmental perturbations used during parameterization. In this effort, we apply the k-OptForce procedure on a kinetic model of E. coli core metabolism constructed using the Ensemble Modeling (EM method and parameterized using multiple mutant strains data under aerobic respiration with glucose as the carbon source. Minimal interventions are identified that improve succinate yield under both aerobic and anaerobic conditions to test the fidelity of model predictions under both genetic and environmental perturbations. Under aerobic condition, k-OptForce identifies interventions that match existing experimental strategies pointing at a number of unexplored flux redirections such as routing glyoxylate flux through the glycerate metabolism to improve succinate yield. Many of the identified interventions rely on the kinetic descriptions and would not be discoverable by a purely stoichiometric description. In contrast, under fermentative (anaerobic conditions, k-OptForce fails to identify key interventions including up-regulation of anaplerotic reactions and elimination of competitive fermentative products. This is due to the fact that the pathways activated under anaerobic conditions were not properly parameterized as only aerobic flux data were used in the model construction. This study shed light on the importance of condition-specific model parameterization and provides insight onto how to augment kinetic models so as to correctly respond to multiple environmental perturbations.

Crystal structure of glutamate-1-semialdehyde-2,1-aminomutase from Arabidopsis thaliana

Energy Technology Data Exchange (ETDEWEB)

Song, Yingxian; Pu, Hua; Jiang, Tian; Zhang, Lixin; Ouyang, Min, E-mail: ouyangmin@ibcas.ac.cn [Chinese Academy of Sciences, Beijing 100093, People’s Republic of (China)

2016-05-23

A structural study of A. thaliana glutamate-1-semialdehyde-2,1-aminomutase (GSAM) has revealed asymmetry in cofactor binding as well as in the gating-loop orientation, which supports the previously proposed negative cooperativity between monomers of GSAM. Glutamate-1-semialdehyde-2,1-aminomutase (GSAM) catalyzes the isomerization of glutamate-1-semialdehyde (GSA) to 5-aminolevulinate (ALA) and is distributed in archaea, most bacteria and plants. Although structures of GSAM from archaea and bacteria have been resolved, a GSAM structure from a higher plant is not available, preventing further structure–function analysis. Here, the structure of GSAM from Arabidopsis thaliana (AtGSA1) obtained by X-ray crystallography is reported at 1.25 Å resolution. AtGSA1 forms an asymmetric dimer and displays asymmetry in cofactor binding as well as in the gating-loop orientation, which is consistent with previously reported Synechococcus GSAM structures. While one monomer binds PMP with the gating loop fixed in the open state, the other monomer binds either PMP or PLP and the gating loop is ready to close. The data also reveal the mobility of residues Gly163, Ser164 and Gly165, which are important for reorientation of the gating loop. Furthermore, the asymmetry of the AtGSA1 structure supports the previously proposed negative cooperativity between monomers of GSAM.

X-ray crystal structure of GarR-tartronate semialdehyde reductase from Salmonella typhimurium.

Science.gov (United States)

Osipiuk, J; Zhou, M; Moy, S; Collart, F; Joachimiak, A

2009-09-01

Tartronate semialdehyde reductases (TSRs), also known as 2-hydroxy-3-oxopropionate reductases, catalyze the reduction of tartronate semialdehyde using NAD as cofactor in the final stage of D-glycerate biosynthesis. These enzymes belong to family of structurally and mechanically related beta-hydroxyacid dehydrogenases which differ in substrate specificity and catalyze reactions in specific metabolic pathways. Here, we present the crystal structure of GarR a TSR from Salmonella typhimurium determined by the single-wavelength anomalous diffraction method and refined to 1.65 A resolution. The active site of the enzyme contains L-tartrate which most likely mimics a position of a glycerate which is a product of the enzyme reaction. The analysis of the TSR structure shows also a putative NADPH binding site in the enzyme.

The Succinated Proteome

Energy Technology Data Exchange (ETDEWEB)

Merkley, Eric D.; Metz, Thomas O.; Smith, Richard D.; Baynes, John; Frizell, Norma

2014-03-30

Succination is a chemical modification of cysteine in protein by the Krebs cycle intermediate, fumarate, yielding S-(2-succino)cysteine (2SC). Intracellular fumarate concentration and succination of proteins are increased by hyperpolarization of the inner mitochondrial membrane, in concert with mitochondrial, endoplasmic reticulum (ER) and oxidative stress in adipocytes grown in high glucose medium and in adipose tissue in obesity and diabetes. Increased succination of proteins is also detected in the kidney of a fumarase conditional knock-out mouse which develops renal tumors. Keap1, the gatekeeper of the antioxidant response, was identified as a major succinated protein in renal cancer cells, suggesting that succination may play a role in activation of the antioxidant response. A wide range of proteins is subject to succination, including enzymes, adipokines, cytoskeletal proteins and ER chaperones with functional cysteine residues. There is also significant overlap between succinated and glutathionylated proteins, and with proteins containing cysteine residues that are readily oxidized to the sulfenic (cysteic) acid. Succination of adipocyte proteins is inhibited by uncouplers, which discharge the mitochondrial membrane potential (Δψm) and by ER stress inhibitors. 2SC serves as a biomarker of mitochondrial stress or dysfunction in chronic diseases, such as obesity, diabetes and cancer, and recent studies suggest that succination is a mechanistic link between mitochondrial dysfunction, oxidative and ER stress, and cellular progression toward apoptosis. In this article, we review the history of the succinated proteome and the challenges associated with measuring this non-enzymatic post-translational modification of proteins by proteomics approaches.

X-Ray crystal structure of GarR—tartronate semialdehyde reductase from Salmonella typhimurium

Science.gov (United States)

Osipiuk, J.; Zhou, M.; Moy, S.; Collart, F.

2009-01-01

Tartronate semialdehyde reductases (TSRs), also known as 2-hydroxy-3-oxopropionate reductases, catalyze the reduction of tartronate semialdehyde using NAD as cofactor in the final stage of D-glycerate biosynthesis. These enzymes belong to family of structurally and mechanically related β-hydroxyacid dehydrogenases which differ in substrate specificity and catalyze reactions in specific metabolic pathways. Here, we present the crystal structure of GarR a TSR from Salmonella typhimurium determined by the single-wavelength anomalous diffraction method and refined to 1.65 Å resolution. The active site of the enzyme contains L-tartrate which most likely mimics a position of a glycerate which is a product of the enzyme reaction. The analysis of the TSR structure shows also a putative NADPH binding site in the enzyme. PMID:19184529

Optimization of sodium hydroxide pretreatment and enzyme loading for efficient hydrolysis of rice straw to improve succinate production by metabolically engineered Escherichia coli KJ122 under simultaneous saccharification and fermentation.

Science.gov (United States)

Sawisit, Apichai; Jampatesh, Surawee; Jantama, Sirima Suvarnakuta; Jantama, Kaemwich

2018-07-01

Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95%. With the optimized enzyme loading of 4% cellulase complex + 0.5% xylanase (endo-glucanase 67 CMC-U/g, β-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 ± 0.8% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 ± 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 ± 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 ± 0.4 g/L and 1.37 ± 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale. Copyright © 2018 Elsevier Ltd. All rights reserved.

THE SUCCINATED PROTEOME

OpenAIRE

Merkley, Eric D.; Metz, Thomas O.; Smith, Richard D.; Baynes, John W.; Frizzell, Norma

2013-01-01

The post-translational modifications (PTMs) of cysteine residues include oxidation, S-glutathionylation, S-nitrosylation, and succination, all of which modify protein function or turnover in response to a changing intracellular redox environment. Succination is a chemical modification of cysteine in proteins by the Krebs cycle intermediate, fumarate, yielding S-(2-succino) cysteine (2SC). Intracellular fumarate concentration and succination of proteins are increased by hyperpolarization of th...

Characterization of the different spectral forms of glutamate 1-semialdehyde aminotransferase by mass spectrometry

DEFF Research Database (Denmark)

Brody, S; Andersen, Jens S.; Kannangara, C G

1995-01-01

Glutamate 1-semialdehyde aminotransferase produces delta-aminolevulinate for the synthesis of chlorophyll, heme, and other tetrapyrrole pigments. The native enzyme from Synechococcus is pale yellow and has absorption maxima at 338 and 418 nm from vitamin B6. Yellow, colorless, and pink forms...

Effect of succinic acid concentration in poly(glycerol citrate/succinate) properties

International Nuclear Information System (INIS)

Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Jose, Nadia M.

2011-01-01

In this work were prepared and characterized polymer based on glycerol, citric and succinic acid, in three different ratios to evaluate the effect of succinic acid concentration in materials properties. The polymers were obtained by polycondensation reaction between polyol and poly acids, and were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The materials are amorphous polyesters and its thermal and morphological properties change depending on the succinic acid concentration. (author)

Succinic Acid: Technology Development and Commercialization

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Nhuan P. Nghiem

2017-06-01

Full Text Available Succinic acid is a precursor of many important, large-volume industrial chemicals and consumer products. It was once common knowledge that many ruminant microorganisms accumulated succinic acid under anaerobic conditions. However, it was not until the discovery of Anaerobiospirillum succiniciproducens at the Michigan Biotechnology Institute (MBI, which was capable of producing succinic acid up to about 50 g/L under optimum conditions, that the commercial feasibility of producing the compound by biological processes was realized. Other microbial strains capable of producing succinic acid to high final concentrations subsequently were isolated and engineered, followed by development of fermentation processes for their uses. Processes for recovery and purification of succinic acid from fermentation broths were simultaneously established along with new applications of succinic acid, e.g., production of biodegradable deicing compounds and solvents. Several technologies for the fermentation-based production of succinic acid and the subsequent conversion to useful products are currently commercialized. This review gives a summary of the development of microbial strains, their fermentation, and the importance of the down-stream recovery and purification efforts to suit various applications in the context of their current commercialization status for biologically derived succinic acid.

Prospects for a bio-based succinate industry.

Science.gov (United States)

McKinlay, James B; Vieille, C; Zeikus, J Gregory

2007-09-01

Bio-based succinate is receiving increasing attention as a potential intermediary feedstock for replacing a large petrochemical-based bulk chemical market. The prospective economical and environmental benefits of a bio-based succinate industry have motivated research and development of succinate-producing organisms. Bio-based succinate is still faced with the challenge of becoming cost competitive against petrochemical-based alternatives. High succinate concentrations must be produced at high rates, with little or no by-products to most efficiently use substrates and to simplify purification procedures. Herein are described the current prospects for a bio-based succinate industry, with emphasis on specific bacteria that show the greatest promise for industrial succinate production. The succinate-producing characteristics and the metabolic pathway used by each bacterial species are described, and the advantages and disadvantages of each bacterial system are discussed.

Mutations in ALDH6A1 encoding methylmalonate semialdehyde dehydrogenase are associated with dysmyelination and transient methylmalonic aciduria

NARCIS (Netherlands)

Marcadier, Julien L.; Smith, Amanda M.; Pohl, Daniela; Schwartzentruber, Jeremy; Al-Dirbashi, Osama Y.; Majewski, Jacek; Ferdinandusse, Sacha; Wanders, Ronald J. A.; Bulman, Dennis E.; Boycott, Kym M.; Chakraborty, Pranesh; Geraghty, Michael T.; Boycott, Kym; Friedman, Jan; Michaud, Jacques; Bernier, Francois; Brudno, Michael; Fernandez, Bridget; Knoppers, Bartha; Samuels, Mark; Scherer, Steve

2013-01-01

Methylmalonate semialdehyde dehydrogenase (MMSDH) deficiency is a rare autosomal recessive disorder with varied metabolite abnormalities, including accumulation of 3-hydroxyisobutyric, 3-hydroxypropionic, 3-aminoisobutyric and methylmalonic acids, as well as β-alanine. Existing reports describe a

Effect of Hydroxyl Monomers on the Enzymatic Degradation of Poly(ethylene succinate, Poly(butylene succinate, and Poly(hexylene succinate

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Zhenhui Bai

2018-01-01

Full Text Available Poly(ethylene succinate (PES, poly(butylene succinate (PBS, and poly(hexylene succinate (PHS, were synthesized using succinic acid and different dihydric alcohols as materials. Enzymatic degradability by cutinase of the three kinds of polyesters was studied, as well as their solid-state properties. The biodegradation behavior relied heavily on the distance between ester groups, crystallinity, and the hydrophilicity-hydrophobicity balance of polyester surfaces. The weight loss through degradation of the three kinds of polyesters with different hydroxyl monomers took place in the order PHS > PBS > PES. The degradation behavior of the polyesters before and after degradation was analyzed by scanning electron microscopy, differential scanning calorimetry, powder X-ray diffraction, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The decrease in relative intensity at 1800–1650 estedpolyesters were degraded simultaneously. The frequencies of the crystalline and amorphous bands were almost identical before and after degradation. Thus, enzymatic degradation did not change the crystalline structure but destroyed it, and the degree of crystallinity markedly decreased. The molecular weight and polydispersity index only changed slightly. The thermal stability of the three kinds of polyesters decreased during enzymatic degradation.

How and why does tomato accumulate a large amount of GABA in the fruit?

OpenAIRE

Takayama, Mariko; Ezura, Hiroshi

2015-01-01

γ-Aminobutyric acid (GABA) has received much attention as a health-promoting functional compound, and several GABA-enriched foods have been commercialized. In higher plants, GABA is primarily metabolized via a short pathway called the GABA shunt. The GABA shunt bypasses two steps (the oxidation of α-ketoglutarate to succinate) of the tricarboxylic acid (TCA) cycle via reactions catalysed by three enzymes: glutamate decarboxylase (GAD), GABA transaminase (GABA-T) and succinic semialdehyde dehy...

21 CFR 582.1091 - Succinic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Succinic acid. 582.1091 Section 582.1091 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1091 Succinic acid. (a) Product. Succinic acid. (b) Conditions of use. This substance is generally...

Succinic acid production from Jerusalem artichoke

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Karakashev, Dimitar Borisov; Angelidaki, Irini

In this work, A. succinogenes 130Z was used to produce succinic acid from Jerusalem artichoke tuber hydrolysate. Results showed that both fructose and glucose in the tuber hydrolysate were utilized for succinic acid production. The sugar utilization was found to be dependent on process control...... that Jerusalem artichoke tubers could be utilized for production of bio-succinic acid....

21 CFR 184.1091 - Succinic acid.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Succinic acid. 184.1091 Section 184.1091 Food and... Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4H6O4, CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical 1,4-butanedioic acid. It is...

Metabolic engineering of Escherichia coli for production of mixed-acid fermentation end products

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Andreas Hartmut Förster

2014-05-01

Full Text Available Mixed-acid fermentation end products have numerous applications in biotechnology. This is probably the main driving force for the development of multiple strains that are supposed to produce individual end products with high yields. The process of engineering Escherichia coli strains for applied production of ethanol, lactate, succinate, or acetate was initiated several decades ago and is still ongoing. This review follows the path of strain development from the general characteristics of aerobic versus anaerobic metabolism over the regulatory machinery that enables the different metabolic routes. Thereafter, major improvements for broadening the substrate spectrum of Escherichia coli towards cheap carbon sources like molasses or lignocellulose are highlighted before major routes of strain development for the production of ethanol, acetate, lactate and succinate are presented.

Hypoxia and GABA shunt activation in the pathogenesis of Alzheimer's disease.

Science.gov (United States)

Salminen, Antero; Jouhten, Paula; Sarajärvi, Timo; Haapasalo, Annakaisa; Hiltunen, Mikko

2016-01-01

We have previously observed that the conversion of mild cognitive impairment to definitive Alzheimer's disease (AD) is associated with a significant increase in the serum level of 2,4-dihydroxybutyrate (2,4-DHBA). The metabolic generation of 2,4-DHBA is linked to the activation of the γ-aminobutyric acid (GABA) shunt, an alternative energy production pathway activated during cellular stress, when the function of Krebs cycle is compromised. The GABA shunt can be triggered by local hypoperfusion and subsequent hypoxia in AD brains caused by cerebral amyloid angiopathy. Succinic semialdehyde dehydrogenase (SSADH) is a key enzyme in the GABA shunt, converting succinic semialdehyde (SSA) into succinate, a Krebs cycle intermediate. A deficiency of SSADH activity stimulates the conversion of SSA into γ-hydroxybutyrate (GHB), an alternative route from the GABA shunt. GHB can exert not only acute neuroprotective activities but unfortunately also chronic detrimental effects which may lead to cognitive impairment. Subsequently, GHB can be metabolized to 2,4-DHBA and secreted from the brain. Thus, the activation of the GABA shunt and the generation of GHB and 2,4-DHBA can have an important role in the early phase of AD pathogenesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Succinated Proteome of FH-Mutant Tumours

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Ming Yang

2014-08-01

Full Text Available Inherited mutations in the Krebs cycle enzyme fumarate hydratase (FH predispose to hereditary leiomyomatosis and renal cell cancer (HLRCC. Loss of FH activity in HLRCC tumours causes accumulation of the Krebs cycle intermediate fumarate to high levels, which may act as an oncometabolite through various, but not necessarily mutually exclusive, mechanisms. One such mechanism, succination, is an irreversible non-enzymatic modification of cysteine residues by fumarate, to form S-(2-succinocysteine (2SC. Previous studies have demonstrated that succination of proteins including glyceraldehyde 3-phosphate dehydrogenase (GAPDH, kelch-like ECH-associated protein 1 (KEAP1 and mitochondrial aconitase (ACO2 can have profound effects on cellular metabolism. Furthermore, immunostaining for 2SC is a sensitive and specific biomarker for HLRCC tumours. Here, we performed a proteomic screen on an FH-mutant tumour and two HLRCC-derived cancer cell lines and identified 60 proteins where one or more cysteine residues were succinated; 10 of which were succinated at cysteine residues either predicted, or experimentally proven, to be functionally significant. Bioinformatic enrichment analyses identified most succinated targets to be involved in redox signaling. To our knowledge, this is the first proteomic-based succination screen performed in human tumours and cancer-derived cells and has identified novel 2SC targets that may be relevant to the pathogenesis of HLRCC.

21 CFR 172.275 - Synthetic paraffin and succinic derivatives.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Synthetic paraffin and succinic derivatives. 172... FOOD FOR HUMAN CONSUMPTION Coatings, Films and Related Substances § 172.275 Synthetic paraffin and succinic derivatives. Synthetic paraffin and succinic derivatives identified in this section may be safely...

MODIFIKASI ASAM SUKSINAT - GELOMBANG PENDEK UNTUK\tPRODUKSI TAPIOKA SUKSINAT Succinic Acid-Microwave Modification to Produce Succinic Tapioca

Directory of Open Access Journals (Sweden)

Heny Herawati

2012-05-01

Full Text Available Indonesia as tropical country has great cassava potency. The great chance of cassava product development could be increased its added value through modified tapioca processing. One of modified starch that could be implemented as a food additive is succinic starch. The tapioca succinilation processed through combination process of reacting tapioca with succinic acid and microwave treatment. The research method was conducted by factorial design with 3 factors: substrate concentration (30 %, 40 %, succinic acid concentration (1 %, 3 %, 5 %, and drying method (oven and microwave. Succinic tapioca was analyzed both physical and chemical characteristics, while optimal product was fur- ther analyzed for nutrition contents and surface microstructure using SEM. Succinic acid and microwave modification influenced to the physical and chemical succinic tapioca, except ash content. The highest substitution degree value was 0.929 which was obtained by combination of substrate concentration 40 %, succinic acid added 5 % and microwave processed. The change of granule size was not significant, just the distribution among granule correlated with the tapi- oca modification. The succinic tapioca granule size ranged 5.35 µm until 17.20 µm with average 11.15 µm. Succinic tapioca characteristic hopefully could be advanced food implementation. ABSTRAK Indonesia merupakan negara tropis yang memiliki potensi produksi ubi kayu yang cukup besar. Peluang pengem- bangan produk berbasis ubi kayu di Indonesia masih cukup besar diantaranya yaitu peningkatan nilai tambah ubi kayu melalui proses modifikasi tapioka. Salah satu potensi pati termodifikasi yang dapat dipergunakan untuk bahan tambahan makanan yaitu pati suksinat. Pada penelitian ini proses suksinilasi tapioka dilakukan dengan cara mereak- sikan asam suksinat yang dikombinasikan dengan mempergunakan microwave. Metodologi penelitian yang dilakukan menggunakan rancangan faktorial dengan 3 faktor, yaitu konsentrasi

Microbiota-Produced Succinate Improves Glucose Homeostasis via Intestinal Gluconeogenesis

DEFF Research Database (Denmark)

De Vadder, Filipe; Kovatcheva-Datchary, Petia; Zitoun, Carine

2016-01-01

Beneficial effects of dietary fiber on glucose and energy homeostasis have long been described, focusing mostly on the production of short-chain fatty acids by the gut commensal bacteria. However, bacterial fermentation of dietary fiber also produces large amounts of succinate and, to date......, no study has focused on the role of succinate on host metabolism. Here, we fed mice a fiber-rich diet and found that succinate was the most abundant carboxylic acid in the cecum. Dietary succinate was identified as a substrate for intestinal gluconeogenesis (IGN), a process that improves glucose...

Molecular photonic imaging of cancer using light-emitting e. coli

International Nuclear Information System (INIS)

Park, Jae Hyo; Min, Jung Joon; Moon, Sung Min; Kim, Hyun Ju; Hong, Yeong Jin; Choy, Hyon E.; Bom, Hee Seung; Jeong, Jae Ho; Cho, Kyoung Oh

2005-01-01

Cancer research has long sought a magic bullet that would selectively target and destroy malignant cells. In this study, we exploited that E. coli injected into tumor-bearing mice selectively target and proliferate in solid tumors by employing optical imaging technique. Lux operon or GFP has been cloned into pUC19 plasmid to engineer pUC19Lux or pUC19gfp which was transformed into varying kinds of wild type (MG1655) or mutant E.coli strains. For stable expression, lux operon was cloned with asd (aspartate β-semialdehyde dehydrogenase) gene and transformed into asd defective E. coli (MG1655asd-/asd+lux). These bacteria were i.v. injected into tumor mice or directly into central necrosis of tumor. The imaging signal from wild type E.coli was detected initially at liver (20min), then migrated to and shine in the tumor mass until 2 weeks of injection which was consistently observed in immuno-defective (nude) and -competent (Balb/c) mice. Imaging signal of stbaly transformed strain (MG1655asd-/asd+lux) was stronger and longer-lasting than that of transiently transformed strain (MG1655lux). Flagella defective E. coli strain failed to reach tumor loci. Only a few amounts of stress regulatory defective E. coli strain arrived at but couldn't survive at the tumor loci. E. coli colonies expressing GFP was mostly observed at the border of central necrosis and peripheral proliferative areas in immunofluorescence studies. Directly injected MG1655ad-/asd+lux was transiently observed at central necrosis followed by spreading to the peripheral tumor mass which was consistent with the finding by tail vein injection. We successfully engineered E. coli strain stably expressing lux reporter gene. E. coli strongly targeted solid tumor regardless of host immune status. Our results support that the targeting of tumor by E.coli is an active process and would be applied as a delivery vehicle of varying imaging markers or therapeutic molecules

Excess capacity of H⁺ ATPase and inverse respiratory control in Escherichia coli

DEFF Research Database (Denmark)

Jensen, Peter Ruhdal; Westerhoff, Hans V.; Michelsen, Ole

1993-01-01

With succinate as free-energy source, Escherichia coli generating virtually all ATP by oxidative phosphorylation might be expected heavily to tax its ATP generating capacity. To examine this the H+-ATPase (ATP synthase) was modulated over a 30-fold range. Decreasing the amount of H+-ATPase reduce...

BER-Myriant Succinic Acid Biorefinery

Energy Technology Data Exchange (ETDEWEB)

Shmorhun, Mark [Myriant Lake Providence, Inc., Lake Providence, LA (United States)

2015-12-31

Myriant Corporation (Myriant) has successfully produced the bioproduct succinic acid by the fermentation of glucose at a commercial scale operation in Lake Providence, Louisiana. The MySAB facility (Myriant Succinic Acid Biorefinery) came on stream in May 2013 and has been producing product since then. The MySAB facility is a demonstration-scale plant, capable of utilizing sorghum grits and commercially available dextrose, to ferment glucose into succinic acid. A downstream processing train has demonstrated the ability to produce an industrial, a standard and a polymer grade product. It consists of cell separation, membrane filtration, continuous chromatography, polishing to remove ionic and color bodies impurities, and final evaporation and crystallization. A by-product of the process is ammonium sulfate which is sold as a liquid fertilizer product. Since 2007 when development work began in the Woburn, Massachusetts R&D laboratories, the succinic acid bio-process has evolved through: Process development (microbiology, fermentation, and downstream) – R&D development laboratories; Piloting efforts at Fermic S.A. de C.V., Mexico City, Mexico – upstream and downstream processes; Design, construction, commissioning, and commercial production operations at the MySAB facility Additionally, Myriant became a wholly-owned subsidiary of the PTT Global Chemical Plc., Thailand, in late 2015, their investment into and support of Myriant goes back to 2011. The support of PTT Global Chemical Plc. helped to improve the upstream and downstream processes, and produce significant metric ton quantities of high quality bio-based succinic acid. The product has gone into a number of commercial markets worldwide for customer applications, development and production. The experience base gained via operations at the MySAB facility since May 2013, along with continued R&D development efforts involving Microbiology, Fermentation, and Downstream processes, at both the Woburn, Massachusetts

2-Amino-5-bromopyridinium hydrogen succinate

Directory of Open Access Journals (Sweden)

Hoong-Kun Fun

2010-03-01

Full Text Available In the title compound, C5H6BrN2+·C4H5O4−, the pyridine N atom of the 2-amino-5-bromopyridine molecule is protonated. The protonated N atom and the amino group are linked via N—H...O hydrogen bonds to the carboxylate O atoms of the singly deprotonated succinate anion. The hydrogen succinate anions are linked via O—H...O hydrogen bonds. A weak intermolecular C—H...O hydrogen bond is also observed.

The effect of alpha-tocopheryl succinate on succinate respiration in rat liver mitochondria

Czech Academy of Sciences Publication Activity Database

Sobotka, O.; Drahota, Zdeněk; Kučera, O.; Endlicher, R.; Rauchová, Hana; Červinková, Z.

2015-01-01

Roč. 64, Suppl.5 (2015), S609-S615 ISSN 0862-8408 Institutional support: RVO:67985823 Keywords : tocopheryl succinate * Complex II * liver * mitochondria * homogenate * hepatocytes Subject RIV: ED - Physiology Impact factor: 1.643, year: 2015

Succinate modulates Ca(2+) transient and cardiomyocyte viability through PKA-dependent pathway.

Science.gov (United States)

Aguiar, Carla J; Andrade, Vanessa L; Gomes, Enéas R M; Alves, Márcia N M; Ladeira, Marina S; Pinheiro, Ana Cristina N; Gomes, Dawidson A; Almeida, Alvair P; Goes, Alfredo M; Resende, Rodrigo R; Guatimosim, Silvia; Leite, M Fatima

2010-01-01

GPR91 is an orphan G-protein-coupled receptor (GPCR) that has been characterized as a receptor for succinate, a citric acid cycle intermediate, in several tissues. In the heart, the role of succinate is unknown. We now report that rat ventricular cardiomyocytes express GPR91. We found that succinate, through GPR91, increases the amplitude and the rate of decline of global Ca(2+) transient, by increasing the phosphorylation levels of ryanodine receptor and phospholamban, two well known Ca(2+) handling proteins. The effects of succinate on Ca(2+) transient were abolished by pre-treatment with adenylyl cyclase and cAMP-dependent protein kinase (PKA) inhibitors. Direct PKA activation by succinate was further confirmed using a FRET-based A-kinase activity reporter. Additionally, succinate decreases cardiomyocyte viability through a caspase-3 activation pathway, effect also prevented by PKA inhibition. Taken together, these observations show that succinate acts as a signaling molecule in cardiomyocytes, modulating global Ca(2+) transient and cell viability through a PKA-dependent pathway. 2009 Elsevier Ltd. All rights reserved.

Metabolic Modeling of Common Escherichia coli Strains in Human Gut Microbiome

Directory of Open Access Journals (Sweden)

Yue-Dong Gao

2014-01-01

Full Text Available The recent high-throughput sequencing has enabled the composition of Escherichia coli strains in the human microbial community to be profiled en masse. However, there are two challenges to address: (1 exploring the genetic differences between E. coli strains in human gut and (2 dynamic responses of E. coli to diverse stress conditions. As a result, we investigated the E. coli strains in human gut microbiome using deep sequencing data and reconstructed genome-wide metabolic networks for the three most common E. coli strains, including E. coli HS, UTI89, and CFT073. The metabolic models show obvious strain-specific characteristics, both in network contents and in behaviors. We predicted optimal biomass production for three models on four different carbon sources (acetate, ethanol, glucose, and succinate and found that these stress-associated genes were involved in host-microbial interactions and increased in human obesity. Besides, it shows that the growth rates are similar among the models, but the flux distributions are different, even in E. coli core reactions. The correlations between human diabetes-associated metabolic reactions in the E. coli models were also predicted. The study provides a systems perspective on E. coli strains in human gut microbiome and will be helpful in integrating diverse data sources in the following study.

Industrial systems biology of Saccharomyces cerevisiae enables novel succinic acid cell factory.

Directory of Open Access Journals (Sweden)

José Manuel Otero

Full Text Available Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol, and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought after added-value chemical for which there is no native pre-disposition for production and accmulation in S. cerevisiae. The genome-scale metabolic network reconstruction of S. cerevisiae enabled in silico gene deletion predictions using an evolutionary programming method to couple biomass and succinate production. Glycine and serine, both essential amino acids required for biomass formation, are formed from both glycolytic and TCA cycle intermediates. Succinate formation results from the isocitrate lyase catalyzed conversion of isocitrate, and from the α-keto-glutarate dehydrogenase catalyzed conversion of α-keto-glutarate. Succinate is subsequently depleted by the succinate dehydrogenase complex. The metabolic engineering strategy identified included deletion of the primary succinate consuming reaction, Sdh3p, and interruption of glycolysis derived serine by deletion of 3-phosphoglycerate dehydrogenase, Ser3p/Ser33p. Pursuing these targets, a multi-gene deletion strain was constructed, and directed evolution with selection used to identify a succinate producing mutant. Physiological characterization coupled with integrated data analysis of transcriptome data in the metabolically engineered strain were used to identify 2(nd-round metabolic engineering targets. The resulting strain represents a 30-fold improvement in succinate titer, and a 43-fold improvement in succinate yield on biomass, with only a 2.8-fold decrease in the specific growth rate compared to the reference strain. Intuitive genetic targets for either over-expression or interruption of succinate producing or consuming pathways, respectively, do not lead to increased succinate. Rather, we

Recovery of succinic acid produced by fermentation of a metabolically engineered Mannheimia succiniciproducens strain.

Science.gov (United States)

Song, Hyohak; Huh, Yun Suk; Lee, Sang Yup; Hong, Won Hi; Hong, Yeon Ki

2007-12-01

There have recently been much advances in the production of succinic acid, an important four-carbon dicarboxylic acid for many industrial applications, by fermentation of several natural and engineered bacterial strains. Mannheimia succiniciproducens MBEL55E isolated from bovine rumen is able to produce succinic acid with high efficiency, but also produces acetic, formic and lactic acids just like other anaerobic succinic acid producers. We recently reported the development of an engineered M. succiniciproducens LPK7 strain which produces succinic acid as a major fermentation product while producing much reduced by-products. Having an improved succinic acid producer developed, it is equally important to develop a cost-effective downstream process for the recovery of succinic acid. In this paper, we report the development of a simpler and more efficient method for the recovery of succinic acid. For the recovery of succinic acid from the fermentation broth of LPK7 strain, a simple process composed of a single reactive extraction, vacuum distillation, and crystallization yielded highly purified succinic acid (greater than 99.5% purity, wt%) with a high yield of 67.05wt%. When the same recovery process or even multiple reactive extraction steps were applied to the fermentation broth of MBEL55E, lower purity and yield of succinic acid were obtained. These results suggest that succinic acid can be purified in a cost-effective manner by using the fermentation broth of engineered LPK7 strain, showing the importance of integrating the strain development, fermentation and downstream process for optimizing the whole processes for succinic acid production.

Preparation of deuterated succinic acids

Energy Technology Data Exchange (ETDEWEB)

Tashiro, Masashi; Tsuzuki, Hirohisa; Goto, Hideyuki; Ogasahara, Shoji; Mataka, Shuntaro (Kyushu Univ., Fukuoka (Japan)); Isobe, Shin-ichiro; Yonemitsu, Tadashi (Kyushu Sangyo Univ., Fukuoka (Japan). Dept. of Industrial Chemistry)

1991-04-01

Succinic (2,3-{sup 2}H{sub 2})- and (2,2,3,3-{sup 2}H{sub 4})-acids were prepared from maleic anhydride and dimethyl fumarate, and acetylene dicarboxylic acid and its dimethyl ester by treatment with Cu-Al and Ni-Al alloys in 10% NaOD-D{sub 2}0 in 95% to 100% isotopic purity. The succinic {sup 2}H{sub 4} acid having high isotopic purity was also obtained on the hydrolysis of 1,2-ethanedinitrile with alkaline deuterium oxide. Based on the {sup 1}H({sup 2}H) spectra analysis of N-(o-biphenyl)(2,3-{sup 2}H{sub 2})succinimide, it was elucidated that the Raney alloy reduction with alkaline deuterium oxide proceeds stepwise. (author).

Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals.

Science.gov (United States)

Wang, Xuan; Yomano, Lorraine P; Lee, James Y; York, Sean W; Zheng, Huabao; Mullinnix, Michael T; Shanmugam, K T; Ingram, Lonnie O

2013-03-05

Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ΔyqhD ackA::PyadC'fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars.

Improvement of succinate production by release of end-product inhibition in Corynebacterium glutamicum.

Science.gov (United States)

Chung, Soon-Chun; Park, Joon-Song; Yun, Jiae; Park, Jin Hwan

2017-03-01

Succinate is a renewable-based platform chemical that may be used to produce a wide range of chemicals including 1,4-butanediol, tetrahydrofurane, and γ-butyrolactone. However, industrial fermentation of organic acids is often subject to end-product inhibition, which significantly retards cell growth and limits metabolic activities and final productivity. In this study, we report the development of metabolically engineered Corynebacterium glutamicum for high production of succinate by release of end-product inhibition coupled with an increase of key metabolic flux. It was found that the rates of glucose consumption and succinate production were significantly reduced by extracellular succinate in an engineered strain, S003. To understand the mechanism underlying the inhibition by succinate, comparative transcriptome analysis was performed. Among the downregulated genes, overexpression of the NCgl0275 gene was found to suppress the inhibition of glucose consumption and succinate production, resulting in a 37.7% increase in succinate production up to 55.4g/L in fed-batch fermentation. Further improvement was achieved by increasing the metabolic flux from PEP to OAA. The final engineered strain was able to produce 152.2g/L succinate, the highest production reported to date, with a yield of 1.1g/g glucose under anaerobic condition. These results suggest that the release of end-product inhibition coupled with an increase in key metabolic flux is a promising strategy for enhancing production of succinate. Copyright © 2017. Published by Elsevier Inc.

An efficient method for synthesis of succinate-based MMP inhibitors.

Science.gov (United States)

Sibi, Mukund P; Hasegawa, Hikaru

2002-10-03

A differentially protected fumarate undergoes radical addition followed by allylstannane trapping to provide disubstituted succinates in good yields and high anti diastereoselectivity. The conversion of the succinate to a known MMP inhibitor has been accomplished. [reaction: see text

TREATMENT OF CHRONIC HEART FAILURE: FOCUS ON METOPROLOL SUCCINATE

Directory of Open Access Journals (Sweden)

O. D. Ostroumova

2012-01-01

Full Text Available Advantages of metoprolol succinate in patients with chronic heart failure (CHF are covered. Results of MERIT-HF study are taken as the main evidences. Patterns of the metoprolol succinate use in the treatment of different categories of patients with CHF (women, the elderly , severe CHF forms, CHF with concomitant hypertension or diabetes are considered.

TREATMENT OF CHRONIC HEART FAILURE: FOCUS ON METOPROLOL SUCCINATE

Directory of Open Access Journals (Sweden)

O. D. Ostroumova

2015-12-01

Full Text Available Advantages of metoprolol succinate in patients with chronic heart failure (CHF are covered. Results of MERIT-HF study are taken as the main evidences. Patterns of the metoprolol succinate use in the treatment of different categories of patients with CHF (women, the elderly , severe CHF forms, CHF with concomitant hypertension or diabetes are considered.

Formation of itraconazole-succinic acid cocrystals by gas antisolvent cocrystallization.

Science.gov (United States)

Ober, Courtney A; Gupta, Ram B

2012-12-01

Cocrystals of itraconazole, an antifungal drug with poor bioavailability, and succinic acid, a water-soluble dicarboxylic acid, were formed by gas antisolvent (GAS) cocrystallization using pressurized CO(2) to improve itraconazole dissolution. In this study, itraconazole and succinic acid were simultaneously dissolved in a liquid solvent, tetrahydrofuran, at ambient conditions. The solution was then pressurized with CO(2), which decreased the solvating power of tetrahydrofuran and caused crystallization of itraconazole-succinic acid cocrystals. The cocrystals prepared by GAS cocrystallization were compared to those produced using a traditional liquid antisolvent, n-heptane, for crystallinity, chemical structure, thermal behavior, size and surface morphology, potential clinical relevance, and stability. Powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and scanning electron microscopy analyses showed that itraconazole-succinic acid cocrystals with physical and chemical properties similar to cocrystals produced using a traditional liquid antisolvent technique can be prepared by CO(2) antisolvent cocrystallization. The dissolution profile of itraconazole was significantly enhanced through GAS cocrystallization with succinic acid, achieving over 90% dissolution in less than 2 h. The cocrystals appeared stable against thermal stress for up to 4 weeks under accelerated stability conditions, showing only moderate decreases in their degree of crystallinity but no change in their crystalline structure. This study shows the utility of an itraconazole-succinic acid cocrystal for improving itraconazole bioavailability while also demonstrating the potential for CO(2) to replace traditional liquid antisolvents in cocrystal preparation, thus making cocrystal production more environmentally benign and scale-up more feasible.

Thermodynamics of U(VI) complexation by succinate at variable temperatures

Energy Technology Data Exchange (ETDEWEB)

Rawat, Neetika [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Tomar, B.S., E-mail: bstomar@barc.gov.in [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Manchanda, V.K. [Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

2011-07-15

Research highlights: > lg {beta} and {Delta}H{sub C} for U(VI)-succinate determined at variable temperatures. > Increase in lg {beta} with temperature well explained by Born equation. > {Delta}S{sub C} plays the dominant role in variation of {Delta}G{sub C} with temperature. > {Delta}H{sub C} for U(VI)-succinate increases linearly with temperature. > {Delta}C{sub P} of U(VI)-succinate is higher than that of oxalate and malonate complexes. - Abstract: Complexation of U(VI) by succinate has been studied at various temperatures in the range of (298 to 338) K by potentiometry and isothermal titration calorimetry at constant ionic strength (1.0 M). The potentiometric titrations revealed the formation of 1:1 uranyl succinate complex in the pH range of 1.5 to 4.5. The stability constant of uranyl succinate complex was found to increase with temperature. Similar trend was observed in the case of enthalpy of complex formation. However, the increase in entropy with temperature over-compensated the increase in enthalpy, thereby favouring the complexation reaction at higher temperatures. The linear increase of enthalpy of complexation with temperature indicates constancy of the change in heat capacity during complexation. The temperature dependence of stability constant data was well explained with the help of Born equation for electrostatic interaction between the metal ion and the ligand. The data have been compared with those for uranyl complexes with malonate and oxalate to study the effect of ligand size and hydrophobicity on the temperature dependence of thermodynamic quantities.

Fermentative Succinate Production: An Emerging Technology to Replace the Traditional Petrochemical Processes

Directory of Open Access Journals (Sweden)

Yujin Cao

2013-01-01

Full Text Available Succinate is a valuable platform chemical for multiple applications. Confronted with the exhaustion of fossil energy resources, fermentative succinate production from renewable biomass to replace the traditional petrochemical process is receiving an increasing amount of attention. During the past few years, the succinate-producing process using microbial fermentation has been made commercially available by the joint efforts of researchers in different fields. In this review, recent attempts and experiences devoted to reduce the production cost of biobased succinate are summarized, including strain improvement, fermentation engineering, and downstream processing. The key limitations and challenges faced in current microbial production systems are also proposed.

Progress of succinic acid production from renewable resources: Metabolic and fermentative strategies.

Science.gov (United States)

Jiang, Min; Ma, Jiangfeng; Wu, Mingke; Liu, Rongming; Liang, Liya; Xin, Fengxue; Zhang, Wenming; Jia, Honghua; Dong, Weiliang

2017-12-01

Succinic acid is a four-carbon dicarboxylic acid, which has attracted much interest due to its abroad usage as a precursor of many industrially important chemicals in the food, chemicals, and pharmaceutical industries. Facing the shortage of crude oil supply and demand of sustainable development, biological production of succinic acid from renewable resources has become a topic of worldwide interest. In recent decades, robust producing strain selection, metabolic engineering of model strains, and process optimization for succinic acid production have been developed. This review provides an overview of succinic acid producers and cultivation technology, highlight some of the successful metabolic engineering approaches. Copyright © 2017 Elsevier Ltd. All rights reserved.

Study of the radiolysis of succinic acid - applications in the dosimetry of high doses

International Nuclear Information System (INIS)

Andrade e Silva, L.G.

1978-01-01

A study is made of the effect of the gama radiation dose and of particle size of succinic acid (fine powder of large crystals) in relation with the formation of CO 2 and CO + H 2 , which are the main gaseous products of radiolysis. A different yield of CO + H 2 is found when the succinic acid is used as powder compared to the material in the form of large crystals. The reason for this difference is searched, studying the influence of heating and sublimation of the succinic acid prior to irradiation. The influence, in the mentioned yield, of the surface area of succinic acid particles, of the presence of oxygen (air) and of the rapid recrystallization of the acid are also studied. The formation of intermediate species in the radiolysis of succinic acid is examined. The system used in ethanol-succinic acid at 77K. Analysis are made using an electronic paramagnetic resonance spectrometer. The possibility of using succinic acid as a dosimeter for high level gama radiation doses is discussed [pt

Vitamin E Succinate as an Adjuvant for Dendritic Cell Based Vaccines

National Research Council Canada - National Science Library

Ramanathapuram, Lalitha

2004-01-01

.... In this study we have employed Vitamin E succinate also known as alpha-tocopheryl succinate (alpha-TOS), a non-toxic esterified analogue of Vitamin E, as an adjuvant to enhance the effectiveness of DC vaccines in treating established murine mammary...

A defined co-culture of Geobacter sulfurreducens and Escherichia coli in a membrane-less microbial fuel cell.

Science.gov (United States)

Bourdakos, Nicholas; Marsili, Enrico; Mahadevan, Radhakrishnan

2014-04-01

Wastewater-fed microbial fuel cells (MFCs) are a promising technology to treat low-organic carbon wastewater and recover part of the chemical energy in wastewater as electrical power. However, the interactions between electrochemically active and fermentative microorganisms cannot be easily studied in wastewater-fed MFCs because of their complex microbial communities. Defined co-culture MFCs provide a detailed understanding of such interactions. In this study, we characterize the extracellular metabolites in laboratory-scale membrane-less MFCs inoculated with Geobacter sulfurreducens and Escherichia coli co-culture and compare them with pure culture MFCs. G. sulfurreducens MFCs are sparged to maintain anaerobic conditions, while co-culture MFCs rely on E. coli for oxygen removal. G. sulfurreducens MFCs have a power output of 128 mW m(-2) , compared to 63 mW m(-2) from the co-culture MFCs. Analysis of metabolites shows that succinate production in co-culture MFCs decreases current production by G. sulfurreducens and that the removal of succinate is responsible for the increased current density in the late co-culture MFCs. Interestingly, pH adjustment is not required for co-culture MFCs but a base addition is necessary for E. coli MFCs and cultures in vials. Our results show that defined co-culture MFCs provide clear insights into metabolic interactions among bacteria while maintaining a low operational complexity. © 2013 Wiley Periodicals, Inc.

Studies on Cross-linking of succinic acid with chitosan/collagen

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Tapas Mitra

2013-01-01

Full Text Available The present study summarizes the cross-linking property of succinic acid with chitosan /collagen. In detail, the chemistry behind the cross-linking and the improvement in mechanical and thermal properties of the cross-linked material were discussed with suitable instruments and bioinformatics tools. The concentration of succinic acid with reference to the chosen polymers was optimized. A 3D scaffold prepared using an optimized concentration of succinic acid (0.2% (w/v with chitosan (1.0% (w/v and similarly with collagen (0.5% (w/v, was subjected to surface morphology, FT-IR analysis, tensile strength assessment, thermal stability and biocompatibility. Results revealed, cross-linking with succinic acid impart appreciable mechanical strength to the scaffold material. In silico analysis suggested the prevalence of non-covalent interactions, which played a crucial role in improving the mechanical and thermal properties of the cross-linked scaffold. The resultant 3D scaffold may find application as wound dressing material, as an implant in clinical applications and as a tissue engineering material.

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

2015-01-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

Vitamin E Succinate as an Adjuvant for Dendritic Cell Based Vaccines

National Research Council Canada - National Science Library

Ramanathapuram, Lalitha V

2006-01-01

.... Vitamin E succinate or alpha tocopheryl succinate ( -TOS) is a non-toxic, esterified analogue of Vitamin E that has been shown to be selectively toxic to tumor cell lines in vitro as well as inhibit the growth of tumors in animal models in vivo...

Vitamin E Succinate as an Adjuvant for Dendritic Cell-Based Vaccines

National Research Council Canada - National Science Library

Ramanathapuram, Lalitha V; Akporiaye, Emmanuel T

2005-01-01

.... Vitamin E succinate or alpha tocopheryl succinate (a-TOS) is a non-toxic, esterified analogue of Vitamin E that has been shown to be selectively toxic to tumor cell lines in vitro as well as inhibit the growth of tumors in animal models in vivo...

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

Science.gov (United States)

Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

2015-04-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

Compatibility of ondansetron hydrochloride and methylprednisolone sodium succinate in multilayer polyolefin containers.

Science.gov (United States)

Bougouin, Christelle; Thelcide, Chloë; Crespin-Maillard, Fabienne; Maillard, Christian; Kinowski, Jean Marie; Favier, Mireille

2005-10-01

The compatibility of ondansetron hydrochloride and methylprednisolone sodium succinate in 5% dextrose injection and 0.9% sodium chloride injection was studied. Test solutions of ondansetron hydrochloride 0.16 mg/mL and methylprednisolone sodium succinate 2.4 mg/mL were prepared in triplicate and tested in duplicate. Total volumes of 4 and 2 mL of ondansetron hydrochloride solution and methylprednisolone sodium succinate solution, respectively, were added to 50-mL multilayer polyolefin bags containing 5% dextrose injection or 0.9% sodium chloride injection. Bags were stored for 24 hours at 20-25 degrees C and for 48 hours at 4-8 degrees C. Chemical compatibility was measured with high-performance liquid chromatography, and physical compatibility was determined visually. Ondansetron hydrochloride was stable for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C. Methylprednisolone sodium succinate was stable for up to 48 hours at 4-8 degrees C. When stored at 20-25 degrees C, methylprednisolone sodium succinate was stable for up to 7 hours in 5% dextrose injection and up to 24 hours in 0.9% sodium chloride injection. Compatibility data for solutions containing ondansetron hydrochloride plus methylprednisolone sodium succinate revealed that each drug was stable for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C. Ondansetron 0.16 mg/mL (as the hydrochloride) and methylprednisolone 2.4 mg/mL (as the sodium succinate) mixed in 50-mL multilayer polyolefin bags were stable in both 5% dextrose injection and 0.9% sodium chloride injection for up to 24 hours at 20-25 degrees C and up to 48 hours at 4-8 degrees C.

SMALL SCALE PREPARATION OF C14 LABELED SUCCINIC, MALIC, FUMARICAND TARTARIC ACIDS

Energy Technology Data Exchange (ETDEWEB)

Jorgensen, E.C.; Bassham, J.A.; Calvin, M.; Tolbert, B.M.

1951-06-12

The directions for preparing the following acids from labeled acetic acid on a 1 to 20 millimole scale is presented: Succinic acid, malic acid, fumaric acid and tartaric acid. Two methods for preparing the succinic acid are detailed.

Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters.

Science.gov (United States)

Xie, Wen-Jie; Zhou, Xiao-Ming

2015-01-01

Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by (1)H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t1/2, Zc and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. Copyright © 2014 Elsevier B.V. All rights reserved.

Tartronate semialdehyde reductase defines a novel rate-limiting step in assimilation and bioconversion of glycerol in Ustilago maydis.

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Yanbin Liu

Full Text Available BACKGROUND: Glycerol is a by-product of biodiesel production. Currently, it has limited applications with low bioconversion efficiency to most metabolites reported. This is partly attributed to the poor knowledge on the glycerol metabolic pathway in bacteria and fungi. METHODOLOGY/PRINCIPAL FINDINGS: We have established a fast screening method for identification of genes that improve glycerol utilization in Ustilago maydis. This was done by comparing the growth rates of T-DNA tagged mutant colonies on solid medium using glycerol as the sole carbon source. We present a detailed characterization of one of the mutants, GUM1, which contains a T-DNA element inserted into the promoter region of UM02592 locus (MIPS Ustilago maydis database, MUMDB, leading to enhanced and constitutive expression of its mRNA. We have demonstrated that um02592 encodes a functional tartronate semialdehyde reductase (Tsr1, which showed dual specificity to cofactors NAD(+ and NADP(+ and strong substrate specificity and enantioselectivity for D-glycerate. Improved glycerol assimilation in GUM1 was associated with elevated expression of tsr1 mRNA and this could be phenocopied by over-expression of the gene. Glycolipid accumulation was reduced by 45.2% in the knockout mutant whereas introduction of an extra copy of tsr1 driven by the glyceraldehyde phosphate dehydrogenase promoter increased it by 40.4%. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that tartronate semialdehyde reductase (TSR plays an important role in glycerol assimilation in U. maydis and defines a novel target in genetic engineering for improved conversion of glycerol to higher value products. Our results add significant depth to the understanding of the glycerol metabolic pathway in fungi. We have demonstrated, for the first time, a biological role of a eukaryotic TSR.

Production of succinic acid from oil palm empty fruit bunch cellulose using Actinobacillus succinogenes

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Pasma, Satriani Aga; Daik, Rusli; Maskat, Mohamad Yusof

2013-11-01

Succinic acid is a common metabolite in plants, animals and microorganisms. It has been used widely in agricultural, food and pharmaceutical industries. Enzymatic hydrolysate glucose from oil palm empty fruit bunch (OPEFB) cellulose was used as a substrate for succinic acid production using Actinobacillus succinogenes. Using cellulose extraction from OPEFB can enhance the production of glucose as a main substrate for succinic acid production. The highest concentration of glucose produced from enzymatic hydrolysis is 167 mg/mL and the sugar recovery is 0.73 g/g of OPEFB. By optimizing the culture medium for succinic acid fermentation with enzymatic hydrolysate of OPEFB cellulose, the nitrogen sources could be reduced to just only 2.5 g yeast extract and 2.5 g corn step liquor. Batch fermentation was carried out using enzymatic hydrolysate of OPEFB cellulose with yeast extract, corn steep liquor and the salts mixture, 23.5 g/L succinic acid was obtained with consumption of 72 g/L glucose in enzymatic hydrolysate of OPEFB cellulose at 38 hours and 37°C. This study suggests that enzymatic hydrolysate of OPEFB cellulose maybe an alternative substrate for the efficient production of succinic acid by Actinobacillus succinogenes.

Succinic Acid as a Byproduct in a Corn-based Ethanol Biorefinery

Energy Technology Data Exchange (ETDEWEB)

MBI International

2007-12-31

MBI endeavored to develop a process for succinic acid production suitable for integration into a corn-based ethanol biorefinery. The project investigated the fermentative production of succinic acid using byproducts of corn mill operations. The fermentation process was attuned to include raw starch, endosperm, as the sugar source. A clean-not-sterile process was established to treat the endosperm and release the monomeric sugars. We developed the fermentation process to utilize a byproduct of corn ethanol fermentations, thin stillage, as the source of complex nitrogen and vitamin components needed to support succinic acid production in A. succinogenes. Further supplementations were eliminated without lowering titers and yields and a productivity above 0.6 g l-1 hr-1was achieved. Strain development was accomplished through generation of a recombinant strain that increased yields of succinic acid production. Isolation of additional strains with improved features was also pursued and frozen stocks were prepared from enriched, characterized cultures. Two recovery processes were evaluated at pilot scale and data obtained was incorporated into our economic analyses.

The succinate receptor as a novel therapeutic target for oxidative and metabolic stress-related conditions.

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Ana Carolina eAriza

2012-02-01

Full Text Available The succinate receptor (also known as GPR91 is a G protein-coupled receptor that is closely related to the family of P2Y purinoreceptors. It is expressed in a variety of tissues, including blood cells, adipose tissue, the liver, retina and kidney. In these tissues, this receptor and its ligand succinate have recently emerged as novel mediators in local stress situations, including ischemia, hypoxia, toxicity and hyperglycemia. Amongst others, the succinate receptor is involved in recruitment of immune cells to transplanted tissues. Moreover, it was shown to play a key role in the development of diabetic retinopathy. However, most prominently, the role of locally increased succinate levels and succinate receptor activation in the kidney, stimulating the systemic and local renin-angiotensin system, starts to unfold: The succinate receptor is a key mediator in the development of hypertension and possibly fibrosis in diabetes mellitus and metabolic syndrome. This makes the succinate receptor a promising drug target to counteract or prevent cardiovascular and fibrotic defects in these expanding disorders. Recent development of SUCNR1-specific antagonists opens novel possibilities for research in models for these disorders and may eventually provide novel opportunities for the treatment of patients.

Separation and Concentration of Succinic Adic from Multicomponent Aqueous Solutions by Nanofiltration Technique

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Antczak Jerzy

2014-06-01

Full Text Available This paper applies the determined suitability of nanofiltration (NF membrane separation for selective isolation and concentration of succinic acid from aqueous solutions which are post-fermentation multicomponent fluids. The study analyzed the influence of concentration and the pH of the separated solutions on the efficiency and selectivity of NF process that runs in a module equipped with a ceramic membrane. Moreover, the effect of applied trans-membrane pressure on the retention of succinic acid and sodium succinate has been studied. The investigations have shown that in the used NF module the retention of succinic acid salt is equal almost 50% in the case of a three-component model solution, although the degree of retention depends on both the transmembrane pressure and the initial concentration of separated salt.

Interaction of Palmitic Acid with Metoprolol Succinate at the Binding Sites of Bovine Serum Albumin

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Mashiur Rahman

2014-12-01

Full Text Available Purpose: The aim of this study was to characterize the binding profile as well as to notify the interaction of palmitic acid with metoprolol succinate at its binding site on albumin. Methods: The binding of metoprolol succinate to bovine serum albumin (BSA was studied by equilibrium dialysis method (ED at 27°C and pH 7.4, in order to have an insight in the binding chemistry of the drug to BSA in presence and absence of palmitic acid. The study was carried out using ranitidine as site-1 and diazepam as site-2 specific probe. Results: Different analysis of binding of metoprolol succinate to bovine serum albumin suggested two sets of association constants: high affinity association constant (k1 = 11.0 x 105 M-1 with low capacity (n1 = 2 and low affinity association (k2 = 4.0×105 M-1 constant with high capacity (n2 = 8 at pH 7.4 and 27°C. During concurrent administration of palmitic acid and metoprolol succinate in presence or absence of ranitidine or diazepam, it was found that palmitic acid displaced metoprolol succinate from its binding site on BSA resulting reduced binding of metoprolol succinate to BSA. The increment in free fraction of metoprolol succinate was from 26.27% to 55.08% upon the addition of increased concentration of palmitic acid at a concentration of 0×10-5 M to 16×10-5 M. In presence of ranitidine and diazepam, palmitic acid further increases the free fraction of metoprolol succinate from 33.05% to 66.95% and 40.68% to 72.88%, respectively. Conclusion: This data provided the evidence of interaction at higher concentration of palmitic acid at the binding sites on BSA, which might change the pharmacokinetic properties of metoprolol succinate.

Krebs cycle metabolite profiling for identification and stratification of pheochromocytomas/paragangliomas due to succinate dehydrogenase deficiency.

Science.gov (United States)

Richter, Susan; Peitzsch, Mirko; Rapizzi, Elena; Lenders, Jacques W; Qin, Nan; de Cubas, Aguirre A; Schiavi, Francesca; Rao, Jyotsna U; Beuschlein, Felix; Quinkler, Marcus; Timmers, Henri J; Opocher, Giuseppe; Mannelli, Massimo; Pacak, Karel; Robledo, Mercedes; Eisenhofer, Graeme

2014-10-01

Mutations of succinate dehydrogenase A/B/C/D genes (SDHx) increase susceptibility to development of pheochromocytomas and paragangliomas (PPGLs), with particularly high rates of malignancy associated with SDHB mutations. We assessed whether altered succinate dehydrogenase product-precursor relationships, manifested by differences in tumor ratios of succinate to fumarate or other metabolites, might aid in identifying and stratifying patients with SDHx mutations. PPGL tumor specimens from 233 patients, including 45 with SDHx mutations, were provided from eight tertiary referral centers for mass spectrometric analyses of Krebs cycle metabolites. Diagnostic performance of the succinate:fumarate ratio for identification of pathogenic SDHx mutations. SDH-deficient PPGLs were characterized by 25-fold higher succinate and 80% lower fumarate, cis-aconitate, and isocitrate tissue levels than PPGLs without SDHx mutations. Receiver-operating characteristic curves for use of ratios of succinate to fumarate or to cis-aconitate and isocitrate to identify SDHx mutations indicated areas under curves of 0.94 to 0.96; an optimal cut-off of 97.7 for the succinate:fumarate ratio provided a diagnostic sensitivity of 93% at a specificity of 97% to identify SDHX-mutated PPGLs. Succinate:fumarate ratios were higher in both SDHB-mutated and metastatic tumors than in those due to SDHD/C mutations or without metastases. Mass spectrometric-based measurements of ratios of succinate:fumarate and other metabolites in PPGLs offer a useful method to identify patients for testing of SDHx mutations, with additional utility to quantitatively assess functionality of mutations and metabolic factors responsible for malignant risk.

Biophysical properties of phenyl succinic acid derivatised hyaluronic acid

DEFF Research Database (Denmark)

Neves-Petersen, Maria Teresa; Klitgaard, Søren; Skovsen, Esben

2010-01-01

Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic materials. In the present study, hyaluronic...... acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA). The fluorescence of PheSA was efficiently quenched by the HA matrix. HA also acted as a singlet oxygen scavenger. Fluorescence lifetime(s) of PheSA in solution and when attached to the HA matrix has been monitored...

Fourier Transform Infrared Spectroscopy Study on Cation adsorption on Viscose Rayon Succinate

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D Khasbaatar

2014-09-01

Full Text Available Ion-exchange materials have been considered as suitable material for the recovery of heavy metals in water. A viscose rayon succinate, synthesized from viscose rayon and succinic anhydride in presence of DMSO, to remove trace bivalent metal ions such as Ag+, Cu2+, Ni2+, Pb2+, Zn2+ and Cr3+, was studied using FT-IR for the behavior of metal adsorption. Both esterification and carboxyl bonding of viscose rayon succinate were assigned essentially at 1729 and 1693cm-1, respectively. And the essential band of bonding between metal and the material was determined at 1625cm-1. The available adsorption capacity of this fiber was 6.2 mequiv/g. The adsorption of metal ions on the viscose rayon succinate follows the order of Cu2+>Cr3+>Ni2+>Pb2+>Zn2+>Ag+ with maximum adsorptions capacities 4.2, 1.42, 0.91, 0.83, 0.69 and 0.35 mmol/g, respectively.DOI: http://dx.doi.org/10.5564/mjc.v12i0.189 Mongolian Journal of Chemistry Vol.12 2011: 136-141

A novel process for recovery of fermentation-derived succinic acid: process design and economic analysis.

Science.gov (United States)

Orjuela, Alvaro; Orjuela, Andrea; Lira, Carl T; Miller, Dennis J

2013-07-01

Recovery and purification of organic acids produced in fermentation constitutes a significant fraction of total production cost. In this paper, the design and economic analysis of a process to recover succinic acid (SA) via dissolution and acidification of succinate salts in ethanol, followed by reactive distillation to form succinate esters, is presented. Process simulation was performed for a range of plant capacities (13-55 million kg/yr SA) and SA fermentation titers (50-100 kg/m(3)). Economics were evaluated for a recovery system installed within an existing fermentation facility producing succinate salts at a cost of $0.66/kg SA. For a SA processing capacity of 54.9 million kg/yr and a titer of 100 kg/m(3) SA, the model predicts a capital investment of $75 million and a net processing cost of $1.85 per kg SA. Required selling price of diethyl succinate for a 30% annual return on investment is $1.57 per kg. Copyright © 2013 Elsevier Ltd. All rights reserved.

Improved sugar-free succinate production by Synechocystis sp. PCC 6803 following identification of the limiting steps in glycogen catabolism

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Tomohisa Hasunuma

2016-12-01

Full Text Available Succinate produced by microorganisms can replace currently used petroleum-based succinate but typically requires mono- or poly-saccharides as a feedstock. The cyanobacterium Synechocystis sp. PCC6803 can produce organic acids such as succinate from CO2 not supplemented with sugars under dark anoxic conditions using an unknown metabolic pathway. The TCA cycle in cyanobacteria branches into oxidative and reductive routes. Time-course analyses of the metabolome, transcriptome and metabolic turnover described here revealed dynamic changes in the metabolism of Synechocystis sp. PCC6803 cultivated under dark anoxic conditions, allowing identification of the carbon flow and rate-limiting steps in glycogen catabolism. Glycogen biosynthesized from CO2 assimilated during periods of light exposure is catabolized to succinate via glycolysis, the anaplerotic pathway, and the reductive TCA cycle under dark anoxic conditions. Expression of the phosphoenolpyruvate (PEP carboxylase gene (ppc was identified as a rate-limiting step in succinate biosynthesis and this rate limitation was alleviated by ppc overexpression, resulting in improved succinate excretion. The sugar-free succinate production was further enhanced by the addition of bicarbonate. In vivo labeling with NaH13CO3 clearly showed carbon incorporation into succinate via the anaplerotic pathway. Bicarbonate is in equilibrium with CO2. Succinate production by Synechocystis sp. PCC6803 therefore holds significant promise for CO2 capture and utilization. Keywords: Autofermentation, Cyanobacteria, Dynamic metabolic profiling, Metabolomics, Succinate, Synechocystis

Structural and magnetic studies on copper succinate dihydrate ...

Indian Academy of Sciences (India)

M P BINITHA

2017-08-21

Aug 21, 2017 ... rials chemistry, heterogeneous catalysis, gas storage, polymer magnets, etc. ... super exchange interactions among copper atoms through bridging .... Thus, these two water molecules in the structure of copper succinate are.

78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

Science.gov (United States)

2013-12-18

..., Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs.; Tolerance Exemption... an exemption from the requirement of a tolerance for residues of tall oil, polymer with polyethylene..., polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. on food or feed...

Genetic manipulation of a metabolic enzyme and a transcriptional regulator increasing succinate excretion from unicellular cyanobacterium

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Takashi eOsanai

2015-10-01

Full Text Available Succinate is a building block compound that the U.S. Department of Energy has declared as important in biorefineries, and it is widely used as a commodity chemical. Here, we identified the two genes increasing succinate production of the unicellular cyanobacterium Synechocystis sp. PCC 6803. Succinate was excreted under dark, anaerobic conditions, and its production level increased by knocking out ackA, which encodes an acetate kinase, and by overexpressing sigE, which encodes an RNA polymerase sigma factor. Glycogen catabolism and organic acid biosynthesis were enhanced in the mutant lacking ackA and overexpressing sigE, leading to an increase in succinate production reaching 5 times of the wild-type levels. Our genetic and metabolomic analyses thus demonstrated the effect of genetic manipulation of a metabolic enzyme and a transcriptional regulator on succinate excretion from this cyanobacterium with the data based on metabolomic technique.

Genotoxicity of meso-2,3-dimercapto succinic acid-coated silver sulfide quantum dot

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Deniz Özkan Vardar

2015-06-01

Full Text Available Nanotecnology products have been used in wide applications in chemistry, electronics, energy generation, and medicine. Despite significant interest in developing quantum dots (QDs for biomedical applications, many researchers are convinced that QDs will never be used for the treatment of patients because of their potential toxicity. In various in vitro cell culture studies, the cytotoxic properties of some QD have been demonstrated and they have been suggested to be toxic in humans. In this study, the cytotoxic properties of Ag2S-(Meso-2,3-Dimercapto Succinic acid nanomaterials in V79 cells (Chinese lung fibroblast cell line were determined by MTT assay. The genotoxic effects of Ag2S-(Meso-2,3-Dimercapto Succinic acid were evaluated by the alkaline single cell gel electrophoresis. The cells were treated with Ag2S-(Meso-2,3-Dimercapto Succinic acid at the concentrations of 5- 2000 µg/ml. No cytotoxic effect of Ag2S-(Meso-2,3-Dimercapto Succinic acid at all concentrations studied was observed. No significant increases in DNA damage were found at the studied concentrations when compared to negative control in V79 cells. In conclusion, further in vitro and in vivo studies are required to determine the safety doses of Ag2S-(Meso-2,3-Dimercapto Succinic acid.

Succinic acid production from orange peel and wheat straw by batch fermentations of Fibrobacter succinogenes S85.

Science.gov (United States)

Li, Qiang; Siles, Jose A; Thompson, Ian P

2010-10-01

Succinic acid is a platform molecule that has recently generated considerable interests. Production of succinate from waste orange peel and wheat straw by consolidated bioprocessing that combines cellulose hydrolysis and sugar fermentation, using a cellulolytic bacterium, Fibrobacter succinogenes S85, was studied. Orange peel contains D-limonene, which is a well-known antibacterial agent. Its effects on batch cultures of F. succinogenes S85 were examined. The minimal concentrations of limonene found to inhibit succinate and acetate generation and bacterial growth were 0.01%, 0.1%, and 0.06% (v/v), respectively. Both pre-treated orange peel by steam distillation to remove D: -limonene and intact wheat straw were used as feedstocks. Increasing the substrate concentrations of both feedstocks, from 5 to 60 g/L, elevated succinate concentration and productivity but lowered the yield. In addition, pre-treated orange peel generated greater succinate productivities than wheat straw but had similar resultant titres. The greatest succinate titres were 1.9 and 2.0 g/L for pre-treated orange peel and wheat straw, respectively. This work demonstrated that agricultural waste such as wheat straw and orange peel can be biotransformed to succinic acid by a one-step consolidated bioprocessing. Measures to increase fermentation efficiency are also discussed.

Receptor structure-based discovery of non-metabolite agonists for the succinate receptor GPR91

DEFF Research Database (Denmark)

Trauelsen, Mette; Rexen Ulven, Elisabeth; Hjorth, Siv A

2017-01-01

OBJECTIVE: Besides functioning as an intracellular metabolite, succinate acts as a stress-induced extracellular signal through activation of GPR91 (SUCNR1) for which we lack suitable pharmacological tools. METHODS AND RESULTS: Here we first determined that the cis conformation of the succinate...

Succinic acid production by Actinobacillus succinogenes using hydrolysates of spent yeast cells and corn fiber.

Science.gov (United States)

Chen, Ke-Quan; Li, Jian; Ma, Jiang-Feng; Jiang, Min; Wei, Ping; Liu, Zhong-Min; Ying, Han-Jie

2011-01-01

The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 μg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

A novel organic nonlinear optical crystal: Creatininium succinate

Energy Technology Data Exchange (ETDEWEB)

Thirumurugan, R.; Anitha, K., E-mail: singlecerystalxrd@gmail.ciom [School of Physics, Madurai Kamraj University, Madurai 625021 (India)

2015-06-24

A novel organic material complex of creatininium succinate (CS) has been synthesized and single crystals were grown by the reaction of creatinine and succinic acid from aqueous solution by employing the technique of slow evaporation at room temperature. The structure of the grown crystal has been elucidated using single crystal X-ray diffraction analysis and the structure was refined by least-squares method to R = 0.027 for 1840 reflections. FT-IR spectral investigation has been carried out to identify the various functional groups in the title compound. UV–Vis transmission was carried out which shows the crystal has a good optical transmittance in the visible region with lower cutoff wavelength around 220 nm. Nonlinear optical property of the crystal was confirmed by Kurtz-Perry powder technique.

Molecular and Supramolecular Changes in Polybutylene Succinate (PBS and Polybutylene Succinate Adipate (PBSA Copolymer during Degradation in Various Environmental Conditions

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Michał Puchalski

2018-03-01

Full Text Available In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS and polybutylene succinate adipate (PBSA copolymer during degradation is described. The experiment was carried out by the use of injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by size-exclusion chromatography (SEC coupled with multiangle laser light scattering (MALLS detection and wide-angle X-ray diffraction (WAXD. Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impacts of the selected degradation conditions on the macroscopic, supramolecular and molecular parameters of the studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

Non-isothermal crystallization kinetics and characterization of biodegradable poly(butylene succinate-co-neopentyl glycol succinate) copolyesters

International Nuclear Information System (INIS)

Xie, Wen-Jie; Zhou, Xiao-Ming

2015-01-01

Both biodegradable aliphatic neat poly(butylene succinate) (PBS) and poly(butylene succinate-co-neopentyl glycol succinate) (P(BS-co-NPGS)) copolyesters with different 1,4-butanediol/neopentyl glycol ratios were synthesized through a two-step process of transesterification and polycondensation using stannous chloride and 4-Methylbenzenesulfonic acid as the co-catalysts. The structure, non-isothermal crystallization behavior, crystalline morphology and crystal structure of neat PBS and P(BS-co-NPGS) copolyesters were characterized by 1 H NMR, differential scanning calorimetry (DSC), polarized optical microscope (POM) and wide angle X-ray diffraction (WAXD), respectively. The Avrami equation modified by Jeziorny and Mo's method was employed to describe the non-isothermal crystallization kinetics of the neat PBS and its copolyesters. The modified Avrami equation could adequately describe the primary stage of non-isothermal crystallization kinetics of the neat PBS and its copolyesters. Mo's method provided a fairly satisfactory description of the non-isothermal crystallization of neat PBS and its copolyesters. Interestingly, the values of 1/t 1/2 , Z c and F(T) obtained by the modified Avrami equation and Mo's method analysis indicated that the crystallization rate increased first and then decreased with an increase of NPGS content compared that of neat PBS, whereas the crystallization mechanism almost kept unchanged. The results of tensile testing showed that the ductility of PBS was largely improved by incorporating NPGS units. The elongation at break increased remarkably with increasing NPGS content. In particular, the sample with 20% NPGS content showed around 548% elongation at break. - Highlights: • The incorporation of NPGS units reduced the spherulite size of BS unit. • The existence of NPGS units did not change the crystal structure of BS unit. • The NPGS units incorporated in PBS could significantly improve the ductility of PBS. • The

Co-Consumption of Methanol and Succinate by Methylobacterium extorquens AM1

Science.gov (United States)

Peyraud, Rémi; Kiefer, Patrick; Christen, Philipp; Portais, Jean-Charles; Vorholt, Julia A.

2012-01-01

Methylobacterium extorquens AM1 is a facultative methylotrophic Alphaproteobacterium and has been subject to intense study under pure methylotrophic as well as pure heterotrophic growth conditions in the past. Here, we investigated the metabolism of M. extorquens AM1 under mixed substrate conditions, i.e., in the presence of methanol plus succinate. We found that both substrates were co-consumed, and the carbon conversion was two-thirds from succinate and one-third from methanol relative to mol carbon. 13C-methanol labeling and liquid chromatography mass spectrometry analyses revealed the different fates of the carbon from the two substrates. Methanol was primarily oxidized to CO2 for energy generation. However, a portion of the methanol entered biosynthetic reactions via reactions specific to the one-carbon carrier tetrahydrofolate. In contrast, succinate was primarily used to provide precursor metabolites for bulk biomass production. This work opens new perspectives on the role of methylotrophy when substrates are simultaneously available, a situation prevailing under environmental conditions. PMID:23133625

Succinate-induced neuronal mitochondrial fission and hexokinase II malfunction in ischemic stroke: Therapeutical effects of kaempferol.

Science.gov (United States)

Wu, Bin; Luo, Hong; Zhou, Xu; Cheng, Cai-Yi; Lin, Lin; Liu, Bao-Lin; Liu, Kang; Li, Ping; Yang, Hua

2017-09-01

Mitochondrial dysfunction is known as one of causative factors in ischemic stroke, leading to neuronal cell death. The present work was undertaken to investigate whether succinate induces neuron apoptosis by regulating mitochondrial morphology and function. In neurons, oxygen-glucose deprivation induced succinate accumulation due to the reversal of succinate dehydrogenase (SDH) activation, leading to mitochondrial fission. Kaempferol inhibited mitochondrial fission and maintained mitochondrial HK-II through activation of Akt, and thereby protected neurons from succinate-mediated ischemi injury. Knockdown of Akt2 with siRNA diminished the effect of kaempferol, indicating that kaempferol suppressed dynamin-related protein 1 (Drp1) activation and promoted HK-II mitochondrial binding dependently on Akt. Moreover, we demonstrated that kaempferol potentiated autophagy during oxygen and glucose deprivation, contributing to protecting neuron survival against succinate insult. In vivo, oral administration of kaempferol in mice attenuated the infract volume after ischemic and reperfusion (I/R) injury and reproduced the similar mitochondrial protective effect in the brain infract area. This study indicates that succinate accumulation plays a pivotal role in I/R injury-induced neuronal mitochondrial dysfunction, and suggests that modulation of Drp1 phosphorylation might be potential therapeutic strategy to protect neuron mitochondrial integrity and treat ischemic stroke. Copyright © 2017 Elsevier B.V. All rights reserved.

Citrate and succinate uptake by potato mitochondria

International Nuclear Information System (INIS)

Jung, D.W.; Laties, G.G.

1979-01-01

Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

Metabolic engineering of Escherichia coli for biotechnological production of high-value organic acids and alcohols

Energy Technology Data Exchange (ETDEWEB)

Yu, Chao; Cao, Yujin; Zou, Huibin; Xian, Mo [Chinese Academy of Sciences, Qingdao (China). Key Lab. of Biofuels

2011-02-15

Confronted with the gradual and inescapable exhaustion of the earth's fossil energy resources, the bio-based process to produce platform chemicals from renewable carbohydrates is attracting growing interest. Escherichia coli has been chosen as a workhouse for the production of many valuable chemicals due to its clear genetic background, convenient to be genetically modified and good growth properties with low nutrient requirements. Rational strain development of E. coli achieved by metabolic engineering strategies has provided new processes for efficiently biotechnological production of various high-value chemical building blocks. Compared to previous reviews, this review focuses on recent advances in metabolic engineering of the industrial model bacteria E. coli that lead to efficient recombinant biocatalysts for the production of high-value organic acids like succinic acid, lactic acid, 3-hydroxypropanoic acid and glucaric acid as well as alcohols like 1,3-propanediol, xylitol, mannitol, and glycerol with the discussion of the future research in this area. Besides, this review also discusses several platform chemicals, including fumaric acid, aspartic acid, glutamic acid, sorbitol, itaconic acid, and 2,5-furan dicarboxylic acid, which have not been produced by E. coli until now. (orig.)

Evaporation of methyl- and dimethyl-substituted malonic, succinic, glutaric and adipic acid particles at ambient temperatures

DEFF Research Database (Denmark)

Mønster, Jacob Garbrecht; Rosenørn, Thomas; Svenningsson, Birgitta

2004-01-01

Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid......Evaporation; organic aerosols; vapor pressure; dicarboxylic acid; maonic acid; succinic acid; glutaric acid; adipic acid...

Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

Science.gov (United States)

Homogeneous modification of cellulose with succinic anhydride was performed in tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU) and TBAA dosage were investigated as paramete...

Stopped-flow studies of the reaction of D-tartronate semialdehyde-2-phosphate with human neuronal enolase and yeast enolase 1.

Science.gov (United States)

Brewer, John M; McKinnon, Jared S; Phillips, Robert S

2010-03-05

We determined the kinetics of the reaction of human neuronal enolase and yeast enolase 1 with the slowly-reacting chromophoric substrate D-tartronate semialdehyde phosphate (TSP), each in tris (tris (hydroxymethyl) aminomethane) and another buffer at several Mg2+ concentrations, 50 or 100 microM, 1 mM and 30 mM. All data were biphasic, and could be satisfactorily fit, assuming either two successive first-order reactions or two independent first-order reactions. Higher Mg2+ concentrations reduce the relative magnitude of the slower reaction. The results are interpreted in terms of a catalytically significant interaction between the two subunits of these enzymes. Copyright (c) 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Volatility of Organic Aerosol: Evaporation of Ammonium Sulfate/Succinic Acid Aqueous Solution Droplets

Science.gov (United States)

2013-01-01

Condensation and evaporation modify the properties and effects of atmospheric aerosol particles. We studied the evaporation of aqueous succinic acid and succinic acid/ammonium sulfate droplets to obtain insights on the effect of ammonium sulfate on the gas/particle partitioning of atmospheric organic acids. Droplet evaporation in a laminar flow tube was measured in a Tandem Differential Mobility Analyzer setup. A wide range of droplet compositions was investigated, and for some of the experiments the composition was tracked using an Aerosol Mass Spectrometer. The measured evaporation was compared to model predictions where the ammonium sulfate was assumed not to directly affect succinic acid evaporation. The model captured the evaporation rates for droplets with large organic content but overestimated the droplet size change when the molar concentration of succinic acid was similar to or lower than that of ammonium sulfate, suggesting that ammonium sulfate enhances the partitioning of dicarboxylic acids to aqueous particles more than currently expected from simple mixture thermodynamics. If extrapolated to the real atmosphere, these results imply enhanced partitioning of secondary organic compounds to particulate phase in environments dominated by inorganic aerosol. PMID:24107221

Biotechnological route for sustainable succinate production utilizing oil palm frond and kenaf as potential carbon sources.

Science.gov (United States)

Luthfi, Abdullah Amru Indera; Manaf, Shareena Fairuz Abdul; Illias, Rosli Md; Harun, Shuhaida; Mohammad, Abdul Wahab; Jahim, Jamaliah Md

2017-04-01

Due to the world's dwindling energy supplies, greater thrust has been placed on the utilization of renewable resources for global succinate production. Exploration of such biotechnological route could be seen as an act of counterbalance to the continued fossil fuel dominance. Malaysia being a tropical country stands out among many other nations for its plenty of resources in the form of lignocellulosic biomass. To date, oil palm frond (OPF) contributes to the largest fraction of agricultural residues in Malaysia, while kenaf, a newly introduced fiber crop with relatively high growth rate, holds great potential for developing sustainable succinate production, apart from OPF. Utilization of non-food, inexhaustible, and low-cost derived biomass in the form of OPF and kenaf for bio-based succinate production remains largely untapped. Owing to the richness of carbohydrates in OPF and kenaf, bio-succinate commercialization using these sources appears as an attractive proposition for future sustainable developments. The aim of this paper was to review some research efforts in developing a biorefinery system based on OPF and kenaf as processing inputs. It presents the importance of the current progress in bio-succinate commercialization, in addition to describing the potential use of different succinate production hosts and various pretreatments-saccharifications under development for OPF and kenaf. Evaluations on the feasibility of OPF and kenaf as fermentation substrates are also discussed.

Amorphous/crystal and polymer/filler interphases in biocomposites from poly(butylene succinate)

Energy Technology Data Exchange (ETDEWEB)

Signori, Francesca [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Pelagaggi, Martina [Universita di Pisa - Dipartimento di Chimica e Chimica Industriale, Via Risorgimento 35, I-56126 Pisa (Italy); Bronco, Simona [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy); Righetti, Maria Cristina, E-mail: righetti@ipcf.cnr.it [Consiglio Nazionale delle Ricerche - Istituto per i Processi Chimico-Fisici (CNR-IPCF), Via G. Moruzzi 1, I-56124 Pisa (Italy)

2012-09-10

Highlights: Black-Right-Pointing-Pointer The existence of intermolecular interactions between poly(butylene succinate) and hemp fibres was proved from specific heat capacities data. Black-Right-Pointing-Pointer Different degrees of mobility of the poly(butylene succinate) amorphous segments were evidenced at the amorphous/crystal interphase. Black-Right-Pointing-Pointer Devitrification of the rigid amorphous fraction in poly(butylene succinate) was found to occur before and simultaneously with the fusion. - Abstract: Poly(butylene succinate)-hemp composites (PBS-hemp), with hemp content in the range 0-40 wt.%, were prepared in the melt and characterized. This paper focuses on the detailed analysis of the thermal behaviour of the PBS-hemp composites, investigated by differential scanning calorimetry (DSC), to enlighten the polymer/fibre interphase features. The occurrence of specific intermolecular interactions between PBS and hemp was assessed from specific heat capacity data. Different degrees of mobility of the PBS amorphous segments were found at the amorphous/crystal interphases. A broadening of the bulk glass transition was observed, and attributed to the presence of polymer segments slightly constrained. Moreover, a rigid amorphous fraction that devitrifies at temperatures higher than the bulk glass transition, partly before the melting region and partly simultaneously with the fusion, was observed and quantified, and attributed to the presence of major constraints probably occurring in geometrically restricted areas.

Structural and magnetic studies on copper succinate dihydrate

Indian Academy of Sciences (India)

The four bis-bidendate succinate anions form syn–syn bridges among two copper atomsto form a polymeric two-dimensional chain. From room temperature vibrating sample magnetometer (VSM) studies themagnetic moment of the material is calculated as 1.35 Bohr magneton (BM), indicating antiferromagnetic interaction ...

Krebs cycle metabolite profiling for identification and stratification of pheochromocytomas/paragangliomas due to succinate dehydrogenase deficiency

NARCIS (Netherlands)

Richter, S; Peitzsch, M.; Rapizzi, E.; Lenders, J.W.M.; Qin, N.; Cubas, A.A. de; Schiavi, F.; Rao, J.U.; Beuschlein, F.; Quinkler, M.; Timmers, H.J.L.M.; Opocher, G.; Mannelli, M.; Pacak, K.; Robledo, M.; Eisenhofer, G.

2014-01-01

CONTEXT: Mutations of succinate dehydrogenase A/B/C/D genes (SDHx) increase susceptibility to development of pheochromocytomas and paragangliomas (PPGLs), with particularly high rates of malignancy associated with SDHB mutations. OBJECTIVE: We assessed whether altered succinate dehydrogenase

Spurious cooperativity in alkylated succinic acids

Science.gov (United States)

Ben-Naim, A.

1998-03-01

The proton-proton correlation, as measured by the ratio between the second and the first dissociation constants of dibasic acid, is sometimes very large and far beyond what could be explained by electrostatic theories. We propose a novel interpretation of this phenomenon based on the idea of spurious cooperativity. The general theoretical framework underlying the onset of spurious cooperativity is developed first. The basic result is that whenever a binding (or dissociating) two-site (or more) system splits into a mixture of noninterconverting isomers the binding isotherm (or the titration curve) behaves as if it is more negatively cooperative compared with the genuine cooperativities of the individual isomer. The theory is applied to a specific system of α-α' dialkyl succinic acid. It is known that the Meso form of these alkylated derivatives show a normal correlation of the same order of magnitude as in succinic acid. On the other hand, the Racemic form of these alkylated derivatives shows anomalous strong negative correlations when the alkyl groups become large (e.g., isopropyl and tert butyl). It is shown that the theory of spurious cooperativity can explain the different behavior of the Racemic and the Meso forms, as well as the onset of anomalous strong negative correlations when the alkyl groups become large.

Succinic acid production from acid hydrolysate of corn fiber by Actinobacillus succinogenes.

Science.gov (United States)

Chen, Kequan; Jiang, Min; Wei, Ping; Yao, Jiaming; Wu, Hao

2010-01-01

Dilute acid hydrolysate of corn fiber was used as carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. The optimized hydrolysis conditions were obtained by orthogonal experiments. When corn fiber particles were of 20 mesh in size and treated with 1.0% sulfuric acid at 121 degrees C for 2 h, the total sugar yield could reach 63.3%. It was found that CaCO(3) neutralization combined with activated carbon adsorption was an effective method to remove fermentation inhibitors especially furfural that presented in the acid hydrolysate of corn fiber. Only 5.2% of the total sugar was lost, while 91.9% of furfural was removed. The yield of succinic acid was higher than 72.0% with the detoxified corn fiber hydrolysate as the carbon source in anaerobic bottles or 7.5 L fermentor cultures. It was proved that the corn fiber hydrolysate could be an alternative to glucose for the production of succinic acid by A. succinogenes NJ113.

Modification of cellulose with succinic anhydride in TBAA/DMSO mixed solvent under catalyst-free conditions

Science.gov (United States)

Ping-Ping Xin; Yao-Bing Huang; Chung-Yun Hse; Huai N. Cheng; Chaobo Huang; Hui. Pan

2017-01-01

Homogeneous modification of cellulose with succinic anhydride was performed using tetrabutylammonium acetate (TBAA)/dimethyl sulfoxide (DMSO) mixed solvent. The molar ratio of succinic anhydride (SA) to free hydroxyl groups in the anhydroglucose units (AGU), TBAA dosage, reaction temperature, and reaction time were investigated. The highest degree of substitution (DS)...

Binary and ternary solid-liquid phase equilibrium for the systems formed by succinic acid, urea and diethylene glycol: Determination and modelling

International Nuclear Information System (INIS)

Li, Yanxun; Li, Congcong; Han, Shuo; Zhao, Hongkun

2017-01-01

Highlights: • Solubility of succinic acid in diethylene glycol was determined. • Solubility of succinic acid + urea + diethylene glycol was determined. • Three ternary phase diagrams were constructed for the ternary system. • The ternary phase diagrams were correlated using NRTL model. - Abstract: In this work, the solid-liquid phase equilibrium for binary system of succinic acid + diethylene glycol at the temperatures ranging from (298.15 to 333.15) K and ternary system of (succinic acid + urea + diethylene glycol) at 298.15 K, 313.15 K and 333.15 K was built by using the isothermal saturation method under atmospheric pressure (101.2 kPa), and the solubilities were determined by a high-performance liquid chromatography. The solid-phases formed in the ternary system of ((succinic acid + urea + diethylene glycol)) were confirmed by Schreinemaker’s method of wet residue, which corresponded to urea, succinic acid, and adduct 2:1 urea-succinic acid (mole ratio). Three isothermal phase diagrams for the ternary system were constructed based on the measured mutual solubility. Each isothermal phase diagram included six crystallization fields, three invariant curves, two invariant points and two co-saturated points. The crystalline region of adduct 2:1 urea-succinic acid is larger than those of the other two solids. The solubility of succinic acid in diethylene glycol was correlated with the modified Apelblat equation, λh equation and NRTL model; and the mutual solubility of the ternary ((succinic acid + urea + diethylene glycol)) system was correlated and calculated by the NRTL model. The interaction parameters’ values of succinic acid-urea were acquired. The value of RMSD was 7.11 × 10 −3 for the ternary system. The calculation results had good agreement with the experiment values. Furthermore, the densities of equilibrium liquid phase were acquired. The phase diagrams and the thermodynamic model of the ternary system could provide the basis for design of

Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept

DEFF Research Database (Denmark)

Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar Borisov

2016-01-01

The aim of this study was to develop integrated biofuel (cellulosic bioethanol) and biochemical (succinic acid) production from industrial hemp (Cannabis sativa L.) in a biorefinery concept. Two types of pretreatments were studied (dilute-acid and alkaline oxidative method). High cellulose recovery...... productivity. With respect to succinic acid production, the highest productivity was obtained after liquid fraction fermentation originated from steam treatment with 1.5% of acid. The mass balance calculations clearly showed that 149 kg of EtOH and 115 kg of succinic acid can be obtained per 1 ton of dry hemp....... Results obtained in this study clearly document the potential of industrial hemp for a biorefinery....

Metabolic Engineering of Saccharomyces cerevisiae Microbial Cell Factories for Succinic Acid Production

DEFF Research Database (Denmark)

Otero, José Manuel; Nielsen, Jens; Olsson, Lisbeth

2007-01-01

anhydride. There are several biomass platforms, all prokaryotic, for succinic acid production; however, overproduction of succinic acid in S. cerevisiae offers distinct process advantages. For example, S. cerevisiae has been awarded GRAS status for use in human consumables, grows well at low p......H significantly minimizing purification and acidification costs associated with organic acid production, and can utilize diverse carbon substrates in chemically defined medium. S. cerevisiae offers the unique advantage of being the most well characterized eukaryotic expression system. Here we describe the use...

Enterobacter sp. LU1 as a novel succinic acid producer - co-utilization of glycerol and lactose.

Science.gov (United States)

Podleśny, Marcin; Jarocki, Piotr; Wyrostek, Jakub; Czernecki, Tomasz; Kucharska, Jagoda; Nowak, Anna; Targoński, Zdzisław

2017-03-01

Succinic acid is an important C4-building chemical platform for many applications. A novel succinic acid-producing bacterial strain was isolated from goat rumen. Phylogenetic analysis based on the 16S rRNA sequence and physiological analysis indicated that the strain belongs to the genus Enterobacter. This is the first report of a wild bacterial strain from the genus Enterobacter that is capable of efficient succinic acid production. Co-fermentation of glycerol and lactose significantly improved glycerol utilization under anaerobic conditions, debottlenecking the utilization pathway of this valuable biodiesel waste product. Succinic acid production reached 35 g l -1 when Enterobacter sp. LU1 was cultured in medium containing 50 g l -1 of glycerol and 25 g l -1 of lactose as carbon sources. © 2016 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

A case of succinic semialdehyde dehydrogenase deficiency with status epilepticus and rapid regression.

Science.gov (United States)

Horino, Asako; Kawawaki, Hisashi; Fukuoka, Masataka; Tsuji, Hitomi; Hattori, Yuka; Inoue, Takeshi; Nukui, Megumi; Kuki, Ichiro; Okazaki, Shin; Tomiwa, Kiyotaka; Hirose, Shinichi

2016-10-01

Clinical phenotypic expression of SSADH deficiency is highly heterogeneous, and some infants may develop refractory secondary generalized seizures. A 9-month-old boy manifested partial seizures, developing severe status epilepticus, and conventional antiepileptic drugs were ineffective. Use of ketamine contributed to the control of status epilepticus, achieving a reduction in frequency of partial seizures, and improving EEG findings without apparent complications. Diffusion-weighted images showed hyperintensities in the bilateral basal ganglia and fornix, and multiple T2 hyperintensity lesions were detected. (123)I-iomazenil (IMZ) SPECT revealed a decrease in binding of (123)I-iomazenil predominantly in the left temporal region by the 18th day of hospitalization. However, repeated IMZ-SPECT on the 46th day of hospitalization demonstrated almost no accumulation across a broad region, sparing the left temporal region. The patient showed rapid regression, refractory myoclonus, and severe progressive brain atrophy. IMZ-SPECT findings demonstrated reduced benzodiazepine receptor binding and its dynamic changes in an SSADH-deficient patient. Considering the down regulation of the GABAA receptor, ketamine should be included in pharmacotherapeutic strategies for treatment of refractory status epilepticus in SSADH-deficient patients. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Elaboration of a fragment library hit produces potent and selective aspartate semialdehyde dehydrogenase inhibitors.

Science.gov (United States)

Thangavelu, Bharani; Bhansali, Pravin; Viola, Ronald E

2015-10-15

Aspartate-β-semialdehyde dehydrogenase (ASADH) lies at the first branch point in the aspartate metabolic pathway which leads to the biosynthesis of several essential amino acids and some important metabolites. This pathway is crucial for many metabolic processes in plants and microbes like bacteria and fungi, but is absent in mammals. Therefore, the key microbial enzymes involved in this pathway are attractive potential targets for development of new antibiotics with novel modes of action. The ASADH enzyme family shares the same substrate binding and active site catalytic groups; however, the enzymes from representative bacterial and fungal species show different inhibition patterns when previously screened against low molecular weight inhibitors identified from fragment library screening. In the present study several approaches, including fragment based drug discovery (FBDD), inhibitor docking, kinetic, and structure-activity relationship (SAR) studies have been used to guide ASADH inhibitor development. Elaboration of a core structure identified by FBDD has led to the synthesis of low micromolar inhibitors of the target enzyme, with high selectivity introduced between the Gram-negative and Gram-positive orthologs of ASADH. This new set of structures open a novel direction for the development of inhibitors against this validated drug-target enzyme. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genome-scale modeling enables metabolic engineering of Saccharomyces cerevisiae for succinic acid production.

Science.gov (United States)

Agren, Rasmus; Otero, José Manuel; Nielsen, Jens

2013-07-01

In this work, we describe the application of a genome-scale metabolic model and flux balance analysis for the prediction of succinic acid overproduction strategies in Saccharomyces cerevisiae. The top three single gene deletion strategies, Δmdh1, Δoac1, and Δdic1, were tested using knock-out strains cultivated anaerobically on glucose, coupled with physiological and DNA microarray characterization. While Δmdh1 and Δoac1 strains failed to produce succinate, Δdic1 produced 0.02 C-mol/C-mol glucose, in close agreement with model predictions (0.03 C-mol/C-mol glucose). Transcriptional profiling suggests that succinate formation is coupled to mitochondrial redox balancing, and more specifically, reductive TCA cycle activity. While far from industrial titers, this proof-of-concept suggests that in silico predictions coupled with experimental validation can be used to identify novel and non-intuitive metabolic engineering strategies.

Crystallization behavior of partially miscible biodegradable poly(butylene succinate)/poly(ethylene succinate) blends

International Nuclear Information System (INIS)

He, Yi-Song; Zeng, Jian-Bing; Li, Shao-Long; Wang, Yu-Zhong

2012-01-01

Graphical abstract: Crystallization rate of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. The rich component formed a continuous phase and the other formed a dispersed phase of the blend. Crystal structures of PBS and PES were almost unchanged after blending with each other. Highlights: ► PBS/PES blend systems are partially miscible. ► Blending did not change the crystallization mechanisms of PBS and PES not affects the crystallization rates. ► The rich component formed the continuous phase while the poor component formed the dispersed phase of the blends. ► Crystal structures of PBS and PES were almost unchanged after blending with each other. - Abstract: Biodegradable blend of poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility of the blends was investigated by differential scanning calorimetry (DSC). The results indicated that PBS and PES were partially miscible. Crystallization kinetics, crystalline morphology and crystal structure of the blends were studied by DSC, polarized optical microscope (POM), and wide-angle X-ray diffraction (WAXD), respectively. Nonisothermal and isothermal crystallization kinetics suggested that the crystallizability of PBS in the blends decreased first and then increased with increase in PES content, and that of PES increased steadily with increase in PBS content. POM observation illustrated that the rich component formed a continuous phase and the other formed a dispersed phase. The results of WAXD indicated that the crystal structures of PBS and PES were almost unchanged before and after blending, since the positions of characteristic diffraction peaks of both components remain almost unchanged.

Multifunctional nanobiocomposite of Poly[(butylene succinate)-co-adipate] and clay

CSIR Research Space (South Africa)

Al-Thabaiti, SA

2015-03-01

Full Text Available The processing and characterization of multifunctional nanobiocomposite of biodegradable poly[(butylene succinate)-co-adipate] (PBSA) and organically modified synthetic fluorine mica (OSFM) are reported. The nanobiocomposite of PBSA with OSFM...

Control of protein synthesis in Escherichia coli: strain differences in control of translational initiation after energy source shift-down.

OpenAIRE

Jacobson, L A; Jen-Jacobson, L

1980-01-01

We have studied the parameters of protein synthesis in a number of Escherichia coli strains after a shift-down from glucose-minimal to succinate-minimal medium. One group of strains, including K-12(lambda) (ATCC 10798) and NF162, showed a postshift translational yield of 50 to 65% and a 2- to 2.5-fold increase in the functional lifetime of general messenger ribonucleic acid. There was no change in the lag time for beta-galactosidase induction in these strains after the shift-down. A second gr...

CLINICAL AND ECONOMICAL ASSESSMENTS OF METOPROLOL TARTRATE/SUCCINATE USAGE IN PATIENTS WITH ISCHEMIC HEART DISEASE

Directory of Open Access Journals (Sweden)

M. V. Soura

2008-01-01

Full Text Available Clinical and clinicoeconomical studies review is presented as well as results of author’s comparative cost analysis on metoprolol tartrate (Betaloc and metoprolol succinate (Betaloc ZOK usage in patients with ischemic heart disease. Efficacy of metoprolol therapy is proven in randomized clinical studies in patients with angina and myocardial infarction (MI. In angina patients metoprolol prevents cardiac attacks, MI, reduces nitroglycerine consumption, increases exercise tolerability, prolongs the exercise time before ST segment depression (succinate better than tartrate, decrease of angina intensity. In MI patients metoprolol therapy reduces mortality, sudden death, recurring MI and the rate of early post MI angina attacks. Nowadays metoprolol is the only β-blocker having indication on secondary MI prevention. Besides for the present metoprolol succinate is the only β-blocker with proven direct antisclerosis effect. According to Swedish clinicoeconomical study in patients after MI secondary prevention with metoprolol therapy saves the costs in comparison with placebo. American clinicoeconomical model of metoprolol and atenolol usage in all patients with MI could result in significant reduction in mortality and recurring MI rate, prolong the life and improve its quality, save financial resources. The cost of monthly treatment of angina patient with metoprolol tartrate (Betaloc and metoprolol succinate (Betaloc ZOK is 135 and 354 rubles, respectively. The price range of comparative β-blockers in ascending order is the following: atenolol (Atenolol Nicomed → metoprolol tartrate (Betaloc → metoprolol succinate (Betaloc ZOK → bisoprolol (Concor → nebivolol (Nebilet. In conclusion, metoprolol therapy is the one of mostly economically reasonable approach.

[Effects of Light Near-Infrared Radiation on Rats Assessed by Succinate Dehydrogenase Activity in Lymphocytes on Blood Smears].

Science.gov (United States)

Khunderyakova, N V; Zakharchenko, A V; Zakharchenko, M V; Muller, H; Fedotcheva, I; Kondrashova, M N

2015-01-01

Biological effects of light near infrared radiation (850 nm), with modulation acoustic frequency of 101 Hz, was studied. The study was conducted on rats, the effect was recorded by succinate dehydrogenase activity in lymphocytes on the blood smear after administration of the activating dose of adrenaline, which simulates the state of the organism in the early stages of the pathogenic effects (stress). A pronounced regulating effect of infrared radiation on the activity of succinate dehydrogenase in animals activated by adrenaline was shown. Infrared radiation has a normalizing effect reducing the degree of inhibition or activation of the enzyme induced by adrenaline and had no effect on the control animals. Thus, by modulating the activity of succinate dehydrogenase infrared radiation regulates energy production in the mitochondria supported by the most powerful oxidation substrate--succinic acid, which is especially pronounced under stress.

Contribution of the tricarboxylic acid (TCA) cycle and the glyoxylate shunt in Saccharomyces cerevisiae to succinic acid production during dough fermentation.

Science.gov (United States)

Rezaei, Mohammad N; Aslankoohi, Elham; Verstrepen, Kevin J; Courtin, Christophe M

2015-07-02

Succinic acid produced by yeast during bread dough fermentation can significantly affect the rheological properties of the dough. By introducing mutations in the model S288C yeast strain, we show that the oxidative pathway of the TCA cycle and the glyoxylate shunt contribute significantly to succinic acid production during dough fermentation. More specifically, deletion of ACO1 and double deletion of ACO1 and ICL1 resulted in a 36 and 77% decrease in succinic acid levels in fermented dough, respectively. Similarly, double deletion of IDH1 and IDP1 decreased succinic acid production by 85%, while also affecting the fermentation rate. By contrast, double deletion of SDH1 and SDH2 resulted in a two-fold higher succinic acid accumulation compared to the wild-type. Deletion of fumarate reductase activity (FRD1 and OSM1) in the reductive pathway of the TCA cycle did not affect the fermentation rate and succinic acid production. The changes in the levels of succinic acid produced by mutants Δidh1Δidp1 (low level) and Δsdh1Δsdh2 (high level) in fermented dough only resulted in small pH differences, reflecting the buffering capacity of dough at a pH of around 5.1. Moreover, Rheofermentometer analysis using these mutants revealed no difference in maximum dough height and gas retention capacity with the dough prepared with S288C. The impact of the changed succinic acid profile on the organoleptic or antimicrobial properties of bread remains to be demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

Succinate-CoA ligase deficiency due to mutations in SUCLA2 and SUCLG1

DEFF Research Database (Denmark)

Carrozzo, Rosalba; Verrigni, Daniela; Rasmussen, Magnhild

2016-01-01

BACKGROUND: The encephalomyopathic mtDNA depletion syndrome with methylmalonic aciduria is associated with deficiency of succinate-CoA ligase, caused by mutations in SUCLA2 or SUCLG1. We report here 25 new patients with succinate-CoA ligase deficiency, and review the clinical and molecular findings...... deficiency of complexes I and IV, but normal histological and biochemical findings in muscle did not preclude a diagnosis of succinate-CoA ligase deficiency. In five patients, the urinary excretion of methylmalonic acid was only marginally elevated, whereas elevated plasma methylmalonic acid was consistently...

Synthesis and characterization of a novel multiblock copolyester containing poly(ethylene succinate) and poly(butylene succinate)

International Nuclear Information System (INIS)

Zhu Qunying; He Yisong; Zeng Jianbing; Huang Qing; Wang Yuzhong

2011-01-01

Highlights: → High-molecular-weight biodegradable multiblock copolyester containing PBS and PES segments was achieved. → PBS and PES are miscible with a single glass transition regardless of composition. → The multiblock copolyester showed excellent tensile strength and elongation at break. → The multiblock copolyester can serve as a potential substitute for conventional non-biodegradable commodity plastics. - Abstract: Multiblock copolyester (PBS-b-PES) containing poly(butylene succinate) (PBS) and poly(ethylene succinate) (PES) was successfully synthesized by chain-extension of dihydroxyl terminated PBS (HO-PBS-OH) and PES (HO-PES-OH) using 1,6-hexmethylene diisocyanate (HDI) as a chain extender. The chemical structures, molecular weights, crystallization behaviors, thermal and mechanical properties of the copolyesters were characterized by proton nuclear magnetic resonance spectroscopy ( 1 H NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), wide-angle X-ray diffraction (WAXD), tensile testing and hydrolytic degradation. High-molecular-weight copolyesters with M w more than 2.0 x 10 5 g mol -1 were easily obtained through chain-extension. The copolyesters showed a single glass transition temperature (T g ) which increased with PES content. The melting point temperature (T m ) and relative degree of crystallinity (X c ) of the copolyesters decreased first and then increased with PES content. The copolyesters manifested excellent mechanical properties, for example, PBS 5 -b-PES 5 had fracture stress of 61.8 MPa and fracture strain of 1173%. The chain-extension reaction provided a very effective way to produce high molecular weight multiblock copolyesters.

Genome-wide Escherichia coli stress response and improved tolerance towards industrially relevant chemicals

DEFF Research Database (Denmark)

Rau, Martin Holm; Calero Valdayo, Patricia; Lennen, Rebecca

2016-01-01

Economically viable biobased production of bulk chemicals and biofuels typically requires high product titers. During microbial bioconversion this often leads to product toxicity, and tolerance is therefore a critical element in the engineering of production strains. Here, a systems biology...... approach was employed to understand the chemical stress response of Escherichia coli, including a genome-wide screen for mutants with increased fitness during chemical stress. Twelve chemicals with significant production potential were selected, consisting of organic solvent-like chemicals (butanol......, hydroxy-γ-butyrolactone, 1,4-butanediol, furfural), organic acids (acetate, itaconic acid, levulinic acid, succinic acid), amino acids (serine, threonine) and membrane-intercalating chemicals (decanoic acid, geraniol). The transcriptional response towards these chemicals revealed large overlaps...

Cloning of a novel gene from Penicillium oxalicum I1 which in Escherichia coli enhances the secretion of acetic acid

Directory of Open Access Journals (Sweden)

Xue, L.

2018-01-01

Full Text Available Description of the subject. Organic acids play an important role in the conversion of insoluble ions into soluble ones in soil. Heterologous overexpression of a single gene in a cell is the optimal strategy for increasing the secretion of organic acids solubilizing phosphate. Objectives. In this study, we constructed a primary cDNA library of Penicillium oxalicum I1, and screened clones that can solubilize P in tricalcium phosphate (TCP medium. We aimed to obtain the gene expressed in Escherichia coli, which can enhance organic acid secretion. Method. A primary cDNA library of Penicillium oxalicum I1 was constructed using the switching mechanism at the 5'-end of RNA transcription. The organic acid secretion ability of E. coli DH5α™ with overexpressed P. oxalicum I1gene was tested in TCP medium where glucose is the sole carbon source. Afterwards, pyruvic acid, citric acid, α-ketoglutaric acid, succinic acid, fumaric acid, and malic acid were used as sole carbon source substitutes for glucose in the TCP medium to test the organic acid secretion ability of the transformed E. coli DH5α™. Results. A total of 106 clones showed halos in TCP medium, among which clone I-2 displayed clear halo. The full-length cDNA of clone I-2 was 1,151 bp, with a complete open reading frame of 702 bp, which encoded a hypothetical protein of 233 amino acids. The cDNA sequence showed 68% identity and 73% query cover with other fungal gene sequences of which the function remains unknown. Escherichia coli containing the cloned gene secreted up to 567 mg·l-1 acetic acid within 48 h. The use of glucose, pyruvic acid, α-ketoglutaric acid, and malic acid improved the acetic acid secretion of the E. coli DH5α™ clone I-2. By contrast, the use of citric acid, succinic acid, and fumaric acid did not improve the acetic acid secretion of clone I-2 compared to a control E. coli DH5α™ strain bearing only the cloning vector without any insert. Conclusions. We obtained a

Influence of VO2+ ions on structural and optical properties of potassium succinate-succinic acid single crystal for non-linear optical applications

Science.gov (United States)

Juliet sheela, K.; Subramanian, P.

2018-04-01

A transparent and good optical quality semi organic single crystal of vanadium doped potassium succinate-succinic acid (KSSA) was synthesized by slow evaporation technique at room temperature. The structural perfection was supported by the powder XRD of the KSSA-VO2+ single crystal. Optical behavior of the material was discovered from the absorption and transmission spectra of UV-vis-NIR characterization. Functional group and presence of metal ion in the specimen are depicted from FTIR traces. From the photoluminescence studies, emission of wavelength in the violet region (418 nm) at the excitation of 243 nm could be ascertained. EDAX, SEM measurements identify presence of elements and pictures the step-line growth and the imperfection presents in the grown crystal. EPR analysis extracts the information about the local site symmetry around the impurity ion, molecular orbital coefficients, admixture coefficients and ground state wave function of VO2+ doped KSSA single crystal. Second harmonic generation (SHG) efficiency of the grown crystal was investigated to explore the NLO characteristic of the material.

Highly Carboxylated Cellulose Nanofibers via Succinic Anhydride Esterification of Wheat Fibers and Facile Mechanical Disintegration.

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Sehaqui, H; Kulasinski, K; Pfenninger, N; Zimmermann, T; Tingaut, P

2017-01-09

We report herein the preparation of 4-6 nm wide carboxyl-functionalized cellulose nanofibers (CNF) via the esterification of wheat fibers with cyclic anhydrides (maleic, phtalic, and succinic) followed by an energy-efficient mechanical disintegration process. Remarkable results were achieved via succinic anhydride esterification that enabled CNF isolation by a single pass through the microfluidizer yielding a transparent and thick gel. These CNF carry the highest content of carboxyl groups ever reported for native cellulose nanofibers (3.8 mmol g -1 ). Compared to conventional carboxylated cellulose nanofibers prepared via Tempo-mediated oxidation of wheat fibers, the present esterified CNF display a higher molar-mass and a better thermal stability. Moreover, highly carboxylated CNF from succinic anhydride esterification were effectively integrated into paper filters for the removal of lead from aqueous solution and are potentially of interest as carrier of active molecules or as transparent films for packaging, biomedical or electronic applications.

[Effects of different neutralizing agents on succinate production by Actinobacillus succinogenes NJ113].

Science.gov (United States)

Yang, Zhuona; Jiang, Min; Li, Jian; Fang, Xiaojiang; Ye, Guizi; Bai, Xuefei; Zheng, Xiaoyu; Wei, Ping

2010-11-01

Different neutralizing agents were used as pH controller to investigate their effects on the growth and succinic acid production of Actinobacillus succinogenes NJ113. The fermentation results showed that Ca(OH)2, CaCO3 and NH4OH were not suitable for succinic acid production by A. succinogenes NJ113 because of their negative effects on cell growth. When Na-base was used, cells would flocculate and lump, and due to the sodium ion concentration reaching to a high level, OD660 dropped sharply after 12 h of fermentation. Mg-base was better because there was no significant inhibition by magnesium ion. Two combined neutralizing agents were used to maintain pH level, one with NaOH and Mg(OH)2 while the other with Na2CO3 and Mg(OH)2. The optimum ratios of the combined neutralizing agents were both 1:1 (g:g) when using 100 g/L glucose. When NaOH and Mg(OH)2 were chosen with the ratio of 1:1(g:g), 69.8 g/L of the succinic acid and 74.5% of the yield was obtained.

Determination of vitamin E acid succinate in biodegradable microspheres by reversed-phase high-performance liquid chromatography.

Science.gov (United States)

Martínez Sancho, C; Herrero Vanrell, R; Negro, S

2004-01-01

A simple, rapid, and reproducible reversed-phase high-performance liquid chromatographic (HPLC) method is applied to the routine assay of vitamin E acid succinate in biodegradable microspheres. Vitamin E acid-succinate-containing poly-(D,L-lactic-co-glycolic acid) microspheres are prepared by the solvent evaporation method. The starting drug-polymer ratio is 1:10 (w/w) and the total amount of drug and polymer processed is always 440 mg. The content of vitamin E acid succinate in the microspheres is evaluated by HPLC. Chromatography is carried out isocratically at 25 degrees C +/- 0.5 degrees C on an Extrasil ODS-2 column with a mobile phase composed of methanol-water (97:3, v/v) (pH 5.6) at a flow rate of 2 mL/min and UV detection at 284 nm. Parameters such as linearity, limits of quantitation (LOQ) and detection (LOD), precision, accuracy, recovery, specificity, and ruggedness are studied as reported in the International Conference on Harmonization guidelines. The stability of vitamin E acid succinate is also studied with satisfactory results after 48 h at 25 degrees C. The method is selective and linear for drug concentrations in the range 15-210 micro g/mL. The LOQ and LOD are 15 and 3 micro g/mL, respectively. The results for accuracy studies are good. Values for coefficient of variation for intra- and interassay are 2.08% and 2.32%, respectively. The mean percentage of vitamin E acid succinate in the recovery studies is 99.52% +/- 0.81%. The mean loading efficiency for microspheres is 96.53% +/- 1.31%.

Organic acids enhance bioavailability of tetracycline in water to Escherichia coli for uptake and expression of antibiotic resistance.

Science.gov (United States)

Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

2014-11-15

Tetracyclines are a large class of antimicrobials used most extensively in livestock feeding operations. A large portion of tetracyclines administered to livestock is excreted in manure and urine which is collected in waste lagoons. Subsequent land application of these wastes introduces tetracyclines into the soil environment, where they could exert selective pressure for the development of antibiotic resistance genes in bacteria. Tetracyclines form metal-complexes in natural waters, which could reduce their bioavailability for bacterial uptake. We hypothesized that many naturally-occurring organic acids could effectively compete with tetracyclines as ligands for metal cations, hence altering the bioavailability of tetracyclines to bacteria in a manner that could enhance the selective pressure. In this study, we investigated the influence of acetic acid, succinic acid, malonic acid, oxalic acid and citric acid on tetracycline uptake from water by Escherichia coli bioreporter construct containing a tetracycline resistance gene which induces the emission of green fluorescence when activated. The presence of the added organic acid ligands altered tetracycline speciation in a manner that enhanced tetracycline uptake by E. coli. Increased bacterial uptake of tetracycline and concomitant enhanced antibiotic resistance response were quantified, and shown to be positively related to the degree of organic acid ligand complexation of metal cations in the order of citric acid > oxalic acid > malonic acid > succinic acid > acetic acid. The magnitude of the bioresponse increased with increasing aqueous organic acid concentration. Apparent positive relation between intracellular tetracycline concentration and zwitterionic tetracycline species in aqueous solution indicates that (net) neutral tetracycline is the species which most readily enters E. coli cells. Understanding how naturally-occurring organic acid ligands affect tetracycline speciation in solution, and how speciation

Integrated production of cellulosic bioethanol and succinic acid from industrial hemp in a biorefinery concept.

Science.gov (United States)

Kuglarz, Mariusz; Alvarado-Morales, Merlin; Karakashev, Dimitar; Angelidaki, Irini

2016-01-01

The aim of this study was to develop integrated biofuel (cellulosic bioethanol) and biochemical (succinic acid) production from industrial hemp (Cannabis sativa L.) in a biorefinery concept. Two types of pretreatments were studied (dilute-acid and alkaline oxidative method). High cellulose recovery (>95%) as well as significant hemicelluloses solubilization (49-59%) after acid-based method and lignin solubilization (35-41%) after alkaline H2O2 method were registered. Alkaline pretreatment showed to be superior over the acid-based method with respect to the rate of enzymatic hydrolysis and ethanol productivity. With respect to succinic acid production, the highest productivity was obtained after liquid fraction fermentation originated from steam treatment with 1.5% of acid. The mass balance calculations clearly showed that 149kg of EtOH and 115kg of succinic acid can be obtained per 1ton of dry hemp. Results obtained in this study clearly document the potential of industrial hemp for a biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of salicylic and succinic acids on antioxidant enzymes activity, heat resistance and productivity of Panicum miliaceum L.

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Miroshnichenko N.N.

2011-05-01

Full Text Available The influence of treatment of millet (Panicum miliaceum L. seeds with the solutions of salicylic and succinic acids on the heat resistance of plantlets and activity of antioxidant enzymes – superoxide dismutase (SOD, catalase and peroxidase – in them have been investigated. In the micro-field experiment the influence of these acids on the millet yield was estimated. The action of salicylic (10 μM and succinic (1 mM acids caused the increase of plantlets resistance to the damaging heating that expressed in the rise of relative quantity of survived plantlets in 5 days after heating at the temperature of 47°С and in the reduced content of lipid peroxidation product malonic dialdehyde during the poststress period. The increase of activity of SOD, catalase and peroxidase took place in millet plantlets under the influence of salicylic and succinic acids. The increase of productivity of millet grain under the action of salicylic and succinic acids on 13,3-52,0 and 6,4-38,8% respectively depending on weather conditions in the field experiments was noted.

A novel mutation in the succinate dehydrogenase subunit D gene in siblings with the hereditary paraganglioma–pheochromocytoma syndrome

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Chaithra Prasad

2014-10-01

Full Text Available Germline mutations in the succinate dehydrogenase complex subunit D gene are now known to be associated with hereditary paraganglioma–pheochromocytoma syndromes. Since the initial succinate dehydrogenase complex subunit D gene mutation was identified about a decade ago, more than 131 unique variants have been reported. We report the case of two siblings presenting with multiple paragangliomas and pheochromocytomas; they were both found to carry a mutation in the succinate dehydrogenase complex subunit D gene involving a substitution of thymine to guanine at nucleotide 236 in exon 3. This particular mutation of the succinate dehydrogenase complex subunit D gene has only been reported in one previous patient in Japan; this is, therefore, the first report of this pathogenic mutation in siblings and the first report of this mutation in North America. With continued screening of more individuals, we will be able to create a robust mutation database that can help us understand disease patterns associated with particular variants and may be a starting point in the development of new therapies for familial paraganglioma syndromes.

Utilization of CO2 fixating bacterium Actinobacillus succinogenes 130Z for simultaneous biogas upgrading and bio-succinic acid production

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Alvarado-Morales, Merlin; Angelidaki, Irini

2014-01-01

Biogas is an attractive renewable energy carrier. However, it contains CO2 which limits certain applications of biogas. Here we report a novel approach for removing CO2 from biogas and capturing it as a biochemical through a biological process. This approach entails converting CO2 into bio...... and titre, CO2 consumption rate and CH4 purity. When using biogas as the only CO2 source at 140 kPa, the CO2 consumption rate corresponded to 2.59 L CO2 L-1 d-1 with a final succinic acid titre of 14.4 g L-1. Under this pressure condition the highest succinic acid yield and biogas quality reached......-succinic acid using the bacterial strain Actinobacillus succinogenes 130Z, and simultaneously producing high purity CH4 (>95%). Results showed that when pressure during fermentation was increased from 101.325 to 140 kPa, higher CO2 solubility was achieved, thereby positively affecting final succinic acid yield...

Receptor structure-based discovery of non-metabolite agonists for the succinate receptor GPR91

DEFF Research Database (Denmark)

Trauelsen, Mette; Rexen Ulven, Elisabeth; Hjorth, Siv A

2017-01-01

therefore binds in a very different mode than generally believed. Importantly, an empty side-pocket is identified next to the succinate binding site. All this information formed the basis for a substructure-based search query, which, combined with molecular docking, was used in virtual screening of the ZINC...... database to pick two serial mini-libraries of a total of only 245 compounds from which sub-micromolar, selective GPR91 agonists of unique structures were identified. The best compounds were backbone-modified succinate analogs in which an amide-linked hydrophobic moiety docked into the side-pocket next...

Nb-Based Zeolites: Efficient bi-Functional Catalysts for the One-Pot Synthesis of Succinic Acid from Glucose

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Magdi El Fergani

2017-12-01

Full Text Available The one-pot production of succinic acid from glucose was investigated in pure hot water as solvent using Nb (0.02 and 0.05 moles%-Beta zeolites obtained by a post-synthesis methodology. Structurally, they are comprised of residual framework Al-acid sites, extra-framework isolated Nb (V and Nb2O5 pore-encapsulated clusters. The Nb-modified Beta-zeolites acted as bi-functional catalysts in which glucose is dehydrated to levulinic acid (LA which, further, suffers an oxidation process to succinic acid (SA. After the optimization of the reaction conditions, that is, at 180 °C, 18 bar O2, and 12 h reaction time, the oxidation of glucose occurred with a selectivity to succinic acid as high as 84% for a total conversion.

Direct Succinic Acid Production from Minimally Pretreated Biomass Using Sequential Solid-State and Slurry Fermentation with Mixed Fungal Cultures

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Jerico Alcantara

2017-06-01

Full Text Available Conventional bio-based succinic acid production involves anaerobic bacterial fermentation of pure sugars. This study explored a new route for directly producing succinic acid from minimally-pretreated lignocellulosic biomass via a consolidated bioprocessing technology employing a mixed lignocellulolytic and acidogenic fungal co-culture. The process involved a solid-state pre-fermentation stage followed by a two-phase slurry fermentation stage. During the solid-state pre-fermentation stage, Aspergillus niger and Trichoderma reesei were co-cultured in a nitrogen-rich substrate (e.g., soybean hull to induce cellulolytic enzyme activity. The ligninolytic fungus Phanerochaete chrysosporium was grown separately on carbon-rich birch wood chips to induce ligninolytic enzymes, rendering the biomass more susceptible to cellulase attack. The solid-state pre-cultures were then combined in a slurry fermentation culture to achieve simultaneous enzymatic cellulolysis and succinic acid production. This approach generated succinic acid at maximum titers of 32.43 g/L after 72 h of batch slurry fermentation (~10 g/L production, and 61.12 g/L after 36 h of addition of fresh birch wood chips at the onset of the slurry fermentation stage (~26 g/L production. Based on this result, this approach is a promising alternative to current bacterial succinic acid production due to its minimal substrate pretreatment requirements, which could reduce production costs.

Co-Expression of ORFCma with PHB Depolymerase (PhaZCma ) in Escherichia coli Induces Efficient Whole-Cell Biodegradation of Polyesters.

Science.gov (United States)

Lee, Ming-Chieh; Liu, En-Jung; Yang, Cheng-Han; Hsiao, Li-Jung; Wu, Tzong-Ming; Li, Si-Yu

2018-04-01

Whole-cell degradation of polyesters not only avoids the tedious process of enzyme separation, but also allows the degraded product to be reused as a carbon source. In this study, Escherichia coli BL21(DE3) harboring phaZ Cma , a gene encoding poly(3-hydroxybutyrate) (PHB) depolymerase from Caldimonas manganoxidans, is constructed. The extra-cellular fraction of E. coli/pPHAZ exhibits a fast PHB degradation rate where it only took 35 h to completely degrade PHB films, while C. manganoxidans takes 81 h to do the same. The co-expression of ORF Cma (a putative periplasmic substrate binding protein that is within the same operon of phaZ Cma ) further improves the PHB degradation. While 28 h is needed for E. coli/pPHAZ to cause an 80% weight loss in PHB films, E. coli/pORFPHAZ needs only 21 h. Furthermore, it is able to degrade at-least four different polyesters, PHB, poly(lactic acid) (PLA), polycaprolactone (PCL), and poly(butylene succinate-co-adipate) (PBSA). Testing of the time course of 3-hydroxybutyrate concentration and the turbidity of the degradation solutions over time shows that PhaZ Cma has both exo- and endo-enzymatic activity. The whole-cell E. coli/pORFPHAZ can be used for recycling various polyesters while ORF Cma can potentially be a universal element for enhancing the secretion of recombinant protein. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bio-oil based biorefinery strategy for the production of succinic acid

DEFF Research Database (Denmark)

Wang, Caixia; Thygesen, Anders; Liu, Yilan

2013-01-01

Background: Succinic acid is one of the key platform chemicals which can be produced via biotechnology process instead of petrochemical process. Biomass derived bio-oil have been investigated intensively as an alternative of diesel and gasoline fuels. Bio-oil could be fractionized into organic...

Viscoelastic and electrical properties of carbon nanotubes filled poly(butylene succinate)

CSIR Research Space (South Africa)

Bandyopadhyay, J

2014-03-01

Full Text Available The carbon nanotubes (CNTs)-containing composites of poly(butylene succinate) (PBS) were prepared by melt-blending in a batch mixer with three concentrations by weight of CNTs: 1, 2 and 3 %. State of dispersion-distribution of the CNTs in the PBS...

Effect of vitamin E succinate on inflammatory cytokines induced by high-intensity interval training.

Science.gov (United States)

Sarir, Hadi; Emdadifard, Ghodsieh; Farhangfar, Homayoun; TaheriChadorneshin, Hossein

2015-12-01

The anti-inflammatory effect of vitamin E under moderate exercises has been evaluated. However, the effect of vitamin E succinate, which has more potent anti-inflammatory effect than other isomers of vitamin E has not been evaluated. Therefore, the aim of the present study was to evaluate the effects of vitamin E succinate on tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) production induced by high-intensity interval training (HIIT). In the present study, 24 rats were randomly divided into control (C), supplementation (S), HIIT, and HIIT + supplementation (HIIT+S) groups. HIIT training protocol on a treadmill (at a speed of 40-54 m/min) and vitamin E succinate supplementation (60 mg/kg/day) was conducted for 6 weeks. Serum IL-6 in the HIIT group significantly increased compared with the C group (350.42 ± 123.31 pg/mL vs 158.60 ± 41.96 pg/mL; P = 0.002). Also, serum TNF-α concentrations significantly enhanced (718.15 ± 133.42 pg/mL vs 350.87 ± 64.93 pg/mL; P = 0.001) in the HIIT group compared with the C group. Treatment of the training group with vitamin E numerically reduced IL-6 and TNF-α when compared with the HIIT group (217.31 ± 29.21 and 510.23 ± 217.88, respectively, P > 0.05). However, no significant changes were observed in serum TNF-α (P = 0.31) and IL-6 (P = 0.52) concentrations in the HIIT + S group compared with the C group. HIIT-induced IL-6 and TNF-α decreased by administration of Vitamin E succinate.

Identification of the enzymatic basis for δ-aminolevulinic acid auxotrophy in a hemA mutant of escherichia coli

International Nuclear Information System (INIS)

Avissar, Y.J.; Beale, S.I.

1989-01-01

The hemA mutation of Escherichia coli K-12 confers a requirement for δ-aminolevulinic acid (ALA). Cell extract prepared from the hemA strain SASX41B was incapable of producing ALA from either glutamate or glutamyl-tRNA, whereas extract of the hem + strain HB101 formed colorimetrically detectable amounts of ALA and transferred label from 1-[ 14 C]glutamate and 3,4-[ 3 H]glutamyl-tRNA to ALA. Extracts of both strains converted glutamate-1-semialdehyde to ALA and were capable of aminoacylating tRNA Glu . Glutamyl-tRNA formed by extracts of both strains could be converted to ALA by the extract of hem + cells. The extract of hemA cells did not convert glutamyl-tRNA formed by either strain to ALA. However, the hemA cell extract, when supplemented in vitro with glutamyl-tRNA dehydrogenase isolated from Chlorella vulgaris cells, formed about as much ALA as did the unsupplemented hem + cell extract. We conclude from these observations that the enzyme activity that is lacking in the ALA auxotrophic strain carrying the hemA mutation is that of glutamyl-tRNA dehydrogenase

Hepatoprotective Activity of a Complex Compound of 5-Hydroxy-6-Methyluracil and Succinic Acid in Experimental Peritonitis

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D. A. Yenikeyev

2008-01-01

Full Text Available Objective: to evaluate the hepatoprotective efficacy of a complex compound of 5-hydroxy-6-methyluracil and succinic acid in experimental peritonitis. Materials and methods. Experiments were carried out on 48 male albino rats in which peritonitis was simulated via intraperitoneal administration of 7% fecal suspension in a dose of 0.6 ml per 100 g bodyweight. The rate of free radical oxidation processes, the activity of antioxidative protection, the degree of endogenous intoxication and cytolytic syndrome, and the effect of the test compound on these parameters were estimated in the experiment. Results. With the development of an abdominal inflammatory process, there were increases in rates of endogenous intoxication and free radical oxidation (FRO, a change in the activity of antioxidative protection enzymes, and a reduction in the levels of ceruloplasmin and sulfahydryl groups. The complex compound, that comprised 5-hydroxy-6-methyluracil and succinic acid used as monotherapy, reduced the degree of endogenous intoxication, FRO, and lipid peroxidation-antioxidative defense system imbalance. Conclusion. The experimental data suggest that the use of the complex compound containing succinic acid and 5-hydroxy-6-methy-luracil is pathogenetically warranted. Key words: peritonitis, lipid peroxidation, antioxidants, succinic acid, pyrim-idine derivatives.

Influence of the course prescription of sodium succinate on functional state and general physical working ability of footballers organism during the training sessions

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Олексій Володимирович Чернєв

2015-09-01

Full Text Available Pharmacological purpose of metabotropic preparations including burshtin acid and its derivative succinate sodium copes with the number of tasks the main of which is an activation of alternative ways of energoproduction at the work of submaximal and maximal force and preliminary training of the separate links of metabolism.The task of research is to ascertain changes that take place in functional state of sportsmen during long physical loadings and optimization of the work of cardiovascular system (CVS and prophylaxis of psychical strains with the help of succinate sodium.Methods and organization of research. There were examined 84 sportsmen to ascertain changes that take place in the functional state of sportsmen during the long physical loadings and optimization of the work of CVS with the help of succinate sodium. Examinations took place during the training sessions (TS in January, February and July 2012-2013 years.Results of research and its discussion. There was studied an efficiency of the course use of succinate sodium in footballers 100 mg 3 times a day during 14 days. Energetic supply of processes of intracellular homeostasis in erythrocytes realizes by means of ATP that is created in the process of glycolysis. According to the results of research after course prescription of succinate sodium in sportsmen the content of ATP in erythrocytes increased and an amount of ADP and AMP decreased. An improvement of general metabolic situation under an influence of succinate sodium was proved by the decrease of products of reactions of peroxidation in blood plasma of footballers.These results indicated an essential antiacidotic effect of the course use of succinate sodium by footballers after loading in anaerobic and glycolytic zone of intensity. At the same time there was ascertain in our research that the use of succinate sodium had a positive effect on the dynamics of lactate content during the processes of renewal after training in aerobic

Succinate-based preparation alleviates manifestations of the climacteric syndrome in women.

Science.gov (United States)

Peskov, A B; Maevskii, E I; Uchitel', M L; Sakharova, N Yu; Vize-Khripunova, M A

2005-09-01

Clinical placebo-controlled study of Enerlit-Clima (bioactive succinate-based food additive) a showed positive effect of the preparation on general clinical and psychoemotional manifestations of the climacteric syndrome. A trend to an increase in estradiol level in early pathological climacteric and normalization of the endometrial status were observed.

Effect of vitamin E succinate on inflammatory cytokines induced by high-intensity interval training

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Hadi Sarir

2015-01-01

Full Text Available Aim and Scope: The anti-inflammatory effect of vitamin E under moderate exercises has been evaluated. However, the effect of vitamin E succinate, which has more potent anti-inflammatory effect than other isomers of vitamin E has not been evaluated. Therefore, the aim of the present study was to evaluate the effects of vitamin E succinate on tumor necrosis factor alpha (TNF-a and interleukin-6 (IL-6 production induced by high-intensity interval training (HIIT. Materials and Methods: In the present study, 24 rats were randomly divided into control (C, supplementation (S, HIIT, and HIIT + supplementation (HIIT+S groups. HIIT training protocol on a treadmill (at a speed of 40-54 m/min and vitamin E succinate supplementation (60 mg/kg/day was conducted for 6 weeks. Results: Serum IL-6 in the HIIT group significantly increased compared with the C group (350.42 ± 123.31 pg/mL vs 158.60 ± 41.96 pg/mL; P = 0.002. Also, serum TNF-a concentrations significantly enhanced (718.15 ± 133.42 pg/mL vs 350.87 ± 64.93 pg/mL; P = 0.001 in the HIIT group compared with the C group. Treatment of the training group with vitamin E numerically reduced IL-6 and TNF-a when compared with the HIIT group (217.31 ± 29.21 and 510.23 ± 217.88, respectively, P > 0.05. However, no significant changes were observed in serum TNF-a (P = 0.31 and IL-6 (P = 0.52 concentrations in the HIIT + S group compared with the C group. Conclusion: HIIT-induced IL-6 and TNF-α decreased by administration of Vitamin E succinate.

Combining CRISPR and CRISPRi Systems for Metabolic Engineering of E. coli and 1,4-BDO Biosynthesis.

Science.gov (United States)

Wu, Meng-Ying; Sung, Li-Yu; Li, Hung; Huang, Chun-Hung; Hu, Yu-Chen

2017-12-15

Biosynthesis of 1,4-butanediol (1,4-BDO) in E. coli requires an artificial pathway that involves six genes and time-consuming, iterative genome engineering. CRISPR is an effective gene editing tool, while CRISPR interference (CRISPRi) is repurposed for programmable gene suppression. This study aimed to combine both CRISPR and CRISPRi for metabolic engineering of E. coli and 1,4-BDO production. We first exploited CRISPR to perform point mutation of gltA, replacement of native lpdA with heterologous lpdA, knockout of sad and knock-in of two large (6.0 and 6.3 kb in length) gene cassettes encoding the six genes (cat1, sucD, 4hbd, cat2, bld, bdh) in the 1,4-BDO biosynthesis pathway. The successive E. coli engineering enabled production of 1,4-BDO to a titer of 0.9 g/L in 48 h. By combining the CRISPRi system to simultaneously suppress competing genes that divert the flux from the 1,4-BDO biosynthesis pathway (gabD, ybgC and tesB) for >85%, we further enhanced the 1,4-BDO titer for 100% to 1.8 g/L while reducing the titers of byproducts gamma-butyrolactone and succinate for 55% and 83%, respectively. These data demonstrate the potential of combining CRISPR and CRISPRi for genome engineering and metabolic flux regulation in microorganisms such as E. coli and production of chemicals (e.g., 1,4-BDO).

Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity.

Science.gov (United States)

Palao-Suay, Raquel; Aguilar, María Rosa; Parra-Ruiz, Francisco J; Maji, Samarendra; Hoogenboom, Richard; Rohner, Nathan A; Thomas, Susan N; Román, Julio San

2016-12-01

Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action. The aim of this work is to demonstrate that the bioactivity of synthetic NPs based on defined reversible addition-fragmentation chain transfer polymerization copolymers can be enhanced by the introduction of hydrophilic comonomers in the hydrophobic segment. The amphiphilic terpolymers are based on poly(ethylene glycol) (PEG) as hydrophilic block, and a hydrophobic block based on a methacrylic derivative of α-tocopheryl succinate (MTOS) and small amounts of 2-hydroxyethyl methacrylate (HEMA) (PEG-b-poly(MTOS-co-HEMA)). The introduction of HEMA reduces hydrophobicity and introduces "disorder" both in the homogeneous blocks and the compact core of the corresponding NPs. These NPs are able to encapsulate additional α-tocopheryl succinate (α-TOS) with high efficiency and their biological activity is much higher than that described for the unmodified copolymers, proposedly due to more efficient degradation and release of α-TOS, demonstrating the importance of the hydrophilic-hydrophobic balance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibition of mitochondrial glycerol-3-phosphate dehydrogenase by alpha-tocopheryl succinate

Czech Academy of Sciences Publication Activity Database

Rauchová, Hana; Vokurková, Martina; Drahota, Zdeněk

2014-01-01

Roč. 53, AUG (2014), s. 409-413 ISSN 1357-2725 R&D Projects: GA ČR(CZ) GAP304/12/0259 Institutional support: RVO:67985823 Keywords : brown adipose tissue mitochondria * oxygen consumption * glycerol-3-phosphate * succinate * reactive oxygen species Subject RIV: ED - Physiology Impact factor: 4.046, year: 2014

Promysalin Elicits Species-Selective Inhibition of Pseudomonas aeruginosa by Targeting Succinate Dehydrogenase.

Science.gov (United States)

Keohane, Colleen E; Steele, Andrew D; Fetzer, Christian; Khowsathit, Jittasak; Van Tyne, Daria; Moynié, Lucile; Gilmore, Michael S; Karanicolas, John; Sieber, Stephan A; Wuest, William M

2018-02-07

Natural products have served as an inspiration to scientists both for their complex three-dimensional architecture and exquisite biological activity. Promysalin is one such Pseudomonad secondary metabolite that exhibits narrow-spectrum antibacterial activity, originally isolated from the rhizosphere. We herein utilize affinity-based protein profiling (AfBPP) to identify succinate dehydrogenase (Sdh) as the biological target of the natural product. The target was further validated in silico, in vitro, in vivo, and through the selection, and sequencing, of a resistant mutant. Succinate dehydrogenase plays an essential role in primary metabolism of Pseudomonas aeruginosa as the only enzyme that is involved both in the tricarboxylic acid cycle (TCA) and in respiration via the electron transport chain. These findings add credence to other studies that suggest that the TCA cycle is an understudied target in the development of novel therapeutics to combat P. aeruginosa, a significant pathogen in clinical settings.

Synthesis, stability and bioavailability of astaxanthin succinate diester.

Science.gov (United States)

Qiao, Xing; Yang, Lu; Zhang, Ting; Zhou, Qingxin; Wang, Yuming; Xu, Jie; Xue, Changhu

2018-06-01

We synthesized astaxanthin succinate diester (ASD), a novel astaxanthin (AST) derivate, with succinic anhydride and free AST. ASD was purified and characterized using silica gel column chromatography and spectrometry, respectively. The ASD final synthesis rate was 82.63%. A stability test revealed a high AST and ASD retention rate at pH 5.0-7.0. ASD showed better stability than did AST under acidic conditions. Both sample ions showed lower retention rates under Fe 2+ and Fe 3+ states. The ASD metabolic curve showed serum and liver area under the curve from 0 h to time t (AUC 0-t ) values of 45.05 ± 4.58 and 120.38 ± 23.66 µg h -1  mL -1 , respectively. The long-term accumulation was significantly higher in the ASD group than in the AST group, which showed higher accumulation in the heart, muscle and spleen than in other tissues in vivo. The thermal stability and bioavailability of ASD were higher than that of the non-esterified free AST and common free AST, respectively. Additionally, AST accumulation in different tissues of the ASD group was multifold higher than that of free AST. These results prove that ASD may serve as a better source of AST for human nutrition than does free AST. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Miscibility, crystallization and mechanical properties of biodegradable blends of poly(L-lactic acid) and poly(butylene succinate-b-ethylene succinate) multiblock copolymer

International Nuclear Information System (INIS)

Jiao, Ling; Huang, Cai-Li; Zeng, Jian-Bing; Wang, Yu-Zhong; Wang, Xiu-Li

2012-01-01

Highlights: ► The blend of PLLA and PBES showed limited miscibility. ► The crystallization rate of PLLA was accelerated by blending with PBES. ► The crystal structures of PLLA and PBES did not change. - Abstract: Poly(L-lactic acid) (PLLA) is regarded as one of the most promising biobased and biodegradable polymers. However, its application was restricted due to the brittle nature. In the present study, PLLA was blended with a novel biodegradable flexible multiblock copolymer, poly(butylene succinate-b-ethylene succinate) (PBES) to produce new biodegradable materials. PLLA/PBES blends with different composition were prepared by solution blending and casting method with chloroform as a mutual solvent. Miscibility, crystallization behavior, and mechanical properties of the blends were investigated by differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and tensile tests. The results indicated that PLLA and PBES showed limited miscibility in the amorphous phase. The crystallization rate of PLLA was accelerated with the increase of PBES in the blends while the crystallization mechanism did not change. The results of tensile tests suggest that the blends showed longer elongation at break than neat PLLA. The elongation at break of PLLA was obtained to be 10%, and those of PLLA/PBES 80/20, 60/40, 40/60 and 20/80 were 29, 110, 442, and 455%, respectively.

Ferulenol specifically inhibits succinate ubiquinone reductase at the level of the ubiquinone cycle

International Nuclear Information System (INIS)

Lahouel, Mesbah; Zini, Roland; Zellagui, Ammar; Rhouati, Salah; Carrupt, Pierre-Alain; Morin, Didier

2007-01-01

The natural compound ferulenol, a sesquiterpene prenylated coumarin derivative, was purified from Ferula vesceritensis and its mitochondrial effects were studied. Ferulenol caused inhibition of oxidative phoshorylation. At low concentrations, ferulenol inhibited ATP synthesis by inhibition of the adenine nucleotide translocase without limitation of mitochondrial respiration. At higher concentrations, ferulenol inhibited oxygen consumption. Ferulenol caused specific inhibition of succinate ubiquinone reductase without altering succinate dehydrogenase activity of the complex II. This inhibition results from a limitation of electron transfers initiated by the reduction of ubiquinone to ubiquinol in the ubiquinone cycle. This original mechanism of action makes ferulenol a useful tool to study the physiological role and the mechanism of electron transfer in the complex II. In addition, these data provide an additional mechanism by which ferulenol may alter cell function and demonstrate that mitochondrial dysfunction is an important determinant in Ferula plant toxicity

Integration of Succinic Acid Production in a Dry Mill Ethanol Facility

Energy Technology Data Exchange (ETDEWEB)

None

2006-08-01

This project seeks to address both issues for a dry mill ethanol biorefinery by lowering the cost of sugars with the development of an advanced pretreatment process, improving the economics of succinic acid (SA), and developing a model of an ethanol dry mill to evaluate the impact of adding different products and processes to a dry mill.

Role of O2 in the Growth of Rhizobium leguminosarum bv. viciae 3841 on Glucose and Succinate

OpenAIRE

Wheatley, Rachel M.; Ramachandran, Vinoy K.; Geddes, Barney A.; Perry, Benjamin J.; Yost, Chris K.; Poole, Philip S.

2016-01-01

Insertion sequencing (INSeq) analysis of Rhizobium leguminosarum bv. viciae 3841 (Rlv3841) grown on glucose or succinate at both 21% and 1% O2 was used to understand how O2 concentration alters metabolism. Two transcriptional regulators were required for growth on glucose (pRL120207 [eryD] and RL0547 [phoB]), five were required on succinate (pRL100388, RL1641, RL1642, RL3427, and RL4524 [ecfL]), and three were required on 1% O2 (pRL110072, RL0545 [phoU], and RL4042). A novel toxin-antitoxin s...

Blend membrane of succinic acid-crosslinked chitosan grafted with heparin/PVA-PEG (polyvinyl alcohol-polyethylene glycol) and its characterization

Science.gov (United States)

Sangkota, V. D. A.; Lusiana, R. A.; Astuti, Y.

2018-04-01

Crosslinking and grafting reactions are required to modify the functional groups on chitosan to increase the number of its active groups. In this study, crosslinking reaction of succinic acid and grafting reaction of heparin on chitosan were conducted to produce a membrane as a candidate of a hemodialysis membrane. The mole ratio between chitosan and succinate acids was varied to obtain the best composition of modified materials. By blending all the material composition with PVA-PEG, the blend was transformed into a membrane. The resulted membrane was then characterized by various test methods such as tests of thickness, weight, water uptake, pH resistance, tensile strength and membrane hydrophilicity. The results showed that the best composition of the membrane reached in the addition of 0.011 gram of succinic acid proved by its highest mechanical strength compared to the other membranes.

[Pathomorphology of regenerative processes in mandibular fracture after sodium succinate treatment and laser magnetotherapy in an experimental setting].

Science.gov (United States)

Faustov, L A; Nedel'ko, N A; Morozova, M V

2001-01-01

Morphological reactions in tissue adjacent to mandibular angular fracture were studied in guinea pigs treated with sodium succinate and laser magnetotherapy. Due to succinate therapy the exudative component of inflammation was less expressed in comparison with the control, macrophagal reaction and neoangiogenesis were activated, the volume of damaged muscle tissue and the incidence of suppurations decreased. The number of osteoblasts increased and new bone structures acquired a lamellar pattern earlier than in the control. Sodium succinate therapy in combination with laser magnetotherapy had a more pronounced positive effect as regards activation of macrophagal reaction and neoangiogenesis and a decrease in the area of fibrosclerotic changes in the zone of damaged muscles, where newly formed myosymplasts differentiated into myotubes and even in muscle fibers. Suppuration of the wound was prevented. Bone tissue in the fracture zone formed without preliminary formation of cartilaginous tissue, which resulted in more rapid osteogenesis (lamellar bone growth in the fracture zone).

O-Succinyl-L-homoserine-based C4-chemical production: succinic acid, homoserine lactone, γ-butyrolactone, γ-butyrolactone derivatives, and 1,4-butanediol.

Science.gov (United States)

Hong, Kuk-Ki; Kim, Jeong Hyun; Yoon, Jong Hyun; Park, Hye-Min; Choi, Su Jin; Song, Gyu Hyeon; Lee, Jea Chun; Yang, Young-Lyeol; Shin, Hyun Kwan; Kim, Ju Nam; Cho, Kyung Ho; Lee, Jung Ho

2014-10-01

There has been a significant global interest to produce bulk chemicals from renewable resources using engineered microorganisms. Large research programs have been launched by academia and industry towards this goal. Particularly, C4 chemicals such as succinic acid (SA) and 1,4-butanediol have been leading the path towards the commercialization of biobased technology with the effort of replacing chemical production. Here we present O-Succinyl-L-homoserine (SH) as a new, potentially important platform biochemical and demonstrate its central role as an intermediate in the production of SA, homoserine lactone (HSL), γ-butyrolactone (GBL) and its derivatives, and 1,4-butanediol (BDO). This technology encompasses (1) the genetic manipulation of Escherichia coli to produce SH with high productivity, (2) hydrolysis into SA and homoserine (HS) or homoserine lactone hydrochloride, and (3) chemical conversion of either HS or homoserine lactone HCL (HSL·HCl) into drop-in chemicals in polymer industry. This production strategy with environmental benefits is discussed in the perspective of targeting of fermented product and a process direction compared to petroleum-based chemical conversion, which may reduce the overall manufacturing cost.

Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

NARCIS (Netherlands)

K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

2008-01-01

textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial

Development of chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis.

Science.gov (United States)

Davoudi, Zahra; Rabiee, Mohammad; Houshmand, Behzad; Eslahi, Niloofar; Khoshroo, Kimia; Rasoulianboroujeni, Morteza; Tahriri, Mohammadreza; Tayebi, Lobat

2018-01-01

The aim of this research was to develop chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis, which was fabricated through an environmental friendly process. Mucoadhesive films increase the advantage of higher efficiency and drug localization in the affected region. In this research, mucoadhesive films, for the release of hydrocortisone sodium succinate, were prepared using different ratios of chitosan, gelatin and keratin. In the first step, chitosan and gelatin proportions were optimized after evaluating the mechanical properties, swelling capacity, water uptake, stability, and biodegradation of the films. Then, keratin was added at different percentages to the optimum composite of chitosan and gelatin together with the drug. The results of surface pH showed that none of the samples were harmful to the buccal cavity. FTIR analysis confirmed the influence of keratin on the structure of the composite. The presence of a higher amount of keratin in the composite films resulted in high mechanical, mucoadhesive properties and stability, low water uptake and biodegradation in phosphate buffer saline (pH = 7.4) containing 10 4  U/ml lysozyme. The release profile of the films ascertained that keratin is a rate controller in the release of the hydrocortisone sodium succinate. Finally, chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate can be employed in dental applications.

Bisoprolol compared with carvedilol and metoprolol succinate in the treatment of patients with chronic heart failure.

Science.gov (United States)

Fröhlich, Hanna; Torres, Lorella; Täger, Tobias; Schellberg, Dieter; Corletto, Anna; Kazmi, Syed; Goode, Kevin; Grundtvig, Morten; Hole, Torstein; Katus, Hugo A; Cleland, John G F; Atar, Dan; Clark, Andrew L; Agewall, Stefan; Frankenstein, Lutz

2017-09-01

Beta-blockers are recommended for the treatment of chronic heart failure (CHF). However, it is disputed whether beta-blockers exert a class effect or whether there are differences in efficacy between agents. 6010 out-patients with stable CHF and a reduced left ventricular ejection fraction prescribed either bisoprolol, carvedilol or metoprolol succinate were identified from three registries in Norway, England, and Germany. In three separate matching procedures, patients were individually matched with respect to both dose equivalents and the respective propensity scores for beta-blocker treatment. During a follow-up of 26,963 patient-years, 302 (29.5%), 637 (37.0%), and 1232 (37.7%) patients died amongst those prescribed bisoprolol, carvedilol, and metoprolol, respectively. In univariable analysis of the general sample, bisoprolol and carvedilol were both associated with lower mortality as compared with metoprolol succinate (HR 0.80, 95% CI 0.71-0.91, p < 0.01, and HR 0.86, 95% CI 0.78-0.94, p < 0.01, respectively). Patients prescribed bisoprolol or carvedilol had similar mortality (HR 0.94, 95% CI 0.82-1.08, p = 0.37). However, there was no significant association between beta-blocker choice and all-cause mortality in any of the matched samples (HR 0.90; 95% CI 0.76-1.06; p = 0.20; HR 1.10, 95% CI 0.93-1.31, p = 0.24; and HR 1.08, 95% CI 0.95-1.22, p = 0.26 for bisoprolol vs. carvedilol, bisoprolol vs. metoprolol succinate, and carvedilol vs. metoprolol succinate, respectively). Results were confirmed in a number of important subgroups. Our results suggest that the three beta-blockers investigated have similar effects on mortality amongst patients with CHF.

Intracellular product recycling in high succinic acid producing yeast at low pH

NARCIS (Netherlands)

Wahl, S.A.; Bernal Martinez, C.; Zhao, Zheng; van Gulik, W.M.; Jansen, Mickel L.A.

2017-01-01

Background: The metabolic engineering of Saccharomyces cerevisiae for the production of succinic acid has progressed dramatically, and a series of high-producing hosts are available. At low cultivation pH and high titers, the product transport can become bidirectional, i.e. the acid is reentering

GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

Energy Technology Data Exchange (ETDEWEB)

Kamei, Yuka; Tamura, Takayuki [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Yoshida, Ryo [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ohta, Shinji [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Fukusaki, Eiichiro [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Mukai, Yukio, E-mail: y_mukai@nagahama-i-bio.ac.jp [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan)

2011-04-01

Highlights: {yields}We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. {yields} Deletion of the UGA1 or GAD1 genes extends replicative lifespan. {yields} Addition of GABA to wild-type cultures has no effect on lifespan. {yields} Intracellular GABA levels do not differ in longevity mutants and wild-type cells. {yields} Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for {gamma}-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The {Delta}uga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for {Delta}uga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of {sup 1}H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan

GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

International Nuclear Information System (INIS)

Kamei, Yuka; Tamura, Takayuki; Yoshida, Ryo; Ohta, Shinji; Fukusaki, Eiichiro; Mukai, Yukio

2011-01-01

Highlights: →We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. → Deletion of the UGA1 or GAD1 genes extends replicative lifespan. → Addition of GABA to wild-type cultures has no effect on lifespan. → Intracellular GABA levels do not differ in longevity mutants and wild-type cells. → Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for γ-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The Δuga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for Δuga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of 1 H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan extension. These results strongly suggest

Alpha-tocopheryl succinate inhibits malignant mesothelioma by disrupting the fibroblast growth factor autocrine loop

Czech Academy of Sciences Publication Activity Database

Stapelberg, M.; Gellert, N.; Swettenham, E.; Tomasetti, M.; Witting, P. K.; Procopio, A.; Neužil, Jiří

2005-01-01

Roč. 280, č. 27 (2005), s. 25369-25376 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50520514 Keywords : alpha-tocopheryl succinate * malignant mesothelioma * fibroblast growth factor Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.854, year: 2005

Tocopherol-associated protein-1 accelerates apoptosis induced by alpha-tocopheryl succinate in mesothelioma cells

Czech Academy of Sciences Publication Activity Database

Neužil, Jiří; Dong, L.F.; Wang, X.F.; Zingg, J.M.

2006-01-01

Roč. 343, č. 4 (2006), s. 1113-1117 ISSN 0006-291X Institutional research plan: CEZ:AV0Z50520514 Keywords : apoptosis * tocopherol-associated protein * alpha-tocopheryl succinate Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.855, year: 2006

Gold-nanoparticle-based catalysts for the oxidative esterification of 1,4-butanediol into dimethyl succinate.

Science.gov (United States)

Brett, Gemma L; Miedziak, Peter J; He, Qian; Knight, David W; Edwards, Jennifer K; Taylor, Stuart H; Kiely, Christopher J; Hutchings, Graham J

2013-10-01

The oxidation of 1,4-butanediol and butyrolactone have been investigated by using supported gold, palladium and gold-palladium nanoparticles. The products of such reactions are valuable chemical intermediates and, for example, can present a viable pathway for the sustainable production of polymers. If both gold and palladium were present, a significant synergistic effect on the selective formation of dimethyl succinate was observed. The support played a significant role in the reaction, with magnesium hydroxide leading to the highest yield of dimethyl succinate. Based on structural characterisation of the fresh and used catalysts, it was determined that small gold-palladium nanoalloys supported on a basic Mg(OH)2 support provided the best catalysts for this reaction. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

76 FR 59141 - Determination That LOXITANE (Loxapine Succinate) Capsules and Three Other Drug Products Were Not...

Science.gov (United States)

2011-09-23

... Applicant NDA 017525 LOXITANE (loxapine Watson Laboratories succinate) Inc., 417 Wakara Capsules, Way, Suite.../milliliter. NDA 020828 FORTOVASE Hoffmann La Roche (saquinavir) Inc., 340 Kingsland Capsule, 200 mg. St...

Physical and chemical stability of palonosetron hydrochloride with dacarbazine and with methylprednisolone sodium succinate during simulated y-site administration.

Science.gov (United States)

Trissel, Lawrence A; Zhang, Yanping; Xu, Quanyun A

2006-01-01

The objective of this study was to evaluate the physical and chemical stability of mixtures of undiluted palonosetron hydrochloride 50 micrograms/mL with dacarbazine 4 mg/mL and with methylprednisolone sodium succinate 5 mg/mL in 5% dextrose injection during simulated Y-site administration. Triplicate test samples were prepared by admixing 7.5 mL of palonosetron hydrochloride with 7.5 mL of dacarbazine solution and, separately, methylprednisolone sodium succinate solution. Physical stability was assessed by using a multistep evaluation procedure that included both turbidimetric and particulate measurement as well as visual inspection. Chemical stability was assessed by using stability-indicating high-performance liquid chromatographic analytical techniques that determined drug concentrations. Evaluations were performed immediately after mixing and 1 and 4 hours after mixing. The palonosetron hydrochloride-dacarbazine samples were clear and colorless when viewed in normal fluorescent room light and when viewed with a Tyndall beam. Measured turbidities remained unchanged; particulate contents were low and exhibited little change. High-performance liquid chromatography analysis revealed that palonosetron hydrochloride and dacarbazine remained stable throughout the 4-hour test with no drug loss. Palonosetron hydrochloride is, therefore, physically compatible and chemically stable with dacarbazine during Y-site administration. Within 4 hours, the mixtures of palonosetron hydrochloride and methylprednisolone sodium succinate developed a microprecipitate that became a white precipitate visible to the unaided eye. The precipitate was analyzed and identified as methylprednisolone. Palonosetron hydrochloride is incompatible with methylprednisolone sodium succinate.

Alpha-Tocopheryl succinate causes mitochondrial permeabilization by preferential formation of Bak channels

Czech Academy of Sciences Publication Activity Database

Procházka, L.; Dong, L.F.; Vališ, Karel; Freeman, R.; Ralph, S.J.; Turánek, J.; Neužil, Jiří

2010-01-01

Roč. 15, č. 7 (2010), s. 782-794 ISSN 1360-8185 R&D Projects: GA AV ČR(CZ) KAN200520703; GA AV ČR(CZ) IAA500520702; GA AV ČR(CZ) IAA500520602 Institutional research plan: CEZ:AV0Z50520701 Keywords : Vitamin E succinate * apoptosis * Noxa-Bak Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.397, year: 2010

Gamma-Hydroxybutyrate (GHB) Content in Hair Samples Correlates Negatively with Age in Succinic Semialdehyde Dehydrogenase Deficiency

DEFF Research Database (Denmark)

Johansen, S S; Wang, X.; Pedersen, Daniel Sejer

2017-01-01

shed light on the developmental course of this neurometabolic disease. Since GHB may be quantified in hair as a potential surrogate to identify victims of drug-related assault, we have opted to examine its level in SSADHD. We quantified GHB in hair derived from ten patients with SSADHD, and documented...

Incorporation of 14C-succinate in Synechococcus

International Nuclear Information System (INIS)

Doehler, G.

1983-01-01

The cyanobacterium Synechococcus (= Anacystis nidulans) was grown under normal air conditions (0.03 vol.% CO 2 ) and in low white light (0.5 x 10 3 μW/cm 2 ) at 37 0 C. Kinetics of 14 C incorporation into several soluble products and pigments were studied after adding 14 C-succinate during photosynthesis and in the dark using the autoradiographic method. Radioactivity was found mainly in glutamate and aspartate during the photosynthetic period independent on 3-(3',4'-dichlorphenyl)-1,1-dimethylurea preincubation. In the dark period 14 C label could also be detected in malate. Short-term kinetics experiments showed a decrease in 14 C label of glutamate and a parallel increase of aspartate. Results were discussed in respect to the interrupted tricarboxylic acid cycle. (author)

Industrial Systems Biology of Saccharomyces cerevisiae Enables Novel Succinic Acid Cell Factory

DEFF Research Database (Denmark)

Otero, José Manuel; Cimini, Donatella; Patil, Kiran Raosaheb

2013-01-01

Saccharomyces cerevisiae is the most well characterized eukaryote, the preferred microbial cell factory for the largest industrial biotechnology product (bioethanol), and a robust commerically compatible scaffold to be exploitted for diverse chemical production. Succinic acid is a highly sought......-direction of carbon fluxes in S. cerevisiae, and hence show proof of concept that this is a potentially attractive cell factory for over-producing different platform chemicals....

ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli

OpenAIRE

ANGGREINI, RAHAYU

2015-01-01

2015 RAHAYU ANGGREINI coli Penelitian ini bertujuan untuk melakukan identifikasi cemaran bakteri E. coli O157:H7 pada daging sapi di kota Makassar. Sampel pada penelitian ini sebanyak 72 sampel Kata Kunci : Daging sapi, pasar tradisional, E. coli, E. coli O157:H7, kontaminasi bakteri, identifikasi E. coli O157:H7.

Formation and stability of Vitamin E enriched nanoemulsions stabilized by Octenyl Succinic Anhydride modified starch

Science.gov (United States)

Vitamin E (VE) is highly susceptible to autoxidation; therefore, it requires systems to encapsulate and protect it from autoxidation.In this study,we developed VE delivery systems, which were stabilized by Capsul® (MS), a starch modified with octenyl succinic anhydride. Influences of interfacial ten...

How and why does tomato accumulate a large amount of GABA in the fruit?

Directory of Open Access Journals (Sweden)

Mariko eTakayama

2015-08-01

Full Text Available γ-Aminobutyric acid (GABA has received much attention as a health-promoting functional compound, and several GABA-enriched foods have been commercialized. In higher plants, GABA is primarily metabolized via a short pathway called the GABA shunt. The GABA shunt bypasses two steps (the oxidation of α-ketoglutarate to succinate of the tricarboxylic acid (TCA cycle via reactions catalysed by three enzymes: glutamate decarboxylase (GAD, GABA transaminase (GABA-T and succinic semialdehyde dehydrogenase (SSADH. The GABA shunt plays a major role in primary carbon and nitrogen metabolism and is an integral part of the TCA cycle under stress and non-stress conditions. Tomato is one of the major crops that accumulate a relatively high level of GABA in its fruits. The GABA levels in tomato fruits dramatically change during fruit development; the GABA levels increase from flowering to the mature green stage and then rapidly decrease during the ripening stage. Although GABA constitutes up to 50% of the free amino acids at the mature green stage, the molecular mechanism of GABA accumulation and the physiological function of GABA during tomato fruit development remain unclear. In this review, we summarize recent studies of GABA accumulation in tomato fruits and discuss the potential biological roles of GABA in tomato fruit development.

Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

Science.gov (United States)

Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

2016-04-01

The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. Copyright © 2016. Published by Elsevier Ltd.

Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA

Directory of Open Access Journals (Sweden)

Artavazd Badalyan

2014-11-01

Full Text Available Biosensors for the detection of benzaldehyde and g-aminobutyric acid (GABA are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below −0.15 V (vs. Ag|AgCl, 1 M KCl. The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A “reagentless” biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10–150 µM and the detection limit of 5 µM (signal to noise ratio 3:1 of benzaldehyde. The relative standard deviation in a series (n = 13 for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T and PaoABC in the osmium containing redox polymer.

Novel Route for Agmatine Catabolism in Aspergillus niger Involves 4-Guanidinobutyrase.

Science.gov (United States)

Kumar, Sunil; Saragadam, Tejaswani; Punekar, Narayan S

2015-08-15

Agmatine, a significant polyamine in bacteria and plants, mostly arises from the decarboxylation of arginine. The functional importance of agmatine in fungi is poorly understood. The metabolism of agmatine and related guanidinium group-containing compounds in Aspergillus niger was explored through growth, metabolite, and enzyme studies. The fungus was able to metabolize and grow on l-arginine, agmatine, or 4-guanidinobutyrate as the sole nitrogen source. Whereas arginase defined the only route for arginine catabolism, biochemical and bioinformatics approaches suggested the absence of arginine decarboxylase in A. niger. Efficient utilization by the parent strain and also by its arginase knockout implied an arginase-independent catabolic route for agmatine. Urea and 4-guanidinobutyrate were detected in the spent medium during growth on agmatine. The agmatine-grown A. niger mycelia contained significant levels of amine oxidase, 4-guanidinobutyraldehyde dehydrogenase, 4-guanidinobutyrase (GBase), and succinic semialdehyde dehydrogenase, but no agmatinase activity was detected. Taken together, the results support a novel route for agmatine utilization in A. niger. The catabolism of agmatine by way of 4-guanidinobutyrate to 4-aminobutyrate into the Krebs cycle is the first report of such a pathway in any organism. A. niger GBase peptide fragments were identified by tandem mass spectrometry analysis. The corresponding open reading frame from the A. niger NCIM 565 genome was located and cloned. Subsequent expression of GBase in both Escherichia coli and A. niger along with its disruption in A. niger functionally defined the GBase locus (gbu) in the A. niger genome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Succinate Functionalization of Hyperbranched Polyglycerol-Coated Magnetic Nanoparticles as a Draw Solute During Forward Osmosis.

Science.gov (United States)

Yang, Hee-Man; Choi, Hye Min; Jang, Sung-Chan; Han, Myeong Jin; Seo, Bum-Kyoung; Moon, Jei-Kwon; Lee, Kune-Woo

2015-10-01

Hyperbranched polyglycerol-coated magnetic nanoparticles (SHPG-MNPs) were functionalized with succinate groups to form a draw solute for use in a forward osmosis (FO). After the one-step synthesis of hyperbranched polyglycerol-coated magnetic nanoparticles (HPG-MNPs), the polyglycerol groups on the surfaces of the HPG-MNPs were functionalized with succinic anhydride moieties. The resulting SHPG-MNPs showed no change of size and magnetic property compared with HPG-MNPs and displayed excellent dispersibility in water up to the concentration of 400 g/L. SHPG-MNPs solution showed higher osmotic pressure than that of HPG-MNPs solution due to the presence of surface carboxyl groups in SHPG-MNPs and could draw water from a feed solution across an FO membrane without any reverse draw solute leakage during FO process. Moreover, the water flux remained nearly constant over several SHPG-MNP darw solute regeneration cycles applied to the ultrafiltration (UF) process. The SHPG-MNPs demonstrate strong potential for use as a draw solute in FO processes.

The impact of nanoclay on the crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) composite

CSIR Research Space (South Africa)

Bandyopadhyay, J

2012-07-01

Full Text Available The impact of nanoclay on the isothermal crystal growth kinetics and morphology of biodegradable poly(ethylene succinate) (PES) is reported. A PES composite (PESNC) containing 5 wt% organically modified montmorillonite, was prepared via solvent...

Citrate- and Succinate-Modified Carbonate Apatite Nanoparticles with Loaded Doxorubicin Exhibit Potent Anticancer Activity against Breast Cancer Cells

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Sultana Mehbuba Hossain

2018-03-01

Full Text Available Biodegradable inorganic apatite-based particle complex is popular for its pH-sensitivity at the endosomal acidic environment to facilitate drug release following cellular uptake. Despite being a powerful anticancer drug, doxorubicin shows severe off-target effects and therefore would need a carrier for the highest effectiveness. We aimed to chemically modify carbonate apatite (CA with Krebs cycle intermediates, such as citrate and succinate in order to control the growth of the resultant particles to more efficiently carry and transport the anticancer drug into the cancer cells. Citrate- or succinate-modified CA particles were synthesized with different concentrations of sodium citrate or sodium succinate, respectively, in the absence or presence of doxorubicin. The drug loading efficiency of the particles and their cellular uptake were observed by quantifying fluorescence intensity. The average diameter and surface charge of the particles were determined using Zetasizer. Cell viability was assessed by MTT assay. Citrate-modified carbonate apatite (CMCA exhibited the highest (31.38% binding affinity for doxorubicin and promoted rapid cellular uptake of the drug, leading to the half-maximal inhibitory concentration 1000 times less than that of the free drug in MCF-7 cells. Hence, CMCA nanoparticles with greater surface area enhance cytotoxicity in different breast cancer cells by enabling higher loading and more efficient cellular uptake of the drug.

A systematic analysis of TCA Escherichia coli mutants reveals suitable genetic backgrounds for enhanced hydrogen and ethanol production using glycerol as main carbon source.

Science.gov (United States)

Valle, Antonio; Cabrera, Gema; Muhamadali, Howbeer; Trivedi, Drupad K; Ratray, Nicholas J W; Goodacre, Royston; Cantero, Domingo; Bolivar, Jorge

2015-09-01

Biodiesel has emerged as an environmentally friendly alternative to fossil fuels; however, the low price of glycerol feed-stocks generated from the biodiesel industry has become a burden to this industry. A feasible alternative is the microbial biotransformation of waste glycerol to hydrogen and ethanol. Escherichia coli, a microorganism commonly used for metabolic engineering, is able to biotransform glycerol into these products. Nevertheless, the wild type strain yields can be improved by rewiring the carbon flux to the desired products by genetic engineering. Due to the importance of the central carbon metabolism in hydrogen and ethanol synthesis, E. coli single null mutant strains for enzymes of the TCA cycle and other related reactions were studied in this work. These strains were grown anaerobically in a glycerol-based medium and the concentrations of ethanol, glycerol, succinate and hydrogen were analysed by HPLC and GC. It was found that the reductive branch is the more relevant pathway for the aim of this work, with malate playing a central role. It was also found that the putative C4-transporter dcuD mutant improved the target product yields. These results will contribute to reveal novel metabolic engineering strategies for improving hydrogen and ethanol production by E. coli. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acetate and succinate production in amoebae, helminths, diplomonads, trichomonads and trypanosomatids: common and diverse metabolic strategies used by parasitic lower eukaryotes.

Science.gov (United States)

Bringaud, F; Ebikeme, C; Boshart, M

2010-08-01

Parasites that often grow anaerobically in their hosts have adopted a fermentative strategy relying on the production of partially oxidized end products, including lactate, glycerol, ethanol, succinate and acetate. This review focuses on recent progress in understanding acetate production in protist parasites, such as amoebae, diplomonads, trichomonads, trypanosomatids and in the metazoan parasites helminths, as well as the succinate production pathway(s) present in some of them. We also describe the unconventional organisation of the tricarboxylic acid cycle associated with the fermentative strategy adopted by the procyclic trypanosomes, which may resemble the probable structure of the primordial TCA cycle in prokaryotes.

Metabolic Effects of a Succinic Acid

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B. N. Shakh

2014-01-01

Full Text Available The paper discusses promises for clinical use of substrate antihypoxants.Objective: to investigate the efficacy of succinate containing  substrate  antihypoxants  on  systemic  oxygen  consumption,  blood  buffer  capacity,  and  changes  in  the  mixed venous blood level of lactate when they are used in gravely sick patients and victims with marked metabolic posthypoxic disorders.Subjects and methods. The trial enrolled 30 patients and victims who had sustained an episode of severe hypoxia of mixed genesis, the severity of which was evaluated by the APACHE II scale and amounted to 23 to 30 scores with a 46 to 70.3% risk of death. The standard infusion program in this group involved the succinate-containing drug 1.5% reamberin solution  in  a  total  dose  of  800  ml.  A  comparison  group  included  15  patients  who  had  undergone  emergency  extensive surgery for abdominal diseases. 400 ml of 10% glucose solution was used as an infusion medium. Oxygen consumption (VO2ml/min and carbon dioxide production (VCO2ml/min were measured before infusion and monitored for 2 hours. Arterial blood gases and acid-base balance (ABB parameters and mixed venous blood lactate levels were examined. Measurements were made before and 30 minutes after the infusion of reamberin or glucose solution.Results. Infusion of 1.5% reamberin solution was followed by a significant increase in minute oxygen consumption from 281.5±21.2 to 310.4±24.4 ml/min. CO2 production declined (on average, from 223.3±6.5 to 206.5±7.59 ml/min. During infusion of 10% glucose solution, all the patients of the comparison group showed a rise in oxygen consumption from 303.6±33.86 to 443.13±32.1 ml/min, i.e. about 1.5-fold. VCO2 changed similarly. The intravenous infusion of 800 ml of 1.5% reamberin solution raised arterial blood buffer capacity, which was reflected by changes in pH, BE, and HCO3. There was a clear trend for lactate values to drop in the

Crystallization and degradation behaviors of poly(butylene succinate)/poly(Z-L-lysine) composites

International Nuclear Information System (INIS)

Tan, Licheng; Hu, Jun; Ye, Suwen; Wei, Junchao; Chen, Yiwang

2014-01-01

Highlights: • A new biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were successfully prepared through physical blend. • PZlys may greatly affected the crystallization behaviors of PBS without changing its crystalline structure. • The degradation speed of PBS may be greatly accelerated by introduction of PZlys in PBS matrix. - Abstract: A new type of biodegradable poly(butylene succinate) (PBS)/poly(Z-L-lysine) (PZlys) composites were prepared. The crystallization behaviors were investigated by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarizing optical microscopy (POM) and the results showed that PZlys can restrict the crystallization of PBS, the crystallization speed of PBS/PZlys were slower than that of PBS, and the crystallization degree of the composites were smaller than that of PBS. However, the WAXD results showed that the incorporation of PZlys did not change the crystalline structure of PBS. The in vitro degradation experiments demonstrated that the degradation speed of the composites were faster than that of PBS. Moreover, the mechanical properties of the composites showed that the composites with a proper composition (for example, 80/20) can keep the mechanical properties of PBS without evident difference, which implied that the composites might be potentially useful as biodegradable materials

Development of a validated HPLC method for the quantitative determination of trelagliptin succinate and its related substances in pharmaceutical dosage forms.

Science.gov (United States)

Luo, Zhiqiang; Chen, Xinjing; Wang, Guopeng; Du, Zhibo; Ma, Xiaoyun; Wang, Hao; Yu, Guohua; Liu, Aoxue; Li, Mengwei; Peng, Wei; Liu, Yang

2018-01-01

Trelagliptin succinate is a dipeptidyl peptidase IV (DPP-4) inhibitor which is used as a new long-acting drug for once-weekly treatment of type 2 diabetes mellitus (DM). In the present study, a rapid, sensitive and accurate high-performance liquid chromatography (HPLC) method was developed and validated for separation and determination of trelagliptin succinate and its eight potential process-related impurities. The chromatographic separation was achieved on a Waters Xselect CSH™ C 18 (250mm×4.6mm, 5.0μm) column. The mobile phases comprised of 0.05% trifluoroacetic acid in water as well as acetonitrile containing 0.05% trifluoroacetic acid. The compounds of interest were monitored at 224nm and 275nm. The stability-indicating capability of this method was evaluated by performing stress test studies. Trelagliptin succinate was found to degrade significantly in acid, base, oxidative and thermal stress conditions and only stable in photolytic degradation condition. The degradation products were well resolved from the main peak and its impurities. In addition, the major degradation impurities formed under acid, base, oxidative and thermal stress conditions were characterized by ultra-high-performance liquid chromatography coupled with linear ion trap-Orbitrap tandem mass spectrometry (UHPLC-LTQ-Orbitrap). The method was validated to fulfill International Conference on Harmonisation (ICH) requirements and this validation included specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision and robustness. The developed method in this study could be applied for routine quality control analysis of trelagliptin succinate tablets, since there is no official monograph. Copyright © 2017 Elsevier B.V. All rights reserved.

INFLUENCE OF METOPROLOL SUCCINATE ON REGULATORY AND ADAPTIVE STATUS OF PATIENTS WITH CHRONIC HEART FAILURE FUNCTIONAL CLASS I. RESULTS OF NOT COMPARATIVE STUDY

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V. G. Tregubov

2011-01-01

Full Text Available Aim. To estimate metoprolol succinate effect on regulatory and adaptive status (RAS of patients with сhronic heart failure (CHF functional class (FC I and arterial hypertension (HT I-II stages. Material and methods. 51 patients with CHF FC I and HT I-II stage, (30 men and 21 women aged 52.6±1.4 yeas. Cardio-respiratory synchronism (CRS test, 6-minute walking test, tread-mill burden test with registration of maximal oxygen consumption, 24-hour blood pressure monitoring, echocardiography and determination of N-terminal pro-brain natriuretic peptide (NT-proBNP blood level were performed initially and after 6 months of therapy with metoprolol succinate (dose 78.1±5.7 mg/day in sustained-release presentation. Results. Metoprolol succinate therapy had no significant effect on RAS (there was no unidirectional dynamics of the basic CRS test parameters: a range of synchronization decreased significantly from 8.8±0.4 to 7.2±0.6 сardio-respiratory cycles per minute (in 18%; р<0.05, and duration of CRS development on the minimal boundary from 18.8±2.2 to 14.3±1.2 сardiocycles (in 24%; р<0,05; RAS index considerably did not change, myocardium structure, exercise tolerance and neuro-humoral activity. Metoprolol therapy only moderately improved left ventricle diastolic function. Conclusion. Metoprolol succinate therapy has no significant effect on RAS of patients with CHF FC I and HT I-II stages.

Radiation-induced alterations in succinate dehydrogenase activity in the muscle of pigeon

International Nuclear Information System (INIS)

Gadhia, P.K.; Shah, V.C.

1983-01-01

The histochemical changes in succinate dehydrogenase were investigated in pectoralis major muscle of pigeon exposed to sub-lethal dose (400 rad) of γ-irradiation. Biochemical study was also carried out after 200, 300 and 400 rad of irradiation. In the present study the overall decrease in enzyme activity could be due to the structural and/or functional damage to mitochondria after treatment of pigeon to different sub-lethal doses of γ-irradiation. The significance of these results has been discussed with special reference to oxidative metabolism. (author)

Escherichia coli pathotypes

Science.gov (United States)

Escherichia coli strains are important commensals of the intestinal tract of humans and animals; however, pathogenic strains, including diarrhea-inducing E. coli and extraintestinal pathogenic E. coli. Intestinal E. coli pathotypes may cause a dehydrating watery diarrhea, or more severe diseases su...

Linkage and radiation hybrid mapping of the porcine gene for subunit C of succinate dehydrogenase complex (SDHC)

Czech Academy of Sciences Publication Activity Database

Stratil, Antonín; Reiner, G.; Peelman, L. J.; Poucke, M.; Geldermann, H.

2001-01-01

Roč. 32, č. 2 (2001), s. 110-112 ISSN 0268-9146 R&D Projects: GA AV ČR KSK5052113; GA ČR GA523/00/0669 Keywords : succinate dehydrogenase complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.020, year: 2001

Alpha-Tocopheryl succinate induces cytostasis and apoptosis in osteosarcoma cells: the role of E2F1

Czech Academy of Sciences Publication Activity Database

Alleva, R.; Benassi, M.S.; Tomasetti, M.; Gellert, N.; Ponticelli, F.; Borghi, B.; Picci, P.; Neužil, Jiří

2005-01-01

Roč. 331, č. 4 (2005), s. 1515-1521 ISSN 0006-291X Institutional research plan: CEZ:AV0Z50520514; CEZ:AV0Z5052915 Keywords : osteosarcoma * alpha-tocopheryl succinate * E2F1 Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.000, year: 2005

Two transgenic mouse models for β-subunit components of succinate-CoA ligase yielding pleiotropic metabolic alterations

DEFF Research Database (Denmark)

Kacso, Gergely; Ravasz, Dora; Doczi, Judit

2016-01-01

Succinate-CoA ligase (SUCL) is a heterodimer enzyme composed of Suclg1 α-subunit and a substrate-specific Sucla2 or Suclg2 β-subunit yielding ATP or GTP, respectively. In humans, the deficiency of this enzyme leads to encephalomyopathy with or without methylmalonyl aciduria, in addition to result...

E coli enteritis

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... coli; Food poisoning - E. coli; E. coli diarrhea; Hamburger disease ... coleslaw or potato salad) that have been out of the refrigerator too ... reheated Fish or oysters Raw fruits or vegetables that have ...

Recent advances in the metabolic engineering of Corynebacterium glutamicum for the production of lactate and succinate from renewable resources.

Science.gov (United States)

Tsuge, Yota; Hasunuma, Tomohisa; Kondo, Akihiko

2015-03-01

Recent increasing attention to environmental issues and the shortage of oil resources have spurred political and industrial interest in the development of environmental friendly and cost-effective processes for the production of bio-based chemicals from renewable resources. Thus, microbial production of commercially important chemicals is viewed as a desirable way to replace current petrochemical production. Corynebacterium glutamicum, a Gram-positive soil bacterium, is one of the most important industrial microorganisms as a platform for the production of various amino acids. Recent research has explored the use of C. glutamicum as a potential cell factory for producing organic acids such as lactate and succinate, both of which are commercially important bulk chemicals. Here, we summarize current understanding in this field and recent metabolic engineering efforts to develop C. glutamicum strains that efficiently produce L- and D-lactate, and succinate from renewable resources.

Transcriptional regulation of the outer membrane porin gene ompW reveals its physiological role during the transition from the aerobic to the anaerobic lifestyle of Escherichia coli

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Minfeng eXiao

2016-05-01

Full Text Available Understanding bacterial physiology relies on elucidating the regulatory mechanisms and cellular functions of those differentially expressed genes in response to environmental changes. A widespread Gram-negative bacterial outer membrane protein OmpW has been implicated in the adaptation to stresses in various species. It is recently found to be present in the regulon of the global anaerobic transcription factor FNR and ArcA in E. coli. However, little is known about the physiological implications of this regulatory disposition. In this study, we demonstrate that transcription of ompW is indeed mediated by a series of global regulators involved in the anaerobiosis of E. coli. We show that FNR can both activate and repress the expression of ompW through its direct binding to two distinctive sites, -81.5 and -126.5 bp respectively, on ompW promoter. ArcA also participates in repression of ompW under anaerobic condition, but in an FNR dependent manner. Additionally, ompW is also subject to the regulation by CRP and NarL which senses the availability and types of carbon sources and respiration electron acceptors in the environment respectively, implying a role of OmpW in the carbon and energy metabolism of E. coli during its anaerobic adaptation. Molecular docking reveals that OmpW can bind fumarate, an alternative electron acceptor in anaerobic respiration, with sufficient affinity. Moreover, supplement of fumarate or succinate which belongs to the C4-dicarboxylates family of metabolite, to E. coli culture rescues OmpW-mediated colicin S4 killing. Taken together, we propose that OmpW is involved in anaerobic carbon and energy metabolism to mediate the transition from aerobic to anaerobic lifestyle in E. coli.

Polystyrene/TiO2 composite electrospun fibers as fillers for poly(butylene succinate-co-adipate): Structure, morphology and properties

CSIR Research Space (South Africa)

Neppalli, R

2014-01-01

Full Text Available In this work, composite polystyrene/titanium dioxide (PS/TiO(sub2)) electrospun fibers were used as a reinforcement for a poly(butylene succinate-co-adipate) (PBSA) matrix. The structure, morphology, mechanical properties and degradation behavior...

Mechanical and thermal properties of basalt fiber reinforced poly(butylene succinate) composites

International Nuclear Information System (INIS)

Zhang Yihe; Yu Chunxiao; Chu, Paul K.; Lv Fengzhu; Zhang Changan; Ji Junhui; Zhang Rui; Wang Heli

2012-01-01

Highlights: ► Novel basalt fiber-reinforced biodegradable poly(butylene succinate) composites have been successfully fabricated with various fiber loadings. ► The tensile and flexural properties of the PBS matrix resin are improved significantly by increasing the fiber loading in the composites. ► The impact strength of the BF/PBS composite decreases with the addition fibers primarily and increases with increasing fiber loading due to energy dissipation when the fibers are pulled out. ► Heat deflection temperature tests clearly show that the HDT of the basalt fiber reinforced PBS composites is significantly higher than the HDT of the PBS resin. - Abstract: Basalt fiber (BF) reinforced poly(butylene succinate) (PBS) composites have been fabricated with different fiber contents by a injection molding method and their tensile, flexural and impact properties, as well as thermal stability have been investigated. The tensile and flexural properties of the PBS matrix resin are improved markedly by increasing the fiber contents in the composites. The values are relatively higher than the natural fiber/PP systems reported earlier by other research groups. The heat deflection temperature (HDT) and Vicat softening temperature (VST) of the composites are significantly higher than those of the neat PBS resin. Scanning electron microscopy (SEM) conducted on the fracture surfaces of the composites reveals superior interfacial linkage between the basalt fibers and PBS matrix. The results suggest that the BF/PBS composites may be a potential candidate of PP or PP composites to manufacturing some daily commodities to solve the “white pollution” in environmental management.

Mitochondrially targeted vitamin E succinate efficiently kills breast tumour-initiating cells in a complex II-dependent manner

Czech Academy of Sciences Publication Activity Database

Yan, B.; Stantic, M.; Zobalová, Renata; Bezawork-Geleta, A.; Stapelberg, M.; Stursa, J.; Prokopová, Kateřina; Dong, L.; Neužil, Jiří

2015-01-01

Roč. 15, č. 401 (2015) ISSN 1471-2407 R&D Projects: GA MZd NT14078; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:86652036 Keywords : Tumour-initiating cells * Mitochondrially targeted vitamin E succinate * Complex II Subject RIV: FD - Oncology ; Hematology Impact factor: 3.265, year: 2015

Mapping of Saccharomyces cerevisiae metabolites in fermenting wheat straight-dough reveals succinic acid as pH-determining factor.

Science.gov (United States)

Jayaram, Vinay B; Cuyvers, Sven; Lagrain, Bert; Verstrepen, Kevin J; Delcour, Jan A; Courtin, Christophe M

2013-01-15

Fermenting yeast does not merely cause dough leavening, but also contributes to the bread aroma and might alter dough rheology. Here, the yeast carbon metabolism was mapped during bread straight-dough fermentation. The concentration of most metabolites changed quasi linearly as a function of fermentation time. Ethanol and carbon dioxide concentrations reached up to 60 mmol/100g flour. Interestingly, high levels of glycerol (up to 10 mmol/100g flour) and succinic acid (up to 1.6 mmol/100g flour) were produced during dough fermentation. Further tests showed that, contrary to current belief, the pH decrease in fermenting dough is primarily caused by the production of succinic acid by the yeast instead of carbon dioxide dissolution or bacterial organic acids. Together, our results provide a comprehensive overview of metabolite production during dough fermentation and yield insight into the importance of some of these metabolites for dough properties. Copyright © 2012 Elsevier Ltd. All rights reserved.

Awakening sleeping beauty: production of propionic acid in Escherichia coli through the sbm operon requires the activity of a methylmalonyl-CoA epimerase.

Science.gov (United States)

Gonzalez-Garcia, Ricardo Axayacatl; McCubbin, Tim; Wille, Annalena; Plan, Manuel; Nielsen, Lars Keld; Marcellin, Esteban

2017-07-17

Propionic acid is used primarily as a food preservative with smaller applications as a chemical building block for the production of many products including fabrics, cosmetics, drugs, and plastics. Biological production using propionibacteria would be competitive against chemical production through hydrocarboxylation of ethylene if native producers could be engineered to reach near-theoretical yield and good productivity. Unfortunately, engineering propionibacteria has proven very challenging. It has been suggested that activation of the sleeping beauty operon in Escherichia coli is sufficient to achieve propionic acid production. Optimising E. coli production should be much easier than engineering propionibacteria if tolerance issues can be addressed. Propionic acid is produced in E. coli via the sleeping beauty mutase operon under anaerobic conditions in rich medium via amino acid degradation. We observed that the sbm operon enhances amino acids degradation to propionic acid and allows E. coli to degrade isoleucine. However, we show here that the operon lacks an epimerase reaction that enables propionic acid production in minimal medium containing glucose as the sole carbon source. Production from glucose can be restored by engineering the system with a methylmalonyl-CoA epimerase from Propionibacterium acidipropionici (0.23 ± 0.02 mM). 1-Propanol production was also detected from the promiscuous activity of the native alcohol dehydrogenase (AdhE). We also show that aerobic conditions are favourable for propionic acid production. Finally, we increase titre 65 times using a combination of promoter engineering and process optimisation. The native sbm operon encodes an incomplete pathway. Production of propionic acid from glucose as sole carbon source is possible when the pathway is complemented with a methylmalonyl-CoA epimerase. Although propionic acid via the restored succinate dissimilation pathway is considered a fermentative process, the engineered pathway

Bid integrates intrinsic and extrinsic signaling in apoptosis induced by alpha-tocopheryl succinate in human gastric carcinoma cells

Czech Academy of Sciences Publication Activity Database

Zhao, Y.; Li, R.; Xia, W.; Neužil, Jiří; Lu, Y.; Zhang, H.; Zhao, X.; Zhang, X.; Sun, C.; Wu, K.

2010-01-01

Roč. 288, č. 1 (2010), s. 42-49 ISSN 0304-3835 R&D Projects: GA ČR(CZ) GA204/08/0811 Institutional research plan: CEZ:AV0Z50520701 Keywords : Alpha-tocopheryl succinate * signaling * apoptosis Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.864, year: 2010

Effect of stretching on the mechanical properties in melt-spun poly(butylene succinate)/microfibrillated cellulose (MFC) nanocomposites.

Science.gov (United States)

Zhou, Mi; Fan, Mao; Zhao, Yongsheng; Jin, Tianxiang; Fu, Qiang

2016-04-20

In order to prepare poly(butylene succinate)/microfibrillated cellulose composites with high performance, in this work, microfibrillated cellulose (MFC) was first treated by acetylchloride with ball-milling to improve its interfacial compatibility with poly(butylene succinate) (PBS). Then melt stretching processing was adopted to further improve the dispersion and orientation of MFC in as-spun PBS fiber. And the effect of MFC on the crystalline structure and mechanical properties were systematically investigated for the melt-spun fibers prepared with two different draw ratios. The dispersion, alignment of the MFC and interfacial crystalline structure in the composite fibers are significantly influenced by the stretching force during the melt spinning. The possible formation of nanohybrid shish kebab (NHSK) superstructure where aligned MFC as shish and PBS lamellae as kebab has been suggested via SEM and SAXS in the composite fibers prepared at the high draw ratio. Large improvement in tensile strength has been realized at the high draw ratio due to the enhanced orientation and dispersion of MFC as well as the formation of NHSK. Copyright © 2015 Elsevier Ltd. All rights reserved.

99mtechnetium-dimercapto-succinic acid renal scanning and excretory urography in diagnosis of renal scars in children

International Nuclear Information System (INIS)

McLorie, G.A.; Aliabadi, H.; Churchill, B.M.; Ash, J.M.; Gilday, D.L.

1989-01-01

We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80%). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars was 84% and the specificity was 83%. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77% and the specificity was 75%. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars

The H+/O ratio of proton translocation linked to the oxidation of succinate by mitochondria. Reply to a commentary.

Science.gov (United States)

Lehninger, A L; Reynafarje, B; Hendler, R W; Shrager, R I

1985-11-18

Costa, L.E., Reynafarje, B. and Lehninger, A.L. [(1984) J. Biol. Chem. 259, 4802-4811] have reported 'second-generation' measurements of the H+/O ratio approaching 8.0 for vectorial H+ translocation coupled to succinate oxidation by rat liver mitochondria. In a Commentary in this Journal [Krab, K., Soos, J. and Wikström, M. (1984) FEBS Lett. 178, 187-192] it was concluded that the measurements of Costa et al. significantly overestimated the true H+/O stoichiometry. It is shown here that the mathematical simulation on which Krab et al. based this claim is faulty and that data reported by Costa et al. had already excluded the criticism advanced by Krab et al. Also reported are new data, obtained under conditions in which the arguments of Krab et al. are irrelevant, which confirm that the H+/O ratio for succinate oxidation extrapolated to level flow is close to 8.

Induced resistance in tomato fruit by γ-aminobutyric acid for the control of alternaria rot caused by Alternaria alternata.

Science.gov (United States)

Yang, Jiali; Sun, Cui; Zhang, Yangyang; Fu, Da; Zheng, Xiaodong; Yu, Ting

2017-04-15

The study investigated the effect of γ-aminobutyric acid (GABA) on the control of alternaria rot in tomato fruit and the possible mechanism involved. Our results showed exogenous GABA could stimulate remarkable resistance to the alternaria rot, while it had no direct antifungal activity against Alternaria alternata. Moreover, the activities of antioxidant enzymes, including peroxidase, superoxide dismutase and catalase, along with the expression of these corresponding genes, were significantly induced in the GABA treatment. The obtained data suggested GABA induced resistance against the necrotrophic pathogen A. alternata, at least in part by activating antioxidant enzymes, restricting the levels of cell death caused by reactive oxygen species. Meanwhile, the key enzyme genes of GABA shunt, GABA transaminase and succinic-semialdehyde dehydrogenase, were found up-regulated in the GABA treatment. The activation of the GABA shunt might play a vital role in the resistance mechanism underpinning GABA-induced plant immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neuroprotection of ebselen against ischemia/reperfusion injury involves GABA shunt enzymes.

Science.gov (United States)

Seo, Jeong Yeol; Lee, Choong Hyun; Cho, Jun Hwi; Choi, Jung Hoon; Yoo, Ki-Yeon; Kim, Dae Won; Park, Ok Kyu; Li, Hua; Choi, Soo Young; Hwang, In Koo; Won, Moo-Ho

2009-10-15

Seleno-organic compound, ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one), is a substrate with radical-scavenging activity. In this study, we observed the neuroprotective effects of ebselen against ischemic damage and on GABA shunt enzymes such as glutamic acid decarboxylase 67 (GAD67), GABA transaminse (GABA-T) and succinic semialdehyde dehydrogenase (SSADH) in the hippocampal CA1 region after 5 min of transient forebrain ischemia in gerbils. For this, vehicle (physiological saline) or ebselen was administered 30 min before or after ischemia/reperfusion and sacrificed 4 days after ischemia/reperfusion. The administration of ebselen significantly reduced the neuronal death in the CA1 region induced by ischemia/reperfusion. In addition, treatment with ebselen markedly elevated GAD67, GABA-T and SSADH immunoreactivity and their protein levels compared to that in the vehicle-treated group, respectively. These results suggest that ebselen protects neurons from ischemic damage via control of the expressions of GABA shunt enzymes to enter the TCA cycle.

Study on fluorescence properties of carbogenic nanoparticles and their application for the determination of ferrous succinate

Energy Technology Data Exchange (ETDEWEB)

Sun Wen [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Du Yingxiang, E-mail: du_yingxiang@126.co [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Modern Chinese Medicines, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Wang Yunqing [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

2010-08-15

A new type of fluorescent nanomaterial named carbogenic nanoparticles (NPs) has drawn considerable attention recently. In this study, we adopted a direct and simple synthetic method to produce the carbogenic NPs and investigated the fluorescence properties of the as-prepared carbogenic NPs in detail. It was found that the fluorescence of carbogenic NPs was stable with the variance of environmental conditions such as pH, temperature and UV irradiation. More interestingly, we found carbogenic NPs exhibited high selectivity and sensitivity towards ferric ions. Under optimum conditions, a good linear relationship could be obtained between the fluorescence intensity and concentration of ferric ions in the range of 5.0x10{sup -5}-5.0x10{sup -4} mol L{sup -1}, and the limit of detection is 11.2 {mu}mol L{sup -1}. Based on the fluorescence quenching of carbogenic NPs, a rapid and specific quantitative method was proposed for the determination of ferrous succinate. The content of ferrous succinate in commercial tablets determined by the present method was agreed with the spectrophotometric method results and the reproducibility and the recovery of the proposed method were satisfactory.

EFFECT OF SUBSTITUTION POSITION OF HYDROXY GROUP AT BENZOIC ACID ON THE LUMINESCENT AND DEGRADATION PROPERTIES OF POLY[DI(CARBOXYPHENYL) SUCCINATE-co-SEBACIC ANHYDRIDE]S

Institute of Scientific and Technical Information of China (English)

Jun Fan; Hong-liang Jiang; Kang-jie Zhu

2007-01-01

In this work, two new diacids, di(m-carboxyphenyl) succinate (m-dCPS) and di(o-carboxyphenyl) succinate (o-dCPS), were synthesized by reaction of m-, o-hydroxy benzoic acid with succinic chloride, respectively. Their corresponding copolymers with sebacic acid (SA), P(m-dCPS:SA) and P(o-dCPS:SA), were prepared by melt copolycondensation and characterized by NMR, UV and DSC methods. Compared with inherently fluorescent poly[di(p-carboxyphenyl) succinateco-sebacic anhydride] (P(p-dCPS:SA)), P(m-dCPS:SA) and P(o-dCPS:SA) displayed different luminescent properties. P(m-dCPS:SA) could emit fluorescence under the excitation of both visible and UV light, while P(o-dCPS:SA) could only emit fluorescence when excited with UV light. Degradation rate of the two new copolyanhydrides increased with the increase of SA fraction in the copolymers. In addition, P(o-dCPS:SA) degraded more rapidly than P(m-dCPS:SA) with the same composition. Typical surface-degradation characteristics of these copolyanhydrides were observed.

Review of succinate dehydrogenase-deficient renal cell carcinoma with focus on clinical and pathobiological aspects

Directory of Open Access Journals (Sweden)

Naoto Kuroda

2016-05-01

Full Text Available Succinate dehydrogenase (SDH-deficient renal cell carcinoma (RCC was first identified in 2004 and has been integrated into the 2016 WHO classification of RCC. Succinate dehydrogenase (SDH is an enzyme complex composed of four protein subunits (SDHA, SDHB, SDHC and SDHD. The tumor which presents this enzyme mutation accounts for 0.05 to 0.2% of all renal carcinomas. Multiple tumors may occur in approximately 30% of affected patients. SDHB-deficient RCC is the most frequent, and the tumor histologically consists of cuboidal cells with eosinophilic cytoplasm, vacuolization, flocculent intracytoplasmic inclusion and indistinct cell borders. Ultrastructurally, the tumor contains abundant mitochondria. Immunohistochemically, tumor cells are positive for SDHA, but negative for SDHB in SDHB-, SDHC- and SDHD-deficient RCCs. However, SDHA-deficient RCC shows negativity for both SDHA and SDHB. In molecular genetic analyses, a germline mutation in the SDHB , SDHC or SDHD gene (in keeping with most patients having germline mutations in an SDH gene has been identified in patients with or without a family history of renal tumors, paraganglioma/pheochromocytoma or gastrointestinal stromal tumor. While most tumors are low grade, some tumors may behave in an aggressive fashion, particularly if they are high nuclear grade, and have coagulative necrosis or sarcomatoid differentiation.

Control of protein synthesis in Escherichia coli: strain differences in control of translational initiation after energy source shift-down.

Science.gov (United States)

Jacobson, L A; Jen-Jacobson, L

1980-06-01

We have studied the parameters of protein synthesis in a number of Escherichia coli strains after a shift-down from glucose-minimal to succinate-minimal medium. One group of strains, including K-12(lambda) (ATCC 10798) and NF162, showed a postshift translational yield of 50 to 65% and a 2- to 2.5-fold increase in the functional lifetime of general messenger ribonucleic acid. There was no change in the lag time for beta-galactosidase induction in these strains after the shift-down. A second group, including W1 and W2, showed no reduction in translational yield, no change in the functional lifetime of messenger ribonucleic acid, and a 50% increase in the lag time for beta-galactosidase induction. Evidence is presented which indicates that this increased lag time is not the result of a decreased rate of polypeptide chain propagation. A third group of strains, including NF161, CP78, and NF859, showed an intermediate pattern: translational yield was reduced to about 75% of normal, and the messenger ribonucleic acid functional lifetime was increased by about 50%. Calculation of the relative postshift rates of translational initiation gave about 0.2, 1.0, and 0.5, respectively, for the three groups. There was no apparent correlation between the ability to control translation and the genotypes of these strains at the relA, relX, or spoT loci. Measurements of the induction lag for beta-galactosidase during short-term glucose starvation or after a down-shift induced by alpha-methylglucoside indicated that these regimens elicit responses that are physiologically distinct from those elicited by a glucose-to-succinate shift-down.

Identification of anti-filarial leads against aspartate semialdehyde dehydrogenase of Wolbachia endosymbiont of Brugia malayi: combined molecular docking and molecular dynamics approaches.

Science.gov (United States)

Amala, Mathimaran; Rajamanikandan, Sundaraj; Prabhu, Dhamodharan; Surekha, Kanagarajan; Jeyakanthan, Jeyaraman

2018-02-06

Lymphatic filariasis is a debilitating vector borne parasitic disease that infects human lymphatic system by nematode Brugia malayi. Currently available anti-filarial drugs are effective only on the larval stages of parasite. So far, no effective drugs are available for humans to treat filarial infections. In this regard, aspartate semialdehyde dehydrogenase (ASDase) in lysine biosynthetic pathway from Wolbachia endosymbiont Brugia malayi represents an attractive therapeutic target for the development of novel anti-filarial agents. In this present study, molecular modeling combined with molecular dynamics simulations and structure-based virtual screening were performed to identify potent lead molecules against ASDase. Based on Glide score, toxicity profile, binding affinity and mode of interactions with the ASDase, five potent lead molecules were selected. The molecular docking and dynamics results revealed that the amino acid residues Arg103, Asn133, Cys134, Gln161, Ser164, Lys218, Arg239, His246, and Asn321 plays a crucial role in effective binding of Top leads into the active site of ASDase. The stability of the ASDase-lead complexes was confirmed by running the 30 ns molecular dynamics simulations. The pharmacokinetic properties of the identified lead molecules are in the acceptable range. Furthermore, density functional theory and binding free energy calculations were performed to rank the lead molecules. Thus, the identified lead molecules can be used for the development of anti-filarial agents to combat the pathogenecity of Brugia malayi.

E. Coli Infections

Science.gov (United States)

E. coli is the name of a type of bacteria that lives in your intestines. Most types of E. coli are harmless. However, some types can make you ... type causes travelers' diarrhea. The worst type of E. coli causes bloody diarrhea, and can sometimes cause kidney ...

Discovering novel Alternaria solani succinate dehydrogenase inhibitors by in silico modeling and virtual screening strategies to combat early blight

NARCIS (Netherlands)

Iftikhar, Sehrish; Shahid, Ahmad A.; Halim, Sobia A.; Wolters, Pieter J.; Vleeshouwers, Vivianne G.A.A.; Khan, Ajmal; Al-Harrasi, Ahmed; Ahmad, Shahbaz

2017-01-01

Alternaria blight is an important foliage disease caused by Alternaria solani. The enzyme Succinate dehydrogenase (SDH) is a potential drug target because of its role in tricarboxylic acid cycle. Hence targeting Alternaria solani SDH enzyme could be efficient tool to design novel fungicides against

Isotopomer profiling of Leishmania mexicana promastigotes reveals important roles for succinate fermentation and aspartate uptake in tricarboxylic acid cycle (TCA) anaplerosis, glutamate synthesis, and growth.

Science.gov (United States)

Saunders, Eleanor C; Ng, William W; Chambers, Jennifer M; Ng, Milica; Naderer, Thomas; Krömer, Jens O; Likic, Vladimir A; McConville, Malcolm J

2011-08-05

Leishmania parasites proliferate within nutritionally complex niches in their sandfly vector and mammalian hosts. However, the extent to which these parasites utilize different carbon sources remains poorly defined. In this study, we have followed the incorporation of various (13)C-labeled carbon sources into the intracellular and secreted metabolites of Leishmania mexicana promastigotes using gas chromatography-mass spectrometry and (13)C NMR. [U-(13)C]Glucose was rapidly incorporated into intermediates in glycolysis, the pentose phosphate pathway, and the cytoplasmic carbohydrate reserve material, mannogen. Enzymes involved in the upper glycolytic pathway are sequestered within glycosomes, and the ATP and NAD(+) consumed by these reactions were primarily regenerated by the fermentation of phosphoenolpyruvate to succinate (glycosomal succinate fermentation). The initiating enzyme in this pathway, phosphoenolpyruvate carboxykinase, was exclusively localized to the glycosome. Although some of the glycosomal succinate was secreted, most of the C4 dicarboxylic acids generated during succinate fermentation were further catabolized in the TCA cycle. A high rate of TCA cycle anaplerosis was further suggested by measurement of [U-(13)C]aspartate and [U-(13)C]alanine uptake and catabolism. TCA cycle anaplerosis is apparently needed to sustain glutamate production under standard culture conditions. Specifically, inhibition of mitochondrial aconitase with sodium fluoroacetate resulted in the rapid depletion of intracellular glutamate pools and growth arrest. Addition of high concentrations of exogenous glutamate alleviated this growth arrest. These findings suggest that glycosomal and mitochondrial metabolism in Leishmania promastigotes is tightly coupled and that, in contrast to the situation in some other trypanosomatid parasites, the TCA cycle has crucial anabolic functions.

E. Coli

Science.gov (United States)

... for the bacteria's medical name Escherichia coli . The strange thing about these bacteria — and lots of other ... In some cases, E. coli poisoning can cause life-threatening kidney problems. What Can Kids Do? Adults ...

Structural and biochemical analyses reveal insights into covalent flavinylation of the Escherichia coli Complex II homolog quinol:fumarate reductase

Energy Technology Data Exchange (ETDEWEB)

Starbird, C.A.; Maklashina, Elena; Sharma, Pankaj; Qualls-Histed, Susan; Cecchini, Gary; Iverson, T.M. (VA); (UCSF); (Vanderbilt)

2017-06-14

The Escherichia coli Complex II homolog quinol:fumarate reductase (QFR, FrdABCD) catalyzes the interconversion of fumarate and succinate at a covalently attached FAD within the FrdA subunit. The SdhE assembly factor enhances covalent flavinylation of Complex II homologs, but the mechanisms underlying the covalent attachment of FAD remain to be fully elucidated. Here, we explored the mechanisms of covalent flavinylation of the E. coli QFR FrdA subunit. Using a ΔsdhE E. coli strain, we show that the requirement for the assembly factor depends on the cellular redox environment. We next identified residues important for the covalent attachment and selected the FrdAE245 residue, which contributes to proton shuttling during fumarate reduction, for detailed biophysical and structural characterization. We found that QFR complexes containing FrdAE245Q have a structure similar to that of the WT flavoprotein, but lack detectable substrate binding and turnover. In the context of the isolated FrdA subunit, the anticipated assembly intermediate during covalent flavinylation, FrdAE245 variants had stability similar to that of WT FrdA, contained noncovalent FAD, and displayed a reduced capacity to interact with SdhE. However, small-angle X-ray scattering (SAXS) analysis of WT FrdA cross-linked to SdhE suggested that the FrdAE245 residue is unlikely to contribute directly to the FrdA-SdhE protein-protein interface. We also found that no auxiliary factor is absolutely required for flavinylation, indicating that the covalent flavinylation is autocatalytic. We propose that multiple factors, including the SdhE assembly factor and bound dicarboxylates, stimulate covalent flavinylation by preorganizing the active site to stabilize the quinone-methide intermediate.

Mitochondrially Targeted Vitamin E Succinate Modulates Expression of Mitochondrial DNA Transcripts and Mitochondrial Biogenesis

Czech Academy of Sciences Publication Activity Database

Truksa, Jaroslav; Dong, L.F.; Rohlena, Jakub; Stursa, J.; Vondrusová, Magdaléna; Goodwin, J.; Nguyen, M.; Klučková, Katarína; Rychtarčíková, Zuzana; Lettlová, Sandra; Spáčilová, Jana; Stapelberg, M.; Zoratti, M.; Neužil, Jiří

2015-01-01

Roč. 22, č. 11 (2015), s. 883-900 ISSN 1523-0864 R&D Projects: GA ČR GAP301/10/1937; GA AV ČR KAN200520703; GA ČR GAP305/12/1708; GA ČR GAP301/12/1851; GA MŠk(CZ) ED1.1.00/02.0109 Institutional research plan: CEZ:AV0Z50520701 Institutional support: RVO:86652036 Keywords : ALPHA-TOCOPHERYL SUCCINATE * ELECTRON-TRANSPORT CHAIN * RESPIRATORY COMPLEX-II Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.093, year: 2015

Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli

DEFF Research Database (Denmark)

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili

2017-01-01

Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production econo...

Reconstitution of TCA cycle with DAOCS to engineer Escherichia coli into an efficient whole cell catalyst of penicillin G.

Science.gov (United States)

Lin, Baixue; Fan, Keqiang; Zhao, Jian; Ji, Junjie; Wu, Linjun; Yang, Keqian; Tao, Yong

2015-08-11

Many medically useful semisynthetic cephalosporins are derived from 7-aminodeacetoxycephalosporanic acid (7-ADCA), which has been traditionally made by the polluting chemical method. Here, a whole-cell biocatalytic process based on an engineered Escherichia coli strain expressing 2-oxoglutarate-dependent deacetoxycephalosporin C synthase (DAOCS) for converting penicillin G to G-7-ADCA is developed. The major engineering strategy is to reconstitute the tricarboxylic acid (TCA) cycle of E. coli to force the metabolic flux to go through DAOCS catalyzed reaction for 2-oxoglutarate to succinate conversion. Then the glyoxylate bypass was disrupted to eliminate metabolic flux that may circumvent the reconstituted TCA cycle. Additional engineering steps were taken to reduce the degradation of penicillin G and G-7-ADCA in the bioconversion process. These steps include engineering strategies to reduce acetate accumulation in the biocatalytic process and to knock out a host β-lactamase involved in the degradation of penicillin G and G-7-ADCA. By combining these manipulations in an engineered strain, the yield of G-7-ADCA was increased from 2.50 ± 0.79 mM (0.89 ± 0.28 g/L, 0.07 ± 0.02 g/gDCW) to 29.01 ± 1.27 mM (10.31 ± 0.46 g/L, 0.77 ± 0.03 g/gDCW) with a conversion rate of 29.01 mol%, representing an 11-fold increase compared with the starting strain (2.50 mol%).

[Changes in cell respiration of postural muscle fibers under long-term gravitational unloading after dietary succinate supplementation].

Science.gov (United States)

Ogneva, I V; Veselova, O M; Larina, I M

2011-01-01

The intensity of cell respiration of the rat m. soleus, m. gastrocnemius c.m. and tibialis anterior fibers during 35-day gravitational unloading, with the addition of succinate in the diet at a dosage rate of 50 mg per 1 kg animal weight has been investigated. The gravitational unloading was modeled by antiorthostatic hindlimb suspension. The intensity of cell respiration was estimated by polarography. It was shown that the rate of oxygen consumption by soleus and gastrocnemius fibers on endogenous and exogenous substrates and with the addition of ADP decreases after the discharge. This may be associated with the transition to the glycolytic energy path due to a decrease in the EMG-activity. At the same time, the respiration rate after the addition of exogenous substrates in soleus fibers did not increase, indicating a disturbance in the function of the NCCR-section of the respiratory chain and more pronounced changes in the structure of muscle fibers. In tibialis anterior fibers, no changes in oxygen consumption velocity were observed. The introduction of succinate to the diet of rats makes it possible to prevent the negative effects of hypokinesia, although it reduces the basal level of intensity of cell respiration.

Mixed ligand complexes of essential metal ions with L-glutamine and succinic acid in SLS-water mixtures

Directory of Open Access Journals (Sweden)

Bindu Hima Gandham

2012-01-01

Full Text Available Speciation of mixed ligand complexes of Co(II, Ni(II and Cu(II with L-glutamine and succinic acid was studied in varying amounts (0.0-2.5% w/v of sodium lauryl sulphate in aqueous solutions maintaining an ionic strength of 0.16 mol L-1 (NaCl at 303.0 K. Titrations were carried out in the presence of different relative concentrations (M : L : X = 1 : 2 : 2, 1 : 4 : 2, 1 : 2 : 4 of metal (M to L-glutamine (L to succinic acid (X with sodium hydroxide. Stability constants of ternary complexes were refined with MINIQUAD75. The best-fit chemical models were selected based on statistical parameters and residual analysis. The species detected were ML2X, MLX, MLXH and MLXH2 for Co(II, Ni(II and Cu(II. Extra stability of ternary complexes compared to their binary complexes was believed to be due to electrostatic interactions of the side chains of ligands, charge neutralization, chelate effect, stacking interactions and hydrogen bonding. The species distribution with pH at different compositions of SLS and plausible equilibria for the formation of species were also presented.

Effect of nanoclay loading on the thermal and mechanical properties of biodegradable Polylactide/Poly[(butylene succinate)- co-adipate] blend composites

CSIR Research Space (South Africa)

Ojijo, Vincent O

2012-04-01

Full Text Available Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0...

Metoprolol succinate extended release/hydrochlorothiazide combination tablets

Directory of Open Access Journals (Sweden)

James W Hainer

2007-07-01

Full Text Available James W Hainer, Jennifer SuggAstraZeneca LP, Wilmington, DE, USAAbstract: Lowering elevated blood pressure (BP with drug therapy reduces the risk for catastrophic fatal and nonfatal cardiovascular events such as stroke and myocardial infarction. Given the heterogeneity of hypertension as a disease, the marked variability in an individual patient’s BP response, and low response rates with monotherapy, expert groups such as the Joint National Committee (JNC emphasize the value of combination antihypertensive regimens, noting that combinations, usually of different classes, have additive antihypertensive effects. Metoprolol succinate extended-release tablet is a beta-1 (cardio-selective adrenoceptor-blocking agent formulated to provide controlled and predictable release of metoprolol. Hydrochlorothiazide (HCT is a well-established diuretic and antihypertensive agent, which promotes natruresis by acting on the distal renal tubule. The pharmacokinetics, efficacy, and safety/tolerability of the antihypertensive combination tablet, metoprolol extended release hydrochlorothiazide, essentially reflect the well-described independent characteristics of each of the component agents. Not only is the combination product more effective than monotherapy with the individual components but the combination product allows a low-dose multidrug regimen as an alternative to high-dose monotherapy, thereby, minimizing the likelihood of dose-related side-effects.Keywords: antihypertensive, blood pressure, cardiovascular disease, combination product

E. Coli and Pregnancy

Science.gov (United States)

... chat Live Help Fact Sheets Share Escherichia coli (E. coli) Friday, 01 September 2017 In every pregnancy, a ... risk. This sheet talks about whether exposure to E. coli may increase the risk for birth defects over ...

Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli.

Science.gov (United States)

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili; Christensen, Jens P; Olsen, John E; Nolan, Lisa; Olsen, Rikke H

2017-01-01

Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production economy and welfare worldwide. An almost defining characteristic of avian pathogenic E. coli is the carriage of plasmids, which may encode virulence factors and antibiotic resistance determinates. For the same reason, plasmids of avian pathogenic E. coli have been intensively studied. However, genes encoded by the chromosome may also be important for disease manifestation and antimicrobial resistance. For the E. coli strain APEC_O2 the plasmids have been sequenced and analyzed in several studies, and E. coli APEC_O2 may therefore serve as a reference strain in future studies. Here we describe the chromosomal features of E. coli APEC_O2. E. coli APEC_O2 is a sequence type ST135, has a chromosome of 4,908,820 bp (plasmid removed), comprising 4672 protein-coding genes, 110 RNA genes, and 156 pseudogenes, with an average G + C content of 50.69%. We identified 82 insertion sequences as well as 4672 protein coding sequences, 12 predicated genomic islands, three prophage-related sequences, and two clustered regularly interspaced short palindromic repeats regions on the chromosome, suggesting the possible occurrence of horizontal gene transfer in this strain. The wildtype strain of E. coli APEC_O2 is resistant towards multiple antimicrobials, however, no (complete) antibiotic resistance genes were present on the chromosome, but a number of genes associated with extra-intestinal disease were identified. Together, the information provided here on E. coli APEC_O2 will assist in future studies of avian pathogenic E. coli strains, in particular regarding strain of E. coli APEC_O2, and aid in the general understanding of the pathogenesis of avian pathogenic E. coli .

Human Meningitis-Associated Escherichia coli

Science.gov (United States)

KIM, KWANG SIK

2016-01-01

E. coli is the most common Gram-negative bacillary organism causing meningitis and E. coli meningitis continues to be an important cause of mortality and morbidity throughout the world. Our incomplete knowledge of its pathogenesis contributes to such mortality and morbidity. Recent reports of E. coli strains producing CTX-M-type or TEM-type extended-spectrum β-lactamases create a challenge. Studies using in vitro and in vivo models of the blood-brain barrier have shown that E. coli meningitis follows a high-degree of bacteremia and invasion of the blood-brain barrier. E. coli invasion of the blood-brain barrier, the essentials step in the development of E. coli meningitis, requires specific microbial and host factors as well as microbe- and host-specific signaling molecules. Blockade of such microbial and host factors contributing to E. coli invasion of the blood-brain barrier is shown to be efficient in preventing E. coli penetration into the brain. The basis for requiring a high-degree of bacteremia for E. coli penetration of the blood-brain barrier, however, remains unclear. Continued investigation on the microbial and host factors contributing to a high-degree of bacteremia and E. coli invasion of the blood-brain barrier is likely to identify new targets for prevention and therapy of E. coli meningitis. PMID:27223820

Diarrheagenic Escherichia coli Markers and Phenotypes among Fecal E. coli Isolates Collected from Nicaraguan Infants ▿

OpenAIRE

Reyes, Daniel; Vilchez, Samuel; Paniagua, Margarita; Colque-Navarro, Patricia; Weintraub, Andrej; Möllby, Roland; Kühn, Inger

2010-01-01

We analyzed the prevalence of diarrheagenic Escherichia coli (DEC) markers and common phenotypes in 2,164 E. coli isolates from 282 DEC-positive samples. Enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) were very diverse and were not correlated with diarrhea. Enterotoxigenic E. coli (ETEC) estA and enterohemorrhagic E. coli (EHEC) belonged to a few phenotypes and were significantly correlated with diarrhea.

Effect of bile on growth, peritoneal absorption, and blood clearance of Escherichia coli in E coli peritonitis

International Nuclear Information System (INIS)

Andersson, R.; Schalen, C.; Tranberg, K.G.

1991-01-01

The effect of intraperitoneal bile on growth, peritoneal absorption, and clearance of Escherichia coli was determined in E coli peritonitis in the rat. In E coli peritonitis, intraperitoneal bacterial counts gradually decreased, whereas they increased (after 2 hours) with subsequent development of bacteremia in E coli plus bile peritonitis. After an intraperitoneal injection of labeled bacteria, blood radioactivity was only initially lower in E coli plus bile peritonitis compared with E coli peritonitis. Clearance from blood was lower in E coli plus bile peritonitis than in E coli peritonitis. Organ localization was similar in E coli peritonitis and E coli plus bile peritonitis with decreased splenic, increased pulmonary, and unchanged hepatic uptakes compared with controls. Impaired peritoneal absorption of bacteria, together with impaired local host defense, is likely to enhance the noxious effect of bile in E coli peritonitis

Conjugation in Escherichia coli

Science.gov (United States)

Boyer, Herbert

1966-01-01

Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

Novel biodegradable aliphatic poly(butylene succinate-co-cyclic carbonate)s bearing functionalizable carbonate building blocks: II. Enzymatic biodegradation and in vitro biocompatibility assay.

Science.gov (United States)

Yang, Jing; Tian, Weisheng; Li, Qiaobo; Li, Yang; Cao, Amin

2004-01-01

In a previous study, we have reported chemical synthesis of novel aliphatic poly(butylene succinate-co-cyclic carbonate) P(BS-co-CC)s bearing various functionalizable carbonate building blocks, and this work will continue to present our new studies on their enzymatic degradation and in vitro cell biocompatibility assay. First, enzymatic degradation of the novel P(BS-co-CC) film samples was investigated with two enzymes of lipase B Candida Antartic (Novozyme 435) and lipase Porcine Pancreas PPL, and it was revealed that copolymerizing linear poly(butylene succinate) PBS with a functionalizable carbonate building block could remarkably accelerate the enzymatic degradation of a synthesized product P(BS-co-CC), and its biodegradation behavior was found to strongly depend on the overall impacts of several important factors as the cyclic carbonate (CC) comonomer structure and molar content, molar mass, thermal characteristics, morphology, the enzyme-substrate specificity, and so forth. Further, the biodegraded residual film samples and water-soluble enzymatic degradation products were allowed to be analyzed by means of proton nuclear magnetic resonance (1H NMR), gel permeation chromatograph (GPC), differential scanning calorimeter (DSC), attenuated total reflection FTIR (ATR-FTIR), scanning electron microscope (SEM), and liquid chromatograph-mass spectrometry (LC-MS). On the experimental evidences, an exo-type mechanism of enzymatic chain hydrolysis preferentially occurring in the noncrystalline domains was suggested for the synthesized new P(BS-co-CC) film samples. With regard to their cell biocompatibilities, an assay with NIH 3T3 mouse fibroblast cell was conducted using the novel synthesized P(BS-co-CC) films as substrates with respect to the cell adhesion and proliferation, and these new biodegradable P(BS-co-CC) samples were found to exhibit as low cell toxicity as the PLLA control, particularly the two samples of poly(butylene succinate-co-18.7 mol % dimethyl

Scaffolds of hydroxyl apatite nanoparticles disseminated in 1, 6-diisocyanatohexane-extended poly(1, 4-butylene succinate)/poly(methyl methacrylate) for bone tissue engineering

International Nuclear Information System (INIS)

Kaur, Kulwinder; Singh, K.J.; Anand, Vikas; Bhatia, Gaurav; Kaur, Raminderjit; Kaur, Manpreet; Nim, Lovedeep; Arora, Daljit Singh

2017-01-01

Poly(1, 4-butyl succinate) extended 1, 6-diisocyanatohexane (PBSu-DCH) polymers and Polymethylmethacrylate (PMMA) scaffolds decorated with nano hydroxyl apatite have been prepared and characterized for regeneration of bone in cranio-maxillofacial region. Synthesized scaffolds revealed good response in bone regeneration and excellent cell viability in comparison to commercial available glass plate, which lead to better proliferation of MG-63 cell lines. Additionally, they demonstrate high porosity and excellent water retention ability. Moreover, controlled degradation (in pH = 7.4) and sustained drug release in pH (4.5 and 7.4) are advantages of these scaffolds to serve as delivery vehicles for therapeutic drugs. Samples also provide the protection against Escherichia coli and Methicillin Resistant Staphylococcus aureus microorganisms which can be helpful for quick recovery of the patient. In-vitro inflammatory response has been assessed via adsorption of human plasma/serum proteins on the surface of the scaffolds. Results suggest that prepared scaffolds have good bone regeneration ability and provide friendly environment for the cell growth with the additional advantage of protection of the surrounding tissues from microbial infection. With all these features, it is speculated that these scaffolds will have wide utility in the area of tissue engineering and regenerative medicine. - Highlights: • Porous scaffolds have been prepared by solvent casting technique. • Scaffolds have shown good antibacterial activity against gram positive and negative microorganisms. • Synthesized scaffolds may find applications in the area of regenerative medicine.

Scaffolds of hydroxyl apatite nanoparticles disseminated in 1, 6-diisocyanatohexane-extended poly(1, 4-butylene succinate)/poly(methyl methacrylate) for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Kaur, Kulwinder [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Singh, K.J., E-mail: kanwarjitsingh@yahoo.com [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Anand, Vikas [Department of Physics, Guru Nanak Dev University, Amritsar 143005 (India); Bhatia, Gaurav; Kaur, Raminderjit [Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar 143005 (India); Kaur, Manpreet [Department of Human Genetics, Guru Nanak Dev University, Amritsar 143005 (India); Nim, Lovedeep; Arora, Daljit Singh [Department of Microbiology, Guru Nanak Dev University, Amritsar 143005 (India)

2017-02-01

Poly(1, 4-butyl succinate) extended 1, 6-diisocyanatohexane (PBSu-DCH) polymers and Polymethylmethacrylate (PMMA) scaffolds decorated with nano hydroxyl apatite have been prepared and characterized for regeneration of bone in cranio-maxillofacial region. Synthesized scaffolds revealed good response in bone regeneration and excellent cell viability in comparison to commercial available glass plate, which lead to better proliferation of MG-63 cell lines. Additionally, they demonstrate high porosity and excellent water retention ability. Moreover, controlled degradation (in pH = 7.4) and sustained drug release in pH (4.5 and 7.4) are advantages of these scaffolds to serve as delivery vehicles for therapeutic drugs. Samples also provide the protection against Escherichia coli and Methicillin Resistant Staphylococcus aureus microorganisms which can be helpful for quick recovery of the patient. In-vitro inflammatory response has been assessed via adsorption of human plasma/serum proteins on the surface of the scaffolds. Results suggest that prepared scaffolds have good bone regeneration ability and provide friendly environment for the cell growth with the additional advantage of protection of the surrounding tissues from microbial infection. With all these features, it is speculated that these scaffolds will have wide utility in the area of tissue engineering and regenerative medicine. - Highlights: • Porous scaffolds have been prepared by solvent casting technique. • Scaffolds have shown good antibacterial activity against gram positive and negative microorganisms. • Synthesized scaffolds may find applications in the area of regenerative medicine.

No evidence for promoter region methylation of the succinate dehydrogenase and fumarate hydratase tumour suppressor genes in breast cancer

Directory of Open Access Journals (Sweden)

Dobrovic Alexander

2009-09-01

Full Text Available Abstract Background Succinate dehydrogenase (SDH and fumarate hydratase (FH are tricarboxylic acid (TCA cycle enzymes that are also known to act as tumour suppressor genes. Increased succinate or fumarate levels as a consequence of SDH and FH deficiency inhibit hypoxia inducible factor-1α (HIF-1α prolyl hydroxylases leading to sustained HIF-1α expression in tumours. Since HIF-1α is frequently expressed in breast carcinomas, DNA methylation at the promoter regions of the SDHA, SDHB, SDHC and SDHD and FH genes was evaluated as a possible mechanism in silencing of SDH and FH expression in breast carcinomas. Findings No DNA methylation was identified in the promoter regions of the SDHA, SDHB, SDHC, SDHD and FH genes in 72 breast carcinomas and 10 breast cancer cell lines using methylation-sensitive high resolution melting which detects both homogeneous and heterogeneous methylation. Conclusion These results show that inactivation via DNA methylation of the promoter CpG islands of SDH and FH is unlikely to play a major role in sporadic breast carcinomas.

Succinate Dehydrogenase Activity Assay in situ with Blue Tetrazolium Salt in Crabtree-Positive Saccharomyces cerevisiae Strain

Directory of Open Access Journals (Sweden)

Joanna Berlowska

2008-01-01

Full Text Available A spectrophotometric method for determining succinate dehydrogenase (SDH activity assay in azide-sensitive yeast Saccharomyces cerevisiae has been developed. The permeabilization of yeast cells by 0.05 % digitonin permitted to study yeast enzymatic activity in situ. The reduction of blue tetrazolium salt (BT to blue tetrazolium formazan (BTf was conducted in the presence of phenazine methosulphate (PMS as an exogenous electron carrier, and sodium azide (SA as an inhibitor of cytochrome oxidase (Cyt pathway. Various factors such as type of substrate, BT concentration, cell number, temperature and time of incubation, and different Cyt pathway blockers were optimized. In earlier studies, dimethyl sulfoxide (DMSO had been selected as the best solvent for extraction of BTf from yeast cells. The linear correlation between permeabilized yeast cell density and amount of formed formazan was evidenced in the range from 9·10^7 to 5·10^8 cells per sample solution. Below the yeast cell concentration of 10^7 the absorbance values were too low to detect formazans with good precision. This standarized procedure allows the estimation of SDH activity in whole cells, depending on vitality level of yeast populations. Significant increases of succinate dehydrogenase activities were observed in sequential passages as the result of the increase of activity of the strain and adaptation to cultivation conditions.

Succinic acid production derived from carbohydrates: An energy and greenhouse gas assessment of a platform chemical toward a bio-based economy

NARCIS (Netherlands)

Cok, B.|info:eu-repo/dai/nl/371750679; Tsiropoulos, I.; Roes, A.L.|info:eu-repo/dai/nl/303022388; Patel, M.K.|info:eu-repo/dai/nl/18988097X

2014-01-01

Bio-based succinic acid has the potential to become a platform chemical, i.e. a key building block for deriving both commodity and high-value chemicals, which makes it an attractive compound in a bio-based economy. A few companies and industrial consortia have begun to develop its industrial

Modification of wheat starch with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures I. Thermophysical and pasting properties.

Science.gov (United States)

Subarić, Drago; Ačkar, Durđica; Babić, Jurislav; Sakač, Nikola; Jozinović, Antun

2014-10-01

The aim of this research was to investigate the influence of modification with succinic acid/acetic anhydride and azelaic acid/acetic anhydride mixtures on thermophysical and pasting properties of wheat starch. Starch was isolated from two wheat varieties and modified with mixtures of succinic acid and acetic anhydride, and azelaic acid and acetic anhydride in 4, 6 and 8 % (w/w). Thermophysical, pasting properties, swelling power, solubility and amylose content of modified starches were determined. The results showed that modifications with mixtures of afore mentioned dicarboxylic acids with acetic anhydride decreased gelatinisation and pasting temperatures. Gelatinisation enthalpy of Golubica starch increased, while of Srpanjka starch decreased by modifications. Retrogradation after 7 and 14 day-storage at 4 °C decreased after modifications of both starches. Maximum, hot and cold paste viscosity of both starches increased, while stability during shearing at high temperatures decreased. % setback of starches modified with azelaic acid/acetic anhydride mixture decreased. Swelling power and solubility of both starches increased by both modifications.

Annual Surveillance Summary: Escherichia coli (E. coli) Infections in the Military Health System (MHS), 2015

Science.gov (United States)

2017-03-01

Annual Surveillance Summary: Escherichia coli ( E . coli ) Infections in the Military Health System (MHS...or position of the Department of the Navy, Department of Defense, nor the U.S. Government. i i E . coli in the MHS: Annual Summary 2015 Prepared...March 2017 EpiData Center Department NMCPHC-EDC-TR-187-2017 ii ii E . coli in the MHS: Annual Summary 2015 Prepared March 2017 EpiData

Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs.

Science.gov (United States)

Vahjen, W; Cuisiniere, T; Zentek, J

2017-10-13

To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic

Enterohemorrhagic Escherichia coli (EHEC

Directory of Open Access Journals (Sweden)

Abdullah Kilic

2011-08-01

Full Text Available Escherichia coli is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless for human. E. coli O157:H7 is the most common member of a group of pathogenic E. coli strains known variously as enterohaemorrhagic, verocytotoxin-producing, or Shiga-toxin-producing organisms. EHEC bacterium is the major cause of haemorrhagic colitis and haemolytic uraemic syndrome. The reservoir of this pathogen appears to be mainly cattle and other ruminants such as camels. It is transmitted to humans primarily through consumption of contaminated foods. [TAF Prev Med Bull 2011; 10(4.000: 387-388

Disease: H01247 [KEGG MEDICUS

Lifescience Database Archive (English)

Full Text Available noadipic semialdehyde (AASA), piperideine-6-carboxylate (P6C) and pipecolic acid, which serve as diagnostic ...501] [KO:K14085] ... Alpha-aminoadipic semialdehyde [CPD:C04076] Piperideine-6-carboxylate [CPD:C00450] Pipecoli

Metabolism of 14C-labeled doxylamine succinate (Bendectin) in the rhesus monkey (Macaca mulatta)

International Nuclear Information System (INIS)

Slikker, W. Jr.; Holder, C.L.; Lipe, G.W.; Korfmacher, W.A.; Thompson, H.C. Jr.; Bailey, J.R.

1986-01-01

The time-course of the metabolic fate of [ 14 C]doxylamine was determined after the p.o. administration of 13 mg/kg doxylamine succinate as Bendectin plus [ 14 C]doxylamine succinate to the rhesus monkey. Urine and plasma samples were analyzed by reversed-phase high performance liquid chromatography (HPLC), chemical derivatization, and mass spectrometry. The cumulative 48-hr urinary metabolic profile contained 81% of the administered radiolabeled dose and consisted of at least six radiolabeled peaks. They were peak 1: unknown polar metabolites (8% of dose); peak 2: 2-[1-phenyl-1-(2-pyridinyl)ethoxy] acetic acid, 1-[1-phenyl-1(2-pyridinyl)ethoxy] methanol, and another minor metabolite(s) (31%); peak 3: doxylamine-N-oxide (1%); peak 4a: N,N-didesmethyldoxylamine (17%); peak 4b: doxylamine (4%); and peak 5: N-desmethyldoxylamine (20%). The plasma metabolic profile was the same as the urinary profile except for the absence of doxylamine-N-oxide. The maximum plasma concentrations and elapsed time to attain these concentrations were as follows. Peak 1: 540 ng/mL, 4 hr; peak 2: 1700 ng/mL, 1 hr; peak 4a: 430 ng/mL, 4 hr; peak 4b: 930 ng/mL, 2 hr; and peak 5: 790 ng/mL, 2 hr. These data suggest that in the monkey, doxylamine metabolism follows at least four pathways: a minor pathway to the N-oxide; a minor pathway to unknown polar metabolites; a major pathway to mono- and didesmethyldoxylamine via successive N-demethylation; and a major pathway to side-chain cleavage products (peak 2) via direct side-chain oxidation and/or deamination

Impact of dry chilling on the genetic diversity of Escherichia coli on beef carcasses and on the survival of E. coli and E. coli O157.

Science.gov (United States)

Visvalingam, Jeyachchandran; Liu, Yang; Yang, Xianqin

2017-03-06

The objective of this study was to examine the effect of dry chilling on the genetic diversity of naturally occurring Escherichia coli on beef carcasses, and to examine whether two populations of E. coli recovered from carcasses during chilling and E. coli O157 differed in their response to desiccation. Isolates of E. coli were obtained from beef carcasses during a 67h dry chilling process and were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA). Ten E. coli genotypes found only at 0h (group A) and found more than once (group B), as well as five strains of E. coli O157 (group C) were inoculated on stainless steel coupons and their survival was examined after exposure to 75 and 100% relative humidity (RH) at 0 or 35°C for 67h. A total of 450 E. coli isolates were obtained, with 254, 49, 49, 51, 23, 20, and 4 from 0, 1, 2, 4, 6, 8 and 24h of chilling, respectively. No E. coli were recovered at 67h. MLVA of the isolates revealed 173 distinct genotypes. Genetic diversity of E. coli isolates, defined as ratio of the number of isolates to the number of genotypes, remained between 2.3 and 1.3 during the 24h of chilling. All strains inoculated on stainless steel coupons and exposed to 75% RH at 35°C were completely inactivated, irrespective of their groups. Inactivation of E. coli of the three groups was not significantly (P>0.05) different by exposure to 75% RH at 0°C. The findings indicate that the genetic diversity of E. coli on beef carcasses was not affected by dry chilling. In addition, inactivation of E. coli genotypes and E. coli O157 by desiccation on stainless steel simulating dry chilling conditions did not differ significantly (P>0.05). Thus, dry chilling may be used as an effective antimicrobial intervention for beef carcasses. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Polymer blends of polylactic acid (PLA) and polybutylene succinate-adipate

Science.gov (United States)

Ma, Wenguang

A series of blends consisting of polylactic acid (PLA) and aliphatic succinate polyester (BionolleRTM #3000) had been prepared and investigated. The results of mechanical property investigations showed that using 20 wt% Bionolle#3000 can significantly increase the toughness of PLA. BionolleRTM #3000 also reduces the physical aging rate of PLA so blends remain tough longer. Conversely, the stiffness of BionolleRTM #3000 can be significantly increased by blending in PLA. DMA and DSC results show that PLA/BionolleRTM 3000 blends are not thermodynamically miscible, but are compatible blends. Studies have also been performed to determine the amount and rate of aerobic biodegradation of PLA/aliphatic succinate polyester blends in biologically active composting, enzymatic, and soil environments. The changes in molecular weight, molecular structure and thermal properties in the composting environment were also studied by GPC, NMR and DSC analyses. The research results showed BionolleRTM #3000 had a high degradation rate, while PLA had a low degradation rate. PLA/BionolleRTM #3000 blends had moderate degradation rates that increased with BionolleRTM #3000 content. The melt flow behavior of PLA/BionolleRTM #3000 blends has been studied by capillary rheometry. The relationship of the blends' viscosity with their composition, shear stress, shear rate, and temperature has been investigated. Power law index and activation energy of PLA, BionolleRTM #3000 and their blends have been calculated. The experimental and theoretical data can let us understand the processability of PLA/BionolleRTM #3000 blends. A scanning electron microscope (SEM) was used to investigate the morphological structure of the PLA/BionolleRTM #3000 blends. Micrographs of the samples made from different methods (blown film, extrudate and compression molding sheet) were taken; their differences in morphology were compared. For comparison, the micrographs of blend PLA/BionolleRTM #6000 was also studied. The

Vickers microhardness studies on solution-grown single crystals of potassium boro-succinate

Science.gov (United States)

Lakshmipriya, M.; Rajan Babu, D.; Ezhil Vizhi, R.

2015-02-01

The semiorganic crystals of potassium boro-succinate (KBS) were grown by slow evaporation method. KBS crystallizes in monoclinic system which was confirmed by powder XRD analysis. Vickers microhardness study has been carried out over a load range of 25-100 g. The Vickers hardness numbers (Hv) of the material increases as the load increases so the material is suitable for device fabrication. The Meyer index 'n' is estimated to be greater than 1.6, the crystal system belongs to the soft material category. The elastic stiffness coefficient, c11, has also been calculated using Wooster's empirical relation from the hardness data. The fracture toughness values 'Kc', determined from measurements of crack lengths, were estimated to be 0.15166 MN/m3/2. The brittleness indices 'Bi' were estimated as 276 m-1/2.

Importance of methodology on (99m)technetium dimercapto-succinic acid scintigraphic image quality: imaging pilot study for RIVUR (Randomized Intervention for Children With Vesicoureteral Reflux) multicenter investigation.

Science.gov (United States)

Ziessman, Harvey A; Majd, Massoud

2009-07-01

We reviewed our experience with (99m)technetium dimercapto-succinic acid scintigraphy obtained during an imaging pilot study for a multicenter investigation (Randomized Intervention for Children With Vesicoureteral Reflux) of the effectiveness of daily antimicrobial prophylaxis for preventing recurrent urinary tract infection and renal scarring. We analyzed imaging methodology and its relation to diagnostic image quality. (99m)Technetium dimercapto-succinic acid imaging guidelines were provided to participating sites. High-resolution planar imaging with parallel hole or pinhole collimation was required. Two core reviewers evaluated all submitted images. Analysis included appropriate views, presence or lack of patient motion, adequate magnification, sufficient counts and diagnostic image quality. Inter-reader agreement was evaluated. We evaluated 70, (99m)technetium dimercapto-succinic acid studies from 14 institutions. Variability was noted in methodology and image quality. Correlation (r value) between dose administered and patient age was 0.780. For parallel hole collimator imaging good correlation was noted between activity administered and counts (r = 0.800). For pinhole imaging the correlation was poor (r = 0.110). A total of 10 studies (17%) were rejected for quality issues of motion, kidney overlap, inadequate magnification, inadequate counts and poor quality images. The submitting institution was informed and provided with recommendations for improving quality, and resubmission of another study was required. Only 4 studies (6%) were judged differently by the 2 reviewers, and the differences were minor. Methodology and image quality for (99m)technetium dimercapto-succinic acid scintigraphy varied more than expected between institutions. The most common reason for poor image quality was inadequate count acquisition with insufficient attention to the tradeoff between administered dose, length of image acquisition, start time of imaging and resulting image

The Glycerate and Phosphorylated Pathways of Serine Synthesis in Plants: The Branches of Plant Glycolysis Linking Carbon and Nitrogen Metabolism.

Science.gov (United States)

Igamberdiev, Abir U; Kleczkowski, Leszek A

2018-01-01

Serine metabolism in plants has been studied mostly in relation to photorespiration where serine is formed from two molecules of glycine. However, two other pathways of serine formation operate in plants and represent the branches of glycolysis diverging at the level of 3-phosphoglyceric acid. One branch (the glycerate - serine pathway) is initiated in the cytosol and involves glycerate formation from 3-phosphoglycerate, while the other (the phosphorylated serine pathway) operates in plastids and forms phosphohydroxypyruvate as an intermediate. Serine formed in these pathways becomes a precursor of glycine, formate and glycolate accumulating in stress conditions. The pathways can be linked to GABA shunt via transamination reactions and via participation of the same reductase for both glyoxylate and succinic semialdehyde. In this review paper we present a hypothesis of the regulation of redox balance in stressed plant cells via participation of the reactions associated with glycerate and phosphorylated serine pathways. We consider these pathways as important processes linking carbon and nitrogen metabolism and maintaining cellular redox and energy levels in stress conditions.

Production of ethanol from thin stillage by metabolically engineered Escherichia coli.

Science.gov (United States)

Gonzalez, Ramon; Campbell, Paul; Wong, Matthew

2010-03-01

Thin stillage is a by-product generated in large amounts during the production of ethanol that is rich in carbon sources like glycerol, glucose and maltose. Unfortunately, the fermentation of thin stillage results in a mixture of organic acids and ethanol and minimum utilization of glycerol, the latter a compound that can represent up to 80% of the available substrates in this stream. We report here the efficient production of ethanol from thin stillage by a metabolically engineered strain of Escherichia coli. Simultaneous utilization of glycerol and sugars was achieved by overexpressing either the fermentative or the respiratory glycerol-utilization pathway. However, amplification of the fermentative pathway (encoded by gldA and dhaKLM) led to more efficient consumption of glycerol and promoted the synthesis of reduced products, including ethanol. A previously constructed strain, EH05, containing mutations that prevented the accumulation of competing by-products (i.e. lactate, acetate, and succinate) and overexpressing the fermentative pathway for glycerol utilization [i.e. strain EH05 (pZSKLMgldA)], efficiently converted thin stillage supplemented with only mineral salts to ethanol at yields close to 85% of the theoretical maximum. Ethanol accounted for about 90% (w/w) of the product mixture. These results, along with the comparable performance of strain EH05 (pZSKLMgldA) in 0.5 and 5 l fermenters, indicate a great potential for the adoption of this process by the biofuels industry.

Can E. coli fly?

DEFF Research Database (Denmark)

Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin

2018-01-01

, and the numbers of flies landing on the exposed rice were counted. Following exposure, the surface of the rice was microbiologically and molecularly analysed for the presence of E. coli and genes of diarrheagenic E. coli and Shigella strains. RESULTS: Rice was at greater risk (p ... with E. coli if flies landed on the rice than if no flies landed on the rice (odds ratio 5·4 (p ...-landings, the average CFU per fly-landing was > 0·6 x 103 CFU. Genes of diarrheagenic E. coli and Shigella species were detected in 39 of 60 (65%) of exposed rice samples. Two fly species were identified; the common housefly (Musca domestica) and the oriental latrine fly (Chrysomya megacephala). CONCLUSION: Flies may...

Urinary AASA excretion is elevated in patients with molybdenum cofactor deficiency and isolated sulphite oxidase deficiency

NARCIS (Netherlands)

Mills, P.B.; Footitt, E.J.; Ceyhan, S.; Waters, P.J.; Jakobs, C.A.J.M.; Clayton, P.T.; Struijs, E.A.

2012-01-01

Analysis of α-aminoadipic semialdehyde is an important tool in the diagnosis of antiquitin deficiency (pyridoxine-dependent epilepsy). However continuing use of this test has revealed that elevated urinary excretion of α-aminoadipic semialdehyde is not only found in patients with

Gamma radiation effects on random copolymers based on poly(butylene succinate) for packaging applications

Science.gov (United States)

Negrin, M.; Macerata, E.; Consolati, G.; Quasso, F.; Genovese, L.; Soccio, M.; Giola, M.; Lotti, N.; Munari, A.; Mariani, M.

2018-01-01

Within the context of new bioplastic materials, poly(butylene succinate) (PBS) and four novel poly(butylene/thiodiethylene succinate) random copolymers (PBS-PTDGS), in sheets as well as in films, were exposed to gamma radiation, in air and in water, and their behavior along with the effect on their biodegradability was investigated. The molecular weight data obtained from gel permeation chromatography indicate that the sensibility to radiation increases with the amount of sulfur-containing co-unit (TDGS). At 200 kGy the average molecular weight of PBS film halves, while for P(BS60TDGS40) the residual molecular weight is about 20%. The calculated intermolecular crosslink Gx and scissioning Gs yields confirmed that degradation is predominant over crosslink for all the aliphatic systems. As shown by thermal analyses, gamma radiation affects the thermal properties, leading to an increased crystallinity of the systems, remarkable for PBS, and lower decomposition temperatures. Variations of crystallinity with the increasing absorbed dose were confirmed also by PALS analyses. Water contact angle measurements revealed post-irradiation wettability alterations that could positively affect polymer biodegradability. In particular, when irradiated in water at 100 kGy PBS film exhibits a water contact angle decrease of about 17%, indicating an enhanced wettability. After degradation in compost, changes in the surface morphology were observed by means of SEM and sample weight losses were determined, at different extent, according to the irradiation environment. Interestingly, after 52 days in compost PBS films, both pristine and irradiated in air at 25 kGy, showed a residual weight of about 60%, while the ones irradiated in water at 25 kGy of about 44%. Experimental data confirmed that gamma irradiation could represent a viable treatment to enhance biodegradation in compost of PBS and PBS-based copolymers.

99mTechnetium labelled Escherichia coli

International Nuclear Information System (INIS)

Diniz, S.O.F.; Cardoso, V.N.; Resende, B.M.; Nunan, E.A.; Simal, C.J.R.

1999-01-01

Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99m Tc (26.0 MBq) was added to each preparation and the results showed a labelling yield of 98% for E. coli. Since the bacterial viability of 99m Tc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99m Tc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation

Complete Oxidation of Propionate, Valerate, Succinate, and Other Organic Compounds by Newly Isolated Types of Marine, Anaerobic, Mesophilic, Gram-Negative, Sulfur-Reducing Eubacteria

Science.gov (United States)

Finster, Kai; Bak, Friedhelm

1993-01-01

Anaerobic enrichment cultures with either propionate, succinate, lactate, or valerate and elemental sulfur and inocula from shallow marine or deep-sea sediments were dominated by rod-shaped motile bacteria after three transfers. By application of deep-agar dilutions, five eubacterial strains were obtained in pure culture and designated Kyprop, Gyprop, Kysw2, Gylac, and Kyval. All strains were gram negative and grew by complete oxidation of the electron donors and concomitant stoichiometric reduction of elemental sulfur to hydrogen sulfide. The isolates used acetate, propionate, succinate, lactate, pyruvate, oxaloacetate, maleate, glutamate, alanine, aspartate, and yeast extract. All isolates, except strain Gylac, used citrate as an electron donor but valerate was oxidized only by strain Kyval. Fumarate and malate were degraded by all strains without an additional electron donor or acceptor. Kyprop, Gyprop, and Gylac utilized elemental sulfur as the sole inorganic electron acceptor, while Kysw2 and Kyval also utilized nitrate, dimethyl sulfoxide, or Fe(III)-citrate as an electron acceptor. Images PMID:16348934

The oxygen effect in E. coli cells

International Nuclear Information System (INIS)

Myasnik, M.N.; Skvortsov, V.G.; Sokolov, V.A.

1982-01-01

In experiments on E. coli strains deficient in some stages of DNA repair from radiation damages, it was demonstrated that the value of the oxygen effect, under optimal conditions for manifestation thereof, decreases in the following order: E. coli WP2 (the wild type) → E. coli WP2 exr - and E. coli B → E. coli WP2 uvr A6 → E. coli WP2 rec Al and E. coli WP2 hcr - exr - . It was detected that 0.14 M NaCl solution sensitizes the anoxic cells of some E. coli strains to the effect of γ-radiation. It was established that mutation of the uvr A-gene increases sharply the sensitivity of cells to iradiation under the anoxic conditions in the presence of NaCl, the reverse'' oxygen effect being observed

Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-12-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

escherichia coli serotypes confirmed in experimental mammary ...

African Journals Online (AJOL)

DJFLEX

VARIATIONS IN VIRULENCE OF THREE (3) ESCHERICHIA COLI. SEROTYPES CONFIRMED IN ... ows are susceptible to E. coli infection because. E. coli exist in the .... Coli infections in mice: A laboratory animal model for research in.

Structural studies on the actinide carboxylates. 4. The crystal and molecular structure of succinate dioxouranium(VI) monohydrate

Energy Technology Data Exchange (ETDEWEB)

Bombieri, G; Benetollo, F [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Del Pra, A; Rojas, R

1979-01-01

The structure of the title compound, UO/sub 2/(CH/sub 2/COO)/sub 2/.H/sub 2/O, has been determined from three-dimensional X-ray data. The crystals are orthorhombic, space group Pbcn with four formula units in a cell. The coordination geometry about the uranium atom is pentagonal bipyramidal. The uranyl ions are equatorially surrounded by one water oxygen and by four carboxylate oxygen atoms of different succinic ligands. Each ligand is shared by four uranyl units giving rise to a polymeric-like structure.

Prevalence and behavior of multidrug-resistant shiga toxin-producing Escherichia coli, enteropathogenic E. coli and enterotoxigenic E. coli on coriander.

Science.gov (United States)

Gómez-Aldapa, Carlos A; Segovia-Cruz, Jesús A; Cerna-Cortes, Jorge F; Rangel-Vargas, Esmeralda; Salas-Rangel, Laura P; Gutiérrez-Alcántara, Eduardo J; Castro-Rosas, Javier

2016-10-01

The prevalence and behavior of multidrug-resistant diarrheagenic Escherichia coli pathotypes on coriander was determined. One hundred coriander samples were collected from markets. Generic E. coli were determined using the most probable number procedure. Diarrheagenic E. coli pathotypes (DEPs) were identified using two multiplex polymerase chain reaction procedures. Susceptibility to sixteen antibiotics was tested for the isolated DEPs strains by standard test. The behavior of multidrug-resistant DEPs isolated from coriander was determined on coriander leaves and chopped coriander at 25°± 2 °C and 3°± 2 °C. Generic E. coli and DEPs were identified, respectively, in 43 and 7% of samples. Nine DEPs strains were isolated from positive coriander samples. The identified DEPs included Shiga toxin-producing E. coli (STEC, 4%) enterotoxigenic E. coli (ETEC, 2%) and enteropathogenic E. coli (EPEC, 1%). All isolated DEPs strains exhibited multi-resistance to antibiotics. On inoculated coriander leaves stored at 25°± 2 °C or 3°± 2 °C, no growth was observed for multidrug-resistant DEPs strains. However, multidrug-resistant DEPs strains grew in chopped coriander: after 24 h at 25° ± 2 °C, DEPs strains had grown to approximately 3 log CFU/g. However, at 3°± 2 °C the bacterial growth was inhibited. To the best of our knowledge, this is the first report of the presence and behavior of multidrug-resistant STEC, ETEC and EPEC on coriander and chopped coriander. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Deletion of the Succinate Dehydrogenase Gene KlSDH1 in Kluyveromyces lactis Does Not Lead to Respiratory Deficiency

Science.gov (United States)

Saliola, Michele; Bartoccioni, Paola Chiara; De Maria, Ilaria; Lodi, Tiziana; Falcone, Claudio

2004-01-01

We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose. PMID:15189981

Identification and Prevalence of Escherichia coli and Escherichia coli O157: H7 in Foods

Directory of Open Access Journals (Sweden)

Ancuta Mihaela Rotar

2013-11-01

Full Text Available The objective of this study is to investigate the incidence of Escherichia coli in animal and non-animal foods, and mainly the incidence of the serotype O157: H7 producing verotoxin. The presence of common Escherichia coli and Escherichia coli O157: H7 in various foods (of animal and non animal origin was performed in Transylvania area. We analyzed a total of one hundred forty-one samples of minced meat, one hundred twenty-six samples of meat , twenty six samples of meat products, five samples of alcoholic beverages, three samples of seafood, one hundred samples of cheese from pasteurized milk, seventeen samples of butter, four samples of vegetables and one sample of milk powder, using the standard cultural method and Vidas Eco method for E. coli O157: H7 strains. E. coli was identified in 50 samples of minced meat, 55 samples of meat prepared, 4 samples of meat products, 2 samples of alcoholic beverages, 25 samples of cheese from pasteurized milk, 6 samples of butter and 1 sample of vegetables. In this study were not been identified any foods contaminated with the E. coli O157: H7 serotype. The results of this reasearch have demostrated that E. coli wich represents a hygienic indicator of recent food contamination, can be destroyed with heat treatment and hygienic handling of foods. Our country over the years has been among the few countries where the incidence of the E. coli O157: H7 serotype has been minimal.

Rapid liquid–liquid extraction of thallium(III from succinate media with 2-octylaminopyridine in chloroform as the extractant

Directory of Open Access Journals (Sweden)

SANDIP V. MAHAMUNI

2008-04-01

Full Text Available A simple solvent extraction study of thallium(III was conducted. Selective and quantitative extraction of thallium(III by 2-octylaminopyridine (2-OAP in chloroform occurred from aqueous sodium succinate medium (0.0075 M at pH 3.0. Thallium(III was back extracted with acetate buffer (pH 4.63. The effect of the concentration of succinate and 2-OAP, the role of various diluents, stripping agents, loading capacity of 2-OAP, equilibrium time and aqueous:organic volume ratio on the extraction of thallium(III was studied. The stoichiometry of the extracted species was determined based on the slope analysis method and found to be 1: 2: 1 (metal:acid:extractant. The temperature dependence of the extraction equilibrium constant was also examined to estimate the apparent thermodynamic functions ∆H, ∆G and ∆S for the extraction reaction. The method is free from interference of a large number of cations and anions. The method was used for the selective extraction of thallium(III from its binary mixture with Zn(II, Cd(II, Hg(II, Bi(III, Pb(II, Se(IV, Te(IV, Sb(III, Ga(III, In(III, Al(III, Tl(I and Fe(III. The proposed method was applied to the synthetic mixtures and alloys. It is simple, selective, rapid and eco-friendly.

Extraction behaviour of 2-octylaminopyridine towards lead(II) from succinate media and its separation from other toxic metals

International Nuclear Information System (INIS)

Mane, Chandrashekhar P.; Anuse, Mansing A.

2008-01-01

Liquid-liquid extraction of lead(II) from succinate media was carried out with 2-octylaminopyridine (2-OAP) in chloroform. Lead(II) was quantitatively extracted with 0.036 M 2-OAP in chloroform from 0.005-0.007 M sodium succinate when equilibrated for 5 min. Lead(II) from the organic phase was stripped with three 10 mL portions of 0.4 M acetic acid and determined titrimetrically with EDTA. The nature of extracted species was determined from the log-log plot. The optimum conditions have been evaluated based on a critical study of weak acid concentration, extractant concentration, period of equilibration and effect of diluents. The metal loading capacity of the reagent was found to be 8 mg of lead(II) with 10 mL 0.036 M of the extractant. The extraction of the lead(II) was carried out in presence of various ions to ascertain the tolerance limit of individual. Temperature dependence of the extraction equilibrium constants was examined to estimate the apparent thermodynamic functions (ΔH, ΔS and ΔG) for extraction reaction. Lead(II) was successfully separated from commonly associated metal ions such as Bi(III), Hg(II), Cr(VI), Cd(II), Zn(II), Al(III), Ca(II), Ba(II) and from binary and ternary mixtures. The method was extended for determination of lead(II) in real samples

Diglycolic acid inhibits succinate dehydrogenase activity in human proximal tubule cells leading to mitochondrial dysfunction and cell death.

Science.gov (United States)

Landry, Greg M; Dunning, Cody L; Conrad, Taylor; Hitt, Mallory J; McMartin, Kenneth E

2013-08-29

Diethylene glycol (DEG) is a solvent used in consumer products allowing the increased risk for consumer exposure. DEG metabolism produces two primary metabolites, 2-hydroxyethoxyacetic acid (2-HEAA) and diglycolic acid (DGA). DGA has been shown to be the toxic metabolite responsible for the proximal tubule cell necrosis seen in DEG poisoning. The mechanism of DGA toxicity in the proximal tubule cell is not yet known. The chemical structure of DGA is very similar to citric acid cycle intermediates. Studies were designed to assess whether its mechanism of toxicity involves disruption of cellular metabolic pathways resulting in mitochondrial dysfunction. First, DGA preferentially inhibited succinate dehydrogenase, including human kidney cell enzyme, but had no effect on other citric acid cycle enzyme activities. DGA produces a cellular ATP depletion that precedes cell death. Human proximal tubule (HPT) cells, pre-treated with increasing DGA concentrations, showed significantly decreased oxygen consumption. DGA did not increase lactate levels, indicating no effect on glycolytic activity. DGA increased reactive oxygen species (ROS) production in HPT cells in a concentration and time dependent manner. These results indicate that DGA produced proximal tubule cell dysfunction by specific inhibition of succinate dehydrogenase and oxygen consumption. Disruption of these processes results in decreased energy production and proximal tubule cell death. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Carvedilol Compared With Metoprolol Succinate in the Treatment and Prognosis of Patients With Stable Chronic Heart Failure: Carvedilol or Metoprolol Evaluation Study.

Science.gov (United States)

Fröhlich, Hanna; Zhao, Jingting; Täger, Tobias; Cebola, Rita; Schellberg, Dieter; Katus, Hugo A; Grundtvig, Morten; Hole, Torstein; Atar, Dan; Agewall, Stefan; Frankenstein, Lutz

2015-09-01

β-Blockers exert a prognostic benefit in the treatment of chronic heart failure. Their pharmacological properties vary. The only substantial comparative trial to date-the Carvedilol or Metoprolol European Trial-has compared carvedilol with short-acting metoprolol tartrate at different dose equivalents. We therefore addressed the relative efficacy of equal doses of carvedilol and metoprolol succinate on survival in multicenter hospital outpatients with chronic heart failure. Four thousand sixteen patients with stable systolic chronic heart failure who were using either carvedilol or metoprolol succinate were identified in the Norwegian Heart Failure Registry and The Heart Failure Registry of the University of Heidelberg, Germany. Patients were individually matched on both the dose equivalents and the respective propensity scores for β-blocker treatment. During a follow-up for 17 672 patient-years, it was found that 304 (27.2%) patients died in the carvedilol group and 1066 (36.8%) in the metoprolol group. In a univariable analysis of the general sample, metoprolol therapy was associated with higher mortality compared with carvedilol therapy (hazard ratio, 1.49; 95% confidence interval, 1.31-1.69; P<0.001). This difference was not seen after multivariable adjustment (hazard ratio, 0.93; 95% confidence interval, 0.57-1.50; P=0.75) and adjustment for propensity score and dose equivalents (hazard ratio, 1.06; 95% confidence interval, 0.94-1.20; P=0.36) or in the propensity and dose equivalent-matched sample (hazard ratio, 1.00; 95% confidence interval, 0.82-1.23; P=0.99). These results were essentially unchanged for all prespecified subgroups. In outpatients with chronic heart failure, no conclusive association between all-cause mortality and treatment with carvedilol or metoprolol succinate was observed after either multivariable adjustment or multilevel propensity score matching. © 2015 American Heart Association, Inc.

The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine

DEFF Research Database (Denmark)

Hancock, Viktoria; Ulett, G.C.; Schembri, M.A.

2006-01-01

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract....... The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory...... to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human...

Influence of adrenaline on the activity of succinate dehydrogenase in peripheral blood lymphocytes of irradiated rats

International Nuclear Information System (INIS)

Koroleva, L.V.; Vasin, M.V.

1988-01-01

In experiments with albino mongrel female rats, the influence of adrenaline on succinate dehydrogenase (SDG) activity in the peripheral blood lymphocytes of irradiated and intact animals has been investigated. Two minutes after the intraperitoneal administration of adrenaline (1 mg/kg) to intact rats SDG activity sharply rises and 3-4 min it drastically falls. In 6 to 8 min the second peak in the enzyme activity is registered. Twenty minutes after irradiation of rats in the crano-caudal direction with a dose of 75 Gy delivered to head, the reaction to adrenaline, manifested by the rise in SDG activity, is absent

A genomically modified Escherichia coli strain carrying an orthogonal E. coli histidyl-tRNA synthetase•tRNAHis pair.

Science.gov (United States)

Englert, Markus; Vargas-Rodriguez, Oscar; Reynolds, Noah M; Wang, Yane-Shih; Söll, Dieter; Umehara, Takuya

2017-11-01

Development of new aminoacyl-tRNA synthetase (aaRS)•tRNA pairs is central for incorporation of novel non-canonical amino acids (ncAAs) into proteins via genetic code expansion (GCE). The Escherichia coli and Caulobacter crescentus histidyl-tRNA synthetases (HisRS) evolved divergent mechanisms of tRNA His recognition that prevent their cross-reactivity. Although the E. coli HisRS•tRNA His pair is a good candidate for GCE, its use in C. crescentus is limited by the lack of established genetic selection methods and by the low transformation efficiency of C. crescentus. E. coli was genetically engineered to use a C. crescentus HisRS•tRNA His pair. Super-folder green fluorescent protein (sfGFP) and chloramphenicol acetyltransferase (CAT) were used as reporters for read-through assays. A library of 313 ncAAs coupled with the sfGFP reporter system was employed to investigate the specificity of E. coli HisRS in vivo. A genomically modified E. coli strain (named MEOV1) was created. MEVO1 requires an active C. crescentus HisRS•tRNA His pair for growth, and displays a similar doubling time as the parental E. coli strain. sfGFP- and CAT-based assays showed that the E. coli HisRS•tRNA His pair is orthogonal in MEOV1 cells. A mutation in the anticodon loop of E. coli tRNA His CUA elevated its suppression efficiency by 2-fold. The C. crescentus HisRS•tRNA His pair functionally complements an E. coli ΔhisS strain. The E. coli HisRS•tRNA His is orthogonal in MEOV1 cells. E. coli tRNA His CUA is an efficient amber suppressor in MEOV1. We developed a platform that allows protein engineering of E. coli HisRS that should facilitate GCE in E. coli. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

Hepatic processing determines dual activity of alpha-tocopheryl succinate: a novel paradigm for a shift in biological activity due to provitamin-to-vitamin conversion

Czech Academy of Sciences Publication Activity Database

Neužil, Jiří; Massa, H.

2005-01-01

Roč. 327, č. 4 (2005), s. 1024-1027 ISSN 0006-291X Institutional research plan: CEZ:AV0Z5052915; CEZ:AV0Z50520514 Keywords : vitamin E * alpha-tocopheryl succinate * hepatic processing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.000, year: 2005

Dissolving polyvinylpyrrolidone-based microneedle systems for in-vitro delivery of sumatriptan succinate.

Science.gov (United States)

Ronnander, P; Simon, L; Spilgies, H; Koch, A; Scherr, S

2018-03-01

In-vitro permeation studies were conducted to assess the feasibility of fabricating dissolving-microneedle-array systems to release sumatriptan succinate. The formulations consisted mainly of the encapsulated active ingredient and a water-soluble biologically compatible polymer, polyvinylpyrrolidone (PVP), approved by the U.S. Food and Drug Administration (FDA). Tests with Franz-type diffusion cells and Göttingen minipig skins showed an increase of the transdermal flux compared to passive diffusion. A preparation, containing 30% by mass of PVP and 8.7mg sumatriptan, produced a delivery rate of 395±31μg/cm 2 h over a 7-hour period after a negligible lag time of approximately 39min. Theoretically, a 10.7cm 2 microneedle-array patch loaded with 118.8mg of the drug would provide the required plasma concentration, 72ng/mL, for nearly 7h. Copyright © 2017 Elsevier B.V. All rights reserved.

Silver nanoparticle-E. coli colloidal interaction in water and effect on E. coli survival.

Science.gov (United States)

Dror-Ehre, A; Mamane, H; Belenkova, T; Markovich, G; Adin, A

2009-11-15

Silver nanoparticles exhibit antibacterial properties via bacterial inactivation and growth inhibition. The mechanism is not yet completely understood. This work was aimed at elucidating the effect of silver nanoparticles on inactivation of Escherichia coli, by studying particle-particle interactions in aqueous suspensions. Stable, molecularly capped, positively or negatively charged silver nanoparticles were mixed at 1 to 60microgmL(-1) with suspended E. coli cells to examine their effect on inactivation of the bacteria. Gold nanoparticles with the same surfactant were used as a control, being of similar size but made up of a presumably inert metal. Log reduction of 5log(10) and complete inactivation were obtained with the silver nanoparticles while the gold nanoparticles did not show any inactivation ability. The effect of molecularly capped nanoparticles on E. coli survival was dependent on particle number. Log reduction of E. coli was associated with the ratio between the number of nanoparticles and the initial bacterial cell count. Electrostatic attraction or repulsion mechanisms in silver nanoparticle-E. coli cell interactions did not contribute to the inactivation process.

Enhanced performance of biodegradable poly(butylene succinate)/graphene oxide nanocomposites via in situ polymerization.

Science.gov (United States)

Wang, X W; Zhang, C-A; Wang, P L; Zhao, J; Zhang, W; Ji, J H; Hua, K; Zhou, J; Yang, X B; Li, X P

2012-05-08

Poly(butylene succinate) (PBS)/graphene oxide (GO) nanocomposites were facilely prepared via in situ polymerization. The properties of the nanocomposites were studied using FTIR, XRD, and (1)H NMR, and the state of dispersion of GO in the PBS matrix was examined by SEM. The crystallization and melting behavior of the PBS matrix in the presence of dispersed GO nanosheets have been studied by DSC and polarized optical microscopy. Through the mechnical testing machine and DMA, PBS/GO nanocomposites with 3% GO have shown a 43% increase in tensile strength and a 45% improvement in storage modulus. This high performance of the nanocomposites is mainly attributed to the high strength of graphene oxide combined with the strong interfacial interactions in the uniformly dispersed PBS/GO nanocomposites.

Surface Functionalization of WO3 Thin Films with (3-Aminopropyl)triethoxysilane and Succinic Anhydride

Science.gov (United States)

Ta, Thi Kieu Hanh; Tran, Thi Nhu Hoa; Tran, Quang Minh Nhat; Pham, Duy Phong; Pham, Kim Ngoc; Cao, Thi Thanh; Kim, Yong Soo; Tran, Dai Lam; Ju, Heongkyu; Phan, Bach Thang

2017-06-01

We report effects of oxygen plasma treatment on the surface functionalization of WO3 thin films with (3-aminopropyl)triethoxysilane (APTES) and succinic anhydride (SA). X-ray diffraction and x-ray photoelectron spectroscopy results indicate the existence of the WO3 phase. Fourier transform infrared spectroscopy measurement shows clear bands at 1040 cm-1 (Si-O-Si), 1556 cm-1 (N-H), 1655 cm-1 (C=O), 2937 cm-1 (C-H) and 3298 cm-1 (N-H), confirming the surface functionalization efficiency enhanced by prior treatment of oxygen plasma. It thus follows that the prior oxygen plasma treatment activates hydroxylation with more -OH groups on the WO3 surface, which can pave a highly efficient way to the surface functionalization by APTES and SA.

Genetic Transfer of Salmonella typhimurium and Escherichia coli Lipopolysaccharide Antigens to Escherichia coli K-12

Science.gov (United States)

Jones, Randall T.; Koeltzow, Donald E.; Stocker, B. A. D.

1972-01-01

Escherichia coli K-12 ϰ971 was crossed with a smooth Salmonella typhimurium donor, HfrK6, which transfers early the ilv-linked rfa region determining lipopolysaccharide (LPS) core structure. Two ilv+ hybrids differing in their response to the LPS-specific phages FO and C21 were then crossed with S. typhimurium HfrK9, which transfers early the rfb gene cluster determining O repeat unit structure. Most recombinants selected for his+ (near rfb) were agglutinated by Salmonella factor 4 antiserum. Transfer of an F′ factor (FS400) carrying the rfb–his region of S. typhimurium to the same two ilv+ hybrids gave similar results. LPS extracted from two ilv+,his+, factor 4-positive hybrids contained abequose, the immunodominant sugar for factor 4 specificity. By contrast, his+ hybrids obtained from ϰ971 itself by similar HfrK9 and F′FS400 crosses were not agglutinated by factor 4 antiserum, indicating that the parental E. coli ϰ971 does not have the capacity to attach Salmonella O repeat units to its LPS core. It is concluded that the Salmonella rfb genes are expressed only in E. coli ϰ971 hybrids which have also acquired ilv-linked genes (presumably rfa genes affecting core structure or O-translocase ability, or both) from a S. typhimurium donor. When E. coli ϰ971 was crossed with a smooth E. coli donor, Hfr59, of serotype O8, which transfers his early, most his+ recombinants were agglutinated by E. coli O8 antiserum and lysed by the O8-specific phage, Ω8. This suggests that, although the parental E. coli K-12 strain ϰ971 cannot attach Salmonella-specific repeat units to its LPS core, it does have the capacity to attach E. coli O8-specific repeat units. PMID:4559827

Preparation of nanocomposites based on poly(Butylene Succinate) and montmorillonite organoclay via in situ polymerization

International Nuclear Information System (INIS)

Ferreira, Leticia P.; Moreira, Andrei N.; Souza Junior, Fernando G. de; Pinto, Jose Carlos Costa da Silva

2014-01-01

Nanocomposites based on poly(butylene succinate) (PBS) and organophilic montmorillonite were synthesized via in situ polymerization using three different clay compositions (4, 6 and 8 wt%). The products were characterized by several different techniques. X-ray diffraction was useful to confirm the increase of the interlayer spacing of the clay due to the presence of the polymer chains among layers. Thermal analysis indicated that the polymerization method chosen led to materials with lower thermal stability compared to the pure PBS, due to the difficulty of chain growth in the presence of the clay. Low-field NMR technique was used to assess clay dispersion in the polymer, with exfoliated structures predominating in the nanocomposites. (author)

Unconventional biomasses as feedstocks for production of biofuels and succinic acid in a biorefinery concept

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi

composition of the specific biomass feedstock, as well as which pretreatment, saccharification, fermentation and extraction techniques are used. Furthermore, integrating biological processes into the biorefinery that effectively consume CO2 will become increasingly important. Such process integration could...... significantly improve the sustainability indicators of the overall biorefinery process. In this study, unconventional lignocellulosic- and aquatic biomasses were investigated as biorefinery feedstocks. The studied biomasses were Jerusalem artichoke, industrial hemp and macroalgae species Laminaria digitata....... The chemical composition of biomasses was determined in order to demonstrate their biorefinery potential. Bioethanol and biogas along with succinic acid production were the explored bioconversion routes, while potential production of other compounds was also investigated. Differences and changes in biomass...

Comparative genomics and transcriptomics of Escherichia coli isolates carrying virulence factors of both enteropathogenic and enterotoxigenic E. coli.

Science.gov (United States)

Hazen, Tracy H; Michalski, Jane; Luo, Qingwei; Shetty, Amol C; Daugherty, Sean C; Fleckenstein, James M; Rasko, David A

2017-06-14

Escherichia coli that are capable of causing human disease are often classified into pathogenic variants (pathovars) based on their virulence gene content. However, disease-associated hybrid E. coli, containing unique combinations of multiple canonical virulence factors have also been described. Such was the case of the E. coli O104:H4 outbreak in 2011, which caused significant morbidity and mortality. Among the pathovars of diarrheagenic E. coli that cause significant human disease are the enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC). In the current study we use comparative genomics, transcriptomics, and functional studies to characterize isolates that contain virulence factors of both EPEC and ETEC. Based on phylogenomic analysis, these hybrid isolates are more genomically-related to EPEC, but appear to have acquired ETEC virulence genes. Global transcriptional analysis using RNA sequencing, demonstrated that the EPEC and ETEC virulence genes of these hybrid isolates were differentially-expressed under virulence-inducing laboratory conditions, similar to reference isolates. Immunoblot assays further verified that the virulence gene products were produced and that the T3SS effector EspB of EPEC, and heat-labile toxin of ETEC were secreted. These findings document the existence and virulence potential of an E. coli pathovar hybrid that blurs the distinction between E. coli pathovars.

Thioredoxin from Escherichia coli

International Nuclear Information System (INIS)

Holmgren, A.; Ohlsson, I.; Grankvist, M.L.

1978-01-01

A competition radioimmunoassay for Escherichia coli thioredoxin using 125 I-labeled thioredoxin-S 2 and a double antibody technique was developed. The method permits determination of picomole amounts of thioredoxin in crude cell extracts and was used to study the localization of thioredoxin cell fractions. E. coli B was calculated to have approximately 10,000 copies of thioredoxin per cell mainly located in the soluble fraction after separation of the membrane and soluble fractions by gentle lysis and centrifugation. E. coli B tsnC mutants which are defective in the replication of phage T7 DNA in vivo and in vitro were examined for their content of thioredoxin. E. coli B tsnC 7004 contained no detectable level of thioredoxin in cell-free extracts examined under a variety of conditions. The results strongly suggest that tsnC 7004 is a nonsense or deletion mutant. Two other E. coli tsnC mutants, 7007 and 7008, contained detectable levels of thioredoxin in crude extracts as measured by thioredoxin reductase and gave similar immunoprecipitation reactions as the parent strain B/1. By radioimmunoassay incompletely cross-reacting material was present in both strains. These results show that tsnC 7007 and 7008 belong to a type of thioredoxin mutants with missence mutations in the thioredoxin gene affecting the function of thioredoxin as subunit in phage T7 DNA polymerase

Hemolytic Porcine Intestinal Escherichia coli without Virulence-Associated Genes Typical of Intestinal Pathogenic E. coli ▿ †

Science.gov (United States)

Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

2011-01-01

Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli. PMID:21965399

Improvement of Protective Properties of Top Coatings Applied on Zinc-Rich Primer by 3-Aminopropyl-Triethoxysilan and 2-(Benzothialylthio) Succinic acid

International Nuclear Information System (INIS)

Truc, Trinh Anh; Hang, Thi Xuan; Oanh, Vu Ke; Dung, Nguyen Tuan

2004-01-01

Corrosion resistance of coating system consisting of zinc-rich primer (ZRP) and topcoat based on polyurethane resin with the presence of 3-aminopropyl-triethoxysilan (APS) and 2-(benzothialylthio) succinic acid (BSA) was studied by electrochemical impedance and wet adhesion. The interface metal/primer/topcoat was analyzed by scanning electronic microscopy. It was found that the presence of APS and BSA improved adhesion and barrier property of the topcoats

Crystallization and crystallographic analysis of the ligand-binding domain of the Pseudomonas putida chemoreceptor McpS in complex with malate and succinate

International Nuclear Information System (INIS)

Gavira, J. A.; Lacal, J.; Ramos, J. L.; García-Ruiz, J. M.; Krell, T.; Pineda-Molina, E.

2012-01-01

The crystallization of the ligand-binding domain of the methyl-accepting chemotaxis protein chemoreceptor McpS (McpS-LBD) is reported. Methyl-accepting chemotaxis proteins (MCPs) are transmembrane proteins that sense changes in environmental signals, generating a chemotactic response and regulating other cellular processes. MCPs are composed of two main domains: a ligand-binding domain (LBD) and a cytosolic signalling domain (CSD). Here, the crystallization of the LBD of the chemoreceptor McpS (McpS-LBD) is reported. McpS-LBD is responsible for sensing most of the TCA-cycle intermediates in the soil bacterium Pseudomonas putida KT2440. McpS-LBD was expressed, purified and crystallized in complex with two of its natural ligands (malate and succinate). Crystals were obtained by both the counter-diffusion and the hanging-drop vapour-diffusion techniques after pre-incubation of McpS-LBD with the ligands. The crystals were isomorphous and belonged to space group C2, with two molecules per asymmetric unit. Diffraction data were collected at the ESRF synchrotron X-ray source to resolutions of 1.8 and 1.9 Å for the malate and succinate complexes, respectively

ESBL-Producing Escherichia coli

DEFF Research Database (Denmark)

Hertz, Frederik Boetius

Urinary tract infection (UTI) is one the most common bacterial infections and is regularly treated in primary health care. The most common cause of UTI is extraintestinal pathogenic Escherichia coli (ExPEC) already present in the intestinal microflora, often as the dominating strain. Resistance...... in E.coli is increasing and especially isolates producing Extended-Spectrum Beta-Lactamases (ESBL) have been reported worldwide. Treatment of UTI is usually initiated by the general practitioners and a significant proportion of clinical isolates are now resistant to first line antibiotics. The global...... to investigate (i) antibiotics involved in selection of ESBL-producing E.coli, in an experimental mouse model in vivo, (ii) risk factors for UTI with ESBL-producing E.coli and (iii) to describe the phylogenetic composition of E.coli populations with different resistance patterns. We found that different...

21 CFR 866.3255 - Escherichia coli serological reagents.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from cultured...

Asymptomatic bacteriuria Escherichia coli strains

DEFF Research Database (Denmark)

Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

2006-01-01

Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...... to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

Nanoformulation of D-α-tocopheryl polyethylene glycol 1000 succinate-b-poly(ε-caprolactone-ran-glycolide) diblock copolymer for breast cancer therapy.

Science.gov (United States)

Huang, Laiqiang; Chen, Hongbo; Zheng, Yi; Song, Xiaosong; Liu, Ranyi; Liu, Kexin; Zeng, Xiaowei; Mei, Lin

2011-10-01

The purpose of this research was to develop formulation of docetaxel-loaded biodegradable TPGS-b-(PCL-ran-PGA) nanoparticles for breast cancer chemotherapy. A novel diblock copolymer, d-α-tocopheryl polyethylene glycol 1000 succinate-b-poly(ε-caprolactone-ran-glycolide) [TPGS-b-(PCL-ran-PGA)], was synthesized from ε-caprolactone, glycolide and d-α-tocopheryl polyethylene glycol 1000 succinate by ring-opening polymerization using stannous octoate as catalyst. The obtained copolymers were characterized by (1)H NMR, GPC and TGA. The docetaxel-loaded TPGS-b-(PCL-ran-PGA) nanoparticles were prepared and characterized. The data showed that the fluorescence TPGS-b-(PCL-ran-PGA) nanoparticles could be internalized by MCF-7 cells. The TPGS-b-(PCL-ran-PGA) nanoparticles achieved significantly higher level of cytotoxicity than commercial Taxotere®. MCF-7 xenograft tumor model on SCID mice showed that docetaxel formulated in the TPGS-b-(PCL-ran-PGA) nanoparticles could effectively inhibit the growth of tumor over a longer period of time than Taxotere® at the same dose. In conclusion, the TPGS-b-(PCL-ran-PGA) copolymer could be acted as a novel and potential biologically active polymeric material for nanoformulation in breast cancer chemotherapy. This journal is © The Royal Society of Chemistry 2011

Escherichia coli EDL933 Requires Gluconeogenic Nutrients To Successfully Colonize the Intestines of Streptomycin-Treated Mice Precolonized with E. coli Nissle 1917

Science.gov (United States)

Schinner, Silvia A. C.; Mokszycki, Matthew E.; Adediran, Jimmy; Leatham-Jensen, Mary; Conway, Tyrrell

2015-01-01

Escherichia coli MG1655, a K-12 strain, uses glycolytic nutrients exclusively to colonize the intestines of streptomycin-treated mice when it is the only E. coli strain present or when it is confronted with E. coli EDL933, an O157:H7 strain. In contrast, E. coli EDL933 uses glycolytic nutrients exclusively when it is the only E. coli strain in the intestine but switches in part to gluconeogenic nutrients when it colonizes mice precolonized with E. coli MG1655 (R. L. Miranda et al., Infect Immun 72:1666–1676, 2004, http://dx.doi.org/10.1128/IAI.72.3.1666-1676.2004). Recently, J. W. Njoroge et al. (mBio 3:e00280-12, 2012, http://dx.doi.org/10.1128/mBio.00280-12) reported that E. coli 86-24, an O157:H7 strain, activates the expression of virulence genes under gluconeogenic conditions, suggesting that colonization of the intestine with a probiotic E. coli strain that outcompetes O157:H7 strains for gluconeogenic nutrients could render them nonpathogenic. Here we report that E. coli Nissle 1917, a probiotic strain, uses both glycolytic and gluconeogenic nutrients to colonize the mouse intestine between 1 and 5 days postfeeding, appears to stop using gluconeogenic nutrients thereafter in a large, long-term colonization niche, but continues to use them in a smaller niche to compete with invading E. coli EDL933. Evidence is also presented suggesting that invading E. coli EDL933 uses both glycolytic and gluconeogenic nutrients and needs the ability to perform gluconeogenesis in order to colonize mice precolonized with E. coli Nissle 1917. The data presented here therefore rule out the possibility that E. coli Nissle 1917 can starve the O157:H7 E. coli strain EDL933 of gluconeogenic nutrients, even though E. coli Nissle 1917 uses such nutrients to compete with E. coli EDL933 in the mouse intestine. PMID:25733524

Clostridium difficile Recombinant Toxin A Repeating Units as a Carrier Protein for Conjugate Vaccines: Studies of Pneumococcal Type 14, Escherichia coli K1, and Shigella flexneri Type 2a Polysaccharides in Mice

Science.gov (United States)

Pavliakova, Danka; Moncrief, J. Scott; Lyerly, David M.; Schiffman, Gerald; Bryla, Dolores A.; Robbins, John B.; Schneerson, Rachel

2000-01-01

Unlike the native protein, a nontoxic peptide (repeating unit of the native toxin designated rARU) from Clostridium difficile toxin A (CDTA) afforded an antigen that could be bound covalently to the surface polysaccharides of pneumococcus type 14, Shigella flexneri type 2a, and Escherichia coli K1. The yields of these polysaccharide-protein conjugates were significantly increased by prior treatment of rARU with succinic anhydride. Conjugates, prepared with rARU or succinylated (rARUsucc), were administered to mice by a clinically relevant dosage and immunization scheme. All conjugates elicited high levels of serum immunoglobulin G both to the polysaccharides and to CDTA. Conjugate-induced anti-CDTA had neutralizing activity in vitro and protected mice challenged with CDTA, similar to the rARU alone. Conjugates prepared with succinylated rARU, therefore, have potential for serving both as effective carrier proteins for polysaccharides and for preventing enteric disease caused by C. difficile. PMID:10722615

Differences between the succinate dehydrogenase sequences of isopyrazam sensitive Zymoseptoria tritici and insensitive Fusarium graminearum strains.

Science.gov (United States)

Dubos, Tiphaine; Pasquali, Matias; Pogoda, Friederike; Casanova, Angèle; Hoffmann, Lucien; Beyer, Marco

2013-01-01

Forty-one Zymoseptoria tritici strains isolated in Luxembourg between 2009 and 2010 were highly sensitive towards the new succinate dehydrogenase inhibitor (SDHI) isopyrazam, with concentrations inhibiting fungal growth by 50% (EC50) ranging from 0.0281 to 4.53μM, whereas 41 Fusarium graminearum strains isolated in Europe and Northern America between 1969 and 2009 were insensitive with the average rate of inhibition converging towards 28% with increasing isopyrazam concentration. Seven isolates of both species covering the range of isopyrazam sensitivities observed in the present study were selected for the sequencing of the subunits B, C and D of the succinate dehydrogenase (sdh) gene. Predicted sdh amino acid sequences of subunits B, C and D were identical among F. graminearum strains. By comparing with fungal strains where resistance towards SDHIs was previously reported, three variations were unique to F. graminearum; B-D130N located in the iron-sulfur cluster [2Fe-2S], B-A275T located in the [3Fe-4S] cluster and an additional S at amino acid position 83-84 of sdhC, probably modifying structurally the ubiquinone binding site and therefore the biological activity of the fungicide. No variation was found among the Z. tritici strains in subunits B and D. Two variations were observed within the subunit C sequences of Z. tritici strains: C-N33T and C-N34T. The difference in EC50 values between Z. tritici strains with the NN and TT configuration was non-significant at P=0.289. Two outliers in the Z. tritici group with significantly higher EC50 values that were not related to mutations in the sdhB, sdhC, or sdhD were detected. The role of isopyrazam for the control of F. graminearum and Z. tritici in Luxembourg is discussed. Copyright © 2012 Elsevier Inc. All rights reserved.

The Agrobacterium tumefaciens Transcription Factor BlcR Is Regulated via Oligomerization

Energy Technology Data Exchange (ETDEWEB)

Pan, Yi; Fiscus, Valena; Meng, Wuyi; Zheng, Zhida; Zhang, Lian-Hui; Fuqua, Clay; Chen, Lingling (IMCB-Singapore); (Indiana)

2012-02-08

The Agrobacterium tumefaciens BlcR is a member of the emerging isocitrate lyase transcription regulators that negatively regulates metabolism of {gamma}-butyrolactone, and its repressing function is relieved by succinate semialdehyde (SSA). Our crystal structure showed that BlcR folded into the DNA- and SSA-binding domains and dimerized via the DNA-binding domains. Mutational analysis identified residues, including Phe{sup 147}, that are important for SSA association; BlcR{sup F147A} existed as tetramer. Two BlcR dimers bound to target DNA and in a cooperative manner, and the distance between the two BlcR-binding sequences in DNA was critical for BlcR-DNA association. Tetrameric BlcR{sup F147A} retained DNA binding activity, and importantly, this activity was not affected by the distance separating the BlcR-binding sequences in DNA. SSA did not dissociate tetrameric BlcR{sup F147A} or BlcR{sup F147A}-DNA. As well as in the SSA-binding site, Phe{sup 147} is located in a structurally flexible loop that may be involved in BlcR oligomerization. We propose that SSA regulates BlcR DNA-binding function via oligomerization.

Physical Stability of Octenyl Succinate-Modified Polysaccharides and Whey Proteins for Potential Use as Bioactive Carriers in Food Systems.

Science.gov (United States)

Puerta-Gomez, Alex F; Castell-Perez, M Elena

2015-06-01

The high cost and potential toxicity of biodegradable polymers like poly(lactic-co-glycolic)acid (PLGA) has increased the interest in natural and modified biopolymers as bioactive carriers. This study characterized the physical stability (water sorption and state transition behavior) of selected starch and proteins: octenyl succinate-modified depolymerized waxy corn starch (DWxCn), waxy rice starch (DWxRc), phytoglycogen, whey protein concentrate (80%, WPC), whey protein isolate (WPI), and α-lactalbumin (α-L) to determine their potential as carriers of bioactive compounds under different environmental conditions. After enzyme modification and particle size characterization, glass transition temperature and moisture isotherms were used to characterize the systems. DWxCn and DWxRc had increased water sorption compared to native starch. The level of octenyl succinate anhydrate (OSA) modification (3% and 7%) did not reduce the water sorption of the DWxCn and phytoglycogen samples. The Guggenheim-Andersen-de Boer model indicated that native waxy corn had significantly (P whey proteins had higher glass transition temperature (Tg) values. On the other hand, depolymerized waxy starches at 7%-OSA modification had a "melted" appearance when exposed to environments with high relative humidity (above 70%) after 10 days at 23 °C. The use of depolymerized and OSA-modified polysaccharides blended with proteins created more stable blends of biopolymers. Hence, this biopolymer would be suitable for materials exposed to high humidity environments in food applications. © 2015 Institute of Food Technologists®

Multiplex PCR Assay for Identification of Human Diarrheagenic Escherichia coli

OpenAIRE

Toma, Claudia; Lu, Yan; Higa, Naomi; Nakasone, Noboru; Chinen, Isabel; Baschkier, Ariela; Rivas, Marta; Iwanaga, Masaaki

2003-01-01

A multiplex PCR assay for the identification of human diarrheagenic Escherichia coli was developed. The targets selected for each category were eae for enteropathogenic E. coli, stx for Shiga toxin-producing E. coli, elt and est for enterotoxigenic E. coli, ipaH for enteroinvasive E. coli, and aggR for enteroaggregative E. coli. This assay allowed the categorization of a diarrheagenic E. coli strain in a single reaction tube.

Characterization of diarrhoeagenic Escherichia coli isolates in Jordanian children.

Science.gov (United States)

Shehabi, Asem A; Bulos, Najawa-Kuri; Hajjaj, Kamal G

2003-01-01

In a prospective study carried out among Jordanian children in Amman, a total of 73/250 (29.2%) stool specimens were positive for 1 or more diarrhoeagenic Escherichia coli strains using a multiplex polymerase chain reaction method. This study indicated that diarrhoeagenic E. coli isolates were found frequently more in stools of children with diarrhoea (34%) than without diarrhoea (23.1%), but without any significant difference (p > 0.05). The predominant diarrhoeagenic E. coli strains associated with diarrhoea were enteropathogenic E. coli (11.3%), followed by enterotoxigenic E. coli (9.8%) and enteroaggrative E. coli (9%), whereas in the control group these were 4.3%, 11.1% and 6%, respectively. Enteroinvasive E. coli strains (2.9%) were found only in stools of children with diarrhoea. This study revealed the absence of enterohaemorrhagic E. coli in both diarrhoeal and control stools, and found that diarrhoeagenic E. coli isolates were highly resistance to tetracycline (55%), co-trimoxazole (60%) and ampicillin (89%), which are commonly used antibiotics in Jordan.

Comparative analysis of succinate dehydrogenase activity in mammalian peripheral blood lymphocytes and radiomodifying action of gas hypoxis mixtures

International Nuclear Information System (INIS)

Gajdamakin, A.N.; Abramov, M.M.

1987-01-01

Radiprotective efficiency of gas hypoxic mixtures (GHM) containing 5-12% of oxygen and the rate of the reaction of succinate dehydrogenase (V SDG ) activity in peripheral blood lymphocytes upon breathing GHM were comparatively studied in rats and dogs. V SDG was 4393.5 (%O 2 ) -2,58 and 130.76 (%O 2 ) -1.42 in dogs and rats respectively. Taking into account that DMF in rats is a function of oxygen concentration in the mixture one can obtain a formula for determining a dose modifying factors (DMF) as a function of the rate of SDG activity reaction

Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

Science.gov (United States)

Yang, Shih-Chun; Lin, Chih-Hung; Aljuffali, Ibrahim A; Fang, Jia-You

2017-08-01

Food contamination by pathogenic microorganisms has been a serious public health problem and a cause of huge economic losses worldwide. Foodborne pathogenic Escherichia coli (E. coli) contamination, such as that with E. coli O157 and O104, is very common, even in developed countries. Bacterial contamination may occur during any of the steps in the farm-to-table continuum from environmental, animal, or human sources and cause foodborne illness. To understand the causes of the foodborne outbreaks by E. coli and food-contamination prevention measures, we collected and investigated the past 10 years' worldwide reports of foodborne E. coli contamination cases. In the first half of this review article, we introduce the infection and symptoms of five major foodborne diarrheagenic E. coli pathotypes: enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli/enterohemorrhagic E. coli (STEC/EHEC), Shigella/enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC). In the second half of this review article, we introduce the foodborne outbreak cases caused by E. coli in natural foods and food products. Finally, we discuss current developments that can be applied to control and prevent bacterial food contamination.

Synthesis and antifungal activity of nicotinamide derivatives as succinate dehydrogenase inhibitors.

Science.gov (United States)

Ye, Yong-Hao; Ma, Liang; Dai, Zhi-Cheng; Xiao, Yu; Zhang, Ying-Ying; Li, Dong-Dong; Wang, Jian-Xin; Zhu, Hai-Liang

2014-05-07

Thirty-eight nicotinamide derivatives were designed and synthesized as potential succinate dehydrogenase inhibitors (SDHI) and precisely characterized by (1)H NMR, ESI-MS, and elemental analysis. The compounds were evaluated against two phytopathogenic fungi, Rhizoctonia solani and Sclerotinia sclerotiorum, by mycelia growth inhibition assay in vitro. Most of the compounds displayed moderate activity, in which, 3a-17 exhibited the most potent antifungal activity against R. solani and S. sclerotiorum with IC50 values of 15.8 and 20.3 μM, respectively, comparable to those of the commonly used fungicides boscalid and carbendazim. The structure-activity relationship (SAR) of nicotinamide derivatives demonstrated that the meta-position of aniline was a key position contributing to the antifungal activity. Inhibition activities against two fungal SDHs were tested and achieved the same tendency with the data acquired from in vitro antifungal assay. Significantly, 3a-17 was demonstrated to successfully suppress disease development in S. sclerotiorum infected cole in vivo. In the molecular docking simulation, sulfur and chlorine of 3a-17 were bound with PHE291 and PRO150 of the SDH homology model, respectively, which could explain the probable mechanism of action between the inhibitory and target protein.

Experimental induced avian E. coli salpingitis

DEFF Research Database (Denmark)

Olsen, Rikke Heidemann; Thøfner, Ida; Pors, Susanne Elisabeth

2016-01-01

Several types of Escherichia coli have been associated with extra-intestinal infections in poultry, however, they may vary significantly in their virulence potential. The aim of the present study was to investigate the virulence of five strains of E. coli obtained from different disease......) had a distinct ability to cause disease. Results of the study shows major differences in virulence of different strains of E. coli in ascending infections; however, there was no indication of tissue-specific adaptation, since strains obtained from lesions unrelated to the reproductive system were...... fully capable of causing experimental infection. In conclusion, the study provides evidence for the clinical outcome of infection with E. coli in poultry is largely influenced by the specific strain as well as individual host factors....

Rheological, pasting, thermal and retrogradation properties of octenyl succinic anhydride modified potato starch

Directory of Open Access Journals (Sweden)

Chuin WON

Full Text Available Abstract The objective of the present study was to investigate the rheological, pasting, and thermal properties of octenyl succinic anhydrate (OSA-modified potato starch. Potato starch was modified using different concentrations of OSA (0, 1, 3, and 5%, v/v. The degree of substitution (DS for the OSA-modified starch ranged from 0.0012 to 0.0055. The amylose leaching values of native and OSA-modified potato starch with different DS levels were in the range of 47.09-87.32%. The gel strength values of the OSA-modified starch were lower than those of native potato starch. Rapid Visco Analyzer data showed that peak, hot pasting, final and setback viscosities of the native starch decreased after OSA modification. Dynamic shear rheological tests, conducted at 4 °C, indicated that OSA-modified potato starch had weak gel-like behavior with the storage moduli (G' higher than the loss moduli (G” over most of the frequency ranges (0.63-63.8 rad·s-1.

Phase Transformation of Adefovir Dipivoxil/Succinic Acid Cocrystals Regulated by Polymeric Additives

Directory of Open Access Journals (Sweden)

Sungyup Jung

2013-12-01

Full Text Available The polymorphic phase transformation in the cocrystallization of adefovir dipivoxil (AD and succinic acid (SUC was investigated. Inspired by biological and biomimetic crystallization, polymeric additives were utilized to control the phase transformation. With addition of poly(acrylic acid, the metastable phase newly identified through the analysis of X-ray diffraction was clearly isolated from the previously reported stable form. Without additives, mixed phases were obtained even at the early stage of cocrystallization. Also, infrared spectroscopy analysis verified the alteration of the hydrogen bonding that was mainly responsible for the cocrystal formation between AD and SUC. The hydrogen bonding in the metastable phase was relatively stronger than that in the stable form, which indicated the locally strong AD/SUC coupling in the initial stage of cocrystallization followed by the overall stabilization during the phase transformation. The stronger hydrogen bonding could be responsible for the faster nucleation of the initially observed metastable phase. The present study demonstrated that the polymeric additives could function as effective regulators for the polymorph-selective cocrystallization.

Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

KAUST Repository

Aljassim, Nada I.; Mantilla-Calderon, David; Wang, Tiannyu; Hong, Pei-Ying

2017-01-01

This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

KAUST Repository

Aljassim, Nada I.

2017-03-06

This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

Poly(ethylene oxide monomethyl ether)- block-poly(propylene succinate) Nanoparticles: Synthesis and Characterization, Enzymatic and Cellular Degradation, Micellar Solubilization of Paclitaxel, and in Vitro and in Vivo Evaluation.

Science.gov (United States)

Jäger, Alessandro; Jäger, Eliézer; Syrová, Zdeňka; Mazel, Tomas; Kováčik, Lubomír; Raška, Ivan; Höcherl, Anita; Kučka, Jan; Konefal, Rafal; Humajova, Jana; Poučková, Pavla; Štěpánek, Petr; Hrubý, Martin

2018-04-11

Polyester-based nanostructures are widely studied as drug-delivery systems due to their biocompatibility and biodegradability. They are already used in the clinic. In this work, we describe a new and simple biodegradable and biocompatible system as the Food and Drug Administration approved polyesters (poly-ε-caprolactone, polylactic acid, and poly(lactic- co-glycolic acid)) for the delivery of the anticancer drug paclitaxel (PTX) as a model drug. A hydrophobic polyester, poly(propylene succinate) (PPS), was prepared from a nontoxic alcohol (propylene glycol) and monomer from the Krebs's cycle (succinic acid) in two steps via esterification and melt polycondensation. Furthermore, their amphiphilic block copolyester, poly(ethylene oxide monomethyl ether)- block-poly(propylene succinate) (mPEO- b-PPS), was prepared by three steps via esterification followed by melt polycondensation and the addition of mPEO to the PPS macromolecules. Analysis of the in vitro cellular behavior of the prepared nanoparticle carriers (NPs) (enzymatic degradation, uptake, localization, and fluorescence resonance energy-transfer pair degradation studies) was performed by fluorescence studies. PTX was loaded to the NPs of variable sizes (30, 70, and 150 nm), and their in vitro release was evaluated in different cell models and compared with commercial PTX formulations. The mPEO- b-PPS copolymer analysis displays glass transition temperature hydrolysis during transport in bloodstream, and simultaneous enzymatic degradability after uptake into the cells. The detailed cytotoxicity in vitro and in vivo tumor efficacy studies have shown the superior efficacy of the NPs compared with PTX and PTX commercial formulations.

Treatment of inflammatory bowel disease associated E. coli with ciprofloxacin and E. coli Nissle in the streptomycin-treated mouse intestine

DEFF Research Database (Denmark)

Petersen, Andreas Munk; Schjørring, Susanne; Gerstrøm, Sarah Choi

2011-01-01

E. coli belonging to the phylogenetic group B2 are linked to Inflammatory Bowel Disease (IBD). Studies have shown that antimicrobials have some effect in the treatment of IBD, and it has been demonstrated that E. coli Nissle has prophylactic abilities comparable to 5-aminosalicylic acid (5-ASA......) therapy in ulcerative colitis. The objective of this study was to test if ciprofloxacin and/or E. coli Nissle could eradicate IBD associated E. coli in the streptomycin-treated mouse intestine....

Lipocalin 2 is protective against E. coli pneumonia

DEFF Research Database (Denmark)

Wu, Hong; Santoni-Rugiu, Eric; Ralfkiaer, Elisabeth

2010-01-01

Lipocalin 2 is a bacteriostatic protein that binds the siderophore enterobactin, an iron-chelating molecule produced by Escherichia coli (E. coli) that is required for bacterial growth. Infection of the lungs by E. coli is rare despite a frequent exposure to this commensal bacterium. Lipocalin 2...... is an effector molecule of the innate immune system and could therefore play a role in hindering growth of E. coli in the lungs....

FTIR nanobiosensors for Escherichia coli detection

Directory of Open Access Journals (Sweden)

Stefania Mura

2012-07-01

Full Text Available Infections due to enterohaemorrhagic E. coli (Escherichia coli have a low incidence but can have severe and sometimes fatal health consequences, and thus represent some of the most serious diseases due to the contamination of water and food. New, fast and simple devices that monitor these pathogens are necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyltriethoxysilane and GA (glutaraldehyde were functionalized with specific antibodies and the absorption properties monitored. The film-based biosensors showed a detection limit for E. coli of 1 × 102 CFU/mL, constituting a simple and selective method for the effective screening of water samples.

The influence of antioxidant and post-synthetic treatment on the properties of biodegradable poly(butylene succinates modified with poly(propylene oxide

Directory of Open Access Journals (Sweden)

DRAGANA PEPIC

2007-12-01

Full Text Available Novel poly(ester–ethers based on poly(butylene succinate (PBS as the hard segments and 30 mass % of poly(propylene oxide (PPO as the soft segments were synthesized with varying amount of the antioxidant (N,N'-diphenyl-p-phenylenediamine, DPPD. The influences of the addition of DPPD and the impact of post-synthetic treatment by precipitation on the molecular structure, thermal and physical properties, as well as on the storage stability of the biodegradable aliphatic copolyesters, were investigated. The structure and composition of the copolymers were determined by means of 1H-NMR spectroscopy. The molecular weight and polydispersity of the poly(ester–ethers were evaluated from solution viscosity and GPC measurements. The thermal properties and stability were evaluated, respecttively, by means of DSC and non-isothermal thermogravimetry in an inert nitrogen atmosphere. The biodegradability potential of the polymers was studied in hydrolytic and enzymatic degradation tests with Candida cylindracea lipase by monitoring the weight loss of polymer films after incubation. The weight losses of the samples increased with time and were in the range from 1 to 5 mass % after 4 weeks. GPC analysis confirmed that there were changes in the molecular weight of the copolyesters during both hydrolytic and enzymatic degradation tests, leading to the conclusion that the degradation mechanism of poly(butylenes succinate modified with PPO occurred through surface erosion and bulk degradation.

Vitamin E succinate-conjugated F68 micelles for mitoxantrone delivery in enhancing anticancer activity

Directory of Open Access Journals (Sweden)

Liu Y

2016-07-01

Full Text Available Yuling Liu,1,* Yingqi Xu,2,* Minghui Wu,3 Lijiao Fan,1 Chengwei He,2 Jian-Bo Wan,2 Peng Li,2 Meiwan Chen,2 Hui Li11Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, People’s Republic of China; 2State Key Laboratory of Quality Research in Chinese Medicine, Institute of Chinese Medical Sciences, University of Macau, Macau, People’s Republic of China; 3Department of Cell Biology and Anatomy, School of Medicine, University of Florida, Gainesville, FL, USA *These authors contributed equally to this work Abstract: Mitoxantrone (MIT is a chemotherapeutic agent with promising anticancer efficacy. In this study, Pluronic F68-vitamine E succinate (F68-VES amphiphilic polymer micelles were developed for delivering MIT and enhancing its anticancer activity. MIT-loaded F68–VES (F68–VES/MIT micelles were prepared via the solvent evaporation method with self-assembly under aqueous conditions. F68–VES/MIT micelles were found to be of optimal particle size with the narrow size distribution. Transmission electron microscopy images of F68–VES/MIT micelles showed homogeneous spherical shapes and smooth surfaces. F68–VES micelles had a low critical micelle concentration value of 3.311 mg/L, as well as high encapsulation efficiency and drug loading. Moreover, F68–VES/MIT micelles were stable in the presence of fetal bovine serum for 24 hours and maintained sustained drug release in vitro. Remarkably, the half maximal inhibitory concentration (IC50 value of F68–VES/MIT micelles was lower than that of free MIT in both MDA-MB-231 and MCF-7 cells (two human breast cancer cell lines. In addition, compared with free MIT, there was an increased trend of apoptosis and cellular uptake of F68–VES/MIT micelles in MDA-MB-231 cells. Taken together, these results indicated that F68–VES polymer micelles were able to effectively deliver MIT and largely improve its potency in cancer therapy. Keywords: F68, vitamin E

Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli

Science.gov (United States)

Mourand, G.; Paboeuf, F.; Fleury, M. A.; Jouy, E.; Bougeard, S.; Denamur, E.

2016-01-01

ABSTRACT Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli. Groups of pigs were orally inoculated with strain E. coli M63 carrying the blaCTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and blaCTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut. PMID:27795372

Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli.

Science.gov (United States)

Mourand, G; Paboeuf, F; Fleury, M A; Jouy, E; Bougeard, S; Denamur, E; Kempf, I

2017-01-01

Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli Groups of pigs were orally inoculated with strain E. coli M63 carrying the bla CTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and bla CTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log 10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut. Copyright © 2016 American Society for Microbiology.

Changes in Activities of Respiratory Enzymes in Lungs of Guinea-pigs Exposed to Silica Dust: II. Comparison of the Effects of Quartz Dust and Lampblack on the Succinate Oxidase System

Science.gov (United States)

Breyer, Maria G.; Kilroe-Smith, T. A.; Prinsloo, H.

1964-01-01

Kilroe-Smith and Breyer (1963) reported that in the early stages of silicosis in guinea-pigs exposed to the inhalation of quartz dust, before the formation of collagen, there were increases in the specific activities of the complete succinate oxidase system and succinate dehydrogenase. The effects on these enzymes of quartz dust have now been compared with the effects of the fibrogenically `inert' lampblack. Lampblack causes a slight increase in the specific activities of these enzymes but the effects are small compared to those caused by quartz. Lampblack also causes a much smaller increase in lung weight than quartz, thus the enzyme increases are roughly parallel to the rise in lung weight. It appears that the effects observed on the enzymes are part of the general pattern associated with the early stages of the development of silicosis. PMID:14106132

Enhanced target-specific signal detection using an Escherichia coli lysate in multiplex microbead immunoassays with E. coli-derived recombinant antigens.

Science.gov (United States)

Crestani, Sandra; Leitolis, Amanda; Lima, Lucianna Freitas Oliveira; Krieger, Marco A; Foti, Leonardo

2016-08-01

Diverse techniques have been developed to analyze antibody-mediated responses to infections. However, the most common tests, i.e., enzyme-linked immunosorbent assays, require separate reactions for each antigen and consequently necessitate large sample volumes. Luminex technology allows the detection of multiple antibodies in a single experiment, but nonspecific binding can impair the results. Therefore, we examined the use of Escherichia coli lysates to reduce nonspecific binding and improve the results of liquid microarrays based on Luminex technology. Anti-bacteria antibodies were detected in human serum samples, as evidenced by high median fluorescence intensity (MFI) in assays performed with paramagnetic microspheres coupled with E. coli lysates. Moreover, the addition of an E. coli lysate as a blocker reduced the nonspecific binding of antigens produced by E. coli in a concentration-dependent manner. Tris-HCl reduced MFI values in negative samples, but did not affect MFI for positive samples. For microspheres coupled with different antigens, an E. coli lysate blocker significantly improved the fluorescence signals from positive samples. The addition of Tris-HCl and the E. coli lysate induced antigen-specific differences in MFI. This combination of the E. coli lysate blocker and Tris-HCl yielded a statistically significant improvement in MFI in the assays for Chagas disease and hepatitis C virus samples. However, for the Treponema pallidum p47 antigen improvement in MFI was only observed for the preparation with the E. coli blocker at a concentration of 3%. In conclusion, the addition of an E. coli lysate and Tris-HCl to the microarray assay reduced the nonspecific binding of human anti-bacteria antibodies and, therefore, increased the specific MFI. Copyright © 2016 Elsevier B.V. All rights reserved.

WGS accurately predicts antimicrobial resistance in Escherichia coli

Science.gov (United States)

Objectives: To determine the effectiveness of whole-genome sequencing (WGS) in identifying resistance genotypes of multidrug-resistant Escherichia coli (E. coli) and whether these correlate with observed phenotypes. Methods: Seventy-six E. coli strains were isolated from farm cattle and measured f...

Profiling of Escherichia coli Chromosome database.

Science.gov (United States)

Yamazaki, Yukiko; Niki, Hironori; Kato, Jun-ichi

2008-01-01

The Profiling of Escherichia coli Chromosome (PEC) database (http://www.shigen.nig.ac.jp/ecoli/pec/) is designed to allow E. coli researchers to efficiently access information from functional genomics studies. The database contains two principal types of data: gene essentiality and a large collection of E. coli genetic research resources. The essentiality data are based on data compilation from published single-gene essentiality studies and on cell growth studies of large-deletion mutants. Using the circular and linear viewers for both whole genomes and the minimal genome, users can not only gain an overview of the genome structure but also retrieve information on contigs, gene products, mutants, deletions, and so forth. In particular, genome-wide exhaustive mutants are an essential resource for studying E. coli gene functions. Although the genomic database was constructed independently from the genetic resources database, users may seamlessly access both types of data. In addition to these data, the PEC database also provides a summary of homologous genes of other bacterial genomes and of protein structure information, with a comprehensive interface. The PEC is thus a convenient and useful platform for contemporary E. coli researchers.

Evaluation of Petrifilm™ Select E. coli Count Plate medium to discriminate antimicrobial resistant Escherichia coli

Directory of Open Access Journals (Sweden)

Jensen Lars

2008-09-01

Full Text Available Abstract Background Screening and enumeration of antimicrobial resistant Escherichia coli directly from samples is needed to identify emerging resistant clones and obtain quantitative data for risk assessment. Aim of this study was to evaluate the performance of 3M™ Petrifilm™ Select E. coli Count Plate (SEC plate supplemented with antimicrobials to discriminate antimicrobial-resistant and non-resistant E. coli. Method A range of E. coli isolates were tested by agar dilution method comparing the Minimal Inhibitory Concentration (MIC for eight antimicrobials obtained by Mueller-Hinton II agar, MacConkey agar and SEC plates. Kappa statistics was used to assess the levels of agreement when classifying strains as resistant, intermediate or susceptible. Results SEC plate showed that 74% of all strains agreed within ± 1 log2 dilution when comparing MICs with Mueller-Hinton II media. High agreement levels were found for gentamicin, ampicillin, chloramphenicol and cefotaxime, resulting in a kappa value of 0.9 and 100% agreement within ± 1 log2 dilution. Significant variances were observed for oxytetracycline and sulphamethoxazole. Further tests showed that the observed discrepancy in classification of susceptibility to oxytetracycline by the two media could be overcome when a plate-dependent breakpoint of 64 mg/L was used for SEC plates. For sulphamethoxazole, SEC plates provided unacceptably high MICs. Conclusion SEC plates showed good agreement with Mueller-Hinton II agar in MIC studies and can be used to screen and discriminate resistant E. coli for ampicillin, cephalothin, streptomycin, chloramphenicol, cefotaxime and gentamicin using CLSI standardized breakpoints, but not for sulphamethoxazole. SEC plates can also be used to discriminate oxytetracycline-resistant E. coli if a plate-dependent breakpoint value of 64 mg/L is used.

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra......-intestinal pathogenic E. coli (ExPEC) are able to colonize tissue outside the gastrointestinal tract and contain a variety of virulence factors that may enable the pathogens to invade and induce infections in the cardiac endothelia. In these cases echocardiography as the imaging technology is of paramount importance...

Effect of Anorganic Substance on Physical Properties of Poly (Butylene Succinate -co- Adipate) Irradiated by Electron Beam

International Nuclear Information System (INIS)

Meri Suhartini

2004-01-01

Poly(butylene succinate-co-adipate), PBSA were electron beam irradiated in the presence of inorganic materials. The samples gave high gel fraction by irradiation in the presence of 2% silicon dioxide and 2% carbon black. It was found that addition of carbon black (CB) was effective for improving the heat stability of the sample. This is because of three-dimensional carbon black- polymer networks. Irradiated PBSA sheets broke immediately at 110 o C with load 6.67 kgf/cm 2 , while irradiated the same sample mixed with 2% carbon black did not break at the same condition. Biodegradability of crosslinked PBSA by soil burial tests was accelerated by addition of carbon black. (author)

Infectious endocarditis caused by Escherichia coli

DEFF Research Database (Denmark)

Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

2011-01-01

Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra...

Glucose uptake regulation in E. coli by the small RNA SgrS: comparative analysis of E. coli K-12 (JM109 and MG1655 and E. coli B (BL21

Directory of Open Access Journals (Sweden)

Ng Weng-Ian

2010-09-01

Full Text Available Abstract Background The effect of high glucose concentration on the transcription levels of the small RNA SgrS and the messenger RNA ptsG, (encoding the glucose transporter IICBGlc, was studied in both E. coli K-12 (MG1655 and JM109 and E. coli B (BL21. It is known that the transcription level of sgrS increases when E. coli K-12 (MG1655 and JM109 is exposed to the non-metabolized glucose alpha methyl glucoside (αMG or when the bacteria with a defective glycolysis pathway is grown in presence of glucose. The increased level of sRNA SgrS reduces the level of the ptsG mRNA and consequently lowers the level of the glucose transporter IICBGlc. The suggested trigger for this action is the accumulation of the corresponding phospho-sugars. Results In the course of the described work, it was found that E. coli B (BL21 and E. coli K-12 (JM109 and MG1655 responded similarly to αMG: both strains increased SgrS transcription and reduced ptsG transcription. However, the two strains reacted differently to high glucose concentration (40 g/L. E. coli B (BL21 reacted by increasing sgrS transcription and reducing ptsG transcription while E. coli K-12 (JM109 and MG1655 did not respond to the high glucose concentration, and, therefore, transcription of sgrS was not detected and ptsG mRNA level was not affected. Conclusions The results suggest that E. coli B (BL21 tolerates high glucose concentration not only by its more efficient central carbon metabolism, but also by controlling the glucose transport into the cells regulated by the sRNA SgrS, which may suggest a way to control glucose consumption and increase its efficient utilization.

Endogenous E. coli endophthalmitis.

Science.gov (United States)

Shammas, H F

1977-01-01

A case of Escherichia coli septicemia with associated metastatic en dophthalmitis and endocarditis is presented. The ocular signs and symptoms were the initial manifestations of sepsis. Irreversible damage to the eye occurred in less than 24 hours. The pattern of metastatic bacterial endophthalmitis has changed since the introduction of potent antimicrobial agents, with an increased incidence of Gram-negative bacillemia. E. coli endophthalmitis carries a poor prognosis. Early diagnosis and systemic treatment will prevent the life-threatening complications of sepsis.

Characterization, in Vivo and in Vitro Evaluation of Solid Dispersion of Curcumin Containing d-α-Tocopheryl Polyethylene Glycol 1000 Succinate and Mannitol

OpenAIRE

Im-Sook Song; Jin-Sun Cha; Min-Koo Choi

2016-01-01

The aim of this study was to prepare a solid dispersion formulation of curcumin to enhance its solubility, dissolution rate, and oral bioavailability. The formulation was prepared with d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) and mannitol using solvent evaporation and freeze-drying methods, which yielded a solid dispersion composed of curcumin, TPGS, and mannitol at a ratio of 1:10:15 (w/w/w). The solubility and dissolution rate of the curcumin solid dispersion markedly improv...

Escherichia coli pyomyositis in an immunocompromised host.

Science.gov (United States)

Sharma, Umesh; Schwan, William R; Agger, William A

2011-08-01

Pyomyositis due to Escherichia coli (E. coil) is rarely reported in immunocompromised patients with hematological malignancy. We present a case report of a 34-year-old man who developed E. coli pyomyositis as a complication of acute myelogenous leukemia (AML). Magnetic resonance imaging (MRI) of the right hip suggested myofascial infection of the gluteal muscles, and a needle muscle aspiration grew E. coli phylogenetic group B2. The patient responded to intravenous piperacillin/tazobactam followed by prolonged oral levofloxacin. Pyomyositis should be suspected in all immunocompromised patients complaining of muscle pain and may exhibit signs of localized muscle infection. Appropriate antibiotic therapy targeting fluoroquinolone-resistant E. coli should be considered for initial empiric therapy of pyomyositis in immunocompromised patients.

Impaired succinic dehydrogenase activity of rat Purkinje cell mitochondria during aging.

Science.gov (United States)

Fattoretti, P; Bertoni-Freddari, C; Caselli, U; Paoloni, R; Meier-Ruge, W

1998-03-16

The perikaryal Purkinje cell mitochondria positive to the copper ferrocyanide histochemical reaction for succinic dehydrogenase (SDH) have been investigated by means of semiautomatic morphometric methods in rats of 3, 12 and 24 months of age. The number of organelles/microm3 of Purkinje cell cytoplasm (Numeric density: Nv), the average mitochondrial volume (V) and the mitochondrial volume fraction (Volume density: Vv) were the ultrastructural parameters taken into account. Nv was significantly higher at 12 than at 3 and 24 months of age. V was significantly decreased at 12 and 24 months of age, but no difference was envisaged between adult and old rats. Vv was significantly decreased in old animals vs. the other age groups. In young and old rats, the percentage of organelles larger than 0.32 microm3 was 13.5 and 11%, respectively, while these enlarged mitochondria accounted for less than 1% in the adult group. Since SDH activity is of critical importance when energy demand is high, the marked decrease of Vv supports an impaired capacity of the old Purkinje cells to match actual energy supply at sustained transmission of the nervous impulse. However, the high percentage of enlarged organelles found in old rats may witness a morphofunctional compensatory response.

Gene encoding virulence markers among Escherichia coli isolates ...

African Journals Online (AJOL)

River water sources and diarrhoeic stools of residents in the Venda Region, Limpopo Province of South Africa were analysed for the prevalence of Escherichia coli (E. coli) and the presence of virulence genes among the isolates. A control group of 100 nondiarrhoeic stool samples was included. Escherichia coli was ...

Genomic Comparative Study of Bovine Mastitis Escherichia coli.

Science.gov (United States)

Kempf, Florent; Slugocki, Cindy; Blum, Shlomo E; Leitner, Gabriel; Germon, Pierre

2016-01-01

Escherichia coli, one of the main causative agents of bovine mastitis, is responsible for significant losses on dairy farms. In order to better understand the pathogenicity of E. coli mastitis, an accurate characterization of E. coli strains isolated from mastitis cases is required. By using phylogenetic analyses and whole genome comparison of 5 currently available mastitis E. coli genome sequences, we searched for genotypic traits specific for mastitis isolates. Our data confirm that there is a bias in the distribution of mastitis isolates in the different phylogenetic groups of the E. coli species, with the majority of strains belonging to phylogenetic groups A and B1. An interesting feature is that clustering of strains based on their accessory genome is very similar to that obtained using the core genome. This finding illustrates the fact that phenotypic properties of strains from different phylogroups are likely to be different. As a consequence, it is possible that different strategies could be used by mastitis isolates of different phylogroups to trigger mastitis. Our results indicate that mastitis E. coli isolates analyzed in this study carry very few of the virulence genes described in other pathogenic E. coli strains. A more detailed analysis of the presence/absence of genes involved in LPS synthesis, iron acquisition and type 6 secretion systems did not uncover specific properties of mastitis isolates. Altogether, these results indicate that mastitis E. coli isolates are rather characterized by a lack of bona fide currently described virulence genes.

Fimbrial adhesins from extraintestinal Escherichia coli

DEFF Research Database (Denmark)

Klemm, Per; Hancock, Viktoria; Schembri, Mark A.

2010-01-01

Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment...

Experimental determination of control by the H⁺-ATPase in Escherichia coli

DEFF Research Database (Denmark)

Jensen, Peter Ruhdal; Michelsen, Ole; Westerhoff, H. V.

1995-01-01

Strains carrying deletions in the atp genes, encoding the H+-ATPase, were unable to grow on nonfermentable substrates such as succinate, whereas with glucose as the substrate the growth rate of an atp deletion mutant was surprisingly high (some 75-80% of wild-type growth rate). The rate of glucos...

PATHOGENIC POTENTIALS OF ESCHERICHIA COLI ISOLATED ...

African Journals Online (AJOL)

Electrolyte and haematological parameters in rabbits infected with pathogenic isolates of Escherichia coli from rural water supplies in Rivers State, Nigeria, where monitored. Rabbits were orally infected with suspension containing 3x107 cfu /ml of Escherichia coli to induce diarrhoea, and the electrolyte (sodium, potassium ...

Synergistic effects in mixed Escherichia coli biofilms

DEFF Research Database (Denmark)

Reisner, A.; Holler, B.M.; Molin, Søren

2006-01-01

Bacterial biofilms, often composed of multiple species and genetically distinct strains, develop under complex influences of cell-cell interactions. Although detailed knowledge about the mechanisms underlying formation of single-species laboratory biofilms has emerged, little is known about...... the pathways governing development of more complex heterogeneous communities. In this study, we established a laboratory model where biofilm-stimulating effects due to interactions between genetically diverse strains of Escherichia coli were monitored. Synergistic induction of biofilm formation resulting from...... the cocultivation of 403 undomesticated E. coli strains with a characterized E. coli K-12 strain was detected at a significant frequency. The survey suggests that different mechanisms underlie the observed stimulation, yet synergistic development of biofilm within the subset of E. coli isolates (n = 56) exhibiting...

Enhancement of malate-production and increase in sensitivity to dimethyl succinate by mutation of the VID24 gene in Saccharomyces cerevisiae.

Science.gov (United States)

Negoro, Hiroaki; Kotaka, Atsushi; Matsumura, Kengo; Tsutsumi, Hiroko; Hata, Yoji

2016-06-01

Malate in sake (a Japanese alcoholic beverage) is an important component for taste that is produced by yeasts during alcoholic fermentation. To date, many researchers have developed methods for breeding high-malate-producing yeasts; however, genes responsible for the high-acidity phenotype are not known. We determined the mutated gene involved in high malate production in yeast, isolated as a sensitive mutant to dimethyl succinate. In the comparative whole genome analysis between high-malate-producing strain and its parent strain, one of the non-synonymous substitutions was identified in the VID24 gene. The mutation of VID24 resulted in enhancement of malate-productivity and sensitivity to dimethyl succinate. The mutation appeared to lead to a deficiency in Vid24p function. Furthermore, disruption of cytoplasmic malate dehydrogenase (Mdh2p) gene in the VID24 mutant inhibited the high-malate-producing phenotype. Vid24p is known as a component of the multisubunit ubiquitin ligase and participates in the degradation of gluconeogenic enzymes such as Mdh2p. We suggest that the enhancement of malate-productivity results from an accumulation of Mdh2p due to the loss of Vid24p function. These findings propose a novel mechanism for the regulation of organic acid production in yeast cells by the component of ubiquitin ligase, Vid24p. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Faecal Escherichia coli from patients with E. coli urinary tract infection and healthy controls who have never had a urinary tract infection

DEFF Research Database (Denmark)

Nielsen, Karen L; Dynesen, Pia; Larsen, Preben

2014-01-01

Urinary tract infections (UTIs) are primarily caused by Escherichia coli with the patient's own faecal flora acting as a reservoir for the infecting E. coli. Here we sought to characterize the E. coli faecal flora of UTI patients and healthy controls who had never had a UTI. Up to 20 E. coli...... colonies from each rectal swab were random amplified polymorphic DNA (RAPD) typed for clonality, dominance in the sample and correlation to the infecting UTI isolate in patients. Each distinct clone was phylotyped and tested for antimicrobial susceptibility. Eighty-seven per cent of the UTI patients...... carried the infecting strain in their faecal flora, and faecal clones causing UTI were more often dominant in the faecal flora. Patients had a larger diversity of E. coli in their gut flora by carrying more unique E. coli clones compared to controls, and patient faecal clones were more often associated...

77 FR 9888 - Shiga Toxin-Producing Escherichia coli

Science.gov (United States)

2012-02-21

... Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service... toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145). This new date..., that are contaminated with Shiga toxin-producing Escherichia coli (STEC) O26, O45, O103, O111, O121...

RRR-alpha-tocopheryl succinate inhibits EL4 thymic lymphoma cell growth by inducing apoptosis and DNA synthesis arrest.

Science.gov (United States)

Yu, W; Sanders, B G; Kline, K

1997-01-01

RRR-alpha-tocopheryl succinate (vitamin E succinate, VES) treatment of murine EL4 T lymphoma cells induced the cells to undergo apoptosis. After 48 hours of VES treatment at 20 micrograms/ml, 95% of cells were apoptotic. Evidence for the induction of apoptosis by VES treatments is based on staining of DNA for detection of chromatin condensation/fragmentation, two-color flow-cytometric analyses of DNA content, and end-labeled DNA and electrophoretic analyses for detection of DNA ladder formation. VES-treated EL4 cells were blocked in the G1 cell cycle phase; however, apoptotic cells came from all cell cycle phases. Analyses of mRNA expression of genes involved in apoptosis revealed decreased c-myc and increased bcl-2, c-fos, and c-jun mRNAs within three to six hours after treatment. Western analyses showed increased c-Jun, c-Fos, and Bcl-2 protein levels. Electrophoretic mobility shift assays showed increased AP-1 binding at 6, 12, and 24 hours after treatment and decreased c-Myc binding after 12 and 24 hours of VES treatment. Treatments of EL4 cells with VES+RRR-alpha-to-copherol reduced apoptosis without effecting DNA synthesis arrest. Treatments of EL4 cells with VES+rac-6-hydroxyl-2, 5,7,8-tetramethyl-chroman-2-carboxylic acid, butylated hydroxytoluene, or butylated hydroxyanisole had no effect on apoptosis or DNA synthesis arrest caused by VES treatments. Analyses of bcl-2, c-myc, c-jun, and c-fos mRNA levels in cells receiving VES + RRR-alpha-tocopherol treatments showed no change from cells receiving VES treatments alone, implying that these changes are correlated with VES treatments but are not causal for apoptosis. However, treatments with VES + RRR-alpha-tocopherol decreased AP-1 binding to consensus DNA oligomer, suggesting AP-1 involvement in apoptosis induced by VES treatments.

Synthesis of avenanthramides using engineered Escherichia coli.

Science.gov (United States)

Lee, Su Jin; Sim, Geun Young; Kang, Hyunook; Yeo, Won Seok; Kim, Bong-Gyu; Ahn, Joong-Hoon

2018-03-22

Hydroxycinnamoyl anthranilates, also known as avenanthramides (avns), are a group of phenolic alkaloids with anti-inflammatory, antioxidant, anti-itch, anti-irritant, and antiatherogenic activities. Some avenanthramides (avn A-H and avn K) are conjugates of hydroxycinnamic acids (HC), including p-coumaric acid, caffeic acid, and ferulic acid, and anthranilate derivatives, including anthranilate, 4-hydroxyanthranilate, and 5-hydroxyanthranilate. Avns are primarily found in oat grain, in which they were originally designated as phytoalexins. Knowledge of the avns biosynthesis pathway has now made it possible to synthesize avns through a genetic engineering strategy, which would help to further elucidate their properties and exploit their beneficial biological activities. The aim of the present study was to synthesize natural avns in Escherichia coli to serve as a valuable resource. We synthesized nine avns in E. coli. We first synthesized avn D from glucose in E. coli harboring tyrosine ammonia lyase (TAL), 4-coumarate:coenzyme A ligase (4CL), anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT), and anthranilate synthase (trpEG). A trpD deletion mutant was used to increase the amount of anthranilate in E. coli. After optimizing the incubation temperature and cell density, approximately 317.2 mg/L of avn D was synthesized. Avn E and avn F were then synthesized from avn D, using either E. coli harboring HpaBC and SOMT9 or E. coli harboring HapBC alone, respectively. Avn A and avn G were synthesized by feeding 5-hydroxyanthranilate or 4-hydroxyanthranilate to E. coli harboring TAL, 4CL, and HCBT. Avn B, avn C, avn H, and avn K were synthesized from avn A or avn G, using the same approach employed for the synthesis of avn E and avn F from avn D. Using different HCs, nine avns were synthesized, three of which (avn D, avn E, and avn F) were synthesized from glucose in E. coli. These diverse avns provide a strategy to synthesize both natural and unnatural avns

Distribution of Diverse Escherichia coli between Cattle and Pasture

OpenAIRE

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N.; Brözel, Volker S.

2017-01-01

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isola...

PART I. ESCHERICHIA COLI

Directory of Open Access Journals (Sweden)

Sanaa Mahdi Oraibi

2016-11-01

Full Text Available The presence of Escherichia coli in the air of facilities involved in management and composting of post-slaughter poultry wastes in selected plants of West Western Pomerania region was studied. Measurements were made on four dates in a variety of weather conditions during the year. The study was conducted at 5 objects that differ in the type of waste and the degree of preparation for composting. These were: chemical treatment and preliminary processing plant, liquid wastes reservoir, platform for preparation of materials for composting, storage of biological sediments, and composting facility. Measurement of bacteria count was carried out in accordance with the applicable procedures on selective chromogenic TBX medium. The assays revealed the presence of E. coli at all test objects, but not always on all measurement dates. It has been shown that the presence of E. coli was from 20 to 3047 CFU∙m-3 of air, although the largest quantities were most frequently detected in the air of the building for post-slaughter waste pre-treatment in chemical treatment plant.

Radioprotective properties of tocopherol succinate against ionizing radiation in mice

International Nuclear Information System (INIS)

Singh, V.K.; Singh, P.K.; Wise, S.Y.; Posarac, A.; Fatanmi, O.O.

2013-01-01

Threats of nuclear and other radiologic exposures have been increasing but no countermeasure for acute radiation syndrome has been approved by regulatory authorities. In prior publications we have demonstrated the efficacy of tocopherol succinate (TS) as a promising radiation countermeasure with the potential to protect against lethal doses of ionizing radiation exposure. The aim of this study was to gain further insight regarding how TS protects mice against a lethal dose of radiation. CD2F1 mice were injected subcutaneously with 400 mg/kg of TS, and 24 h later exposed to 60 Co γ-radiation. Intestinal tissues or spleen/thymus were harvested after irradiation and analyzed for CD68-positive inflammatory cells and apoptotic cells by immunostaining of jejunal cross-sections. Comet assay was used to analyze DNA damage in various tissues. Phospho-histone H3 (pH3) and the proliferating cell nuclear antigen (PCNA) were used as mitotic markers for immunostaining jejunal cross-sections. We observed that injecting TS significantly decreased the number of CD68-positive cells, DNA damage and apoptotic cells (bcl-associated X protein (BAX), caspase 3 and cleaved poly (ADP-ribose) polymerase-positive cells) as judged by various apoptotic pathway markers. TS treatment also increased proliferating cells in irradiated mice. Results of this study further support our contention that TS protects mice against lethal doses of ionizing radiation by inhibiting radiation-induced apoptosis and DNA damage while enhancing cell proliferation. (author)

The effect of epoxidized soybean oil on mechanical and rheological properties of poly(butylene succinate)/lignin via vane extruder

Science.gov (United States)

Liu, Huanyu; Huang, Zhaoxia; Qu, Jinping; Meng, Cong

2016-03-01

Epoxidized Soybean Oil (ESO) have been used as the compatilizer in the Poly (butylene succinate)/lignin (PBS/lignin) composites. Compatibilized composites were fabricated by a novel vane extruder (VE) which can generate global and dynamic elongational flow. The effects of ESO on the mechanical, rheological properties and morphology of PBS/lignin were studied. The results indicated that the use of ESO had plasticizing effect on the matrix PBS while the addition reduced tensile strength. From SEM micrographs it could be clearly observed that there was a better interfacial adhesion between lignin and matrix. Meanwhile, rheological tests showed the incorporation of ESO improved its Newtonian behavior and can enhance PBS's flexibility.

Colonization of Enteroaggregative Escherichia coli and Shiga toxin-producing Escherichia coli in chickens and humans in southern Vietnam

NARCIS (Netherlands)

Trung, Nguyen Vinh; Nhung, Hoang Ngoc; Carrique-Mas, Juan J.; Mai, Ho Huynh; Tuyen, Ha Thanh; Campbell, James; Nhung, Nguyen Thi; van Minh, Pham; Wagenaar, Jaap A.; Mai, Nguyen Thi Nhu; Hieu, Thai Quoc; Schultsz, Constance; Hoa, Ngo Thi

2016-01-01

Enteroaggregative (EAEC) and Shiga-toxin producing Escherichia coli (STEC) are a major cause of diarrhea worldwide. E. coli carrying both virulence factors characteristic for EAEC and STEC and producing extended-spectrum beta-lactamase caused severe and protracted disease during an outbreak of E.

EsrE-A yigP Locus-Encoded Transcript-Is a 3′ UTR sRNA Involved in the Respiratory Chain of E. coli

Directory of Open Access Journals (Sweden)

Hui Xia

2017-08-01

Full Text Available The yigP locus is widely conserved among γ-proteobacteria. Mutation of the yigP locus impacts aerobic growth of Gram-negative bacteria. However, the underlying mechanism of how the yigP locus influences aerobic growth remains largely unknown. Here, we demonstrated that the yigP locus in Escherichia coli encodes two transcripts; the mRNA of ubiquinone biosynthesis protein, UbiJ, and the 3′ untranslated region small regulatory RNA (sRNA, EsrE. EsrE is an independent transcript that is transcribed using an internal promoter of the yigP locus. Surprisingly, we found that both the EsrE sRNA and UbiJ protein were required for Q8 biosynthesis, and were sufficient to rescue the growth defect ascribed to deletion of the yigP locus. Moreover, our data showed that EsrE targeted multiple mRNAs involved in several cellular processes including murein biosynthesis and the tricarboxylic acid cycle. Among these targets, sdhD mRNA that encodes one subunit of succinate dehydrogenase (SDH, was significantly activated. Our findings provided an insight into the important function of EsrE in bacterial adaptation to various environments, as well as coordinating different aspects of bacterial physiology.

Survival of pathogenic Escherichia coli on basil, lettuce, and spinach

Science.gov (United States)

The contamination of lettuce, spinach and basil with pathogenic E. coli has caused numerous illnesses over the past decade. E. coli O157:H7, E. coli O104:H4 and avian pathogenic E. coli (APECstx- and APECstx+) were inoculated on basil plants and in promix soiless substrate using drip and overhead ir...

Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

Science.gov (United States)

Li, Tianzhen; Zhou, Wei; Bi, Huiping; Zhuang, Yibin; Zhang, Tongcun; Liu, Tao

2018-07-01

To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli. We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli-E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L. Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

Characterization of Escherichia coli Phylogenetic Groups ...

African Journals Online (AJOL)

Background: Escherichia coli strains mainly fall into four phylogenetic groups (A, B1, B2, and D) and that virulent extra‑intestinal strains mainly belong to groups B2 and D. Aim: The aim was to determine the association between phylogenetic groups of E. coli causing extraintestinal infections (ExPEC) regarding the site of ...

Interaction of Escherichia coli with growing salad spinach plants.

Science.gov (United States)

Warriner, Keith; Ibrahim, Faozia; Dickinson, Matthew; Wright, Charles; Waites, William M

2003-10-01

In this study, the interaction of a bioluminescence-labeled Escherichia coli strain with growing spinach plants was assessed. Through bioluminescence profiles, the direct visualization of E. coli growing around the roots of developing seedlings was accomplished. Subsequent in situ glucuronidase (GUS) staining of seedlings confirmed that E. coli had become internalized within root tissue and, to a limited extent, within hypocotyls. When inoculated seeds were sown in soil microcosms and cultivated for 42 days, E. coli was recovered from the external surfaces of spinach roots and leaves as well as from surface-sterilized roots. When 20-day-old spinach seedlings (from uninoculated seeds) were transferred to soil inoculated with E. coli, the bacterium became established on the plant surface, but internalization into the inner root tissue was restricted. However, for seedlings transferred to a hydroponic system containing 10(2) or 10(3) CFU of E. coli per ml of the circulating nutrient solution, the bacterium was recovered from surface-sterilized roots, indicating that it had been internalized. Differences between E. coli interactions in the soil and those in the hydroponic system may be attributed to greater accessibility of the roots in the latter model. Alternatively, the presence of a competitive microflora in soil may have restricted root colonization by E. coli. The implications of this study's findings with regard to the microbiological safety of minimally processed vegetables are discussed.

Crystal growth, structural, spectral, thermal, dielectric, linear and nonlinear optical characteristics of a new organic acentric material: L-Methionine-Succinic acid (2/1)

Science.gov (United States)

Nageshwari, M.; Kumari, C. Rathika Thaya; Vinitha, G.; Mohamed, M. Peer; Sudha, S.; Caroline, M. Lydia

2018-03-01

L-Methionine-Succinic acid (2/1) (LMSA), 2C5H11NO2S·C4H6O4, a novel nonlinear optical material which belongs to the class of organic category was grown-up for the first time by the technique of slow evaporation. Purity of LMSA was improved using repetitive recrystallization. LMSA was analyzed by single crystal and powder X-ray diffraction investigation to affirm the crystal structure and crystalline character. The single crystal XRD revealed that LMSA corresponds to the crystal system of triclinic with P1 as space group showing the asymmetric unit consists of a neutral succinic acid molecule and two methionine residues which are crystallographically independent existing in zwitterionic form. The functional groups existing in LMSA was accomplished using Fourier transform infrared spectroscopy. The optical transparency and the band gap energy were identified utilizing UV-Visible spectrum. The optical constants specifically reflectance and extinction coefficient clearly indicate the elevated transparency of LMSA. The thermal analyses affirmed its thermal stability. The luminescence behavior of LMSA has been analyzed by Photoluminescence (PL) spectral study. The mechanical, laser damage threshold and dielectric investigation of LMSA was done to suggest the material for practical applications. The second and third harmonic generation efficacy was confirmed by means of Kurtz-Perry and Z-scan procedure which attest its potentiality in the domain of nonlinear optics.

A scoping study on the prevalence of Escherichia coli and ...

African Journals Online (AJOL)

In the Eastern Cape Province E. coli and enterococci were detected in 7 and 4 of the 15 RHRW tanks, respectively. Enterococci were detected only from one river whereas E. coli was detected in all three rivers; in spring water neither enterococci nor E. coli were detected. Samples from GRWH tanks were positive for E. coli ...

Asymptomatic bacteriuria Escherichia coli are live biotherapeutics for UTI.

Science.gov (United States)

Rudick, Charles N; Taylor, Aisha K; Yaggie, Ryan E; Schaeffer, Anthony J; Klumpp, David J

2014-01-01

Urinary tract infections (UTI) account for approximately 8 million clinic visits annually with symptoms that include acute pelvic pain, dysuria, and irritative voiding. Empiric UTI management with antimicrobials is complicated by increasing antimicrobial resistance among uropathogens, but live biotherapeutics products (LBPs), such as asymptomatic bacteriuria (ASB) strains of E. coli, offer the potential to circumvent antimicrobial resistance. Here we evaluated ASB E. coli as LBPs, relative to ciprofloxacin, for efficacy against infection and visceral pain in a murine UTI model. Visceral pain was quantified as tactile allodynia of the pelvic region in response to mechanical stimulation with von Frey filaments. Whereas ciprofloxacin promoted clearance of uropathogenic E. coli (UPEC), it did not reduce pelvic tactile allodynia, a measure of visceral pain. In contrast, ASB E. coli administered intravesically or intravaginally provided comparable reduction of allodynia similar to intravesical lidocaine. Moreover, ASB E. coli were similarly effective against UTI allodynia induced by Proteus mirabilis, Enterococccus faecalis and Klebsiella pneumoniae. Therefore, ASB E. coli have anti-infective activity comparable to the current standard of care yet also provide superior analgesia. These studies suggest that ASB E. coli represent novel LBPs for UTI symptoms.

Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

Science.gov (United States)

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

Science.gov (United States)

Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing...

Complete Genome Sequence of Escherichia coli Strain WG5

DEFF Research Database (Denmark)

Imamovic, Lejla; Misiakou, Maria-Anna; van der Helm, Eric

2018-01-01

Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.......Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain....

Environmental Escherichia coli: Ecology and public health implications - A review

Science.gov (United States)

Jang, Jeonghwan; Hur, Hor-Gil; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Yan, Tao; Ishii, Satoshi

2017-01-01

Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through feces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent fecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extra-intestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a fecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics provide the diversity and complexity of E. coli strains in various environments, affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments in regards to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.

Neonatal infections caused by Escherichia coli at the National ...

African Journals Online (AJOL)

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

neonatal infections caused by escherichia coli at the national

African Journals Online (AJOL)

boaz

Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

Molecular prophage typing of avian pathogenic Escherichia coli.

Science.gov (United States)

Kwon, Hyuk-Joon; Seong, Won-Jin; Kim, Jae-Hong

2013-03-23

Escherichia coli prophages confer virulence and resistance to physico-chemical, nutritional, and antibiotic stresses on their hosts, and they enhance the evolution of E. coli. Thus, studies on profiles of E. coli prophages are valuable to understand the population structure and evolution of E. coli pathogenicity. Large terminase genes participate in phage genome packaging and are one of the cornerstones for the identification of prophages. Thus, we designed primers to detect 16 types of large terminase genes and analyzed the genomes of 48 E. coli and Shigella reference strains for the prophage markers. We also investigated the distribution of the 16 prophage markers among 92 avian pathogenic E. coli (APEC) strains. APEC strains were classified into 61 prophage types (PPTs). Each strain was different from the reference strains as measured by the PPTs and from the frequency of each prophage marker. Investigation of the distribution of prophage-related serum resistance (bor), toxin (stx1 and cdtI), and T3SS effector (lom, espK, sopE, nleB, and ospG) genes revealed the presence of bor (44.1%), lom (95.5%) and cdtI (9.1%) in APEC strains with related prophages. Therefore, the molecular prophage typing method may be useful to understand population structure and evolution of E. coli pathogenicity, and further studies on the mobility of the prophages and the roles of virulence genes in APEC pathogenicity may be valuable. Copyright © 2012 Elsevier B.V. All rights reserved.

Preparation and structural characterisation of novel and versatile amphiphilic octenyl succinic anhydride-modified hyaluronic acid derivatives

DEFF Research Database (Denmark)

Eenschooten, Corinne Diane; Guillaumie, Fanny; Kontogeorgis, Georgios

2010-01-01

and structurally characterised by Fourier transform-infrared spectroscopy and proton nuclear magnetic resonance spectroscopy (1H NMR). The influence of four reaction parameters on the DS of the derivatives was studied by means of an experimental design. The results showed that the OSA/HA molar ratio, the buffer......The purpose of the present study was to prepare amphiphilic hyaluronic acid (HA) derivatives and to study the influence of a selection of reaction parameters on the degree of substitution (DS) of the derivatives. Octenyl succinic anhydride (OSA)–modified HA (OSA–HA) derivatives were prepared...... (NaHCO3) concentration and their interaction had the largest influence while the HA concentration and the reaction time only had a negligible effect. According to 1H NMR the maximum DS achieved within the experimental conditions tested was 43% per disaccharide unit. Moreover optimal reaction...

Non-Escherichia coli versus Escherichia coli community-acquired urinary tract infections in children hospitalized in a tertiary center: relative frequency, risk factors, antimicrobial resistance and outcome.

Science.gov (United States)

Marcus, Nir; Ashkenazi, Shai; Yaari, Arnon; Samra, Zmira; Livni, Gilat

2005-07-01

Currently hospitalization for children with urinary tract infections (UTIs) is reserved for severe or complicated cases. Changes may have taken place in the characteristics and causative uropathogens of hospital-treated community-acquired UTI. To study children hospitalized in a tertiary center with community-acquired UTI, compare Escherichia coli and non-E. coli UTI, define predictors for non-E. coli UTI and elucidate the appropriate therapeutic approach. A prospective clinical and laboratory study from 2001 through 2002 in a tertiary pediatric medical center. Patients were divided by results of the urine culture into E. coli and non-E. coli UTI groups, which were compared. Of 175 episodes of culture-proved UTI, 70 (40%) were caused by non-E. coli pathogens. Non-E. coli UTI was more commonly found in children who were male (P = 0.005), who had underlying renal abnormalities (P = 0.0085) and who had received antibiotic therapy in the prior month (P = 0.0009). Non-E. coli uropathogens were often resistant to antibiotics usually recommended for initial therapy for UTI, including cephalosporins and aminoglycosides; 19% were initially treated with inappropriate empiric intravenous antibiotics (compared with 2% for E. coli UTI, P = 0.0001), with a longer hospitalization. Current treatment routines are often inappropriate for hospitalized children with non-E. coli UTI, which is relatively common in this population. The defined risk factors associated with non-E. coli UTIs and its antimicrobial resistance patterns should be considered to improve empiric antibiotic therapy for these infections.

Pulsed-Plasma Disinfection of Water Containing Escherichia coli

Science.gov (United States)

Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

2007-03-01

The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

Increased multi-drug resistant Escherichia coli from hospitals in ...

African Journals Online (AJOL)

Background: Multidrug-resistant Escherichia coli (MDR E. coli) has become a major public health concern in Sudan and many countries, causing failure in treatment with consequent huge health burden. Objectives: To determine the prevalence and susceptibility of MDR E. coli isolated from patients in hospitals at Khartoum ...

Mechanical properties and crystallization behavior of hydroxyapatite/poly(butylenes succinate) composites.

Science.gov (United States)

Guo, Wenmin; Zhang, Yihe; Zhang, Wei

2013-09-01

Biodegradable synthetic polymers have attracted much attention nowadays, and more and more researches have been done on biodegradable polymers due to their excellent mechanical properties, biocompatibility, and biodegradability. In this work, hydroxyapatite (HA) particles were melt-mixing with poly (butylenes succinate) (PBS) to prepare the material, which could be used in the biomedical industry. To develop high-performance PBS for cryogenic engineering applications, it is necessary to investigate the cryogenic mechanical properties and crystallization behavior of HA/PBS composites. Cryogenic mechanical behaviors of the composites were studied in terms of tensile and impact strength at the glass transition temperature (-30°C) and compared to their corresponding behaviors at room temperature. With the increase of HA content, the crystallization of HA/PBS composites decreased and crystallization onset temperature shifted to a lower temperature. The diameter of spherulites increased at first and decreased with a further HA content. At the same time, the crystallization rate became slow when the HA content was no more than 15wt% and increased when HA content reached 20wt%. In all, the results we obtained demonstrate that HA/PBS composites reveal a better tensile strength at -30°C in contrast to the strength at room temperature. HA particles with different amount affect the crystallization of PBS in different ways. Copyright © 2013 Wiley Periodicals, Inc.

Effect of Rubberwood Content on Biodegradability of Poly(butylene succinate Biocomposites

Directory of Open Access Journals (Sweden)

Hemhong Anankaphong

2015-01-01

Full Text Available Poly(butylene succinate (PBS biocomposites incorporated with rubberwood powder (RWP were fabricated with various RWP weight fractions (i.e., 0 to 40% wt by injection moulding process. The soil burial test was employed to examine the biodegradability of such biocomposites under outdoor environment for 60 days. The physical appearance, percentage weight loss, chemical structure, and mechanical properties before and after the soil burial test were determined. Apparent changes in physical appearance of the biocomposites from optical micrographs were detected in terms of surface morphology and colour. The percentage of crystallinity of PBS/RWP biocomposites was studied by the X-ray diffraction (XRD technique, and the XRD pattern revealed a decrease in percentage of crystallinity due to enhancing RWP weight fractions. This may be attributed to a presence of rubberwood powders providing more disordered molecular chain arrangement of PBS matrix and also an agglomeration of the rubberwood powder content at greater concentration as seen in SEM micrographs. With increasing RWP weight fractions and burial time, the results exhibited a considerable change in chemical structure (essentially ester linkage due to biodegradation mechanism of PBS, relatively greater percentage weight loss, and a substantial decrease in flexural properties. Consequently, the results indicate that incorporating RWP enhances biodegradability of PBS/RWP biocomposites; that is, the biodegradation rate of biocomposites increases with increasing RWP weight fractions and burial time.

Insights into the evolution of pathogenicity of Escherichia coli from genomic analysis of intestinal E. coli of Marmota himalayana in Qinghai-Tibet plateau of China.

Science.gov (United States)

Lu, Shan; Jin, Dong; Wu, Shusheng; Yang, Jing; Lan, Ruiting; Bai, Xiangning; Liu, Sha; Meng, Qiong; Yuan, Xuejiao; Zhou, Juan; Pu, Ji; Chen, Qiang; Dai, Hang; Hu, Yuanyuan; Xiong, Yanwen; Ye, Changyun; Xu, Jianguo

2016-12-07

Escherichia coli is both of a widespread harmless gut commensal and a versatile pathogen of humans. Domestic animals are a well-known reservoir for pathogenic E. coli. However, studies of E. coli populations from wild animals that have been separated from human activities had been very limited. Here we obtained 580 isolates from intestinal contents of 116 wild Marmot Marmota himalayana from Qinghai-Tibet plateau, China, with five isolates per animal. We selected 125 (hereinafter referred to as strains) from the 580 isolates for genome sequencing, based on unique pulse field gel electrophoresis patterns and at least one isolate per animal. Whole genome sequence analysis revealed that all 125 strains carried at least one and the majority (79.2%) carried multiple virulence genes based on the analysis of 22 selected virulence genes. In particular, the majority of the strains carried virulence genes from different pathovars as potential 'hybrid pathogens'. The alleles of eight virulence genes from the Marmot E. coli were found to have diverged earlier than all known alleles from human and other animal E. coli. Phylogenetic analysis of the 125 Marmot E. coli genomes and 355 genomes selected from 1622 human and other E. coli strains identified two new phylogroups, G and H, both of which diverged earlier than the other phylogroups. Eight of the 12 well-known pathogenic E. coli lineages were found to share a most recent common ancestor with one or more Marmot E. coli strains. Our results suggested that the intestinal E. coli of the Marmots contained a diverse virulence gene pool and is potentially pathogenic to humans. These findings provided a new understanding of the evolutionary origin of pathogenic E. coli.

Ischemic colitis or melanosis coli: a case report

Directory of Open Access Journals (Sweden)

Nadeem Mohammed

2007-09-01

Full Text Available Abstract Background Melanosis Coli is described as black or brown discolouration of the mucosa of the colon. Its a benign condition, which arises from anthraquinone laxative abuse and has no symptoms of its own. The main importance of diagnosing Melanosis Coli correctly lies in the fact that if its extensive, there may be difficulty in differentiating it from ischemic colitis. Case presentation We present a case of extensive Melanosis Coli involving the whole of large bowel that appeared gangrenous. A sub total colectomy was performed on presumed diagnosis of ischemic bowel. Conclusion This report reminds the clinicians that extensive Melanosis Coli may mimic ischemic colitis and thus must be considered as a differential diagnosis.

Escherichia Coli

Science.gov (United States)

Goodsell, David S.

2009-01-01

Diverse biological data may be used to create illustrations of molecules in their cellular context. I describe the scientific results that support a recent textbook illustration of an "Escherichia coli cell". The image magnifies a portion of the bacterium at one million times, showing the location and form of individual macromolecules. Results…

Hyperthermo-chemo-radiotherapy for patients with carcinoma of the esophagus and prediction of the clinical remedial value using the in vitro succinate dehydrogenase inhibition test

International Nuclear Information System (INIS)

Matsuda, Hiroyuki; Sugimachi, Keizo; Ohno, Shinji; Mori, Masaki; Kuwano, Hiroyuki; Maehara, Yoshihiko

1989-01-01

Hyperthermia combined with irradiation and chemotherapy was prescribed for patients with resectable (n=88) and unresectable (n=36) carcinoma of the esophagus. The histopathological effectiveness, and the long term results were compared between two groups of patients treated with hyperthermo-chemo-radiotherapy (HCR therapy) and those treated with chemoradiotherapy (CR therapy). A correlation between the hyperthermia sensitivity test, using the in vitro succinate dehydrogenase inhibition test, and the clinical remedial value was also examined in malignant tissues from 47 patients with esophageal cancer, and treated with HCR therapy. In the resected cases, preoperative HCR therapy resulted in a significantly higher histopathological effectiveness rate (69%) compared with that in cases treated by CR therapy (48%) (P<0.05). The long term results of patients with both resectable and unresectable carcinoma, given HCR therapy were significanly better than those given CR therapy (P<0.05). On the other hand, the clinical remedial value, determined radiographically showed a correlation rate of 77% to the hyperthermia sensitivity test. Thus, the HCR therapy resulted in not only a higher histopathological effectiveness rate but also a significantly longer survival without severe side effects, and this hyperthermia sensitivity test using the succinate dehydrogenase inhibition test facilitates prediction of the outcome of the HCR therapy. (author)

Presence of non-O157 Shiga toxin-producing Escherichia coli, enterotoxigenic E. coli, enteropathogenic E. coli and Salmonella in fresh beetroot (Beta vulgaris L.) juice from public markets in Mexico.

Science.gov (United States)

Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Bautista-De León, Haydee; Castro-Rosas, Javier

2014-10-01

Unpasteurized juice has been associated with foodborne illness outbreaks for many years. Beetroot is a vegetable grown all over the world in temperate areas. In Mexico beetroot is consumed cooked in salads or raw as fresh unpasteurized juices. No data about the microbiological quality or safety of unpasteurized beetroot juices are available. Indicator bacteria, diarrheagenic Escherichia coli pathotypes (DEP) and Salmonella frequencies were determined for fresh unpasteurized beetroot juice from restaurants. One hundred unpasteurized beetroot juice samples were collected from public markets in Pachuca, Mexico. Frequencies in these samples were 100%, 75%, 53%, 9% and 4% of positive samples, for coliform bacteria, fecal coliforms, E. coli, DEP and Salmonella, respectively. Identified DEP included enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC) and non-O157 Shiga toxin-producing E. coli (STEC). Identified Salmonella serotypes included Typhimurium and Enteritidis. This is the first report of microbiological quality and atypical EPEC, ETEC, non-O157 STEC and Salmonella isolation from fresh raw beetroot juice in Mexico. Fresh raw beetroot juice from markets is very probably an important factor contributing to the endemicity of atypical EPEC, ETEC, non-O157 STEC and Salmonella-related gastroenteritis in Mexico. © 2014 Society of Chemical Industry.

Escherichia coli survival in waters: Temperature dependence

Science.gov (United States)

Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 mo...

Environmental Escherichia coli: ecology and public health implications-a review.

Science.gov (United States)

Jang, J; Hur, H-G; Sadowsky, M J; Byappanahalli, M N; Yan, T; Ishii, S

2017-09-01

Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through faeces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent faecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extraintestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a faecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics revealed the diversity and complexity of E. coli strains in various environments, which are affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments with regard to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed. © 2017 The Society for Applied Microbiology.

Fecal colonization with P-fimbriated Escherichia coli in newborn children and relation to development of extraintestinal E. coli infections.

Science.gov (United States)

Tullus, K

1987-01-01

The incidence of E. coli pyelonephritis before the age of one year among the children born at Danderyd Hospital during a ten year period was studied. During the study period, 4 or 5 outbreaks of E. coli pyelonephritis occurred among the children who had previously been staying in the hospital's neonatal ward. These outbreaks seemed to have been caused by nosocomial spread of and fecal colonization with certain virulent E. coli strains among the children staying in the ward during certain periods of time. The strains that were spread in the ward seemed to belong to certain pyelonephritogenic E. coli clones of the serotypes O6:K5, O4:K3 and possibly O6:K2. Although the children became fecally colonized with the strains in the neonatal ward, most fell ill some time after they had left the ward. The mean age at the development of their first pyelonephritis was 3.4 months for the boys and 6.2 months for the girls, who had been cared for in this ward. A correlation between the number of infections and the bed occupancy of the ward could be found (p less than 0.01). The risk for a child staying in the ward during an outbreak to develop pyelonephritis was about 5-10%. There was a baseline incidence rate of 0.6-0.7% during non-epidemic periods. During one of the outbreaks there was also an increased incidence rate of E. coli septicemia among the children staying in the neonatal ward. The predictive value of fecal colonization with P-fimbriated E. coli for the later development of extraintestinal E. coli infections was studied in a 2.5 year prospective study. During this study period there was a baseline incidence rate of 10-20% fecal colonization with P-fimbriated E. coli among the children staying in both the neonatal and maternity wards, interrupted only by minor peaks of colonization with such strains. Length of stay in the neonatal ward and a high bed occupancy of the neonatal ward were statistically correlated to fecal colonization with P-fimbriated E. coli strains (p

Ontology-based literature mining of E. coli vaccine-associated gene interaction networks.

Science.gov (United States)

Hur, Junguk; Özgür, Arzucan; He, Yongqun

2017-03-14

Pathogenic Escherichia coli infections cause various diseases in humans and many animal species. However, with extensive E. coli vaccine research, we are still unable to fully protect ourselves against E. coli infections. To more rational development of effective and safe E. coli vaccine, it is important to better understand E. coli vaccine-associated gene interaction networks. In this study, we first extended the Vaccine Ontology (VO) to semantically represent various E. coli vaccines and genes used in the vaccine development. We also normalized E. coli gene names compiled from the annotations of various E. coli strains using a pan-genome-based annotation strategy. The Interaction Network Ontology (INO) includes a hierarchy of various interaction-related keywords useful for literature mining. Using VO, INO, and normalized E. coli gene names, we applied an ontology-based SciMiner literature mining strategy to mine all PubMed abstracts and retrieve E. coli vaccine-associated E. coli gene interactions. Four centrality metrics (i.e., degree, eigenvector, closeness, and betweenness) were calculated for identifying highly ranked genes and interaction types. Using vaccine-related PubMed abstracts, our study identified 11,350 sentences that contain 88 unique INO interactions types and 1,781 unique E. coli genes. Each sentence contained at least one interaction type and two unique E. coli genes. An E. coli gene interaction network of genes and INO interaction types was created. From this big network, a sub-network consisting of 5 E. coli vaccine genes, including carA, carB, fimH, fepA, and vat, and 62 other E. coli genes, and 25 INO interaction types was identified. While many interaction types represent direct interactions between two indicated genes, our study has also shown that many of these retrieved interaction types are indirect in that the two genes participated in the specified interaction process in a required but indirect process. Our centrality analysis of

Melanosis coli in patients with colon cancer

Directory of Open Access Journals (Sweden)

Dorota Biernacka-Wawrzonek

2016-12-01

Full Text Available Intoduction: Melanosis coli is a benign lesion affecting the mucosa of the large intestine. There is a relationship between the presence of melanosis and anthraquinone laxative use. Melanosis coli is also observed in patients with colon cancer, but there is doubt whether these two conditions are related. Aim : To analyze the correlation between melanosis and colon cancer. Material and methods: We analyzed retrospectively 436 patients undergoing colon cancer surgery. There were 246 women and 190 men. Patients were divided into three age groups: under 50 years, between 51 and 65 years, and over 66 years. We analyzed sections of the cancer and intestinal mucosa from the tumor’s proximal (2–5 cm and distal (8–10 cm zone. Results : Melanosis coli was present in 52 patients, which represents 11.9% of patients with colon cancer. More often it was present in women. The most common location of melanosis and colon cancer was the terminal part of the large intestine. In patients below 50 years of age in both sexes melanosis coli did not occur. In men, melanosis was more common in the age group over 66 years. Intensity of pigmentation was higher in the tumor’s distal zone. Conclusions : The incidence of melanosis coli increases with age, similar to that of colon cancer. Melanosis was not present inside tumors, in almost half of the cases it was not present in the proximal zone, and the degree of pigmentation increased in distal zone. The cause-effect relationship between melanosis coli and colon cancer remains uncertain.

Effect of organo-modified montmorillonite on poly(butylene succinate/poly(butylene adipate-co-terephthalate nanocomposites

Directory of Open Access Journals (Sweden)

2010-07-01

Full Text Available The composite material based on poly(butylene succinate (PBS, poly(butylene adipate-co-terephthalate (PBAT and organo-modified montmorillonite (OMMT were prepared by melt blending technique and characterized. Sodium montmorillonite (Na-MMT was successfully modified by octadecylammonium (ODA and dimethyldioctadecylammonium (DDOA salts to become OMMT through cation exchange technique which is shown by the increase of basal spacing of clay by XRD. The addition of the OMMT to the PBS/PBAT blends produced nanocomposites which is proved by XRD and TEM. Tensile tests showed increase in tensile strength and modulus which is attributed to the existence of strong interactions between PBS/PBAT and clay, particularly with OMMT. Highest tensile strength of nanocomposite was observed at 1 wt% of OMMT incorporated. TGA study showed that the thermal stability of the blend increased after the addition of clays. SEM micrographs of the fracture surfaces show that the morphology of the blend becomes homogeneous and smoother with presence of OMMT.

No evidence for a bovine mastitis Escherichia coli pathotype.

Science.gov (United States)

Leimbach, Andreas; Poehlein, Anja; Vollmers, John; Görlich, Dennis; Daniel, Rolf; Dobrindt, Ulrich

2017-05-08

Escherichia coli bovine mastitis is a disease of significant economic importance in the dairy industry. Molecular characterization of mastitis-associated E. coli (MAEC) did not result in the identification of common traits. Nevertheless, a mammary pathogenic E. coli (MPEC) pathotype has been proposed suggesting virulence traits that differentiate MAEC from commensal E. coli. The present study was designed to investigate the MPEC pathotype hypothesis by comparing the genomes of MAEC and commensal bovine E. coli. We sequenced the genomes of eight E. coli isolated from bovine mastitis cases and six fecal commensal isolates from udder-healthy cows. We analyzed the phylogenetic history of bovine E. coli genomes by supplementing this strain panel with eleven bovine-associated E. coli from public databases. The majority of the isolates originate from phylogroups A and B1, but neither MAEC nor commensal strains could be unambiguously distinguished by phylogenetic lineage. The gene content of both MAEC and commensal strains is highly diverse and dominated by their phylogenetic background. Although individual strains carry some typical E. coli virulence-associated genes, no traits important for pathogenicity could be specifically attributed to MAEC. Instead, both commensal strains and MAEC have very few gene families enriched in either pathotype. Only the aerobactin siderophore gene cluster was enriched in commensal E. coli within our strain panel. This is the first characterization of a phylogenetically diverse strain panel including several MAEC and commensal isolates. With our comparative genomics approach we could not confirm previous studies that argue for a positive selection of specific traits enabling MAEC to elicit bovine mastitis. Instead, MAEC are facultative and opportunistic pathogens recruited from the highly diverse bovine gastrointestinal microbiota. Virulence-associated genes implicated in mastitis are a by-product of commensalism with the primary function

The role of Cra in regulating acetate excretion and osmotic tolerance in E. coli K-12 and E. coli B at high density growth.

Science.gov (United States)

Son, Young-Jin; Phue, Je-Nie; Trinh, Loc B; Lee, Sang Jun; Shiloach, Joseph

2011-06-30

E. coli B (BL21), unlike E.coli K-12 (JM109) is insensitive to glucose concentration and, therefore, grows faster and produces less acetate than E. coli K-12, especially when growing to high cell densities at high glucose concentration. By performing genomic analysis, it was demonstrated that the cause of this difference in sensitivity to the glucose concentration is the result of the differences in the central carbon metabolism activity. We hypothesized that the global transcription regulator Cra (FruR) is constitutively expressed in E. coli B and may be responsible for the different behaviour of the two strains. To investigate this possibility and better understand the function of Cra in the two strains, cra - negative E. coli B (BL21) and E. coli K-12 (JM109) were prepared and their growth behaviour and gene expression at high glucose were evaluated using microarray and real-time PCR. The deletion of the cra gene in E. coli B (BL21) minimally affected the growth and maximal acetate accumulation, while the deletion of the same gene in E.coli K-12 (JM109) caused the cells to stop growing as soon as acetate concentration reached 6.6 g/L and the media conductivity reached 21 mS/cm. ppsA (gluconeogenesis gene), aceBA (the glyoxylate shunt genes) and poxB (the acetate producing gene) were down-regulated in both strains, while acs (acetate uptake gene) was down-regulated only in E.coli B (BL21). These transcriptional differences had little effect on acetate and pyruvate production. Additionally, it was found that the lower growth of E. coli K-12 (JM109) strain was the result of transcription inhibition of the osmoprotectant producing bet operon (betABT). The transcriptional changes caused by the deletion of cra gene did not affect the activity of the central carbon metabolism, suggesting that Cra does not act alone; rather it interacts with other pleiotropic regulators to create a network of metabolic effects. An unexpected outcome of this work is the finding that cra

Comparison of 61 Sequenced Escherichia coli Genomes

DEFF Research Database (Denmark)

Lukjancenko, Oksana; Wassenaar, T. M.; Ussery, David

2010-01-01

Escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. Sixty-one publically available E. coli and Shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics...

lactamase in clinical isolates of Escherichia coli

African Journals Online (AJOL)

Jane

2011-08-22

Aug 22, 2011 ... The beta lactamase enzyme producing E. coli, resistant to β-lactam antibiotics, created many problems ... Key words: Escherichia coli, β-lactamase enzymes, TEM-type extended spectrum ... difficulties in treatment using antibiotics that are currently ... and chloramphenicol (30 µg) (Mast Diagnostics Ltd., UK).

Thermal and Mechanical Properties of Poly(butylene succinate Films Reinforced with Silica

Directory of Open Access Journals (Sweden)

Sangviroon Nanthaporn

2015-01-01

Full Text Available In recent year, bioplastics have become more popular resulting from the growing concerns on environmental issues and the rising fossil fuel price. However, their applications were limited by its mechanical and thermal properties. The aim of this research is thus to improve mechanical and thermal properties of PBS bioplastic films by reinforcing with silica. Due to the poor interfacial interaction between the PBS matrix and silica, glycidyl methacrylate grafted poly(butylene succinate (PBS-g-GMA was used as a compatibilizer in order to improve the interaction between bioplastic films and filler. PBS-g-GMA was prepared in a twin-screw extruder and analyzed by the FTIR spectrometer. PBS and silica were then mixed in a twin-screw extruder and processed into films by a chill-roll cast extruder. The effects of silica loading on thermal and mechanical properties of the prepared bioplastic films were investigated. It was found that the mechanical properties of PBS/silica composite films were improved when 1%wt of silica was added. However, the mechanical properties decreased with increasing silica loading due to the agglomeration of silica particles. The results also show that the silica/PBS films with PBS-g-GMA possessed improved mechanical properties over the films without the compatibilizer.

Can Escherichia coli fly? The role of flies as transmitters of E. coli to food in an urban slum in Bangladesh.

Science.gov (United States)

Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin; Phelps, Matthew; Tulsiani, Suhella; Farhana, Israt; Begum, Anowara; Jensen, Peter Kjaer Mackie

2018-01-01

To investigate the transmission of faecal bacteria by flies to food under natural settings. Over a period of 2 months, paired (exposed and non-exposed) containers with cooked rice were placed on the ground in kitchen areas in an urban slum area in Dhaka, Bangladesh, and the numbers of flies landing on the exposed rice were counted. Following exposure, the surface of the rice was microbiologically and molecularly analysed for the presence of Escherichia coli and genes of diarrhoeagenic E. coli and Shigella strains. Rice was at greater risk (P E. coli if flies landed on the rice than if no flies landed on the rice (odds ratio 5·4 (P 0·6 × 103 CFU. Genes of diarrhoeagenic E. coli and Shigella species were detected in 39 of 60 (65%) of exposed rice samples. Two fly species were identified: the common housefly (Musca domestica) and the oriental latrine fly (Chrysomya megacephala). Flies may transmit large quantities of E. coli to food under field settings. The findings highlight the importance of implementing control measures to minimise exposure of food to flies to ensure food safety. Fly control measures should be considered for the prevention of diarrhoeal diseases caused by E. coli. © 2017 John Wiley & Sons Ltd.

Photoreactivating enzyme from Escherichia coli

International Nuclear Information System (INIS)

Snapka, R.M.; Fuselier, C.O.

1977-01-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

Photoreactivating enzyme from Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

1977-05-01

Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

Valorization of macroalga Saccharina latissima as novel feedstock for fermentation-based succinic acid production in a biorefinery approach and economic aspects

DEFF Research Database (Denmark)

Silva Marinho, Goncalo; Alvarado-Morales, Merlin; Angelidaki, Irini

2016-01-01

with a maximum productivity of 3.9 g L-1 h-1 was achieved. The high content of total phenolic compounds (TPCs) in the macroalgal biomass (July-August: 5-1% DM), and high concentration of macro- (Ca, K, Na, Mg, P, N and Fe) and micronutrients in the solid residue recovered after enzymatic hydrolysis (PHSR), makes...... co-production of antioxidants (i.e. phenolics) and fertilizer very attractive. Finally, a simplified economic assessment showed that for the analyzed scenarios the main product's selling price (succinic acid) can be lowered significantly by coproducing added value products (fertilizers) and high...

High temperature in combination with UV irradiation enhances horizontal transfer of stx2 gene from E. coli O157:H7 to non-pathogenic E. coli.

Directory of Open Access Journals (Sweden)

Wan-Fu Yue

Full Text Available Shiga toxin (stx genes have been transferred to numerous bacteria, one of which is E. coli O157:H7. It is a common belief that stx gene is transferred by bacteriophages, because stx genes are located on lambdoid prophages in the E. coli O157:H7 genome. Both E. coli O157:H7 and non-pathogenic E. coli are highly enriched in cattle feedlots. We hypothesized that strong UV radiation in combination with high temperature accelerates stx gene transfer into non-pathogenic E. coli in feedlots.E. coli O157:H7 EDL933 strain were subjected to different UV irradiation (0 or 0.5 kJ/m(2 combination with different temperature (22, 28, 30, 32, and 37 °C treatments, and the activation of lambdoid prophages was analyzed by plaque forming unit while induction of Stx2 prophages was quantified by quantitative real-time PCR. Data showed that lambdoid prophages in E. coli O157:H7, including phages carrying stx2, were activated under UV radiation, a process enhanced by elevated temperature. Consistently, western blotting analysis indicated that the production of Shiga toxin 2 was also dramatically increased by UV irradiation and high temperature. In situ colony hybridization screening indicated that these activated Stx2 prophages were capable of converting laboratory strain of E. coli K12 into new Shiga toxigenic E. coli, which were further confirmed by PCR and ELISA analysis.These data implicate that high environmental temperature in combination with UV irradiation accelerates the spread of stx genes through enhancing Stx prophage induction and Stx phage mediated gene transfer. Cattle feedlot sludge are teemed with E. coli O157:H7 and non-pathogenic E. coli, and is frequently exposed to UV radiation via sunlight, which may contribute to the rapid spread of stx gene to non-pathogenic E. coli and diversity of shiga toxin producing E. coli.

The presence of verotoxinogenic E. coli in some foods

Directory of Open Access Journals (Sweden)

Bostan K.

2005-01-01

Full Text Available In this study 30 samples each of ready-to-cook meatballs and white cheese as well as 96 samples of various ready-to-eat foods, obtained from different sales outlets in Istanbul, were analyzed for the presence of verotoxins (consequently vemtoxigenic E. coli E. coli with the aid of the enzyme immunoassay technique. Additionally, total coli-form and chromogenic E. coli count were determined by cultural methods for all food samples. E. coli growth was detected in all ready-to-cook meatballs (100%, in 27 of the white cheese samples (90% and in 69 of the other ready-to-eat food samples (71.9%. Verotoxins, however, could not be detected in any of the samples examined with the aid of the ELISA technique. The findings of this study indicate a low microbiological quality of the analyzed meatball, white cheese and ready-to-eat food samples; a considerable part of them did not conform to legal standards. However, within the sensitivity limits of the method applied no verotoxinogenic E. coli could be detected.

Lethality prediction for Escherichia coli 0157:H7 and Uropathogenic E. coli in ground chicken treated with high pressure processing and trans-cinnamaldehyde

Science.gov (United States)

Pathogenic Escherichia coli, intestinal (O157:H7) as well as extraintestinal types (Uropathogenic E. coli (UPEC)) are commonly found in many foods including chicken meat. In this study we compared the resistance of E. coli O157:H7 to UPEC in chicken meat under the stresses of high hydrostatic pressu...

One-step Conversion of Levulinic Acid to Succinic Acid Using I2/t-BuOK System: The Iodoform Reaction Revisited.

Science.gov (United States)

Kawasumi, Ryosuke; Narita, Shodai; Miyamoto, Kazunori; Tominaga, Ken-Ichi; Takita, Ryo; Uchiyama, Masanobu

2017-12-21

The iodoform reaction has long been used as a qualitative test for acetyl and/or ethanol units in organic molecules. However, its synthetic applications are quite limited. Here, we describe a tuned iodoform reaction for oxidative demethylation reaction with I 2 and t-BuOK in t-BuOH, in which in situ-generated t-BuOI serves as the chemoselective iodinating agent. This system enables one-step conversion of levulinic acid to succinic acid, a major four-carbon chemical feedstock. This oxidative demethylation is also applicable to other compounds containing an acetyl group/ethanol unit, affording the corresponding carboxylic acids in a selective manner.

Effects of Radiation on Mechanical Properties of Poly (butylene succinate) and Cassava Starch Blends

International Nuclear Information System (INIS)

Hemvichian, K.; Dechasasawat, K.; Kangsumrith, W.; Suwanmala, P.

2014-01-01

This research compared the effects of gamma and electron beam irradiation at different doses on the mechanical properties of polymer blends between poly(butylene succinate) (PBS) and cassava starch. Two types of starch were used to prepare thermoplastic starch (TPS), native cassava starch and hydrophobic starch. PBS/TPS blends were compounded at five different weight ratios using a twin-screw extruder. Mechanical properties and degradation were evaluated in comparison to unirradiated samples. Results indicated that the incorpora- tion of TPS prepared from native cassava starch decreased the mechanical properties of PBS/TPS blends, whereas the addition of TPS prepared from hydrophobic starch improved the mechanical properties of the blends. In addition, the maximum mechanical properties of PBS/TPS blends were achieved when samples were exposed to irradiation at 120 kGy. Using soil burial evaluation, the degradation rate of blends was found to increase with the addition of TPS. Therefore we have demonstrated in this study that the type of TPS and irradiation treatment can significantly alter the mechanical properties and degradation of PBS/TPS blends.

Cloning and functional analysis of succinate dehydrogenase gene PsSDHA in Phytophthora sojae.

Science.gov (United States)

Pan, Yuemin; Ye, Tao; Gao, Zhimou

2017-07-01

Succinate dehydrogenase (SDH) is one of the key enzymes of the tricarboxylic acid cycle (TCA cycle) and a proven target of fungicides for true fungi. To explore the roles of the SDHA gene in Phytophthora sojae, we first cloned PsSDHA to construct the PsSDHA silenced expression vector pHAM34-PsSDHA, and then utilized PEG to mediate the P. sojae protoplast transformation experiment. Through transformation screening, we obtained the silenced mutants A1 and A3, which have significant suppressive effect. Further study showed that the hyphae of the silenced mutant strains were shorter and more bifurcated; the growth of the silenced mutants was clearly inhibited in 10% V8 agar medium containing sodium chloride (NaCl), hydrogen peroxide (H 2 O 2 ) or Congo Red, respectively. The pathogenicity of the silenced mutants was significantly reduced compared with the wild-type strain and the mock. The results could help us better to understand the position and function of SDH in P. sojae and provide a proven target of fungicides for the oomycete. Copyright © 2017. Published by Elsevier Ltd.

Application of finite inverse gas chromatography in hypromellose acetate succinate-water-acetone systems.

Science.gov (United States)

Chiu, Sheng-Wei; Sturm, Derek R; Moser, Justin D; Danner, Ronald P

2016-09-30

A modification of a GC was developed to investigate both infinitely dilute and finite concentrations of solvents in polymers. Thermodynamic properties of hypromellose acetate succinate (HPMCAS-L)-acetone-water systems are important for the optimization of spray-drying processes used in pharmaceutical manufacturing of solid dispersion formulations. These properties, at temperatures below the glass transition temperature, were investigated using capillary column inverse gas chromatography (CCIGC). Water was much less soluble in the HPMCAS-L than acetone. Experiments were also conducted at infinitely dilute concentrations of one of the solvents in HPMCAS-L that was already saturated with the other solvent. Overall the partitioning of the water was not significantly affected by the presence of either water or acetone in the polymer. The acetone partition coefficient decreased as either acetone or water was added to the HPMCAS-L. A representation of the HPMCAS-L structure in terms of UNIFAC groups has been developed. With these groups, the UNIFAC-vdw-FV model did a reasonable job of predicting the phase equilibria in the binary and ternary systems. The Flory-Huggins correlation with fitted interaction parameters represented the data well. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular epidemiology of extended-spectrum beta-lactamase-producing Escherichia coli

Directory of Open Access Journals (Sweden)

Catherine Ludden

2014-09-01

Full Text Available Objectives: E. coli O25b-ST131 has disseminated worldwide in hospitals and the community. The objective of this study was to determine the extent to which E. coli O25b-ST131 accounts for extended-spectrum beta-lactamase (ESBLproducing E. coli from clinical samples from all sources in this region. Methods: Between January and June 2010 ESBL-producing E. coli were collected from 94 routine samples including 47 from residents of 25 nursing homes, 15 categorized as hospital acquired and 32 others. PCR was performed for detection of bla CTX-M, bla OXA-1, bla TEM, bla SHV and for the identification of members of the E. coli O25b:ST131 clonal group. PFGE was carried out using Xba I in accordance with PulseNet protocols. Results: The majority (97% of isolates harbored a bla CTX-M gene.E. coli O25b-ST131 accounted for 87% of all ESBL-producing E. coliand for 96% of isolates from nursing home residents. Conclusion:The E. coli O25b-ST131 clonal group predominated in the collection of ESBL-producing E. coli, particularly in nursing home isolates. J Microbiol Infect Dis 2014; 4(3: 92-96

Third International E. coli genome meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-12-31

Proceedings of the Third E. Coli Genome Meeting are provided. Presentations were divided into sessions entitled (1) Large Scale Sequencing, Sequence Analysis; (2) Databases; (3) Sequence Analysis; (4) Sequence Divergence in E. coli Strains; (5) Repeated Sequences and Regulatory Motifs; (6) Mutations, Rearrangements and Stress Responses; and (7) Origins of New Genes. The document provides a collection of abstracts of oral and poster presentations.

Impact of persistent and nonpersistent generic Escherichia coli and Salmonella sp. recovered from a beef packing plant on biofilm formation by E. coli O157.

Science.gov (United States)

Visvalingam, J; Ells, T C; Yang, X

2017-12-01

To examine the influence of meat plant Escherichia coli and Salmonella sp. isolates on E. coli O157 biofilm formation. Biofilm formation was quantified by crystal violet staining (A 570 nm ) and viable cell numbers for up to 6 days at 15°C. All five persistent E. coli genotypes formed strong biofilms when cultured alone or co-cultured with E. coli O157, with A 570 nm values reaching ≥4·8 at day 4, while only two of five nonpersistent genotypes formed such biofilms. For E. coli O157:H7 co-culture biofilms with E. coli genotypes 136 and 533, its numbers were ≥1·5 and ≥1 log CFU per peg lower than those observed for its mono-culture biofilm at days 2 and 4, respectively. The number of E. coli O157:NM in similar co-culture biofilms was 1 log CFU per peg lower than in its mono-culture biofilm at day 4 and 6, respectively. Salmonella sp. lowered the number of E. coli O157:NM by 0·5 log unit, once, at day 6. Generic E. coli may outcompete E. coli O157 strains while establishing biofilms. Findings advance knowledge regarding inter-strain competition for a similar ecological niche and may aid development of biocontrol strategies for E. coli O157 in food processing environments. © 2017 Her Majesty the Queen in Right of Canada. Journal of Applied Microbiology © 2017 The Society for Applied Microbiology Reproduced with the permission of the Minister of the Department of Agriculture and Agri-Food Canada.

Protection against an infectious disease by enterohaemorrhagic E. coli 0-157.

Science.gov (United States)

Ota, A

1999-07-01

Preventive measures against infection by enterohaemorrhagic E. coli 0-157 are described. Eating yoghurt and Kefir supposedly induces more bifid bacteria and lactic acid bacteria to colonize in the intestines, thereby protecting humans from infection by E. coli 0-157. Some foods, such as plum extract, act as a mild antibiotic and produce an acidic environment within the intestine, thus interfering with growth of the E. coli 0-157. The natural colonization of harmless E. coli or other bacteria that are more powerful than E. coli 0-157 can possibly protect against infection. A vaccination against E. coli 0-157 H7 may also be effective. In addition, it has been suggested that the correct levels of nitric oxide and calcium in the blood may activate immunity and protect against infection by E. coli 0-157.

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained from 382 samples.

Antimicrobial resistance among commensal Escherichia coli from ...

African Journals Online (AJOL)

user1

2012-07-19

Jul 19, 2012 ... Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained.

Enteroaggregative Escherichia coli is the predominant diarrheagenic E. coli pathotype among irrigation water and food sources in South Africa.

Science.gov (United States)

Aijuka, Matthew; Santiago, Araceli E; Girón, Jorge A; Nataro, James P; Buys, Elna M

2018-08-02

Diarrheagenic E. coli (DEC) has been implicated in foodborne outbreaks worldwide and have been associated with childhood stunting in the absence of diarrhoea. Infection is extraordinarily common, but the routes of transmission have not been determined. Therefore, determining the most prevalent pathotypes in food and environmental sources may help provide better guidance to various stakeholders in ensuring food safety and public health and advancing understanding of the epidemiology of enteric disease. We characterized 205 E. coli strains previously isolated from producer distributor bulk milk (PDBM)(118), irrigation water (48), irrigated lettuce (29) and street vendor coleslaw (10) in South Africa. Enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC) and diffusely adherent E. coli (DAEC) were sought. We used PCR and partial gene sequencing for all 205 strains while 46 out of 205 that showed poor resolution were subsequently characterized using cell adherence (HeLa cells). PCR and partial gene sequencing of aatA and/or aaiC genes confirmed EAEC (2%, 5 out of 205) as the only pathotype. Phylogenetic analysis of sequenced EAEC strains with E. coli strains in GenBank showing ≥80% nucleotide sequence similarity based on possession of aaiC and aatA generated distinct clusters of strains separated predominantly based on their source of isolation (food source or human stool) suggesting a potential role of virulence genes in source tracking. EAEC 24%, 11 out of 46 strains (PDBM = 15%, irrigation water = 7%, irrigated lettuce = 2%) was similarly the predominant pathotype followed by strains showing invasiveness to HeLa cells, 4%, 2 out of 46 (PDBM = 2%, irrigated lettuce = 2%), among stains characterized using cell adherence. Therefore, EAEC may be the leading cause of DEC associated food and water-borne enteric infection in South Africa. Additionally, solely using molecular based methods targeting virulence

Fluoroquinolone-resistant Escherichia coli carriage in long-term care facility.

Science.gov (United States)

Maslow, Joel N; Lee, Betsy; Lautenbach, Ebbing

2005-06-01

We conducted a cross-sectional study to determine the prevalence of, and risk factors for, colonization with fluoroquinolone (FQ)-resistant Escherichia coli in residents in a long-term care facility. FQ-resistant E. coli were identified from rectal swabs for 25 (51%) of 49 participants at study entry. On multivariable analyses, prior FQ use was the only independent risk factor for FQ-resistant E. coli carriage and was consistent for FQ exposures in the previous 3, 6, 9, or 12 months. Pulsed-field gel electrophoresis of FQ-resistant E. coli identified clonal spread of 1 strain among 16 residents. Loss (6 residents) or acquisition (7 residents) of FQ-resistant E. coli was documented and was associated with de novo colonization with genetically distinct strains. Unlike the case in the hospital setting, FQ-resistant E. coli carriage in long-term care facilities is associated with clonal spread.

Expression in E. coli systems

DEFF Research Database (Denmark)

Krogsdam, Anne-M; Kristiansen, Karsten; Nøhr, Jane

2003-01-01

intracellularly in soluble form. In E. coli, proteins containing disulfide bonds are best produced by secretion because the disulfide forming foldases reside in the periplasm. Likewise, a correct N-terminus is more likely to be obtained upon secretion. Moreover, potentially toxic proteins are more likely......Owing to cost advantage, speed of production, and often high product yield (up to 50% of total cell protein), expression in Escherichia coli is generally the first choice when attempting to express a recombinant protein. Expression systems exist to produce recombinant protein intracellularly...

Strategies for Protein Overproduction in Escherichia coli.

Science.gov (United States)

Mott, John E.

1984-01-01

Examines heterologous expression in Escherichia coli and the role of regulatory sequences which control gene expression at transcription resulting in abundant production of messenger RNA and regulatory sequences in mRNA which promote efficient translation. Also examines the role of E. coli cells in stabilizing mRNA and protein that is…

Triglyceride kinetics in fasted and fed E.coli septic rats

International Nuclear Information System (INIS)

Lanza-Jacoby, S.; Tabares, A.

1990-01-01

The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studies by examining the liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess the liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant intravenous infusion of [2- 3 H] glycerol-labeled VLDL in fasted control, fasted E. coli-treated, fed control, and fed E.coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 x 10 7 live E.coli colonies per 100 g body weight. Twenty-four hours following E.coli injection serum TG of fasted E.coli-treated rats was elevated by 170% which was attributed to a 67% decrease in the clearance rate of VLDL-TG in fasted E.coli-treated rats compared with their fasted controls. The secretion of VLDL-TG declined by 31% in the livers of the fasted E.coli-treated rats which was accompanied by a 2-fold increase in the composition of liver TG. In a second series of experiments control and E.coli-treated rats were fed intragastrically (IG) a balanced solution containing glucose plus fat as the sources of nonprotein calories. Serum TG were 26% lower in the fed E.coli-treated rats because the clearance rate increased by 86%. The secretion of TG in the fed septic rats increased by 40% but this difference was not significant. In the septic rat the ability to clear triglycerides from the plasma depends upon the nutritional state

ECMDB: The E. coli Metabolome Database

OpenAIRE

Guo, An Chi; Jewison, Timothy; Wilson, Michael; Liu, Yifeng; Knox, Craig; Djoumbou, Yannick; Lo, Patrick; Mandal, Rupasri; Krishnamurthy, Ram; Wishart, David S.

2012-01-01

The Escherichia coli Metabolome Database (ECMDB, http://www.ecmdb.ca) is a comprehensively annotated metabolomic database containing detailed information about the metabolome of E. coli (K-12). Modelled closely on the Human and Yeast Metabolome Databases, the ECMDB contains >2600 metabolites with links to ?1500 different genes and proteins, including enzymes and transporters. The information in the ECMDB has been collected from dozens of textbooks, journal articles and electronic databases. E...

Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

African Journals Online (AJOL)

Erah

PMQR) genes and the prevalence of extended spectrum β-lactamase (ESBL) types in Escherichia coli clinical isolates. Methods: Sixty-one ESBL-producing urinary E. coli isolates were studied. An antibiotic susceptibility test was performed ...

Photoinactivation of mcr-1 positive Escherichia coli

Science.gov (United States)

Caires, C. S. A.; Leal, C. R. B.; Rodrigues, A. C. S.; Lima, A. R.; Silva, C. M.; Ramos, C. A. N.; Chang, M. R.; Arruda, E. J.; Oliveira, S. L.; Nascimento, V. A.; Caires, A. R. L.

2018-01-01

The emergence of plasmid-mediated colistin resistance in Enterobacteriaceae, mostly in Escherichia coli due to the mcr-1 gene, has revealed the need to develop alternative approaches in treating mcr-1 positive bacterial infections. This is because colistin is a broad-spectrum antibiotic and one of the ‘last-resort’ antibiotics for multidrug resistant bacteria. The present study evaluated for the first time, to the best of our knowledge, the efficacy of photoinactivation processes to kill a known mcr-1 positive E. coli strain. Eosin methylene-blue (EMB) was investigated as a photoantimicrobial agent for inhibiting the growth of a mcr-1 positive E. coli strain obtained from a patient with a diabetic foot infection. The photoantimicrobial activity of EMB was also tested in a non-multidrug resistant E. coli strain. The photoinactivation process was tested using light doses in the 30-45 J cm-2 range provided by a LED device emitting at 625 nm. Our findings demonstrate that a mcr-1 positive E. coli strain is susceptible to photoinactivation. The results show that the EMB was successfully photoactivated, regardless of the bacterial multidrug resistance; inactivating the bacterial growth by oxidizing the cells in accordance with the generation of the oxygen reactive species. Our results suggest that bacterial photoinactivation is an alternative and effective approach to kill mcr-1 positive bacteria.

Anti E. coli Activity of Herbal Medicines: a Review

Directory of Open Access Journals (Sweden)

Nahid Rezaei

2017-12-01

Full Text Available Escherichia coli is the gram negative bacilli of Entrobacteriaceae family that commonly found in intestinal infections and many infections outside the intestine, like urinary tract infections (UTI, cholecystitis, wound infections, meningitis, septicemia, pulmonary infections, and many more. Plants are rich sources of bioactive compounds, hence they can be effective in a wide variety of diseases. The pandemic spread of multidrug-resistant (MDR bacteria (i.e., extended-spectrum b-lactamase-producing Enterobacteriaceae (ESBLPE, Carbapenemase-producing Enterobacteriaceae (CPE threaten healthcare Worldwide. The present review is a report of the most effective medicinal plants against E. coli. In this research, the required online database searches were conducted using the key words such as bacteria, E. coli and medicinal plants. Databases of Web of Science, PubMed, Scopus, Google Scholar, and ScienceDirect were explored to find and explore related articles. Since the incidence of E. coli is high, the aim of this study is to identify and report anti E. coli medicinal plants in Iran. The obtained results showed that there were 51 medicinal herbs that could be considered as the main medicinal plants capable of affecting E. coli.

Biochemical and serological characterization of Escherichia coli ...

African Journals Online (AJOL)

This study was designed to determine the isolation rate, serotypes and biochemical profiles of E. coli from colibacillosis and dead-in-shell embryos in Zaria, Northern-Nigeria. The isolation rate of E. coli from hatcheries studied were 4.67% and 7.50% from farms of Simtu Agricultural Company and National Animal Production ...

Cytolysin a expressing E. coli a promising candidate for imageable therapeutic probe

International Nuclear Information System (INIS)

Nguyen, Vu Hong; Phan, Thuy Xuan; Hong, Yeoung Jin; Min, Jung Joon

2007-01-01

Using bacteria for cancer treatment has a long history. Discovery of optical reporter genes consisting of fluorescent and luminescent protein facilitates the monitor of bacteria in vivo, non-invasively and repeatedly. E. coli, the natural enteric bacteria possessing capacity of tumor-targeting ability, seems to be suitable candidate for cancer treatment. In this study, we established the strain light-emitting E. coli for diagnostic purpose and Cytolysin A (Cly A) expressing E. coli for therapeutic purpose. E. coli (MG1655, wild type strain) was transformed plasmid pUC19 carrying lux gene to create the light expressing bacteria and test the tumor targeting-capacity by injecting the bacteria into CT26-tumor bearing mice via tail vein. On the other hand, for therapeutic purpose, plasmid containing Cly A gene, which is encoded for a pore-forming protein toxin, was introduced into E. coli. The toxicity of Cly A was evaluated in vitro by inoculating the bacteria with various cultured cancer cell lines. On the other hand, to test the therapeutic effect, the bacteria were injected intratumorally and intravenously into s.c.CT26-bearing as well as CT26-lung metastasized Balb/c mice. In vivo imaging data showed that the E. coli strains selectively located in the tumor. The in vitro result showed that the number of death cells were significantly higher in the samples containing E. coli expressing Cly A (E. coli Cly A) compared with the samples containing wild type strain. The growth of tumors was repressed in mice injected with either E. coli Cly A (significantly) or wild type E. coli (mildly), while tumors in no treatment group still grew fast. Furthermore, the tumors inoculated with E. coli cly A were necrotized but not with wild type E. coli. In the CT26-lung metastasized mouse model, the life span of mice was elongated when inject E. coli and longer in the group injected with E. coli cly A. Cly A expressing E. coli can become an effective candidate for imageable

Transport proteins promoting Escherichia coli pathogenesis

Science.gov (United States)

Tang, Fengyi; Saier, Milton H.

2014-01-01

Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. PMID:24747185

Transport proteins promoting Escherichia coli pathogenesis.

Science.gov (United States)

Tang, Fengyi; Saier, Milton H

2014-01-01

Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

E.coli O157:H7

Directory of Open Access Journals (Sweden)

Treor Francis Fernandez

2008-06-01

Full Text Available The serious nature of the symptoms of haemorrhagic colitis and HUS and the apparent low infectious dose (<100 cells of E.coli O157:H7 places this food borne pathogen a most serious of known food borne pathogens. Persuasive evidence suggests that healthy cattle are a reservoir of O157 and they can enter the food chain to provide a source of exposure for humans. A possible route of transmission of O157 VTEC may involve infections initially in calves that shed their organism into faecal slurry that may be used on grazing grass. This provides potential for infection of other animals from which the organism may contaminate milk or carcasses at slaughter. Possible sources of VTEC in healthy animals other E.coli O157:H7 than cattle and a wider range of foodstuffs require further investigation. Many features of E.coli O157:H7 strains remain poorly understood. It includes: (i Role of virulent genes in the animal, (ii Mechanism of evolution of the organism, (iii The progress of individual cases of E.coli O157:H7 infection, and (iv The difference in incidence of infection in different geographical areas. [Veterinary World 2008; 1(3.000: 83-87

Brote causado por Escherichia coli en Chalco, México Outbreak caused by Escherichia coli in Chalco, México

Directory of Open Access Journals (Sweden)

Iliana Alejandra Cortés-Ortiz

2002-07-01

Full Text Available Objetivo. Identificar el agente causal del brote de diarrea asociado con el desbordamiento del canal de aguas negras en Chalco. Material y métodos. Estudio retrospectivo y transversal, efectuado en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, de la Secretaría de Salud, con 1 550 hisopos rectales para el aislamiento e identificación bioquímica de V. cholerae y enterobacterias, obtenidos de la población del Valle de Chalco, que presentó diarrea y vómito durante el desastre natural acontecido el 31 de mayo de 2000. El análisis de los resultados se efectuó por la diferencia entre las proporciones de dos poblaciones (prueba de Ji cuadrada. Las cepas de E. coli se hibridaron por "colony blot" para los grupos ETEC, EIEC, EPEC y EHEC. Resultados. El 0.45% correspondió a Salmonella: S. agona, S. infantis, S. enteritidis, S. muenchen, S. typhimurium; 0.06% a Shigella flexneri 3a, y 76.6% a E. coli: 62.2% a ETEC (44.6 % con LT, 11.2% con ST, y 44.1% con ambas sondas, 0.84% a EIEC (sonda ial, 0.84% a EPEC (sonda bundle-forming pilus BFP, 0.08% a E. coli enterohemorrágica no-O157:H7 (sonda pCVD419, y 36.02% no hibridó. No se encontró asociación entre E. coli patógena con la edad y género. Conclusiones. Escherichia coli podría ser responsable del brote de diarrea. Es importante conocer el agente etiológico del brote para encaminar las estrategias en el estudio y control sanitario del mismo.Objective. To identify the etiologic agent responsible for a disease outbreak following an overflow of sewage water in Valle de Chalco, Mexico. Material and Methods. A retrospective cross-sectional study was carried out. Rectal samples were collected from the population of Chalco valley, who suffered from diarrhea and vomiting during a natural disaster that took place on May 31, 2000. The Instituto de Diagnóstico y Referencia Epidemiológicos (Epidemic Reference and Diagnosis Institute, InDRE, Ministry of Health, received 1521 rectal

Toxicity mechanism of carbon nanotubes on Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

Young, Yu-Fu [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Lee, Hui-Ju [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Tai, Nyan-Hwa, E-mail: nhtai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Chang, Hwan-You, E-mail: hychang@mx.nthu.edu.tw [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

2012-05-15

Highlights: Black-Right-Pointing-Pointer F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. Black-Right-Pointing-Pointer E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. Black-Right-Pointing-Pointer The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

Toxicity mechanism of carbon nanotubes on Escherichia coli

International Nuclear Information System (INIS)

Young, Yu-Fu; Lee, Hui-Ju; Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young; Tai, Nyan-Hwa; Chang, Hwan-You

2012-01-01

Highlights: ► F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. ► E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. ► The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

Recent Advances in Understanding Enteric Pathogenic Escherichia coli

Science.gov (United States)

Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

2013-01-01

SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

Assessment of the efficiency of ColiSure™ for coliforms Escherichia coli enumeration in pasteurizad milk / Avaliação do desempenho do ColiSure™ na enumeração de coliformes totais e Escherichia coli em leite pasteurizado

Directory of Open Access Journals (Sweden)

Elsa Helena Walter de Santana

2000-12-01

Full Text Available In the dairy industry the coliforms detection can he used as indicative of hygiene production of the raw milk and the contamination after-pasteurization. The traditional methods for the enumeration of the total and faecal coliforms are laborious and needs an incubation time of 96 hours. Rapid methods for detection of these microorganisms have been developed and among them the ColsSuroit is a rapid method that gives results in 24 hours and involves defined substrates for simultaneous determination of total conforms and E. coli in water based in specific enzymatic reactions of these microorganisms. The objective of this study was to evaluate its utilization in milk. Ninety-five samples of pasteurized milk were collected from the markets in Londrina city, Parana and analyzed by the Most Probable Number (NMP enumeration using the Brilliant Green Bile Lactose Broth (BGBL and ColiSure™. There was a correlation of 0.80 betwee-n the mediums when the incubation time was 43 hours for total conforms. The low down occurrence of E. coffin the analyzed samples made impossible to comparate the performance of methods for this microorganism. Compfementary analysis showed a greater sensibility and especifity of the ColiSure™ in comparation with the BGBL. The CofiSure™ can be indicated as a substitute for the traditional method, with the advantage to be faster and easier.Na indústria láctea a detecção de microrganismos do grupo coliformes é utilizada como indicativo da higiene na produção do leite e de contaminação pós-pasteurizaçüo. Os métodos tradicionais para a enumeração de coliformes totais e fecais são trabalhosos, com tempo de incubação longo, de até 96 horas. Métodos rápidos para a detecção destes microrganismos têm sido desenvolvidos na área de microbiologia de alimentos. O ColiSure™ é um método rápido, que fornece resultados simultaneamente para a presença ou a ausência de coliformes totais e Escherichia coli em �

Escherichia Coli Removal from Water Using Electrophotocatalytic ...

African Journals Online (AJOL)

Michael Horsfall

inactivation of bacterial microorganisms in areas with low ... disinfection of water contaminated with fecal indicators such as E. coli ... media, brain heart infusion, sodium chloride, sodium hydroxide ... furnace at temperature 105 and 320°C f0r 60 min. For 2- and .... charge of E. coli logarithmic growth phase might affect the ...

The SDH mutation database: an online resource for succinate dehydrogenase sequence variants involved in pheochromocytoma, paraganglioma and mitochondrial complex II deficiency

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Devilee Peter

2005-11-01

Full Text Available Abstract Background The SDHA, SDHB, SDHC and SDHD genes encode the subunits of succinate dehydrogenase (succinate: ubiquinone oxidoreductase, a component of both the Krebs cycle and the mitochondrial respiratory chain. SDHA, a flavoprotein and SDHB, an iron-sulfur protein together constitute the catalytic domain, while SDHC and SDHD encode membrane anchors that allow the complex to participate in the respiratory chain as complex II. Germline mutations of SDHD and SDHB are a major cause of the hereditary forms of the tumors paraganglioma and pheochromocytoma. The largest subunit, SDHA, is mutated in patients with Leigh syndrome and late-onset optic atrophy, but has not as yet been identified as a factor in hereditary cancer. Description The SDH mutation database is based on the recently described Leiden Open (source Variation Database (LOVD system. The variants currently described in the database were extracted from the published literature and in some cases annotated to conform to current mutation nomenclature. Researchers can also directly submit new sequence variants online. Since the identification of SDHD, SDHC, and SDHB as classic tumor suppressor genes in 2000 and 2001, studies from research groups around the world have identified a total of 120 variants. Here we introduce all reported paraganglioma and pheochromocytoma related sequence variations in these genes, in addition to all reported mutations of SDHA. The database is now accessible online. Conclusion The SDH mutation database offers a valuable tool and resource for clinicians involved in the treatment of patients with paraganglioma-pheochromocytoma, clinical geneticists needing an overview of current knowledge, and geneticists and other researchers needing a solid foundation for further exploration of both these tumor syndromes and SDHA-related phenotypes.

The Escherichia coli transcriptome linked to growth fitness

Directory of Open Access Journals (Sweden)

Bei-Wen Ying

2016-03-01

Full Text Available A series of Escherichia coli strains with varied genomic sequences were subjected to high-density microarray analyses to elucidate the fitness-correlated transcriptomes. Fitness, which is commonly evaluated by the growth rate during the exponential phase, is not only determined by the genome but is also linked to growth conditions, e.g., temperature. We previously reported genetic and environmental contributions to E. coli transcriptomes and evolutionary transcriptome changes in thermal adaptation. Here, we describe experimental details on how to prepare microarray samples that truly represent the growth fitness of the E. coli cells. A step-by-step record of sample preparation procedures that correspond to growing cells and transcriptome data sets that are deposited at the GEO database (GSE33212, GSE52770, GSE61739 are also provided for reference. Keywords: Transcriptome, Growth fitness, Escherichia coli, Microarray

Effect of low dose x irradiation on the succinate dehydrogenase activity of guinea pig, rat and mouse tissues

Energy Technology Data Exchange (ETDEWEB)

Shah, V C; Bhatavdekar, J M; Aravinda Babu, K [Gujarat Univ., Ahmedabad (India). Dept. of Zoology

1976-07-01

The histochemical changes in succinate dehydrogenase (SDH) were investigated in pectoralis major muscle of guinea pig, rat and mouse after level X-irradiation (72 R and 240 R) and compared with control animals. Biochemical studies were carried out on liver, kidney, muscle (pectoralis major), adrenal and spleen of these animals after low dose local X-irradiation and compared with control animals. Changes in SDH activity were studied up to 72-h post-irradiation, which shows that low dose local X-irradiation leads to increased enzymic activity. The increase in enzymic activity was remarkable in mouse tissues as compared with guinea pig and rat. Adrenals of all the three animals showed significant activation after all the doses of radiation studied. The significance of these results, with special reference to oxidative metabolism, has been discussed.

E. coli Surface Properties Differ between Stream Water and Sediment Environments

Directory of Open Access Journals (Sweden)

Xiao Liang

2016-11-01

Full Text Available The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10mM and 22˚C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity and extracellular polymeric substance (EPS composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli. A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli. Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli.

E. coli Surface Properties Differ between Stream Water and Sediment Environments.

Science.gov (United States)

Liang, Xiao; Liao, Chunyu; Thompson, Michael L; Soupir, Michelle L; Jarboe, Laura R; Dixon, Philip M

2016-01-01

The importance of E. coli as an indicator organism in fresh water has led to numerous studies focusing on cell properties and transport behavior. However, previous studies have been unable to assess if differences in E. coli cell surface properties and genomic variation are associated with different environmental habitats. In this study, we investigated the variation in characteristics of E. coli obtained from stream water and stream bottom sediments. Cell properties were measured for 77 genomically different E. coli strains (44 strains isolated from sediments and 33 strains isolated from water) under common stream conditions in the Upper Midwestern United States: pH 8.0, ionic strength 10 mM and 22°C. Measured cell properties include hydrophobicity, zeta potential, net charge, total acidity, and extracellular polymeric substance (EPS) composition. Our results indicate that stream sediment E. coli had significantly greater hydrophobicity, greater EPS protein content and EPS sugar content, less negative net charge, and higher point of zero charge than stream water E. coli . A significant positive correlation was observed between hydrophobicity and EPS protein for stream sediment E. coli but not for stream water E. coli . Additionally, E. coli surviving in the same habitat tended to have significantly larger (GTG) 5 genome similarity. After accounting for the intrinsic impact from the genome, environmental habitat was determined to be a factor influencing some cell surface properties, such as hydrophobicity. The diversity of cell properties and its resulting impact on particle interactions should be considered for environmental fate and transport modeling of aquatic indicator organisms such as E. coli .

Pathogenic Escherichia coli and food handlers in luxury hotels in Nairobi, Kenya.

Science.gov (United States)

Onyango, Abel O; Kenya, Eucharia U; Mbithi, John J N; Ng'ayo, Musa O

2009-11-01

The epidemiology and virulence properties of pathogenic Escherichia coli among food handlers in tourist destination hotels in Kenya are largely uncharacterized. This cross-sectional study among consenting 885 food handlers working in nine luxurious tourist hotels in Nairobi, Kenya determined the epidemiology, virulence properties, antibiotics susceptibility profiles and conjugation abilities of pathogenic Escherichia coli. Pathogenic Escherichia coli was detected among 39 (4.4%) subjects, including 1.8% enteroaggregative Escherichia coli (EAEC) harboring aggR genes, 1.2% enterotoxigenic Escherichia coli (ETEC) expressing both LT and STp toxins, 1.1% enteropathogenic Escherichia coli (EPEC) and 0.2% Shiga-like Escherichia coli (EHEC) both harboring eaeA and stx2 genes respectively. All the pathotypes had increased surface hydrophobicity. Using multivariate analyses, food handlers with loose stools were more likely to be infected with pathogenic Escherichia coli. Majority 53.8% of the pathotypes were resistant to tetracycline with 40.2% being multi-drug resistant. About 85.7% pathotypes trans-conjugated with Escherichia coli K12 F(-) NA(r) LA. The carriage of multi-drug resistant, toxin expressing pathogenic Escherichia coli by this population is of public health concern because exposure to low doses can result in infection. Screening food handlers and implementing public awareness programs is recommended as an intervention to control transmission of enteric pathogens.

Antimicrobial susceptibility patterns of E. coli from clinical sources in ...

African Journals Online (AJOL)

Background: Escherichia coli is the leading cause of urinary tract, ear, wound and other infections in humans. Increasing rates of antimicrobial resistance among E. coli is a growing concern worldwide. Objectives: The aim of this study was to determine the prevalence and antimicrobial susceptibility of E. coli from clinical ...

Meta-Analysis of Transcriptional Responses to Mastitis-Causing Escherichia coli.

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Sidra Younis

Full Text Available Bovine mastitis is a widespread disease in dairy cows, and is often caused by bacterial mammary gland infection. Mastitis causes reduced milk production and leads to excessive use of antibiotics. We present meta-analysis of transcriptional profiles of bovine mastitis from 10 studies and 307 microarrays, allowing identification of much larger sets of affected genes than any individual study. Combining multiple studies provides insight into the molecular effects of Escherichia coli infection in vivo and uncovers differences between the consequences of E. coli vs. Staphylococcus aureus infection of primary mammary epithelial cells (PMECs. In udders, live E. coli elicits inflammatory and immune defenses through numerous cytokines and chemokines. Importantly, E. coli infection causes downregulation of genes encoding lipid biosynthesis enzymes that are involved in milk production. Additionally, host metabolism is generally suppressed. Finally, defensins and bacteria-recognition genes are upregulated, while the expression of the extracellular matrix protein transcripts is silenced. In PMECs, heat-inactivated E. coli elicits expression of ribosomal, cytoskeletal and angiogenic signaling genes, and causes suppression of the cell cycle and energy production genes. We hypothesize that heat-inactivated E. coli may have prophylactic effects against mastitis. Heat-inactivated S. aureus promotes stronger inflammatory and immune defenses than E. coli. Lipopolysaccharide by itself induces MHC antigen presentation components, an effect not seen in response to E. coli bacteria. These results provide the basis for strategies to prevent and treat mastitis and may lead to the reduction in the use of antibiotics.

Incidence of Escherichia coli  - Glucuronidase Positive on Goat Milk

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Zorica Voşgan

2016-11-01

Full Text Available Papers on beta- glucuronidase sensitivity and specificity for identifying Escherichia coli in sources of environment, food, water, etc. have been published since 1976. In this study we conducted a review of the incidence of E. coli β- glucuronidase -positive in goat milk, obtained by hand milking throughout the lactation: spring, summer, autumn. The presence of E. coli in milk is considered both as a health indicator and a pathogenic factor capable of causing food poisoning. The determination of the E. coli β-glucuronidase-positive was carried using TBX medium by cultivating colonies typical blue at 440C. The absence of E. coli in milk yielded during the spring, when the animal milking is done three times a day, was found in the performed analyses; the same was observed during fall, when the milk production is lower and the milking is done once a day. The load of E. coli β-glucuronidase-positive was averaging 66.67 CFU/ml of goat milk, during the middle lactation period (July-August, in conditions of higher temperature. During this period, milking is done in the mountain zone, where the transhumance of animals takes place in summer. The presence of the species E. coli was also confirmed by microscopic examination. Attention should be paid to hygiene and milk should be immediately cooled, during hot weather, as E. coli can be a source of food poisoning.

Adsorption, sedimentation, and inactivation of E. coli within wastewater treatment wetlands.

Science.gov (United States)

Boutilier, L; Jamieson, R; Gordon, R; Lake, C; Hart, W

2009-09-01

Bacteria fate and transport within constructed wetlands must be understood if engineered wetlands are to become a reliable form of wastewater treatment. This study investigated the relative importance of microbial treatment mechanisms in constructed wetlands treating both domestic and agricultural wastewater. Escherichia coli (E. coli) inactivation, adsorption, and settling rates were measured in the lab within two types of wastewater (dairy wastewater lagoon effluent and domestic septic tank effluent). In situ E. coli inactivation was also measured within a domestic wastewater treatment wetland and the adsorption of E. coli was also measured within the wetland effluent. Inactivation of E. coli appears to be the most significant contributor to E. coli removal within the wastewaters and wetland environments examined in this study. E. coli survived longer within the dairy wastewater (DW) compared to the domestic wastewater treatment wetland water (WW). First order rate constants for E. coli inactivation within the WW in the lab ranged from 0.09 day(-1) (d(-1)) at 7.6 degrees C to 0.18d(-1) at 22.8 degrees C. The average in situ rate constant observed within the domestic wetland ranged from 0.02 d(-1) to 0.03 d(-1) at an average water temperature of 17 degrees C. First order rate constants for E. coli inactivation within the DW ranged from 0.01 d(-1) at 7.7 degrees C to 0.04 d(-1) at 24.6 degrees C. Calculated distribution coefficients (K(d)) were 19,000 mL g(-1), 324,000 mL g(-1), and 293 mL g(-1) for E. coli with domestic septic tank effluent (STE), treated wetland effluent (WLE), and DW, respectively. Approximately 50%, 20%, and 90% of E. coli were "free floating" or associated with particles 5 microm within both the STE and DW, settling did not appear to contribute to E. coli removal within sedimentation experiments, indicating that the particles the bacteria were associated with had very small settling velocities. The results of this study highlight the

Chromatin architecture and gene expression in Escherichia coli

DEFF Research Database (Denmark)

Willenbrock, Hanni; Ussery, David

2004-01-01

Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli.......Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli....

Epidemiology and clinical manifestations of enteroaggregative Escherichia coli

DEFF Research Database (Denmark)

Hebbelstrup Jensen, Betina; Olsen, Katharina E P; Struve, Carsten

2014-01-01

Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission...

Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

Science.gov (United States)

Alrowais, Hind; McElheny, Christi L; Spychala, Caressa N; Sastry, Sangeeta; Guo, Qinglan; Butt, Adeel A; Doi, Yohei

2015-11-01

Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase-producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described.

Escherichia coli in broiler chickens with airsacculitis

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Leandro S. Machado

2014-09-01

Full Text Available ABSTRACT. Machado L.S., do Nascimento E.R., Pereira V.L.A., Abreu D.L.C., Gouvea R. & Santos L.M.M. 2014. [Escherichia coli in broiler chickens with airsacculitis.] Escherichia coli em frangos de corte com aerossaculite. Revista Brasileira de Medicina Veterinária, 36(3:261-265, 2014. Departamento de Medicina Veterinária Preventiva e Saúde Pública, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Dr. Vital Brazil Filho 64, Vital Brazil, Niterói, RJ 24230-340, Brazil. E-mail: leandromachadovet@yahoo.com.br The Brazilian poultry industry grows each year and becomes increasingly representative in the production and export of products. The health care with poultry have accompanied and favored this evolution, however, respiratory agents that affect the weight and carcass quality, continue to cause great damage to the poultry industry. Airsacculitis is considered the main cause of total and partial condemnation of carcasses of broilers, and has been attributed to Mycoplasmosis mostly caused by Mycoplasma gallisepticum (MG and Mycoplasma synoviae (MS and Escherichia coli. The aim of this study was to relate the positivity of MG / MS and E. coli detected by PCR as a risk factor for airsacculitis in condemnation of broilers in Health Inspection Service. We studied 30 broiler poultry slaughtered in a slaughterhouse under Federal Sanitary Inspection, located in the State of Rio de Janeiro. 30 chickens were randomly collected from different lots and tracheas obtained in each PCR. DNA was extracted by phenol-chloroform method and amplified using pairs of “primer”specific for MG, MS and E. coli. Of the 30 chickens analyzed by PCR, 30% (9/30 had lesions in air sacs. None of the birds showed infection with MG and/or MS PCR, however 33.3% (3/9 birds were positive for airsacculitis iss gene from E.coli. E.coli found in broiler chickens that were negative for mycoplasma airsacculitis, implying the presence of such bacteria may be sufficient

Escherichia coli pathotypes in Pakistan from consecutive floods in 2010 and 2011.

Science.gov (United States)

Bokhari, Habib; Shah, Muhammad Ali; Asad, Saba; Akhtar, Sania; Akram, Muhammad; Wren, Brendan W

2013-03-01

This study compares Escherichia coli pathotypes circulating among children in Pakistan during the floods of 2010 and 2011 and from sporadic cases outside flood affected areas. Using multiplex polymerase chain reaction 115 of 205 stool samples (56.29%) were positive for diarrheagenic E. coli from specimens taken during the floods compared with 50 of 400 (12.5%) stool samples being positive for sporadic cases. The E. coli pathotypes were categorized as Enteropathogenic E. coli 33 (28.69%) and 13 (26%), Enterotoxigenic E. coli 29 (25.21%) and 15 (30%), Enteroaggregative E. coli 21 (18.2%) and 18 (36%), Enterohemorrhagic E. coli 5 (4.34%) and 1 (2%) from flood and sporadic cases, respectively. Furthermore, patients co-infected with more than one pathotype were 26 (22.60%) and 3 (6%) from flood and sporadic cases, respectively. The study shows an unexpectedly high rate of isolation of E. coli pathotypes suggesting Pakistan as an endemic region that requires active surveillance particularly during flood periods.

Experimental evolution of E. coli

Science.gov (United States)

Zhang, Mengshi

The evolution from unicellular to multicellular behavior is an essential step in the history of life. Our aim is to investigate the emergence of collective behavior in the model organism Escherichia coli (E. coli) and its selection advantages, such as better utilization of public goods. Our preliminary results suggest that the evolution of collective behavior may be a natural response to stressed conditions. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: mengshi0928@gmail.com.

Production and Purification Immunoglobulin against E. coli in Egg Yolk

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Mohammadreza Nassiri

2016-08-01

Full Text Available Introduction Chicken is the only avian species in which polyclonal antibodies, like IgG is transported from the hen to the egg yolk in a similar manner as the transport of mammalian IgG from the mother to the fetus. Immunoglobulin Y in the chicken is transported to the egg and accumulates in the egg yolk in large quantities. IgY is an egg yolk antibody that has been used widely for treatment and prevention of infections in humans and animal. IgY is used for passive protection of the pathogen infections such as Escherichia coli, bovine and human rotavirus, bovine coronavirus, salmonella, staphylococcus and Pseudomonas. IgY is a promising candidate as an alternative to antibiotics. Eschericha coli strains of serotype O157: H7 belongs to a family of pathogenic E. coli called enterohemorrhagic E. coli (EHEC strains responsible for hemorrhagic colitis, bloody or non-bloody diarrhea, and hemolytic uremic syndrome in humans. This strain of E. coli pathogenises by adhering to host intestinal epithelium and forming bacterial colonies. The purpose of this study was to produce and purify immunoglobulin Y against E. coli O157:H7 and develop specific polyclonal anti E. coli antibody in the egg yolk. Materials and Methods Sixteen-week-old laying hens (Mashhad, Iran were kept in individual cages with food and water ad libitum. Immunization of hens was performed by intramuscularly injecting killed E. coli O157: H7 with an equal volume of Freund’s complete adjuvant into two sides of chest area (Sigma, USA for the first immunization. Two booster immunizations followed up using complete and incomplete Freund’s adjuvants in two weeks interval. Freund’s adjuvant without antigen was injected to the control group. Two weeks after the last injection, the eggs were collected daily for eight weeks, marked and stored at 4 ºC. In order to IgY purification, eggs were collected. Purification of IgY from egg yolk was based on Polson and using PEG6000. Finally, the

Physicochemical Factors: Impact on Spermagglutination Induced by Escherichia coli

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Kiranjeet Kaur

2014-02-01

Full Text Available Motility is a sensitive parameter of sperm function which is predictive of its fertilization potential in vitro. The decrease in sperm motility may be associated with sperm agglutination and immobilization due to mere presence of bacteria or excretion of bacterial toxic products. Supplementation with various agents like sucrose, mannitol, calcium, and EDTA is well known to improve the sperm motility in vitro. The present study was designed to check any protective role exerted by the addition of different agents on spermatozoal motility against E. coli induced sperm agglutination. 52 semen specimens were screened for the presence of sperm-agglutinating strain of E. coli. Further, influence of various factors, namely, sugars, salts, and chelating agents was studied. Also, the impact of exposure to high temperature and alcohol on sperm-agglutinating efficiency of E. coli was observed. None of the factors could inhibit the sperm agglutination induced by E. coli, except high temperature suggesting the involvement of protein moiety. In addition, it was observed that agglutinating efficiency of E. coli was limited to spermatozoa and RBCs. It may be concluded that sperm-agglutinating property of E. coli is quite stable as various physicochemical factors tested did not show any negative effect on the same except high temperature.

Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

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mojtaba boniadian

2017-01-01

Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

Quantitative Brightness Analysis of Fluorescence Intensity Fluctuations in E. Coli.

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Kwang-Ho Hur

Full Text Available The brightness measured by fluorescence fluctuation spectroscopy specifies the average stoichiometry of a labeled protein in a sample. Here we extended brightness analysis, which has been mainly applied in eukaryotic cells, to prokaryotic cells with E. coli serving as a model system. The small size of the E. coli cell introduces unique challenges for applying brightness analysis that are addressed in this work. Photobleaching leads to a depletion of fluorophores and a reduction of the brightness of protein complexes. In addition, the E. coli cell and the point spread function of the instrument only partially overlap, which influences intensity fluctuations. To address these challenges we developed MSQ analysis, which is based on the mean Q-value of segmented photon count data, and combined it with the analysis of axial scans through the E. coli cell. The MSQ method recovers brightness, concentration, and diffusion time of soluble proteins in E. coli. We applied MSQ to measure the brightness of EGFP in E. coli and compared it to solution measurements. We further used MSQ analysis to determine the oligomeric state of nuclear transport factor 2 labeled with EGFP expressed in E. coli cells. The results obtained demonstrate the feasibility of quantifying the stoichiometry of proteins by brightness analysis in a prokaryotic cell.

Preparation And Physicochemical Properties of Octenyl Succinic Anhydride (OSA) Modified Sago Starch

International Nuclear Information System (INIS)

Nur Farhana Zainal Abiddin; Anida Yusoff; Noorlaila Ahmad

2016-01-01

Starch from sago (Metroxylon sagu) was esterified with octenyl succinic anhydride (OSA) in order to regulate its shortcoming by adding amphiphilic properties. The objective of this work is to determine the physicochemical properties of native sago and OSA sago starches. The OSA sago starch was produced according to the optimum condition generated via response surface methodology (RSM) with 5.00 % OSA at pH 7.20 and a reaction time of 9.65 hours. The esterified sago starch gives a degree of substitution (DS) value of 0.012. The physicochemical properties of OSA sago starch was determined by measuring the amylose content, laser diffraction particle size analyzer, scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The amylose content for OSA sago starch was found to be reduced after esterification reaction. The particle size of OSA sago starch was found to increase significantly (p<0.05) compared to their native starches. Scanning electron microscopy (SEM) revealed that OSA starch developed slightly rough surface and their edges lost some definition. FT-IR spectroscopy shows that there was appearance of new absorption correspond to ester carbonyl group (1717 cm -1 ) and carboxylate RCOO- (1569 cm -1 ). This study showed that the physicochemical properties of modified starches were influenced not only by DS but also on the botanical origin of the starches. (author)

Deuterium incorporation into Escherichia-coli proteins

DEFF Research Database (Denmark)

Lederer, H.; May, R. P.; Kjems, Jørgen

1986-01-01

Neutron small-angle scattering studies of single protein subunits in a protein-DNA complex require the adjustment of the neutron scattering-length densities of protein and DNA, which is attainable by specific deuteration of the protein. The neutron scattering densities of unlabelled DNA and DNA......-dependent RNA polymerase of Escherichia coli match when RNA polymerase is isolated from cells grown in a medium containing 46% D2O and unlabelled glucose as carbon source. Their contrasts vanish simultaneously in a dialysis buffer containing 65% D2O. An expression was evaluated which allows the calculation...... of the degree of deuteration and match point of any E. coli protein from the D2O content of the growth medium, taking the 2H incorporation into RNA polymerase amino acids to be representative for all amino acids in E. coli proteins. The small-angle scattering results, on which the calculation of the degree...

Sugar-Based Ethanol Biorefinery: Ethanol, Succinic Acid and By-Product Production

Energy Technology Data Exchange (ETDEWEB)

Donal F. Day

2009-03-31

The work conducted in this project is an extension of the developments itemized in DE-FG-36-04GO14236. This program is designed to help the development of a biorefinery based around a raw sugar mill, which in Louisiana is an underutilized asset. Some technical questions were answered regarding the addition of a biomass to ethanol facility to existing sugar mills. The focus of this work is on developing technology to produce ethanol and valuable by-products from bagasse. Three major areas are addressed, feedstock storage, potential by-products and the technology for producing ethanol from dilute ammonia pre-treated bagasse. Sugar mills normally store bagasse in a simple pile. During the off season there is a natural degradation of the bagasse, due to the composting action of microorganisms in the pile. This has serious implications if bagasse must be stored to operate a bagasse/biorefinery for a 300+ day operating cycle. Deterioration of the fermentables in bagasse was found to be 6.5% per month, on pile storage. This indicates that long term storage of adequate amounts of bagasse for year-round operation is probably not feasible. Lignin from pretreatment seemed to offer a potential source of valuable by-products. Although a wide range of phenolic compounds were present in the effluent from dilute ammonia pretreatment, the concentrations of each (except for benzoic acid) were too low to consider for extraction. The cellulosic hydrolysis system was modified to produce commercially recoverable quantities of cellobiose, which has a small but growing market in the food process industries. A spin-off of this led to the production of a specific oligosaccharide which appears to have both medical and commercial implications as a fungal growth inhibitor. An alternate use of sugars produced from biomass hydrolysis would be to produce succinic acid as a chemical feedstock for other conversions. An organism was developed which can do this bioconversion, but the economics of

Rare Case of Polymicrobial Keratitis With Balantidium coli.

Science.gov (United States)

Hazarika, Manali; Pai H, Vijaya; Khanna, Vinay; Reddy, Harish; Tilak, Kriti; Chawla, Kiran

2016-12-01

To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.

Incidence of Escherichia coli O157:H7 in Thailand

International Nuclear Information System (INIS)

Sukhumungoon, P.

2015-01-01

Entero hemorrhagic Escherichia coli (EHEC) especially serotype O157:H7 is one of the important food-borne pathogens because it is able to produce crucial toxins Shiga. However, the outbreak of this organism in Thailand has not been reported. Antibody to O157 antigen was detected in some Thai populations and Shiga toxin-producing E. coli were detected in low numbers of clinical specimens. Interestingly, some E. coli that showed positive to O157 fimbriae probe and lack of virulence gene were isolated from certain patients and one isolate of E. coli O157:H7 which possessed stx1, stx2v was detected in a normal child. In addition, the incidence of E. coli O157:H7 strains were monitored by the samples from cattle and retail beef in Thailand although their inability to produce toxins or produce in a low concentration was demonstrated. This review discusses the incidences of E. coli O157 in clinical and environmental samples of Thailand including the transmission possibility of this bacterium across the Thai border through food trade. (author)

Reconstitution of active mycobacterial binuclear iron monooxygenase complex in Escherichia coli.

Science.gov (United States)

Furuya, Toshiki; Hayashi, Mika; Kino, Kuniki

2013-10-01

Bacterial binuclear iron monooxygenases play numerous physiological roles in oxidative metabolism. Monooxygenases of this type found in actinomycetes also catalyze various useful reactions and have attracted much attention as oxidation biocatalysts. However, difficulties in expressing these multicomponent monooxygenases in heterologous hosts, particularly in Escherichia coli, have hampered the development of engineered oxidation biocatalysts. Here, we describe a strategy to functionally express the mycobacterial binuclear iron monooxygenase MimABCD in Escherichia coli. Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the mimABCD gene expression in E. coli revealed that the oxygenase components MimA and MimC were insoluble. Furthermore, although the reductase MimB was expressed at a low level in the soluble fraction of E. coli cells, a band corresponding to the coupling protein MimD was not evident. This situation rendered the transformed E. coli cells inactive. We found that the following factors are important for functional expression of MimABCD in E. coli: coexpression of the specific chaperonin MimG, which caused MimA and MimC to be soluble in E. coli cells, and the optimization of the mimD nucleotide sequence, which led to efficient expression of this gene product. These two remedies enabled this multicomponent monooxygenase to be actively expressed in E. coli. The strategy described here should be generally applicable to the E. coli expression of other actinomycetous binuclear iron monooxygenases and related enzymes and will accelerate the development of engineered oxidation biocatalysts for industrial processes.

[Virulence markers of Escherichia coli O1 strains].

Science.gov (United States)

Makarova, M A; Kaftyreva, L A; Grigor'eva, N S; Kicha, E V; Lipatova, L A

2011-01-01

To detect virulence genes in clinical isolates of Escherichia coli O1 using polymerase chain reaction (PCR). One hundred and twenty strains of E.coli O1 strains isolated from faeces of patients with acute diarrhea (n = 45) and healthy persons (n = 75) were studied. PCR with primers for rfb and fliC genes, which control synthesis of O- and H- antigens respectively, was used. Fourteen virulence genes (pap, aaf, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, st, and aer) were detected by PCR primers. K1-antigen was determined by Pastorex Meningo B/E. coli O1 kit (Bio-Rad). rfb gene controlling O-antigen synthesis in serogroup O1 as well as fliC gene controlling synthesis of H7 and K1 antigens were detected in all strains. Thus all E. coli strains had antigenic structure O1:K1 :H-:F7. Virulence genes aafl, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, and st were not detected. All strains owned pap and aer genes regardless of the presence of acute diarrhea symptoms. It was shown that E. coli O1:KI:H-:F7 strains do not have virulence genes which are characteristic for diarrhea-causing Escherichia. In accordance with the presence of pap and aer genes they could be attributed to uropathogenic Escherichia (UPEC) or avian-pathogenic Escherichia (APEC). It is necessary to detect virulence factors in order to determine E. coli as a cause of intestinal infection.

Pathogenic Potential to Humans of Bovine Escherichia coli O26, Scotland

Science.gov (United States)

Rosser, Tracy; Allison, Lesley J.; Courcier, Emily; Evans, Judith; McKendrick, Iain J.; Pearce, Michael C.; Handel, Ian; Caprioli, Alfredo; Karch, Helge; Hanson, Mary F.; Pollock, Kevin G.J.; Locking, Mary E.; Woolhouse, Mark E.J.; Matthews, Louise; Low, J. Chris; Gally, David L.

2012-01-01

Escherichia coli O26 and O157 have similar overall prevalences in cattle in Scotland, but in humans, Shiga toxin–producing E. coli O26 infections are fewer and clinically less severe than E. coli O157 infections. To investigate this discrepancy, we genotyped E. coli O26 isolates from cattle and humans in Scotland and continental Europe. The genetic background of some strains from Scotland was closely related to that of strains causing severe infections in Europe. Nonmetric multidimensional scaling found an association between hemolytic uremic syndrome (HUS) and multilocus sequence type 21 strains and confirmed the role of stx2 in severe human disease. Although the prevalences of E. coli O26 and O157 on cattle farms in Scotland are equivalent, prevalence of more virulent strains is low, reducing human infection risk. However, new data on E. coli O26–associated HUS in humans highlight the need for surveillance of non-O157 enterohemorrhagic E. coli and for understanding stx2 phage acquisition. PMID:22377426

Isolation and genomic characterization of Escherichia coli O157:NM ...

African Journals Online (AJOL)

Human diseases caused by Escherichia coli O157:NM and E. coli O157:H7 strains have been reported throughout the world. In developed countries, serotype O157:H7 represents the major cause of human diseases; however, there have been increasing reports of non-O157 Shiga toxin (Stx)-producing E. coli strains ...

77 FR 58091 - Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and...

Science.gov (United States)

2012-09-19

... for exposure of carcasses and parts to any contamination or food safety hazard during the removal of... DEPARTMENT OF AGRICULTURE Food Safety and Inspection Service [Docket No. FSIS-2012-0020] Risk-Based Sampling of Beef Manufacturing Trimmings for Escherichia coli (E. coli) O157:H7 and Plans for Beef...

Escherichia coli ST131, an Intriguing Clonal Group

Science.gov (United States)

Bertrand, Xavier; Madec, Jean-Yves

2014-01-01

SUMMARY In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131. PMID:24982321

Structural control of co-continuous poly(L-lactide)/poly(butylene succinate)/clay nanocomposites.

Science.gov (United States)

Zhao, Li; Li, Yongjin; Shimizu, Hiroshi

2009-04-01

Poly(L-lactide) (PLLA)/poly(butylene succinate) (PBS) (55/45 w/w) blends with different amounts of nanoclay loadings were prepared using a specially designed high-shear extruder, HSE3000mini, which can reach a maximum shear rate of 4400 sec(-1). The resulted co-continuous structural morphologies were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). SEM observation revealed that through the combination of various amounts of nanoclay loadings and processing under various shear conditions, the phase size of co-continuous structures of PLLA/PBS blends can be controlled over a wide range from several tens of micrometers to submicrometers. TEM observation shows that all the nanoclays are selectively dispersed in the PBS phase. We also found that clays in low-shear processed sample were mainly located at the interface of PBS phase, while in high-shear sample, the clays were mainly located inside of the PBS phase. It was considered that the dependence of nanoclay location in the PBS phase on the shear conditions, as well as the changing of the viscosity ratio of PBS and PLLA phase with different amounts of clay loading, play important roles in controlling the phase size of the co-continuous structures of PLLA/PBS blends.

Acylation Modification of Antheraea pernyi Silk Fibroin Using Succinic Anhydride and Its Effects on Enzymatic Degradation Behavior

Directory of Open Access Journals (Sweden)

Xiufang Li

2013-01-01

Full Text Available The degradation rate of tissue engineering scaffolds should match the regeneration rate of new tissues. Controlling the degradation behavior of silk fibroin is an important subject for silk-based tissue engineering scaffolds. In this study, Antheraea pernyi silk fibroin was successfully modified with succinic anhydride and then characterized by zeta potential, ninhydrin method, and FTIR. In vitro, three-dimensional scaffolds prepared with modified silk fibroin were incubated in collagenase IA solution for 18 days to evaluate the impact of acylation on the degradation behavior. The results demonstrated that the degradation rate of modified silk fibroin scaffolds was more rapid than unmodified ones. The content of the β-sheet structure in silk fibroin obviously decreased after acylation, resulting in a high degradation rate. Above all, the degradation behavior of silk fibroin scaffolds could be regulated by acylation to match the requirements of various tissues regeneration.

Glycan-functionalized diamond nanoparticles as potent E. coli anti-adhesives

Science.gov (United States)

Barras, Alexandre; Martin, Fernando Ariel; Bande, Omprakash; Baumann, Jean-Sébastien; Ghigo, Jean-Marc; Boukherroub, Rabah; Beloin, Christophe; Siriwardena, Aloysius; Szunerits, Sabine

2013-02-01

Bacterial attachment and subsequent biofilm formation on biotic surfaces or medical devices is an increasing source of infections in clinical settings. A large proportion of these biofilm-related infections are caused by Escherichia coli, a major nosocomial pathogen, in which the major adhesion factor is the FimH adhesin located at the tip of type 1 fimbriae. Inhibition of FimH-mediated adhesion has been identified as an efficient antibiotic-alternative strategy to potentially reduce E. coli-related infections. In this article we demonstrate that nanodiamond particles, covently modified with mannose moieties by a ``click'' chemistry approach, are able to efficiently inhibit E. coli type 1 fimbriae-mediated adhesion to eukaryotic cells with relative inhibitory potency (RIP) of as high as 9259 (bladder cell adhesion assay), which is unprecedented when compared with RIP values previously reported for alternate multivalent mannose-functionalized nanostructures designed to inhibit E. coli adhesion. Also remarkable is that these novel mannose-modified NDs reduce E. coli biofilm formation, a property previously not observed for multivalent glyco-nanoparticles and rarely demonstrated for other multivalent or monovalent mannose glycans. This work sets the stage for the further evaluation of these novel NDs as an anti-adhesive therapeutic strategy against E. coli-derived infections.Bacterial attachment and subsequent biofilm formation on biotic surfaces or medical devices is an increasing source of infections in clinical settings. A large proportion of these biofilm-related infections are caused by Escherichia coli, a major nosocomial pathogen, in which the major adhesion factor is the FimH adhesin located at the tip of type 1 fimbriae. Inhibition of FimH-mediated adhesion has been identified as an efficient antibiotic-alternative strategy to potentially reduce E. coli-related infections. In this article we demonstrate that nanodiamond particles, covently modified with

Antibiotic resistant Salmonella and Escherichia coli isolated from ...

African Journals Online (AJOL)

Results: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern ...

Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC).

Science.gov (United States)

Sanches, Lilian Aparecida; Gomes, Marcelo da Silva; Teixeira, Rodrigo Hidalgo Friciello; Cunha, Marcos Paulo Vieira; Oliveira, Maria Gabriela Xavier de; Vieira, Mônica Aparecida Midolli; Gomes, Tânia Aparecida Tardelli; Knobl, Terezinha

Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Genome analysis of E. coli isolated from Crohn's disease patients.

Science.gov (United States)

Rakitina, Daria V; Manolov, Alexander I; Kanygina, Alexandra V; Garushyants, Sofya K; Baikova, Julia P; Alexeev, Dmitry G; Ladygina, Valentina G; Kostryukova, Elena S; Larin, Andrei K; Semashko, Tatiana A; Karpova, Irina Y; Babenko, Vladislav V; Ismagilova, Ruzilya K; Malanin, Sergei Y; Gelfand, Mikhail S; Ilina, Elena N; Gorodnichev, Roman B; Lisitsyna, Eugenia S; Aleshkin, Gennady I; Scherbakov, Petr L; Khalif, Igor L; Shapina, Marina V; Maev, Igor V; Andreev, Dmitry N; Govorun, Vadim M

2017-07-19

Escherichia coli (E. coli) has been increasingly implicated in the pathogenesis of Crohn's disease (CD). The phylogeny of E. coli isolated from Crohn's disease patients (CDEC) was controversial, and while genotyping results suggested heterogeneity, the sequenced strains of E. coli from CD patients were closely related. We performed the shotgun genome sequencing of 28 E. coli isolates from ten CD patients and compared genomes from these isolates with already published genomes of CD strains and other pathogenic and non-pathogenic strains. CDEC was shown to belong to A, B1, B2 and D phylogenetic groups. The plasmid and several operons from the reference CD-associated E. coli strain LF82 were demonstrated to be more often present in CDEC genomes belonging to different phylogenetic groups than in genomes of commensal strains. The operons include carbon-source induced invasion GimA island, prophage I, iron uptake operons I and II, capsular assembly pathogenetic island IV and propanediol and galactitol utilization operons. Our findings suggest that CDEC are phylogenetically diverse. However, some strains isolated from independent sources possess highly similar chromosome or plasmids. Though no CD-specific genes or functional domains were present in all CD-associated strains, some genes and operons are more often found in the genomes of CDEC than in commensal E. coli. They are principally linked to gut colonization and utilization of propanediol and other sugar alcohols.

The propagation of Escherichia Coli and of conservative tracers. A comparison

International Nuclear Information System (INIS)

Alexander, I.; Seiler, K.P.

1982-01-01

The propagation of Escherichia Coli (ATCC 11229, Gelsenkirchen) is compared with that of conservative tracers in groundwater. The experiments were performed with injection quantities of 10 7 , 10 8 , 10 10 and 10 11 of Escherichia Coli. Both, bacteria and conservative tracers pass their maximum at the same instant in the observation gauges. With injection quantities of more than 10 8 , the propagation of the Escherichia Coli sets in at the same time as it begins with the dyes. When the quantities range below 10 8 , the propagation begins after that of conservative tracers, because Coli bacteria were measured with a lower degree of detecting sensitivity than the tracers. With Coli injection quantities ranging above 10 10 , an increased filtering of these bacteria can be observed. Coli bacteria propagate more laterally than conservative tracers, however it could not be proved that this lateral propagation depends on the bacteria concentration. (orig.) [de

Drug Resistance Patterns of Escherichia coli in Ethiopia: A Meta-Analysis.

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Tuem, Kald Beshir; Gebre, Abadi Kahsu; Atey, Tesfay Mehari; Bitew, Helen; Yimer, Ebrahim M; Berhe, Derbew Fikadu

2018-01-01

Antimicrobial drug resistance is a global threat for treatment of infectious diseases and costs life and money and threatens health delivery system's effectiveness. The resistance of E. coli to frequently utilized antimicrobial drugs is becoming a major challenge in Ethiopia. However, there is no inclusive countrywide study. Therefore, this study intended to assess the prevalence of E. coli resistance and antimicrobial-specific resistance pattern among E. coli clinical isolates in Ethiopia. Articles were retrieved from PubMed, Embase, and grey literature from 2007 to 2017. The main outcome measures were overall E. coli and drug-specific resistance patterns. A random-effects model was used to determine pooled prevalence with 95% confidence interval (CI), using DerSimonian and Laird method. In addition, subgroup analysis was conducted to improve the outcome. The study bias was assessed by Begg's funnel plot. This study was registered in PROSPERO as follows: PROSPERO 2017: CRD42017070106. Of 164 articles retrieved, 35 articles were included. A total of 19,235 study samples participated in the studies and 2,635 E. coli strains were isolated. Overall, E. coli antibacterial resistance was 45.38% (95% confidence interval (CI): 33.50 to 57.27). The resistance pattern ranges from 62.55% in Addis Ababa to 27.51% in Tigray region. The highest resistance of E. coli reported was to ampicillin (83.81%) and amoxicillin (75.79%), whereas only 13.55% of E. coli isolates showed resistance to nitrofurantoin. E. coli antimicrobial resistance remains high with disparities observed among regions. The bacterium was found to be highly resistant to aminopenicillins. The finding implies the need for effective prevention strategies for the E. coli drug resistance and calls for multifaceted approaches with full involvement of all stakeholders.

Highly sensitive immunoassay based on E. coli with autodisplayed Z-domain

International Nuclear Information System (INIS)

Jose, Joachim; Park, Min; Pyun, Jae-Chul

2010-01-01

The Z-domain of protein A has been known to bind specifically to the F c region of antibodies (IgGs). In this work, the Z-domain of protein A was expressed on the outer membrane of Escherichia coli by using 'Autodisplay' technology as a fusion protein of autotransport domain. The E. coli with autodisplayed Z-domain was applied to the sandwich-type immunoassay as a solid-support of detection-antibodies against a target analyte. For the feasibility demonstration of the E. coli based immunoassay, C-reactive protein (CRP) assay was carried out by using E. coli with autodisplayed Z-domain. The limit of detection (LOD) and binding capacity of the E. coli based immunoassay were estimated to be far more sensitive than the conventional ELISA. Such a far higher sensitivity of E. coli based immunoassay than conventional ELISA was explained by the orientation control of immobilized antibodies and the mobility of E. coli in assay matrix. From the test results of 45 rheumatoid arthritis (RA) patients' serum and 15 healthy samples, a cut-off value was established to have optimal sensitivity and selectivity values for RA. The CRP test result of each individual sample was compared with ELISA which is the reference method for RA diagnosis. From this work, the E. coli with Z-domain was proved to be feasible for the medical diagnosis based on sandwich-type immunoassay.

Replication and Transcription of Eukaryotic DNA in Esherichia coli

Science.gov (United States)

Morrow, John F.; Cohen, Stanley N.; Chang, Annie C. Y.; Boyer, Herbert W.; Goodman, Howard M.; Helling, Robert B.

1974-01-01

Fragments of amplified Xenopus laevis DNA, coding for 18S and 28S ribosomal RNA and generated by EcoRI restriction endonuclease, have been linked in vitro to the bacterial plasmid pSC101; and the recombinant molecular species have been introduced into E. coli by transformation. These recombinant plasmids, containing both eukaryotic and prokaryotic DNA, replicate stably in E. coli. RNA isolated from E. coli minicells harboring the plasmids hybridizes to amplified X. laevis rDNA. Images PMID:4600264

Antibiotic Resistance and Virulence Properties in Escherichia coli ...

African Journals Online (AJOL)

This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife, Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods.

Deactivation of Escherichia coli by the plasma needle

International Nuclear Information System (INIS)

Sladek, R E J; Stoffels, E

2005-01-01

In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 10 4 -10 5 colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively

Deactivation of Escherichia coli by the plasma needle

Energy Technology Data Exchange (ETDEWEB)

Sladek, R E J; Stoffels, E [Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

2005-06-07

In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 10{sup 4}-10{sup 5} colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively.

Sucralose Increases Antimicrobial Resistance and Stimulates Recovery of Escherichia coli Mutants.

Science.gov (United States)

Qu, Yilin; Li, Rongyan; Jiang, Mingshan; Wang, Xiuhong

2017-07-01

Because of heavy use of antimicrobials, antimicrobial resistance in bacteria has become of great concern. The effect of some widely used food additives such as sucralose on bacteria in the gut and the environment has also drawn increasing attention. In this study, we investigated the interaction between antimicrobials and sucralose impacting antimicrobial resistance and mutation of Escherichia coli (E. coli). To examine antimicrobial resistance and mutation frequency, different subinhibitory concentrations of sucralose were added to cultures of E.coli BW25113 that were then treated with antimicrobials, oxolinic acid, or moxifloxacin. Then the E.coli were assayed for bacterial survival and recovery of mutants resistant to an unrelated antimicrobial, rifampicin. Pre-treatment of E.coli BW25113 with 1/2 minimal inhibitory concentration (MIC) of sucralose increased the survival rate in oxolinic acid or moxifloxacin. A 1/3 MIC of sucralose increased rifampicin-resistant mutation rate of E.coli BW25113 after 72 h, while rifampicin-resistant mutation rate was increased when co-treated with 1/8 MIC, 1/4 MIC, 1/3 MIC sucralose, and oxolinic acid after 24 h. Sucralose can increase the antimicrobial resistance and mutation frequency of E.coli to some antimicrobials.

Action of sodium deoxycholate on Escherichia coli

International Nuclear Information System (INIS)

D'Mello, A.; Yotis, W.W.

1987-01-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of [U- 14 C]glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order

Action of sodium deoxycholate on Escherichia coli

Energy Technology Data Exchange (ETDEWEB)

D' Mello, A.; Yotis, W.W.

1987-08-01

Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of (U-/sup 14/C)glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order.

Occurrence of Coliform and Escherichia coli Contamination and Absence of Escherichia coli O157:H7 on Romaine Lettuce from Retail Stores in the Upper Midwest.

Science.gov (United States)

Greve, Josephine D; Zietlow, Mark S; Miller, Kevin M; Ellingson, Jay L E

2015-09-01

A total of 720 whole, romaine lettuce heads were purchased from retail locations in the Upper Midwest and assessed for coliform and Escherichia coli contamination and for the presence of E. coli O157:H7. During a 16-month period (August 2010 through December 2011), coliform and E. coli counts were enumerated on Petrifilm, and the presence of E. coli O157:H7 and the virulence gene eae was evaluated by real-time PCR (qPCR). Over half (400 of 720) of the lettuce samples were processed with an immunomagnetic separation step before the qPCR assay. All retail lettuce samples were negative for E. coli O157:H7 when tested with the R.A.P.I.D. LT qPCR targeting a region of the O-antigen, and only two (0.28%) were positive for the eae gene when tested with LightCycler qPCR. On Petrifilm, coliform counts of most lettuce samples (96.4%) were between lettuce samples (98.2%) were lettuce heads. These results contribute to the limited recorded data and understanding of microbial contamination of whole romaine lettuce heads purchased from retail locations, specifically revealing the absence of E. coli O157:H7 and low levels of contamination with coliforms and other E. coli strains.

Spontaneous Escherichia coli Meningitis Associated with Hemophagocytic Lymphohistiocytosis

Directory of Open Access Journals (Sweden)

Kuo-Hsuan Chang

2006-01-01

Full Text Available Spontaneous Escherichia coli meningitis has not been previously reported in association with hemophago-cytic lymphohistiocytosis (HLH. A previously healthy 72-year-old woman was admitted due to fever, nuchal rigidity, disturbed consciousness and splenomegaly. Anemia, thrombocytopenia and hyperfer-ritinemia developed on the 8th day of hospitalization. Cultures of cerebrospinal fluid and blood grew E. coli. Abundant macrophages overwhelmed erythrocytes in the bone marrow aspirate, confirming the presence of hemophagocytosis. E. coli meningitis was managed with a 40-day course of antibiotic treatment. However, the severity of anemia and thrombocytopenia progressed despite intensive transfusion therapy. The patient died of HLH on the 60th day of hospitalization.

Escherichia coli growth modeling using neural network | Shamsudin ...

African Journals Online (AJOL)

technique that has the ability to predict with efficient and good performance. Using NARX, a highly accurate model was developed to predict the growth of Escherichia coli (E. coli) based on pH water parameter. The multiparameter portable sensor and spectrophotometer data were used to build and train the neural network.

Engineering Escherichia coli for methanol conversion.

Science.gov (United States)

Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

2015-03-01

Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Diarrheagenic Escherichia coli and acute and persistent diarrhea in returned travelers

NARCIS (Netherlands)

Schultsz, C.; van den Ende, J.; Cobelens, F.; Vervoort, T.; van Gompel, A.; Wetsteyn, J. C.; Dankert, J.

2000-01-01

To determine the role of diarrheagenic Escherichia coli in acute and persistent diarrhea in returned travelers, a case control study was performed. Enterotoxigenic E. coli (ETEC) was detected in stool samples from 18 (10.7%) of 169 patients and 4 (3.7%) of 108 controls. Enteroaggregative E. coli

Recyclable Escherichia coli-Specific-Killing AuNP-Polymer (ESKAP) Nanocomposites.

Science.gov (United States)

Yuan, Yuqi; Liu, Feng; Xue, Lulu; Wang, Hongwei; Pan, Jingjing; Cui, Yuecheng; Chen, Hong; Yuan, Lin

2016-05-11

Escherichia coli plays a crucial role in various inflammatory diseases and infections that pose significant threats to both human health and the global environment. Specifically inhibiting the growth of pathogenic E. coli is of great and urgent concern. By modifying gold nanoparticles (AuNPs) with both poly[2-(methacrylamido)glucopyranose] (pMAG) and poly[2-(methacryloyloxy)ethyl trimethylammonium iodide] (pMETAI), a novel recyclable E. coli-specific-killing AuNP-polymer (ESKAP) nanocomposite is proposed in this study, which based on both the high affinity of glycopolymers toward E. coli pili and the merits of antibacterial quaternized polymers attached to gold nanoparticles. The properties of nanocomposites with different ratios of pMAG to pMETAI grafted onto AuNPs are studied. With a pMAG:pMETAI feed ratio of 1:3, the nanocomposite appeared to specifically adhere to E. coli and highly inhibit the bacterial cells. After addition of mannose, which possesses higher affinity for the lectin on bacterial pili and has a competitive advantage over pMAG for adhesion to pili, the nanocomposite was able to escape from dead E. coli cells, becoming available for repeat use. The recycled nanocomposite retained good antibacterial activity for at least three cycles. Thus, this novel ESKAP nanocomposite is a promising, highly effective, and readily recyclable antibacterial agent that specifically kills E. coli. This nanocomposite has potential applications in biological sensing, biomedical diagnostics, biomedical imaging, drug delivery, and therapeutics.

Human exposure assessment to antibiotic-resistant Escherichia coli through drinking water.

Science.gov (United States)

O'Flaherty, E; Borrego, C M; Balcázar, J L; Cummins, E

2018-03-01

Antibiotic-resistant bacteria (ARB) are a potential threat to human health through drinking water with strong evidence of ARB presence in post treated tap water around the world. This study examines potential human exposure to antibiotic-resistant (AR) Escherichia coli (E. coli) through drinking water, the effect of different drinking water treatments on AR E. coli and the concentration of AR E. coli required in the source water for the EU Drinking Water Directive (DWD) (Council Directive 98/83/EC, 0CFU/100ml of E. coli in drinking water) to be exceeded. A number of scenarios were evaluated to examine different water treatment combinations and to reflect site specific conditions at a study site in Europe. A literature search was carried out to collate data on the effect of environmental conditions on AR E. coli, the effect of different water treatments on AR E. coli and typical human consumption levels of tap water. A human exposure assessment model was developed with probability distributions used to characterise uncertainty and variability in the input data. Overall results show the mean adult human exposure to AR E. coli from tap water consumption ranged between 3.44×10 -7 and 2.95×10 -1 cfu/day for the scenarios tested and varied depending on the water treatments used. The level of AR E. coli required in the source water pre-treatment to exceed the DWD varied between 1 and 5logcfu/ml, depending on the water treatments used. This can be used to set possible monitoring criteria in pre-treated water for potential ARB exposure in drinking water. Copyright © 2017 Elsevier B.V. All rights reserved.

lactamases genes among0 Escherichia coli from patients with ...

African Journals Online (AJOL)

-lactamases (ESBLs) that mediate resistance to b-lactam drugs among Escherichia coli and other uropathogens have been reported worldwide. However, there is little information on the detection of ESBLs genes in E. coli from patients with ...

Succinate, iron chelation, and monovalent cations affect the transformation efficiency of Acinetobacter baylyi ATCC 33305 during growth in complex media.

Science.gov (United States)

Leong, Colleen G; Boyd, Caroline M; Roush, Kaleb S; Tenente, Ricardo; Lang, Kristine M; Lostroh, C Phoebe

2017-10-01

Natural transformation is the acquisition of new genetic material via the uptake of exogenous DNA by competent bacteria. Acinetobacter baylyi is model for natural transformation. Here we focus on the natural transformation of A. baylyi ATCC 33305 grown in complex media and seek environmental conditions that appreciably affect transformation efficiency. We find that the transformation efficiency for A. baylyi is a resilient characteristic that remains high under most conditions tested. We do find several distinct conditions that alter natural transformation efficiency including addition of succinate, Fe 2+ (ferrous) iron chelation, and substitution of sodium ions with potassium ones. These distinct conditions could be useful to fine tune transformation efficiency for researchers using A. baylyi as a model organism to study natural transformation.

Characterization of Climical and Commensal Escherichia coli Isolates from an Integrated Turkey Operation

OpenAIRE

Altekruse, Sean Fitzgerald

2001-01-01

Pathogenic E. coli infections cause approximately one quarter of disease losses in commercial turkey flocks. A small subgroup of E. coli causes most infections. Epidemiologic studies of this disease have been hindered by a lack of reliable markers to discriminate between pathogenic and fecal E. coli and by the diversity of poultry strains. Reliance on antimicrobials to control E. coli infections has caused widespread antimicrobial resistance. One hundred five clinical E. coli were obtaine...

Uncomplicated E Coli Urinary Tract Infection in College Women: A Follow-Up Study of E Coli Sensitivities to Commonly Prescribed Antibiotics

Science.gov (United States)

Ansbach, Robert K.; Dybus, Karen; Bergeson, Rachel

2005-01-01

Treatment of uncomplicated urinary tract infections (UTIs) has changed in the past few years with researchers advocating empiric treatment for shorter periods of time without the use of cultures. Researchers report that antibiotic resistance of Escherichia coli (E coli) to commonly prescribed antibiotics in uncomplicated UTIs has been increasing.…

Distribution of Diverse Escherichia coli between Cattle and Pasture.

Science.gov (United States)

NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N; Brözel, Volker S

2017-09-27

Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment.

Temporal variations of Escherichia coli concentrations in a large Midwestern river

Science.gov (United States)

Schilling, K.E.; Zhang, Y.-K.; Hill, D.R.; Jones, C.S.; Wolter, C.F.

2009-01-01

The Raccoon River used by the Des Moines Water Works to serve more than 400,000 people in central Iowa is threatened by contamination from Escherichia coli bacteria from point and nonpoint sources. The 9389 km2 watershed is highly agricultural, with 73% of the land in row crop production and widespread animal production. Results from 2155 grab samples from 1997 to 2005 for E. coli analysis were examined for temporal variations. E. coli concentrations were found to vary across years, seasons, and flow conditions, with a 9-year mean value of 1156 most probable number (MPN)/100 ml. Monthly concentrations exhibited clear seasonality with highest values in May through July. Although E. coli concentrations were higher during periods of greater discharge, the relation of log E. coli to log discharge was not particularly strong (r2 = 0.35). The variogram of E. coli concentrations showed temporal correlation within a span of 4 days suggesting that concentrations measured on 1 day may be related in time to concentrations measured up to 3 days later and beyond 4 days the concentrations vary randomly. The spectral analysis of the time series of E. coli was also carried out and was fitted well with the spectrum of an exponential covariance function. Deciphering temporal patterns and correlation of E. coli bacteria in streams may be useful for developing future monitoring strategies to track concentration patterns and loads. ?? 2008 Elsevier B.V. All rights reserved.

Isolation and evaluation of cocktail phages for the control of multidrug-resistant Escherichia coli serotype O104: H4 and E. coli O157: H7 isolates causing diarrhea.

Science.gov (United States)

Safwat Mohamed, Doaa; Farouk Ahmed, Eman; Mohamed Mahmoud, Abobakr; Abd El-Baky, Rehab Mahmoud; John, James

2018-02-01

Escherichia coli serotype O157: H7 and E. coli O104: H4 are well known foodborne pathogens causing sever enteric illness. Using bacteriophages as biocontrol agents of some foodborne pathogens and multidrug-resistant (MDR) bacteria has a great attention nowadays. This study aims to test the effect of cocktail phages on the growth of some foodborne pathogens and MDR E. coli. Routine conventional PCR was used to confirm the identification of E. coli isolates. Double-layered culture technique was used to isolate phages from sewage water. Morphology of bacteriophage was described using transmission electron microscopy, and spot test was performed to determine host range of the phage cocktail. Phage cocktail of Siphoviridae and Podoviridae family infecting E. coli O157: H7, E. coli O104: H4 and untypeable E. coli (neither O157 nor O104) has been isolated from sewage water. Phage cocktail showed both lytic and lysogenic activity. Lytic activity was observed against E. coli O157: H7, E. coli O104: H4 isolates, Staphylococcus. aureus ATCC6538 and Pseudomonas aeruginosa ATCC 10145, while the lysogenic activity was observed against the untypeable strain. The tested phage cocktail showed a promising inhibitory action on E. coli O157: H7 and O104: H4, S. aureus ATCC6538 and P. aeruginosa ATCC 10145, suggesting the possibility of its use as a biocontrol tool or as natural food preservatives for many food products. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Alterations induced in Escherichia Coli cells by gamma radiation

International Nuclear Information System (INIS)

Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da; Jesus, E.F.O. de; Lopes, R.T.; Carlin, N.; Toledo, E.S.

2007-01-01

Modifications occurred in Escherichia coli cells exposed to gamma radiation ( 60 Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

Stimulation of Escherichia coli F-18Col- Type-1 fimbriae synthesis by leuX

DEFF Research Database (Denmark)

Newman, Joseph V.; Burghoff, Robert L.; Pallesen, Lars

1994-01-01

Escherichia coli F-18, a normal human fecal isolate, is an excellent colonizer of the streptomycin-treated mouse large intestine. E. coli F-18Col-, a derivative of E. coli F-18 which no longer makes the E. coli F-18 colicin, colonizes the large intestine as well as E. coli F-18 when fed to mice...... alone but is eliminated when fed together with E. coli F-18. Recently we randomly cloned E. coli F-18 DNA into E. coli F-18Col- and let the mouse intestine select the best colonizer. In this way, we isolated a 6.5-kb E. coli F-18 DNA sequence that simultaneously stimulated synthesis of type 1 fimbriae...... and enhanced E. coli F-18Col- colonizing ability. In the present investigation we show that the gene responsible for stimulation of type 1 fimbriae synthesis appears to be leuX, which encodes a tRNA specific for the rare leucine codon UUG. Moreover, it appears that expression of leuX may be regulated by two...

Transferability of antimicrobial resistance from multidrug-resistant Escherichia coli isolated from cattle in the USA to E. coli and Salmonella Newport recipients

Science.gov (United States)

The objective of this study was to evaluate conjugative transfer of cephalosporin resistance among (n=100) strains of multi-drug resistant Escherichia coli (MDRE) to Salmonella Newport and E. coli DH5-alpha recipients. To accomplish this, phenotypic and genotypic profiles were determined for MDRE, ...

Reproducible gene targeting in recalcitrant Escherichia coli isolates

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De Greve Henri

2011-06-01

Full Text Available Abstract Background A number of allele replacement methods can be used to mutate bacterial genes. For instance, the Red recombinase system of phage Lambda has been used very efficiently to inactivate chromosomal genes in E. coli K-12, through recombination between regions of homology. However, this method does not work reproducibly in some clinical E. coli isolates. Findings The procedure was modified by using longer homologous regions (85 bp and 500-600 bp, to inactivate genes in the uropathogenic E. coli strain UTI89. An lrhA regulator mutant, and deletions of the lac operon as well as the complete type 1 fimbrial gene cluster, were obtained reproducibly. The modified method is also functional in other recalcitrant E. coli, like the avian pathogenic E. coli strain APEC1. The lrhA regulator and lac operon deletion mutants of APEC1 were successfully constructed in the same way as the UTI89 mutants. In other avian pathogenic E. coli strains (APEC3E, APEC11A and APEC16A it was very difficult or impossible to construct these mutants, with the original Red recombinase-based method, with a Red recombinase-based method using longer (85 bp homologous regions or with our modified protocol, using 500 - 600 bp homologous regions. Conclusions The method using 500-600 bp homologous regions can be used reliably in some clinical isolates, to delete single genes or entire operons by homologous recombination. However, it does not invariably show a greater efficiency in obtaining mutants, when compared to the original Red-mediated gene targeting method or to the gene targeting method with 85 bp homologous regions. Therefore the length of the homology regions is not the only limiting factor for the construction of mutants in these recalcitrant strains.

Occurrence and characterization of Shiga toxin-producing Escherichia coli O157:H7 and other non-sorbitol-fermenting E. coli in cattle and humans in urban areas of Morogoro, Tanzania.

Science.gov (United States)

Lupindu, Athumani M; Olsen, John E; Ngowi, Helena A; Msoffe, Peter L M; Mtambo, Madundo M; Scheutz, Flemming; Dalsgaard, Anders

2014-07-01

Escherichia coli strains such as Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli, enterotoxigenic, attaching, and effacing E. coli, and enteroinvasive E. coli cause diarrhea in humans. Although other serotypes exist, the most commonly reported STEC in outbreaks is O157:H7. A cross-sectional study was conducted to isolate and characterize non-sorbitol-fermenting (NSF) E. coli O157:H7 from urban and periurban livestock settings of Morogoro, Tanzania. Human stool, cattle feces, and soil and water samples were collected. Observations and questionnaire interview studies were used to gather information about cattle and manure management practices in the study area. E. coli were isolated on sorbitol MacConkey agar and characterized by conventional biochemical tests. Out of 1049 samples, 143 (13.7%) yielded NSF E. coli. Serological and antimicrobial tests and molecular typing were performed to NSF E. coli isolates. These procedures detected 10 (7%) pathogenic E. coli including STEC (n=7), enteropathogenic E. coli (EPEC) (n=2), and attaching and effacing E. coli (A/EEC) (n=1) strains. The STEC strains had the ability to produce VT1 and different VT2 toxin subtypes that caused cytopathic effects on Vero cells. The prevalence of STEC in cattle was 1.6%, out of which 0.9% was serotype O157:H7 and the overall prevalence of diarrheagenic E. coli in cattle was 2.2%. The serotypes O157:H7, O142:H34, O113:H21, O+:H-, O+:H16, and O25:H4 were identified. One ESBL-producing isolate showed the MLST type ST131. To our knowledge, this is the first finding in Tanzania of this recently emerged worldwide pandemic clonal group, causing widespread antimicrobial-resistant infections, and adds knowledge of the geographical distribution of ST131. Cattle manure was indiscriminately deposited within residential areas, and there was direct contact between humans and cattle feces during manure handling. Cattle and manure management practices expose humans, animals, and the environment

Escherichia coli O104 associated with human diarrhea, South Africa, 2004-2011.

Science.gov (United States)

Tau, Nomsa P; Meidany, Parastu; Smith, Anthony M; Sooka, Arvinda; Keddy, Karen H

2012-08-01

To determine the origin of >4,000 suspected diarrheagenic Escherichia coli strains isolated during 2004-2011 in South Africa, we identified 7 isolates as serotype O104; 5 as enteroaggregative E. coli O104:H4, and 2 as enteropathogenic E. coli O104:non-H4. Pulsed-field gel electrophoresis showed that these isolates were unrelated to the 2011 E. coli O104:H4 outbreak strain from Germany.

Sigma factors in a thousand E. coli genomes

DEFF Research Database (Denmark)

Cook, Helen Victoria; Ussery, David

2013-01-01

, 2013), only less than half (983) are of sufficient quality to use in comparative genomic work. Unfortunately, even some of the ‘complete’ E. coli genomes are in pieces, and a few ‘draft’ genomes are good quality. Six of the seven known sigma factors in E. coli strain K‐12 are extremely well conserved...

γ-Glutamyl semialdehyde and 2-amino-adipic semialdehyde: biomarkers of oxidative damage to proteins

DEFF Research Database (Denmark)

Daneshvar, B.; Frandsen, H.; Autrup, Herman

1997-01-01

proteins collected from eight different mammalian species was found to be inversely proportional to their maximum lifespan potential. The content of AAS in plasma proteins of untreated adult rats showed a positive correlation with the age of the rat. In young rats a negative correlation with age was found......Reactive oxygen species are formed in the body by several natural processes and by induced oxidative stress. The reactive oxygen species may react with the various biomolecules of the body, including proteins. In order to assess the impact of oxidative damage to proteins, we have tried to identify...

Influence of protoporphyrin IX loaded phloroglucinol succinic acid dendrimer in photodynamic therapy

Science.gov (United States)

Kumar, M. Suresh; Aruna, P.; Ganesan, S.

2018-03-01

One of the major problems reported clinically for photosensitizers (PS) in Photodynamic therapy (PDT) is, the cause of side-effects to normal tissue due to dark toxicity. The usefulness of photosensitizers can be made possible by reducing its dark toxicity nature. In such scenario, biocompatible carriers can be used as a drug delivery system to evade the problems that arises while using free (dark toxic) drugs. So in this study, we have developed a nano drug delivery system called Phloroglucinol Succinic acid (PGSA) dendrimer, entrapped a photosensitizer, protoporphyrin IX (PpIX) inside the system and investigated whether the photodynamic efficacy of the anionic surface charged dendrimer-PpIX nano formulation is enhanced than achieved by the free PpIX in HeLa cancer cell lines. Moreover, the Reactive oxygen species (ROS) production was monitored using 2‧,7‧-dichlorodihydrofluorescein diacetate (H2DCF-DA)- ROS Marker with phase contrast microscopy for the IC50 values of free and dendrimer-PpIX nano formulation. Similarly, the mode of cell death has been confirmed by cell cycle analysis for the same. For the in vitro PDT application, we have used a simple light source (Light Emitting Diode) with a power of 30-50 mW for 20 min irradiation. Hence, in this study we have taken steps to report this anionic drug delivery system is good to consider for the photodynamic therapy applications with the photosensitizer, PpIX which satisfied the prime requirement of PDT.

Stoichiometry of mitochondrial H+ translocation coupled to succinate oxidation at level flow.

Science.gov (United States)

Costa, L E; Reynafarje, B; Lehninger, A L

1984-04-25

The mechanistic stoichiometry of vectorial H+ translocation coupled to succinate oxidation by rat liver mitochondria in the presence of a permeant cation has been determined under level flow conditions with a membraneless fast responding O2 electrode kinetically matched with a glass pH electrode. The reactions were initiated by rapid injection of O2 into the anaerobically preincubated test system under conditions in which interfering H+ backflow was minimized. The rates of O2 uptake and H+ ejection, obtained from computer-fitted regression lines, were monotonic and first order over 75% of the course of O2 consumption. Extrapolation of the observed rates to zero time, at which zero delta mu H+ and thus level flow prevails, yielded vectorial H+/O flow ratios above 7 and closely approaching 8. The mitochondria undergo no irreversible change and give identical H+/O ratios on repeated tests. In a further refinement, the lower and upper limits of the mechanistic H+/O ratio were determined to be 7.55 and 8.56, respectively, from plots of the rates of O2 uptake versus H+ ejection at increasing malonate and increasing valinomycin concentrations, respectively. It is therefore concluded that the mechanistic H+/O ratio for energy-conserving sites 2 + 3 is 8, in confirmation of earlier measurements. KCl concentration is critical for maximal observed H+/O ratios. Optimum conditions and possible errors in determination of mechanistic H+/O translocation ratios are discussed.

The Escherichia coli argW-dsdCXA genetic island is highly variable, and E. coli K1 strains commonly possess two copies of dsdCXA.

Science.gov (United States)

Moritz, Rebecca L; Welch, Rodney A

2006-11-01

The genome sequences of Escherichia coli pathotypes reveal extensive genetic variability in the argW-dsdCXA island. Interestingly, the archetype E. coli K1 neonatal meningitis strain, strain RS218, has two copies of the dsdCXA genes for d-serine utilization at the argW and leuX islands. Because the human brain contains d-serine, an epidemiological study emphasizing K1 isolates surveyed the dsdCXA copy number and function. Forty of 41 (97.5%) independent E. coli K1 isolates could utilize d-serine. Southern blot hybridization revealed physical variability within the argW-dsdC region, even among 22 E. coli O18:K1:H7 isolates. In addition, 30 of 41 K1 strains, including 21 of 22 O18:K1:H7 isolates, had two dsdCXA loci. Mutational analysis indicated that each of the dsdA genes is functional in a rifampin-resistant mutant of RS218, mutant E44. The high percentage of K1 strains that can use d-serine is in striking contrast to our previous observation that only 4 of 74 (5%) isolates in the diarrheagenic E. coli (DEC) collection have this activity. The genome sequence of diarrheagenic E. coli isolates indicates that the csrRAKB genes for sucrose utilization are often substituted for dsdC and a portion of dsdX present at the argW-dsdCXA island of extraintestinal isolates. Among DEC isolates there is a reciprocal pattern of sucrose fermentation versus d-serine utilization. The ability to use d-serine is a trait strongly selected for among E. coli K1 strains, which have the ability to infect a wide range of extraintestinal sites. Conversely, diarrheagenic E. coli pathotypes appear to have substituted sucrose for d-serine as a potential nutrient.

Emergence and mechanism of carbapenem-resistant Escherichia coli in Henan, China, 2014

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Wen-juan Liang

2018-05-01

Full Text Available The emergence and dissemination of carbapenem-resistant Escherichia coli (E. coli strains is a main risk for global public health, but little is known of carbapenemase producing E. coli in Henan, China. The study was undertaken to investigate the prevalence and mechanism of carbapenem-resistant E. coli strains in a hospital in Xinxiang, Henan, China, 2014. A total of 5 carbapenemase-producing E. coli strains were screened from 1014 isolates. We found that they were all resistant to meropenem and imipenem. Amikacin showed the best sensitivity, with gentamicin coming up next. The positive rate of blaNDM was 80% (4/5. The sequencing results showed that two isolates belonged to blaNDM-1 whereas other 2 isolates carried the blaNDM-5. Other carbapenemase genes including blaIMP, blaVIM, blaKPC and blaOXA-48 were not detected. The blaCTX-M-15, blaTEM-1, sul2, aad, and aac(6”–Ib–cr were also detected. MLST analysis showed that NDM-producing E. coli were sporadic. Conjugation test indicated blaNDM could be transferred. In conclusion, the blaNDM was the principal resistance mechanism of carbapenem-resistant E. coli in the hospital, Henan, China. Keywords: blaNDM, Carbapenem-resistant, Escherichia coli

Occurrence and characterization of Shiga toxin-producing Escherichia coli O157:H7 and other non-sorbitol-fermenting E. coli in cattle and humans in urban areas of Morogoro, Tanzania

DEFF Research Database (Denmark)

Lupindu, Athumani M; Olsen, John Elmerdahl; Ngowi, Helena A

2014-01-01

Escherichia coli strains such as Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli, enterotoxigenic, attaching, and effacing E. coli, and enteroinvasive E. coli cause diarrhea in humans. Although other serotypes exist, the most commonly reported STEC in outbreaks is O157:H7. A cross-...

Escherichia coli Contamination of Lettuce Grown in Soils Amended with Animal Slurry

DEFF Research Database (Denmark)

Jensen, Annette Nygaard; Storm, Christina; Forslund, Anita

2013-01-01

A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish agric...... types between slurry, soil, and lettuce. The frequent finding of fecal-contaminated lettuce indicates that human pathogens such as Salmonella and Campylobacter can be present and represent food safety hazards.......A pilot study was conducted to assess the transfer of Escherichia coli from animal slurry fertilizer to lettuce, with E. coli serving as an indicator of fecal contamination and as an indicator for potential bacterial enteric pathogens. Animal slurry was applied as fertilizer to three Danish....... coli. A relatively higher frequency of E. coli in lettuce compared with the soil samples at harvest suggests environmental sources of fecal contamination, e.g., wildlife. The higher frequency was supported by the finding of 21 different PFGE types among the E. coli isolates, with only a few common PFGE...