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Sample records for corynebacterium pseudodiphteriticum una

  1. Corynebacterium ulcerans cutaneous diphtheria.

    Science.gov (United States)

    Moore, Luke S P; Leslie, Asuka; Meltzer, Margie; Sandison, Ann; Efstratiou, Androulla; Sriskandan, Shiranee

    2015-09-01

    We describe the case of a patient with cutaneous diphtheria caused by toxigenic Corynebacterium ulcerans who developed a right hand flexor sheath infection and symptoms of sepsis such as fever, tachycardia, and elevated C-reactive protein, after contact with domestic cats and dogs, and a fox. We summarise the epidemiology, clinical presentation, microbiology, diagnosis, therapy, and public health aspects of this disease, with emphasis on improving recognition. In many European countries, C ulcerans has become the organism commonly associated with cutaneous diphtheria, usually seen as an imported tropical disease or resulting from contact with domestic and agricultural animals. Diagnosis relies on bacterial culture and confirmation of toxin production, with management requiring appropriate antimicrobial therapy and prompt administration of antitoxin, if necessary. Early diagnosis is essential for implementation of control measures and clear guidelines are needed to assist clinicians in managing clinical diphtheria. This case was a catalyst to the redrafting of the 2014 national UK interim guidelines for the public health management of diphtheria, released as final guidelines in March, 2015. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Corynebacterium species isolated from patients with mastitis.

    Science.gov (United States)

    Paviour, Sue; Musaad, Sahar; Roberts, Sally; Taylor, Graeme; Taylor, Susan; Shore, Keith; Lang, Selwyn; Holland, David

    2002-12-01

    Corynebacteria were isolated from breast tissue, pus, or deep wound swabs of 24 women; the most common species isolated was the newly described Corynebacterium kroppenstedtii, followed by Corynebacterium amycolatum and Corynebacterium tuberculostearicum. Gram-positive bacilli were seen in samples sent for culture or in histological specimens for 12 women, and 9 of the 12 women from whom adequate histological specimens were obtained had conditions that met the criteria for granulomatous lobular mastitis, a chronic inflammatory disease of unknown etiology.

  3. Corynebacterium propinquum associated with acute, nongonococcal urethritis.

    Science.gov (United States)

    Abdolrasouli, Alireza; Roushan, Azita

    2013-10-01

    Corynebacterium propinquum is usually considered part of the normal human oropharyngeal flora and is rarely responsible for clinical infection. We report here what seems to be the first case of acute purulent urethral discharge in a young Iranian man with urethritis acquired after orogenital contact. Attention should be devoted to less common nondiphtheriae Corynebacterium species for differential diagnosis.

  4. Cystic neutrophilic granulomatous mastitis associated with Corynebacterium including Corynebacterium kroppenstedtii.

    Science.gov (United States)

    Johnstone, Kate J; Robson, Jennifer; Cherian, Sarah G; Wan Sai Cheong, Jenny; Kerr, Kris; Bligh, Judith F

    2017-06-01

    Granulomatous (lobular) mastitis is a rare inflammatory breast disease affecting parous reproductive-aged women. Once considered idiopathic, there is growing evidence of an association with corynebacteria infection, especially in the setting of a distinct histological pattern termed cystic neutrophilic granulomatous mastitis (CNGM). We describe 15 cases with histological features either confirming (n = 12) or suggesting (n = 3) CNGM, and concurrent microbiological evidence of Corynebacterium species. The organism was detected by culture or 16S rRNA gene sequencing of specimens obtained at surgery or fine needle aspiration. In seven cases, Gram-positive organisms were seen within vacuolated spaces. Speciation was performed in nine cases, with Corynebacterium kroppenstedtii subsequently identified. These cases provide further evidence in support of this association and in doing so highlight the importance of recognising these histological clues as well as the limitations of Gram stain and microbiological culture in detecting this previously under-recognised disease process. Copyright © 2017 Royal College of Pathologists of Australasia. All rights reserved.

  5. SIALIDASE (NEURAMINIDASE) OF CORYNEBACTERIUM DIPHTHERIAE.

    Science.gov (United States)

    WARREN, L; SPEARING, C W

    1963-11-01

    Warren, Leonard (National Institute of Arthritis and Metabolic Diseases, Bethesda, Md.) and C. W. Spearing. Sialidase (neuraminidase) of Corynebacterium diphtheriae. J. Bacteriol. 86:950-955. 1963.-The characteristics of a sialidase produced by Corynebacterium diphtheriae were studied. The enzyme was partially purified from preparations of diphtheria toxin on a column of Sephadex G-75. By this means the lethal factor of diphtheria toxin was separated, in part, from the sialidase activity. There appeared to be a close immunological relationship between the sialidases of C. diphtheriae and clostridia, since a preparation of diphtheria antitoxin was as effective an inhibitor of diphtheria sialidase as of the sialidase of three species of clostridia. Conversely, antitoxin to clostridia inhibited diphtheria sialidase. Diphtheria antitoxin was essentially inactive toward influenza virus sialidase, and was completely inactive against purified sialidase of Vibrio cholerae. Removal of sialic acid from the proteins in a preparation of diphtheria antitoxin did not alter the inhibitory activity of the antitoxin against diphtheria sialidase. The enzyme operated optimally at pH 5.5 and did not require calcium ions for activity. The substrate specificity of diphtheria sialidase appears to be the same as that of other previously described sialidases.

  6. Draft Genome Sequence of Corynebacterium kefirresidentii SB, Isolated from Kefir.

    Science.gov (United States)

    Blasche, Sonja; Kim, Yongkyu; Patil, Kiran R

    2017-09-14

    The genus Corynebacterium includes Gram-positive species with a high G+C content. We report here a novel species, Corynebacterium kefirresidentii SB, isolated from kefir grains collected in Germany. Its draft genome sequence was remarkably dissimilar (average nucleotide identity, 76.54%) to those of other Corynebacterium spp., confirming that this is a unique novel species. Copyright © 2017 Blasche et al.

  7. Corynebacterium macginleyi isolated from a corneal ulcer

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    Kathryn Ruoff

    2010-02-01

    Full Text Available We report the isolation of Corynebacterium macginleyi from the corneal ulcer culture of a patient, later enrolled in the Steroids for Corneal Ulcer Trial (SCUT. To our knowledge this is the first published report from North America of the recovery of C. macginleyi from a serious ocular infection.

  8. A Spontaneous Joint Infection with Corynebacterium striatum▿

    OpenAIRE

    Scholle, David

    2006-01-01

    Corynebacterium striatum is a ubiquitous saprophyte with the potential to cause bacteremia in immunocompromised patients. Until now, spontaneous infection of a natural joint has not been reported. When phenotyping failed, gene sequencing was used to identify the species. The isolate demonstrated high-level resistance to most antibiotics.

  9. Sigma factors and promoters in Corynebacterium glutamicum

    Czech Academy of Sciences Publication Activity Database

    Pátek, Miroslav; Nešvera, Jan

    2011-01-01

    Roč. 154, 2-3 (2011), s. 101-113 ISSN 0168-1656 R&D Projects: GA ČR GC204/09/J015 Institutional research plan: CEZ:AV0Z50200510 Keywords : Corynebacterium glutamicum * Sigma factors * Promoters Subject RIV: EE - Microbiology, Virology Impact factor: 3.045, year: 2011

  10. Corynebacterium pilbarense sp. nov., a non-lipophilic corynebacterium isolated from a human ankle aspirate.

    Science.gov (United States)

    Aravena-Roman, M; Spröer, C; Sträubler, B; Inglis, T; Yassin, A F

    2010-07-01

    A non-lipophilic coryneform bacterium isolated from an anaerobic Bactec bottle inoculated with an ankle aspirate from a male patient was characterized by phenotypic and molecular taxonomic methods. Chemotaxonomic investigations revealed the presence of short-chain mycolic acids in the cell wall of the bacterium, a feature consistent with members of the genus Corynebacterium. Comparative 16S rRNA gene sequence analysis demonstrated that the isolate displayed 92.0-99.0 % gene sequence similarity with members of the genus Corynebacterium, with Corynebacterium ureicelerivorans as the most closely related phylogenetic species (99.0 % gene sequence similarity). However, the isolate could be genomically separated from C. ureicelerivorans on the basis of DNA-DNA hybridization studies (39.5 % relatedness). Furthermore, the isolate could also be differentiated from C. ureicelerivorans and other species of the genus Corynebacterium on the basis of biochemical properties. Based on both phenotypic and phylogenetic evidence, it is proposed that this isolate be classified as representing a novel species, Corynebacterium pilbarense sp. nov. (type strain IMMIB WACC 658(T)=DSM 45350(T)=CCUG 57942(T)).

  11. Isolamento de Corynebacterium aquaticum em leite bubalino

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    Andréa Alice da Fonseca Oliveira

    2005-08-01

    Full Text Available Estudou-se 548 quartos mamários de búfalas, realizando-se exame clínico, CMT para detecção de mastite e coleta de amostras para isolamento bacteriano. Houve crescimento em duas amostras de Corynebacterium aquaticum caracterizadas bioquimicamente. Relata-se a participação do agente como colonizador do úbere e possível causador de mastites em bubalinos.

  12. J-GLOBAL MeSH Dictionary: Corynebacterium pseudotuberculosis [MeCab user dictionary for science technology term[Archive

    Lifescience Database Archive (English)

    Full Text Available MeCab user dictionary for science technology term Corynebacterium pseudotuberculosis... 名詞 一般 * * * * Corynebacterium pseudotuberculosis ... MeSH D016925 200906025325177003 C LS07 UNKNOWN_2 Corynebacterium pseudotuberculosis

  13. Optimization of lysine metabolism in Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Rytter, Jakob Vang

    ,000,000 tons. The aim of this project is to optimize the yield of lysine in C. glutamicum using metabolic engineering strategies. According to a genome scale model of C. glutamicum, theoretically there is much room for increasing the lysine yield (Kjeldsen and Nielsen 2009). Lysine synthesis requires NADPH......Commercial pig and poultry production use the essential amino acid lysine as a feed additive with the purpose of optimizing the feed utilization. Lysine is produced by a fermentation process involving either Corynebacterium glutamicum or Escherichia coli. The global annual production is around 1...... the project intends to eliminate. PGI catalyzes the conversion of alpha-D-glucose-6-phosphate to fructose-6-phosphate just downstream of the branch in the glycolysis, but it also catalyzes the reverse reaction. It is unknown whether up- or down-regulation of the pgi is required to increase the flux through...

  14. Staphylococcus aureus shifts towards commensalism in response to Corynebacterium species

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    Matthew M Ramsey

    2016-08-01

    Full Text Available Staphylococcus aureus–human interactions result in a continuum of outcomes from commensalism to pathogenesis. S. aureus is a clinically important pathogen that asymptomatically colonizes ~25% of humans as a member of the nostril and skin microbiota, where it resides with other bacteria including commensal Corynebacterium species. Commensal Corynebacterium spp. are also positively correlated with S. aureus in chronic polymicrobial diabetic foot infections, distinct from acute monomicrobial S. aureus infections. Recent work by our lab and others indicates that microbe-microbe interactions between S. aureus and human skin/nasal commensals, including Corynebacterium species, affect S. aureus behavior and fitness. Thus, we hypothesized that S. aureus interactions with Corynebacterium spp. diminish S. aureus virulence. We tested this by assaying for changes in S. aureus gene expression during in vitro mono- versus coculture with Corynebacterium striatum, a common skin and nasal commensal. We observed a broad shift in S. aureus gene transcription during in vitro growth with C. striatum, including increased transcription of genes known to exhibit increased expression during human nasal colonization and decreased transcription of virulence genes. S. aureus uses several regulatory pathways to transition between commensal and pathogenic states. One of these, the quorum signal accessory gene regulator (agr system, was strongly inhibited in response to Corynebacterium spp. Phenotypically, S. aureus exposed to C. striatum exhibited increased adhesion to epithelial cells, reflecting a commensal state, and decreased hemolysin activity, reflecting an attenuation of virulence. Consistent with this, S. aureus displayed diminished fitness in experimental in vivo coinfection with C. striatum when compared to monoinfection. These data support a model in which S. aureus shifts from virulence towards a commensal state when exposed to commensal Corynebacterium species.

  15. Patchoulol Production with Metabolically Engineered Corynebacterium glutamicum

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    Nadja A. Henke

    2018-04-01

    Full Text Available Patchoulol is a sesquiterpene alcohol and an important natural product for the perfume industry. Corynebacterium glutamicum is the prominent host for the fermentative production of amino acids with an average annual production volume of ~6 million tons. Due to its robustness and well established large-scale fermentation, C. glutamicum has been engineered for the production of a number of value-added compounds including terpenoids. Both C40 and C50 carotenoids, including the industrially relevant astaxanthin, and short-chain terpenes such as the sesquiterpene valencene can be produced with this organism. In this study, systematic metabolic engineering enabled construction of a patchoulol producing C. glutamicum strain by applying the following strategies: (i construction of a farnesyl pyrophosphate-producing platform strain by combining genomic deletions with heterologous expression of ispA from Escherichia coli; (ii prevention of carotenoid-like byproduct formation; (iii overproduction of limiting enzymes from the 2-c-methyl-d-erythritol 4-phosphate (MEP-pathway to increase precursor supply; and (iv heterologous expression of the plant patchoulol synthase gene PcPS from Pogostemon cablin. Additionally, a proof of principle liter-scale fermentation with a two-phase organic overlay-culture medium system for terpenoid capture was performed. To the best of our knowledge, the patchoulol titers demonstrated here are the highest reported to date with up to 60 mg L−1 and volumetric productivities of up to 18 mg L−1 d−1.

  16. Synthetic promoter libraries for Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Rytter, Jakob Vang; Helmark, Søren; Chen, Jun

    2014-01-01

    The ability to modulate gene expression is an important genetic tool in systems biology and biotechnology. Here, we demonstrate that a previously published easy and fast PCR-based method for modulating gene expression in lactic acid bacteria is also applicable to Corynebacterium glutamicum. We co...... promoter library (SPL) technology is convenient for modulating gene expression in C. glutamicum and should have many future applications, within basic research as well as for optimizing industrial production organisms....... constructed constitutive promoter libraries based on various combinations of a previously reported C. glutamicum -10 consensus sequence (gngnTA(c/t)aaTgg) and the Escherichia coli -35 consensus, either with or without an AT-rich region upstream. A promoter library based on consensus sequences frequently found...... in low-GC Gram-positive microorganisms was also included. The strongest promoters were found in the library with a -35 region and a C. glutamicum -10 consensus, and this library also represents the largest activity span. Using the alternative -10 consensus TATAAT, which can be found in many other...

  17. Corynebacterium minutissimum vascular graft infection: case report and review of 281 cases of prosthetic device-related Corynebacterium infection.

    Science.gov (United States)

    Reece, Rebecca M; Cunha, Cheston B; Rich, Josiah D

    2014-09-01

    Corynebacterium spp. have proven their pathogenic potential in causing infections, particularly in the setting of immunosuppression and prosthetic devices. We conducted a PubMed literature review of all cases of Corynebacterium prosthetic device infections published in the English language through December 2013. The majority of cases involved peritoneal dialysis and central venous catheters, but prosthetic joints and central nervous system shunts/drains were also involved. The management of these cases in terms of retention or removal of the device was not uniform; however, the overall mortality remained the same among both groups. All of these prosthetic device infections pose potential problems in management when the device cannot be removed safely for the patient, especially with the lack of data on the pathogenicity of Corynebacterium species. However with better identification of species and sensitivities, successful treatment is possible even with retention of the device.

  18. Early prosthetic valve endocarditis caused by Corynebacterium kroppenstedtii.

    Science.gov (United States)

    Hagemann, Jürgen Benjamin; Essig, Andreas; Herrmann, Manuel; Liebold, Andreas; Quader, Mohamed Abo

    2015-12-01

    Corynebacterium (C.) kroppenstedtii is a rarely detected agent of bacterial infections in humans. Here, we describe the first case of prosthetic valve endocarditis caused by C. kroppenstedtii. Application of molecular methods using surgically excised valve tissue was a cornerstone for the establishment of the microbiological diagnosis, which is crucial for targeted antimicrobial treatment. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Tools for genetic manipulations in Corynebacterium glutamicum and their applications

    Czech Academy of Sciences Publication Activity Database

    Nešvera, Jan; Pátek, Miroslav

    2011-01-01

    Roč. 90, č. 5 (2011), s. 1641-1654 ISSN 0175-7598 R&D Projects: GA ČR GC204/09/J015 Institutional research plan: CEZ:AV0Z50200510 Keywords : Corynebacterium glutamicum * Plasmid vectors * Promoters Subject RIV: EE - Microbiology, Virology Impact factor: 3.425, year: 2011

  20. Urethritis due to corynebacterium striatum: An emerging germ.

    Science.gov (United States)

    Frikh, Mohammed; El Yaagoubi, Imad; Lemnouer, Abdelhay; Elouennass, Mostafa

    2015-01-01

    Corynedbacterium striatum (CS) is a Gram-positive coryneform bacillus that is part of mucous and skin flora. It has been considered as a causative agent of many infections in intensive care, neurology, traumatology and urology, but was never implicated in non-gonococcal urethritis. We report the case of a nosocomial urethritis due to Corynebacterium striatum following resection of an intrameatus condyloma.

  1. Over-expression of NAD kinase in Corynebacterium crenatum and ...

    African Journals Online (AJOL)

    in Corynebacterium crenatum SYPA5-5 and to study its impact in presence of high (HOS) ... Results: In HOS condition, NAD+ kinase activity increased by 116 %, while ... (NADPH), an important co-enzyme during ... Polymerase, TaKaRa) using C. crenatum .... were washed with cold 100 mM PBS (pH 7.5) ..... Catalase and.

  2. Experimental transmission of Corynebacterium pseudotuberculosis in horses by house flies

    Science.gov (United States)

    The route of infection of pigeon fever remains undetermined. The purpose of this study was to investigate house flies (Musca domestica L.) as vectors of Corynebacterium pseudotuberculosis in horses. Eight ponies were used in a randomized, controlled, blinded experimental study. Ten wounds were creat...

  3. Native valve endocarditis due to Corynebacterium group JK.

    Science.gov (United States)

    Moffie, B G; Veenendaal, R A; Thompson, J

    1990-12-01

    We report a case of a 32-yr-old woman on chronic intermittent haemodialysis, who developed endocarditis due to a Corynebacterium group JK, involving both the native aortic and mitral valves. Despite a four-week treatment with vancomycin, an aortic root abscess developed. The diagnosis was confirmed on autopsy.

  4. Corynebacterium tapiri sp. nov. and Corynebacterium nasicanis sp. nov., isolated from a tapir and a dog, respectively.

    Science.gov (United States)

    Baumgardt, Sandra; Loncaric, Igor; Kämpfer, Peter; Busse, Hans-Jürgen

    2015-11-01

    Two Gram-stain-positive bacterial isolates, strain 2385/12T and strain 2673/12T were isolated from a tapir and a dog's nose, respectively. The two strains were rod to coccoid-shaped, catalase-positive and oxidase-negative. The highest 16S rRNA gene sequence similarity identified Corynebacterium singulare CCUG 37330T (96.3% similarity) as the nearest relative of strain 2385/12T and suggested the isolate represented a novel species. Corynebacterium humireducens DSM 45392T (98.7% 16S rRNA gene sequence similarity) was identified as the nearest relative of strain 2673/12T. Results from DNA-DNA hybridization with the type strain of C. humireducens demonstrated that strain 2673/12T also represented a novel species. Strain 2385/12T showed a quinone system consisting predominantly of menaquinones MK-8(H2) and MK-9(H2) whereas strain 2673/12T contained only MK-8(H2) as predominant quinone. The polar lipid profiles of the two strains showed the major compounds phosphatidylglycerol, diphosphatidylglycerol and an unidentified glycolipid. Phosphatidylinositol was identified as another major lipid in 2673/12T whereas it was only found in moderate amounts in strain 2385/12T. Furthermore, moderate to minor amounts of phosphatidylinositol-mannoside, β-gentiobiosyl diacylglycerol and variable counts of several unidentified lipids were detected in the two strains. Both strains contained corynemycolic acids. The polyamine patterns were characterized by the major compound putrescine in strain 2385/12T and spermidine in strain 2673/12T. In the fatty acid profiles, predominantly C18:1ω9c and C16:0 were detected. The two strains are distinguishable from each other and the nearest related established species of the genus Corynebacterium phylogenetically and phenotypically. In conclusion, two novel species of the genus Corynebacterium are proposed, namely Corynebacterium tapiri sp. nov. (type strain, 2385/12T = CCUG 65456T = LMG 28165T) and Corynebacterium nasicanis sp. nov. (type

  5. Interdigital foot infections: Corynebacterium minutissimum and agents of superficial mycoses

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    Fatma Mutlu Sariguzel

    2014-09-01

    Full Text Available Interdigital foot infections are mostly caused initially by dermatophytes, yeasts and less frequently by bacteria. Erythrasma caused by Corynebacterium minutissimum can be confused with superficial mycoses. The aim of the study was to determine the prevalence of the etiologic agents of superficial mycoses and the frequency of Corynebacterium minutissimum in interdigital foot infections. All the samples obtained from the 121 patients with interdigital foot infections were examined directly with the use of 20% potassium hydroxide mounts and Gram stain under the microscope and cultured on Sabouraud's dextrose agar plates. In identification of superficial mycoses, the rate was found to be 14% with the cultural method and 14% with direct microscopic examination. Using a combination of direct microscopic examination and culture, a 33.8% ratio was achieved. In the culture of these samples, the most isolated factor was Trichophyton rubrum (33.7%. In 24 of the patients (19.8% Corynebacterium minutissimum was detected by Gram staining, in 6 of these patients Trichophyton rubrum was found, Trichophyton mentagrophytes was found in 2 and Trichosporon spp. was found in 1. The examination of interdigital foot lesions in the laboratory, the coexistence of erythrasma with dermatophytes and yeast should be considered.

  6. A microbiological and clinical review on Corynebacterium kroppenstedtii

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    Andreas Tauch

    2016-07-01

    Full Text Available The genus Corynebacterium represents a taxon of Gram-positive bacteria with a high G + C content in the genomic DNA. Corynebacterium kroppenstedtii is an unusual member of this taxon as it lacks the characteristic mycolic acids in the cell envelope. Genome sequence analysis of the C. kroppenstedtii type strain has revealed a lipophilic (lipid-requiring lifestyle and a remarkable repertoire of carbohydrate uptake and utilization systems. Clinical isolates of C. kroppenstedtii have been obtained almost exclusively from female patients and mainly from breast abscesses and cases of granulomatous mastitis. However, the role of C. kroppenstedtii in breast pathologies remains unclear. This review provides a comprehensive overview of the taxonomy, microbiology, and microbiological identification of C. kroppenstedtii, including polyphasic phenotypic approaches, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the use of 16S rRNA gene sequencing. A clinical review presents reported cases, various antimicrobial treatments, antibiotic susceptibility assays, and antibiotic resistance genes detected during genome sequencing. C. kroppenstedtii must be considered a potential opportunistic human pathogen and should be identified accurately in clinical laboratories.

  7. Functional characterization of a vanillin dehydrogenase in Corynebacterium glutamicum

    Science.gov (United States)

    Ding, Wei; Si, Meiru; Zhang, Weipeng; Zhang, Yaoling; Chen, Can; Zhang, Lei; Lu, Zhiqiang; Chen, Shaolin; Shen, Xihui

    2015-01-01

    Vanillin dehydrogenase (VDH) is a crucial enzyme involved in the degradation of lignin-derived aromatic compounds. Herein, the VDH from Corynebacterium glutamicum was characterized. The relative molecular mass (Mr) determined by SDS-PAGE was ~51kDa, whereas the apparent native Mr values revealed by gel filtration chromatography were 49.5, 92.3, 159.0 and 199.2kDa, indicating the presence of dimeric, trimeric and tetrameric forms. Moreover, the enzyme showed its highest level of activity toward vanillin at pH 7.0 and 30C, and interestingly, it could utilize NAD+ and NADP+ as coenzymes with similar efficiency and showed no obvious difference toward NAD+ and NADP+. In addition to vanillin, this enzyme exhibited catalytic activity toward a broad range of substrates, including p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, o-phthaldialdehyde, cinnamaldehyde, syringaldehyde and benzaldehyde. Conserved catalytic residues or putative cofactor interactive sites were identified based on sequence alignment and comparison with previous studies, and the function of selected residues were verified by site-directed mutagenesis analysis. Finally, the vdh deletion mutant partially lost its ability to grow on vanillin, indicating the presence of alternative VDH(s) in Corynebacterium glutamicum. Taken together, this study contributes to understanding the VDH diversity from bacteria and the aromatic metabolism pathways in C. glutamicum. PMID:25622822

  8. Insight of Genus Corynebacterium: Ascertaining the Role of Pathogenic and Non-pathogenic Species.

    Science.gov (United States)

    Oliveira, Alberto; Oliveira, Leticia C; Aburjaile, Flavia; Benevides, Leandro; Tiwari, Sandeep; Jamal, Syed B; Silva, Arthur; Figueiredo, Henrique C P; Ghosh, Preetam; Portela, Ricardo W; De Carvalho Azevedo, Vasco A; Wattam, Alice R

    2017-01-01

    This review gathers recent information about genomic and transcriptomic studies in the Corynebacterium genus, exploring, for example, prediction of pathogenicity islands and stress response in different pathogenic and non-pathogenic species. In addition, is described several phylogeny studies to Corynebacterium , exploring since the identification of species until biological speciation in one species belonging to the genus Corynebacterium . Important concepts associated with virulence highlighting the role of Pld protein and Tox gene. The adhesion, characteristic of virulence factor, was described using the sortase mechanism that is associated to anchorage to the cell wall. In addition, survival inside the host cell and some diseases, were too addressed for pathogenic corynebacteria, while important biochemical pathways and biotechnological applications retain the focus of this review for non-pathogenic corynebacteria. Concluding, this review broadly explores characteristics in genus Corynebacterium showing to have strong relevance inside the medical, veterinary, and biotechnology field.

  9. Experimental transmission of Corynebacterium pseudotuberculosis biovar equi in horses by house flies

    Science.gov (United States)

    The route of Corynebacterium pseudotuberculosis infection in horses remains undetermined, but transmission by insects is suspected. Scientists from CMAVE and Auburn University investigated house flies (Musca domestica L.) as possible vectors. Three ponies were directly inoculated with C. pseudotuber...

  10. Complete genome sequence of Corynebacterium pseudotuberculosis Cp31, isolated from an Egyptian buffalo

    DEFF Research Database (Denmark)

    Silva, Artur; Ramos, Rommel Thiago Jucá; Ribeiro Carneiro, Adriana

    2012-01-01

    Corynebacterium pseudotuberculosis is of major veterinary importance because it affects many animal species, causing economically significant livestock diseases and losses. Therefore, the genomic sequencing of various lines of this organism, isolated from different hosts, will aid in the developm...

  11. Corynebacterium species: an uncommon agent of peritoneal dialysis-related peritonitis and a challenging treatment

    OpenAIRE

    Ferreira, Joel; Teixeira e Costa, Fernando; Ramos, Aura

    2015-01-01

    Introduction: Corynebacterium is a component of normal skin flora and it is responsible for an increasing incidence of nosocomial infections in the last decades. Peritonitis and exit-site infections caused by this microorganism are uncommon but have a significant clinical impact due to their high relapsing rate. The ideal therapeutic approach in these situations is not yet clearly defined. Methods: Retrospective analysis of Corynebacterium spp peritonitis in a peritoneal dialysis unit between...

  12. Desulfurization of dibenzothiophene by Corynebacterium sp. strain SY1

    International Nuclear Information System (INIS)

    Omori, Toshio; Monna, L.; Saiki, Yuko; Kodama, Tohru

    1992-01-01

    Strain SY1, identified as a Corynebacterium sp., was isolated on the basis of the ability to utilize dibenzothiophene (DBT) as a sole source of sulfur. Strain SY1 could utilize a wide range of organic and inorganic sulfur compounds, such as DBT sulfone, dimethyl sulfide, dimethyl sulfoxide, dimethyl sulfone, CS 2 , FeS 2 , and even elemental sulfur. Strain SY1 metabolized DBT to dibenzothiophene-5-oxide, DBT sulfone, and 2-hydroxybiphenyl, which was subsequently nitrated to produce at least two different hydroxynitrobiphenyls during cultivation. These metabolites were separated by silica gel column chromatography and identified by nuclear magnetic resonance, UV, and mass spectral techniques. Resting cells of SY1 desulfurized toluenesulfonic acid and released sulfite anion. On the basis of these results, a new DBT degradation pathway is proposed

  13. Production of L-valine from metabolically engineered Corynebacterium glutamicum.

    Science.gov (United States)

    Wang, Xiaoyuan; Zhang, Hailing; Quinn, Peter J

    2018-05-01

    L-Valine is one of the three branched-chain amino acids (valine, leucine, and isoleucine) essential for animal health and important in metabolism; therefore, it is widely added in the products of food, medicine, and feed. L-Valine is predominantly produced through microbial fermentation, and the production efficiency largely depends on the quality of microorganisms. In recent years, continuing efforts have been made in revealing the mechanisms and regulation of L-valine biosynthesis in Corynebacterium glutamicum, the most utilitarian bacterium for amino acid production. Metabolic engineering based on the metabolic biosynthesis and regulation of L-valine provides an effective alternative to the traditional breeding for strain development. Industrially competitive L-valine-producing C. glutamicum strains have been constructed by genetically defined metabolic engineering. This article reviews the global metabolic and regulatory networks responsible for L-valine biosynthesis, the molecular mechanisms of regulation, and the strategies employed in C. glutamicum strain engineering.

  14. A Novel Corynebacterium glutamicum l-Glutamate Exporter.

    Science.gov (United States)

    Wang, Yu; Cao, Guoqiang; Xu, Deyu; Fan, Liwen; Wu, Xinyang; Ni, Xiaomeng; Zhao, Shuxin; Zheng, Ping; Sun, Jibin; Ma, Yanhe

    2018-03-15

    Besides metabolic pathways and regulatory networks, transport systems are also pivotal for cellular metabolism and hyperproduction of biochemicals using microbial cell factories. The identification and characterization of transporters are therefore of great significance for the understanding and engineering of transport reactions. Herein, a novel l-glutamate exporter, MscCG2, which exists extensively in Corynebacterium glutamicum strains but is distinct from the only known l-glutamate exporter, MscCG, was discovered in an industrial l-glutamate-producing C. glutamicum strain. MscCG2 was predicted to possess three transmembrane helices in the N-terminal region and located in the cytoplasmic membrane, which are typical structural characteristics of the mechanosensitive channel of small conductance. MscCG2 has a low amino acid sequence identity (23%) to MscCG and evolved separately from MscCG with four transmembrane helices. Despite the considerable differences between MscCG2 and MscCG in sequence and structure, gene deletion and complementation confirmed that MscCG2 also functioned as an l-glutamate exporter and an osmotic safety valve in C. glutamicum Besides, transcriptional analysis showed that MscCG2 and MscCG genes were transcribed in similar patterns and not induced by l-glutamate-producing conditions. It was also demonstrated that MscCG2-mediated l-glutamate excretion was activated by biotin limitation or penicillin treatment and that constitutive l-glutamate excretion was triggered by a gain-of-function mutation of MscCG2 (A151V). Discovery of MscCG2 will enrich the understanding of bacterial amino acid transport and provide additional targets for exporter engineering. IMPORTANCE The exchange of matter, energy, and information with surroundings is fundamental for cellular metabolism. Therefore, studying transport systems that are essential for these processes is of great significance. Besides, transport systems of bacterial cells are usually related to

  15. Comparison of antimicrobial susceptibilities of Corynebacterium species by broth microdilution and disk diffusion methods.

    Science.gov (United States)

    Weiss, K; Laverdière, M; Rivest, R

    1996-01-01

    Corynebacterium species are increasingly being implicated in foreign-body infections and in immunocompromised-host infections. However, there are no specific recommendations on the method or the criteria to use in order to determine the in vitro activities of the antibiotics commonly used to treat Corynebacterium infections. The first aim of our study was to compare the susceptibilities of various species of Corynebacterium to vancomycin, erythromycin, and penicillin by using a broth microdilution method and a disk diffusion method. Second, the activity of penicillin against our isolates was assessed by using the interpretative criteria recommended by the National Committee for Clinical Laboratory Standards for the determination of the susceptibility of streptococci and Listeria monocytogenes to penicillin. Overall, 100% of the isolates were susceptible to vancomycin, while considerable variations in the activities of erythromycin and penicillin were noted for the different species tested, including the non-Corynebacterium jeikeium species. A good correlation in the susceptibilities of vancomycin and erythromycin between the disk diffusion and the microdilution methods was observed. However, a 5% rate of major or very major errors was detected with the Listeria criteria, while a high rate of minor errors (18%) was noted when the streptococcus criteria were used. Our findings indicate considerable variations in the activities of erythromycin and penicillin against the various species of Corynebacterium. Because of the absence of definite recommendations, important discrepancies were observed between the methods and the interpretations of the penicillin activity. PMID:8849254

  16. [Skin and Soft Tissue Infections Due to Corynebacterium ulcerans - Case Reports].

    Science.gov (United States)

    Jenssen, Christian; Schwede, Ilona; Neumann, Volker; Pietsch, Cristine; Handrick, Werner

    2017-10-01

    History and clinical findings  We report on three patients suffering from skin and soft tissue infections of the legs due to toxigenic Corynebacterium ulcerans strains. In all three patients, there was a predisposition due to chronic diseases. Three patients had domestic animals (cat, dog) in their households. Investigations and diagnosis  A mixed bacterial flora including Corynebacterium ulcerans was found in wound swab samples. Diphtheric toxin was produced by the Corynebacterium ulcerans strains in all three cases. Treatment and course  In all three patients, successful handling of the skin and soft tissue infections was possible by combining local treatment with antibiotics. Diphtheria antitoxin was not administered in any case. Conclusion  Based on a review of the recent literature pathogenesis, clinical symptoms and signs, diagnostics and therapy of skin and soft tissue infections due to Corynebacterium ulcerans are discussed. Corynebacterium ulcerans should be considered as a potential cause of severe skin and soft tissue infections. Occupational or domestic animal contacts should be evaluated. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Comparative evolutionary genomics of Corynebacterium with special reference to codon and amino acid usage diversities.

    Science.gov (United States)

    Pal, Shilpee; Sarkar, Indrani; Roy, Ayan; Mohapatra, Pradeep K Das; Mondal, Keshab C; Sen, Arnab

    2018-02-01

    The present study has been aimed to the comparative analysis of high GC composition containing Corynebacterium genomes and their evolutionary study by exploring codon and amino acid usage patterns. Phylogenetic study by MLSA approach, indel analysis and BLAST matrix differentiated Corynebacterium species in pathogenic and non-pathogenic clusters. Correspondence analysis on synonymous codon usage reveals that, gene length, optimal codon frequencies and tRNA abundance affect the gene expression of Corynebacterium. Most of the optimal codons as well as translationally optimal codons are C ending i.e. RNY (R-purine, N-any nucleotide base, and Y-pyrimidine) and reveal translational selection pressure on codon bias of Corynebacterium. Amino acid usage is affected by hydrophobicity, aromaticity, protein energy cost, etc. Highly expressed genes followed the cost minimization hypothesis and are less diverged at their synonymous positions of codons. Functional analysis of core genes shows significant difference in pathogenic and non-pathogenic Corynebacterium. The study reveals close relationship between non-pathogenic and opportunistic pathogenic Corynebaterium as well as between molecular evolution and survival niches of the organism.

  18. Corynebacterium species causing breast abscesses among patients attending a tertiary care hospital in Chennai, South India.

    Science.gov (United States)

    Poojary, Indira; Kurian, Ann; V A, Jayalekshmi; Devapriya J, Debora; M A, Thirunarayan

    2017-07-01

    Corynebacterium species other than Corynebacterium diphtheriae were mostly considered contaminants in the past, but there are reports of their association with wide variety of human infections lately. In this study, we look into Corynebacterium species isolated from breast abscess patients and assess their antimicrobial susceptibility pattern and treatment outcomes. Pus samples from suspected breast abscess cases were examined from October 2014 to September 2015. Growth of Gram-positive bacilli morphologically resembling Corynebacterium species were identified by matrix-assisted laser desorption/ionization- time of flight mass spectrometry identifications generated by the Vitek MS system (bioMérieux, France) (MALDI-TOF Vitek MS system) and antimicrobial susceptibility was done. Corynebacterium species were isolated from 10 female breast abscess patients with median age of 36 years (range 25-59 years). Out of the 10 isolates four isolates were identified as C. kroppenstedtii; one isolate as C. striatum and five isolates were identified as C. amycolatum/C.xerosis. Out of four isolates of C .kroppenstedtii, two isolates were resistant to cotrimoxazole and one C. striatum isolate was resistant to penicillin, ampicillin, cotrimoxazole and clindamycin. Of the five isolates identified as C amycolatum/C xerosis, all were sensitive to vancomycin and linezolid but resistant to clindamycin. All the patients were treated with incision, drainage and antibiotics based on the sensitivity pattern; eight were cured and two patients did not come for follow-up. Corynebacterium species should be considered one of the causative agents of breast abscess and a varied susceptibility profile amongst the different species makes susceptibility testing important. Identification by MALDI-TOF Vitek MS system may not differentiate between C. amycolatum and C. xerosis.

  19. Tips and tricks for the assembly of a Corynebacterium pseudotuberculosis genome using a semiconductor sequencer

    DEFF Research Database (Denmark)

    Ramos, Rommel Thiago Jucá; Carneiro, Adriana Ribeiro; Soares, Siomar de Castro

    2013-01-01

    that enable reference-based assembly, such as the one used in the present study, Corynebacterium pseudotuberculosis biovar equi, which causes high economic losses in the US equine industry. The quality treatment strategy incorporated into the assembly pipeline enabled a 16-fold greater use of the sequencing...... was validated by comparative genomics with other species of the genus Corynebacterium. The present study presents a modus operandi that enables a greater and better use of data obtained from semiconductor sequencing for obtaining the complete genome from a prokaryotic microorganism, C. pseudotuberculosis, which...

  20. Fatal case of bacteremia caused by an atypical strain of Corynebacterium mucifaciens

    Directory of Open Access Journals (Sweden)

    Vlademir Vicente Cantarelli

    Full Text Available Corynebacterium species have often been considered normal skin flora or contaminants; however, in recent years they have been increasingly implicated in serious infections. Moreover, many new species have been discovered and old species renamed, especially after molecular biology techniques were introduced. Corynebacterium mucifaciens is mainly isolated from blood and from other normally-sterile body fluids; it forms slightly yellow, mucoid colonies on blood agar. We report a fatal case of bacteremia due to an atypical strain of C. mucifaciens. This strain had atypical colony morphology; analysis of the 16S rRNA gene was used to define the species.

  1. Metabolic Engineering of Corynebacterium glutamicum for Methanol Metabolism

    Science.gov (United States)

    Witthoff, Sabrina; Schmitz, Katja; Niedenführ, Sebastian; Nöh, Katharina; Noack, Stephan

    2015-01-01

    Methanol is already an important carbon feedstock in the chemical industry, but it has found only limited application in biotechnological production processes. This can be mostly attributed to the inability of most microbial platform organisms to utilize methanol as a carbon and energy source. With the aim to turn methanol into a suitable feedstock for microbial production processes, we engineered the industrially important but nonmethylotrophic bacterium Corynebacterium glutamicum toward the utilization of methanol as an auxiliary carbon source in a sugar-based medium. Initial oxidation of methanol to formaldehyde was achieved by heterologous expression of a methanol dehydrogenase from Bacillus methanolicus, whereas assimilation of formaldehyde was realized by implementing the two key enzymes of the ribulose monophosphate pathway of Bacillus subtilis: 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase. The recombinant C. glutamicum strain showed an average methanol consumption rate of 1.7 ± 0.3 mM/h (mean ± standard deviation) in a glucose-methanol medium, and the culture grew to a higher cell density than in medium without methanol. In addition, [13C]methanol-labeling experiments revealed labeling fractions of 3 to 10% in the m + 1 mass isotopomers of various intracellular metabolites. In the background of a C. glutamicum Δald ΔadhE mutant being strongly impaired in its ability to oxidize formaldehyde to CO2, the m + 1 labeling of these intermediates was increased (8 to 25%), pointing toward higher formaldehyde assimilation capabilities of this strain. The engineered C. glutamicum strains represent a promising starting point for the development of sugar-based biotechnological production processes using methanol as an auxiliary substrate. PMID:25595770

  2. Rapid detection of Corynebacterium pseudotuberculosis in clinical samples from sheep.

    Science.gov (United States)

    Kumar, Jyoti; Tripathi, Bhupendra Nath; Kumar, Rajiv; Sonawane, Ganesh Gangaram; Dixit, Shivendra Kumar

    2013-08-01

    Corynebacterium pseudotuberculosis, a Gram-positive bacterium is the causative agent of caseous lymphadenitis (CLA), a chronic disease of sheep, goats and other warm blooded animals. In the present study, a total of 1,080 sheep reared under semi-intensive system on organized farms situated in the semi arid tropical region of Rajasthan, India, was clinically examined. Pus samples from superficial lymph nodes of 25 (2.31%) adult sheep showing clinical lesions similar to CLA were collected for laboratory analyses. On the basis of morphological, cultural and biochemical characteristics 12 (48%) bacterial isolates from pus identified it as C. pseudotuberculosis. A polymerase chain reaction (PCR) assay targeting Putative oligopeptide/dipeptide ABC transporter, nicotinamide adenine dinucleotide phosphate (NADP) oxidoreductase coenzyme F420-dependent and proline iminopeptidase (PIP) genes of C. pseudotuberculosis was developed that showed 14 pus samples as positive. All C. pseudotuberculosis isolates were also found positive for these genes in the PCR. The specificity of the PCR products was confirmed by sequencing of the amplified products that showed 98-100% homology with published sequences available in the NCBI database. The present study shows the incidence of CLA as 2.31%, 1.1% and 1.29% based on clinical, bacterial culture and direct pus PCR assay, respectively. The PCR assay was rapid, specific and as significant as bacterial culture in detecting bacteria directly in the clinical pus samples. The PCR assay developed in the study can be applied for the diagnosis and control of CLA. Furthermore, the assay can also be applied to detect C. pseudotuberculosis in various clinical samples.

  3. Activity of disinfectants and biofilm production of Corynebacterium pseudotuberculosis

    Directory of Open Access Journals (Sweden)

    Maria da C.A. Sá

    2013-11-01

    Full Text Available To verify the occurrence of caseous lymphadenitis in sheep and goats on farms of Pernambuco, Brazil, and in animals slaughtered in two Brazilian cities (Petrolina/PE and Juazeiro/BA, and to characterize the susceptibility profile of Corynebacterium pseudotuberculosis to disinfectants and antimicrobials, and its relationship with biofilm production were the objectives of this study. 398 samples were tested for sensitivity to antimicrobial drugs, disinfectants, and biofilm production. Among the 108 samples collected on the properties, 75% were positive for C. pseudotuberculosis. Slaughterhouse samples indicated an occurrence of caseous lymphadenitis in 15.66% and 6.31% for animals slaughtered in Petrolina and Juazeiro respectively. With respect to antimicrobials, the sensitivity obtained was 100% for florfenicol and tetracycline; 99.25% for enrofloxacin, ciprofloxacin and lincomycin; 98.99% for cephalothin; 98.74% for norfloxacin and sulfazotrim; 97.74% for gentamicin; 94.22% for ampicillin; 91.71% for amoxicillin; 91.21% for penicillin G; 89.19% for neomycin and 0% for novobiocin. In analyzes with disinfectants, the efficiency for chlorhexidine was 100%, 97.20% for quaternary ammonium, 87.40% for chlorine and 84.40% for iodine. 75% of the isolates were weak or non-biofilm producers. For the consolidated biofilm, found that iodine decreased biofilm formation in 13 isolates and quaternary ammonia in 11 isolates. The reduction of the biofilm formation was observed for iodine and quaternary ammonium in consolidated biofilm formation in 33% and 28% of the isolates, respectively. The results of this study highlight the importance of establishing measures to prevent and control the disease.

  4. Molecular epidemiology of Corynebacterium pseudotuberculosis isolated from horses in California.

    Science.gov (United States)

    Haas, Dionei J; Dorneles, Elaine M S; Spier, Sharon J; Carroll, Scott P; Edman, Judy; Azevedo, Vasco A; Heinemann, Marcos B; Lage, Andrey P

    2017-04-01

    Corynebacterium pseudotuberculosis biovar Equi is an important pathogen of horses. It is increasing in frequency in the United States, and is responsible for various clinical forms of infection, including external abscesses, internal abscesses of the abdominal or thoracic cavities, and ulcerative lymphangitis. The host/pathogen factors dictating the form or severity of infection are currently unknown. Our recent investigations have shown that genotyping C. pseudotuberculosis isolates using enterobacterial repetitive intergenic consensus (ERIC)-PCR is useful for understanding the evolutionary genetics of the species as well for molecular epidemiology studies. The aims of the present study were to assess (i) the genetic diversity of C. pseudotuberculosis strains isolated from horses in California, United States and (ii) the epidemiologic relationships among isolates. One hundred and seven C. pseudotuberculosis biovar Equi isolates from ninety-five horses, and two C. pseudotuberculosis biovar Ovis strains, C. pseudotuberculosis ATCC 19410 T type strain and C. pseudotuberculosis 1002 vaccine strain, were fingerprinted using the ERIC 1+2-PCR. C. pseudotuberculosis isolated from horses showed a high genetic diversity, clustering in twenty-seven genotypes with a diversity index of 0.91. Minimal spanning tree showed four major clonal complexes with a pattern of temporal clustering. Strains isolated from the same horse showed identical ERIC 1+2-PCR genotype, with the exception of two strains isolated from the same animal that showed distinct genotypes, suggesting a co-infection. We found no strong genetic signals related to clinical form (including internal versus external infections). However, temporal clustering of genotypes was observed. Copyright © 2016. Published by Elsevier B.V.

  5. Corynebacterium renale as a cause of reactions to the complement fixation test for Johne's disease

    NARCIS (Netherlands)

    Gilmour, N.J.L.; Goudswaard, J.

    Complement fixation (C.F.) tests and fluorescent antibody (F.A.) tests were carried out on sera from rabbits inoculated with Corynebacterium renale and Mycobacterium johnei, and on sera from cattle with C. renale pyelonephritis and with Johne's disease. Cross-reactions were a feature of the C.F.

  6. Function of Corynebacterium glutamicum promoters in Eschrichia coli, Streptomyces lividans, and Baccillus subtilis

    Czech Academy of Sciences Publication Activity Database

    Pátek, Miroslav; Muth, G.; Wohlleben, W.

    2003-01-01

    Roč. 104, - (2003), s. 325-334 ISSN 0168-1656 R&D Projects: GA AV ČR IPP1050128; GA ČR GA525/01/0916 Institutional research plan: CEZ:AV0Z5020903 Keywords : corynebacterium glutamicum * escherichia coli * promoters Subject RIV: EE - Microbiology, Virology Impact factor: 2.543, year: 2003

  7. Metabolic engineering of the L-valine biosynthesis pathway in Corynebacterium glutamicum using promoter activity modulation

    Czech Academy of Sciences Publication Activity Database

    Holátko, Jiří; Elišáková, Veronika; Prouza, Marek; Sobotka, Miroslav; Nešvera, Jan; Pátek, Miroslav

    2009-01-01

    Roč. 139, č. 3 (2009), s. 203-210 ISSN 0168-1656 R&D Projects: GA ČR GA204/06/0330 Institutional research plan: CEZ:AV0Z50200510 Keywords : corynebacterium glutamicum * valine production * promoters Subject RIV: EE - Microbiology, Virology Impact factor: 2.881, year: 2009

  8. Physiological roles of sigma factor SigD in Corynebacterium glutamicum

    Czech Academy of Sciences Publication Activity Database

    Taniguchi, H.; Busche, T.; Patschkowski, T.; Niehaus, K.; Pátek, Miroslav; Kalinowski, J.; Wendisch, V.F.

    2017-01-01

    Roč. 17, č. 158 (2017), s. 158 ISSN 1471-2180 R&D Projects: GA ČR(CZ) GA17-06991S Institutional support: RVO:61388971 Keywords : Corynebacterium glutamicum * Sigma factor * SigD Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 2.644, year: 2016

  9. Complete Sucrose Metabolism Requires Fructose Phosphotransferase Activity in Corynebacterium glutamicum To Ensure Phosphorylation of Liberated Fructose

    OpenAIRE

    Dominguez, H.; Lindley, N. D.

    1996-01-01

    Sucrose uptake by Corynebacterium glutamicum involves a phosphoenolpyruvate-dependent sucrose phosphotransferase (PTS), but in the absence of fructokinase, further metabolism of the liberated fructose requires efflux of the fructose and reassimilation via the fructose PTS. Mutant strains lacking detectable fructose-transporting PTS activity accumulated fructose extracellularly but consumed sucrose at rates comparable to those of the wild-type strain.

  10. An unusual etiological agent of implantable cardioverter device endocarditis: Corynebacterium mucifaciens

    Directory of Open Access Journals (Sweden)

    Adnan Kaya

    2016-03-01

    Full Text Available Cardiac pacing devices and implantable cardioverter defibrillator (ICD are becoming the mainstay of therapy in cardiology and infective endocarditis (IE and pocket infection; however, these devices require careful monitoring. Here, we describe a case of a 68-year-old female with an ICD presenting with a previously unknown etiological agent of IE, Corynebacterium mucifaciens.

  11. Assignment of sigma factors of RNA polymerase to promoters in Corynebacterium glutamicum

    Czech Academy of Sciences Publication Activity Database

    Dostálová, Hana; Holátko, Jiří; Busche, T.; Rucká, Lenka; Rapoport, Andrey; Halada, Petr; Nešvera, Jan; Kalinowski, J.; Pátek, Miroslav

    2017-01-01

    Roč. 7, JUN 23 (2017), s. 1-13, č. článku 133. ISSN 2191-0855 R&D Projects: GA ČR(CZ) GA17-06991S Institutional support: RVO:61388971 Keywords : Corynebacterium glutamicum * Promoter * Sigma factor Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.825, year: 2016

  12. Plasmid Vectors for Testing In Vivo Promoter Activities in Corynebacterium glutamicum and Rhodococcus erythropolis

    Czech Academy of Sciences Publication Activity Database

    Knoppová, Monika; Phensaijai, M.; Veselý, Martin; Zemanová, Martina; Nešvera, Jan; Pátek, Miroslav

    2007-01-01

    Roč. 55, - (2007), s. 234-239 ISSN 0343-8651 R&D Projects: GA ČR GA526/04/0542; GA ČR GA204/06/0330 Institutional research plan: CEZ:AV0Z50200510 Keywords : corynebacterium * rhodoccoccus * promoter-probe vectors Subject RIV: EE - Microbiology , Virology Impact factor: 1.167, year: 2007

  13. Development of Biotin-Prototrophic and -Hyperauxotrophic Corynebacterium glutamicum Strains

    Science.gov (United States)

    Miyamoto, Aya; Mutoh, Sumire; Kitano, Yuko; Tajima, Mei; Shirakura, Daisuke; Takasaki, Manami; Mitsuhashi, Satoshi; Takeno, Seiki

    2013-01-01

    To develop the infrastructure for biotin production through naturally biotin-auxotrophic Corynebacterium glutamicum, we attempted to engineer the organism into a biotin prototroph and a biotin hyperauxotroph. To confer biotin prototrophy on the organism, the cotranscribed bioBF genes of Escherichia coli were introduced into the C. glutamicum genome, which originally lacked the bioF gene. The resulting strain still required biotin for growth, but it could be replaced by exogenous pimelic acid, a source of the biotin precursor pimelate thioester linked to either coenzyme A (CoA) or acyl carrier protein (ACP). To bridge the gap between the pimelate thioester and its dedicated precursor acyl-CoA (or -ACP), the bioI gene of Bacillus subtilis, which encoded a P450 protein that cleaves a carbon-carbon bond of an acyl-ACP to generate pimeloyl-ACP, was further expressed in the engineered strain by using a plasmid system. This resulted in a biotin prototroph that is capable of the de novo synthesis of biotin. On the other hand, the bioY gene responsible for biotin uptake was disrupted in wild-type C. glutamicum. Whereas the wild-type strain required approximately 1 μg of biotin per liter for normal growth, the bioY disruptant (ΔbioY) required approximately 1 mg of biotin per liter, almost 3 orders of magnitude higher than the wild-type level. The ΔbioY strain showed a similar high requirement for the precursor dethiobiotin, a substrate for bioB-encoded biotin synthase. To eliminate the dependency on dethiobiotin, the bioB gene was further disrupted in both the wild-type strain and the ΔbioY strain. By selectively using the resulting two strains (ΔbioB and ΔbioBY) as indicator strains, we developed a practical biotin bioassay system that can quantify biotin in the seven-digit range, from approximately 0.1 μg to 1 g per liter. This bioassay proved that the engineered biotin prototroph of C. glutamicum produced biotin directly from glucose, albeit at a marginally

  14. Development of biotin-prototrophic and -hyperauxotrophic Corynebacterium glutamicum strains.

    Science.gov (United States)

    Ikeda, Masato; Miyamoto, Aya; Mutoh, Sumire; Kitano, Yuko; Tajima, Mei; Shirakura, Daisuke; Takasaki, Manami; Mitsuhashi, Satoshi; Takeno, Seiki

    2013-08-01

    To develop the infrastructure for biotin production through naturally biotin-auxotrophic Corynebacterium glutamicum, we attempted to engineer the organism into a biotin prototroph and a biotin hyperauxotroph. To confer biotin prototrophy on the organism, the cotranscribed bioBF genes of Escherichia coli were introduced into the C. glutamicum genome, which originally lacked the bioF gene. The resulting strain still required biotin for growth, but it could be replaced by exogenous pimelic acid, a source of the biotin precursor pimelate thioester linked to either coenzyme A (CoA) or acyl carrier protein (ACP). To bridge the gap between the pimelate thioester and its dedicated precursor acyl-CoA (or -ACP), the bioI gene of Bacillus subtilis, which encoded a P450 protein that cleaves a carbon-carbon bond of an acyl-ACP to generate pimeloyl-ACP, was further expressed in the engineered strain by using a plasmid system. This resulted in a biotin prototroph that is capable of the de novo synthesis of biotin. On the other hand, the bioY gene responsible for biotin uptake was disrupted in wild-type C. glutamicum. Whereas the wild-type strain required approximately 1 μg of biotin per liter for normal growth, the bioY disruptant (ΔbioY) required approximately 1 mg of biotin per liter, almost 3 orders of magnitude higher than the wild-type level. The ΔbioY strain showed a similar high requirement for the precursor dethiobiotin, a substrate for bioB-encoded biotin synthase. To eliminate the dependency on dethiobiotin, the bioB gene was further disrupted in both the wild-type strain and the ΔbioY strain. By selectively using the resulting two strains (ΔbioB and ΔbioBY) as indicator strains, we developed a practical biotin bioassay system that can quantify biotin in the seven-digit range, from approximately 0.1 μg to 1 g per liter. This bioassay proved that the engineered biotin prototroph of C. glutamicum produced biotin directly from glucose, albeit at a marginally

  15. Screening for Corynebacterium diphtheriae and Corynebacterium ulcerans in patients with upper respiratory tract infections 2007-2008: a multicentre European study.

    LENUS (Irish Health Repository)

    Wagner, K S

    2011-04-01

    Diphtheria is now rare in most European countries but, when cases do arise, the case fatality rate is high (5-10%). Because few countries continue to routinely screen for the causative organisms of diphtheria, the extent to which they are circulating amongst different European populations is largely unknown. During 2007-2008, ten European countries each screened between 968 and 8551 throat swabs from patients with upper respiratory tract infections. Six toxigenic strains of Corynebacterium diphtheriae were identified: two from symptomatic patients in Latvia (the country with the highest reported incidence of diphtheria in the European Union) and four from Lithuania (two cases, two carriers); the last reported case of diphtheria in Lithuania was in 2002. Carriage rates of non-toxigenic organisms ranged from 0 (Bulgaria, Finland, Greece, Ireland, Italy) to 4.0 per 1000 (95% CI 2.0-7.1) in Turkey. A total of 28 non-toxigenic strains were identified during the study (26 C. diphtheriae, one Corynebacterium ulcerans, one Corynebacterium pseudotuberculosis). The non-toxigenic C. ulcerans strain was isolated from the UK, the country with the highest reported incidence of cases due to C. ulcerans. Of the eleven ribotypes detected, Cluj was seen most frequently in the non-toxigenic isolates and, amongst toxigenic isolates, the major epidemic clone, Sankt-Petersburg, is still in circulation. Isolation of toxigenic C. diphtheriae and non-toxigenic C. diphtheriae and C. ulcerans in highly-vaccinated populations highlights the need to maintain microbiological surveillance, laboratory expertise and an awareness of these organisms amongst public health specialists, microbiologists and clinicians.

  16. POTENSI GEN dtx DAN dtxR SEBAGAI MARKER UNTUK DETEKSI DAN PEMERIKSAAN TOKSIGENISITAS Corynebacterium diphtheriae

    Directory of Open Access Journals (Sweden)

    Sunarno Sunarno

    2013-05-01

    Full Text Available Abstract.   Corynebacterium diphtheriae is the causative agent of diphtheria. The main virulence determinant of the bacteria is diphtheria toxin, the cause of the systemic complication seen with diphtheria. Production of diphtheria toxin by toxigenic strain encoded by dtx/tox gene and repressed by dtxR gene. Gold standard for bacterial toxigenicity test carried out by conventional methods (Elek test, Guinea pig and vero cell cytotoxicity. However, Elek test have variety result, time consume and problem of the reagent availability. On the other hand, the animal (Guinea pig testing was opposed by many animal lovers and the vero cell cytotoxicity test require high cost. The study purposed to evaluate the using of dtx and dtxR genes as a detection marker of C.diphtheriae and bacterial toxigenicity test simultaneusly by Multiplex PCR. The study examined 44 bacterial and fungal isolates, included 22 C.diphtheriae (4 reference strains and 18 clinical isolates, 5 other specieses of Corynebacterium  (reference strains and 17 non-Corynebacterium (10 reference strains and 7 stock cultures . All of sample were examined by Multiplex PCR for 2 primer pairs targeted dtx and dtxR genes. The study showed that the Multiplex PCR for dtx and dtxR as target genes able to detect all of sample correctly thus concluded that dtx and dtxR genes could be used as a marker for alternative detection and toxigenicity test of C.diphtheriae by Multiplex PCR rapidly and accuratelly. Key words: Corynebacterium diphtheriae, dtx, dan dtxR Abstrak. Corynebacterium diphtheriae merupakan agen penyebab penyakit difteri.. Faktor virulensi utama  C. diphtheriae adalah toksigenisitas (kemampuan memproduksi toksin bakteri toxin. Produksi toksin diatur seperangkat gen yang disebut gen tox/dtx dan diregulasi oleh gen dtxR. Gold standard untuk pemeriksaan toksigenisitas C.diphtheriae adalah dengan metode konvensional (Elek test, Guinea pig dan vero cell cytotoxigenicity,namun  Elek test

  17. An unusual case of chronic nonhealing periorbital ulceration due to a new species of Corynebacterium sp. strain UCL557

    Directory of Open Access Journals (Sweden)

    Bipasa Chakraborty

    2016-01-01

    Full Text Available Nondiphtherial Corynebacterium (diphtheroids has been related to blood and wound infections but are an uncommon cause for soft tissue infection. We report a case of periorbital soft tissue infection with ulceration caused by multidrug-resistant Corynebacterium spp. in a 9-year-old girl who is apparently immunocompetant. Computed tomography scan showed soft tissue involvement of right periorbital region with no bony destructions or focal calcifications. Vision remained unaffected. Patient was treated by debridement and skin grafting, but condition did not improve. Pus collected from the periorbital ulcerated area was cultured in blood agar and Corynebacterium spp. was isolated from the pure culture, which was identified as a new species Corynebacterium sp. strain UCL557 using 16S rDNA- based molecular technique based on nucleotide homology and phylogenetic analysis. Antibiogram showed multiresistance pattern with sensitivity to ceftriaxone-sulbactum vancomycin and linezolid. After initiation of treatment with vancomycin infusion and oral linezolid, the patient responded well and lesion started to heal. To the best of our knowledge, this is the first ever case report of periorbital ulceration by new species of Corynebacterium sp. strain UCL557.

  18. Microbe Profile: Corynebacterium diphtheriae - an old foe always ready to seize opportunity.

    Science.gov (United States)

    Hoskisson, Paul A

    2018-02-21

    Corynebacterium diphtheriae is a globally important Gram-positive aerobic Actinobacterium capable of causing the toxin-mediated disease, diphtheria. Diphtheria was a major cause of childhood mortality prior to the introduction of the toxoid vaccine, yet it is capable of rapid resurgence following the breakdown of healthcare provision, vaccination or displacement of people. The mechanism and treatment of toxin-mediated disease is well understood, however there are key gaps in our knowledge on the basic biology of C. diphtheriae particularly relating to host colonisation, the nature of asymptomatic carriage, population genomics and host adaptation.

  19. A RecET-assisted CRISPR-Cas9 genome editing in Corynebacterium glutamicum.

    Science.gov (United States)

    Wang, Bo; Hu, Qitiao; Zhang, Yu; Shi, Ruilin; Chai, Xin; Liu, Zhe; Shang, Xiuling; Zhang, Yun; Wen, Tingyi

    2018-04-23

    Extensive modification of genome is an efficient manner to regulate the metabolic network for producing target metabolites or non-native products using Corynebacterium glutamicum as a cell factory. Genome editing approaches by means of homologous recombination and counter-selection markers are laborious and time consuming due to multiple round manipulations and low editing efficiencies. The current two-plasmid-based CRISPR-Cas9 editing methods generate false positives due to the potential instability of Cas9 on the plasmid, and require a high transformation efficiency for co-occurrence of two plasmids transformation. Here, we developed a RecET-assisted CRISPR-Cas9 genome editing method using a chromosome-borne Cas9-RecET and a single plasmid harboring sgRNA and repair templates. The inducible expression of chromosomal RecET promoted the frequencies of homologous recombination, and increased the efficiency for gene deletion. Due to the high transformation efficiency of a single plasmid, this method enabled 10- and 20-kb region deletion, 2.5-, 5.7- and 7.5-kb expression cassette insertion and precise site-specific mutation, suggesting a versatility of this method. Deletion of argR and farR regulators as well as site-directed mutation of argB and pgi genes generated the mutant capable of accumulating L-arginine, indicating the stability of chromosome-borne Cas9 for iterative genome editing. Using this method, the model-predicted target genes were modified to redirect metabolic flux towards 1,2-propanediol biosynthetic pathway. The final engineered strain produced 6.75 ± 0.46 g/L of 1,2-propanediol that is the highest titer reported in C. glutamicum. Furthermore, this method is available for Corynebacterium pekinense 1.563, suggesting its universal applicability in other Corynebacterium species. The RecET-assisted CRISPR-Cas9 genome editing method will facilitate engineering of metabolic networks for the synthesis of interested bio-based products from renewable

  20. Toxigenic Corynebacterium ulcerans isolated from a free-roaming red fox (Vulpes vulpes).

    Science.gov (United States)

    Sting, Reinhard; Ketterer-Pintur, Sandra; Contzen, Matthias; Mauder, Norman; Süss-Dombrowski, Christine

    2015-01-01

    Corynebacterium (C.) ulcerans could be isolated from the spleen of a red fox (Vulpes vulpes) that had been found dead in the state of Baden-Württemberg, Germany. Pathohistological examination suggested that the fox had died of distemper, as was confirmed by PCR. The isolate was identified biochemically, by MALDI-TOF MS, FT-IR and by partial 16S rRNA, rpoB and tox gene sequencing. Using the Elek test the C. ulcerans isolate demonstrated diphtheria toxin production. FT-IR and sequencing data obtained from the C. ulcerans isolate from the red fox showed higher similarity to isolates from humans than to those from wild game.

  1. APLICACION DE TECNICAS DE INGENIERIA METABOLICA AL MEJORAMIENTO DE LA PRODUCCION DE TREHALOSA POR CORYNEBACTERIUM GLUTAMICUM.

    OpenAIRE

    PADILLA IGLESIAS, LEANDRO MAURICIO

    2004-01-01

    La Trehalosa es un disacárido con tremendas aplicaciones en la industria biotecnológica y alimenticia. Este compuesto se encuentra en muchos organismos, a causa de su capacidad de proteger las células contra el calor y la deshidratación. Un ejemplo, es la bacteria Gram-positiva Corynebacterium glutamicum, la cual sintetiza trehalosa a través de dos rutas principales, TreYZ y OtsBA, usando ADP-glucosa (especulativamente) y UDP-glucosa, respectivamente, como dadores de unidades de ...

  2. Structural Basis of a Thiol-Disulfide Oxidoreductase in the Hedgehog-Forming Actinobacterium Corynebacterium matruchotii.

    Science.gov (United States)

    Luong, Truc Thanh; Tirgar, Reyhaneh; Reardon-Robinson, Melissa E; Joachimiak, Andrzej; Osipiuk, Jerzy; Ton-That, Hung

    2018-05-01

    The actinobacterium Corynebacterium matruchotii has been implicated in nucleation of oral microbial consortia leading to biofilm formation. Due to the lack of genetic tools, little is known about basic cellular processes, including protein secretion and folding, in this organism. We report here a survey of the C. matruchotii genome, which encodes a large number of exported proteins containing paired cysteine residues, and identified an oxidoreductase that is highly homologous to the Corynebacterium diphtheriae thiol-disulfide oxidoreductase MdbA (MdbA Cd ). Crystallization studies uncovered that the 1.2-Å resolution structure of C. matruchotii MdbA (MdbA Cm ) possesses two conserved features found in actinobacterial MdbA enzymes, a thioredoxin-like fold and an extended α-helical domain. By reconstituting the disulfide bond-forming machine in vitro , we demonstrated that MdbA Cm catalyzes disulfide bond formation within the actinobacterial pilin FimA. A new gene deletion method supported that mdbA is essential in C. matruchotii Remarkably, heterologous expression of MdbA Cm in the C. diphtheriae Δ mdbA mutant rescued its known defects in cell growth and morphology, toxin production, and pilus assembly, and this thiol-disulfide oxidoreductase activity required the catalytic motif CXXC. Altogether, the results suggest that MdbA Cm is a major thiol-disulfide oxidoreductase, which likely mediates posttranslocational protein folding in C. matruchotii by a mechanism that is conserved in Actinobacteria IMPORTANCE The actinobacterium Corynebacterium matruchotii has been implicated in the development of oral biofilms or dental plaque; however, little is known about the basic cellular processes in this organism. We report here a high-resolution structure of a C. matruchotii oxidoreductase that is highly homologous to the Corynebacterium diphtheriae thiol-disulfide oxidoreductase MdbA. By biochemical analysis, we demonstrated that C. matruchotii MdbA catalyzes disulfide

  3. Corynebacterium glutamicum for Sustainable Bioproduction: From Metabolic Physiology to Systems Metabolic Engineering.

    Science.gov (United States)

    Becker, Judith; Gießelmann, Gideon; Hoffmann, Sarah Lisa; Wittmann, Christoph

    Since its discovery 60 years ago, Corynebacterium glutamicum has evolved into a workhorse for industrial biotechnology. Traditionally well known for its remarkable capacity to produce amino acids, this Gram-positive soil bacterium, has become a flexible, efficient production platform for various bulk and fine chemicals, materials, and biofuels. The central turnstile of all these achievements is our excellent understanding of its metabolism and physiology. This knowledge base, together with innovative systems metabolic engineering concepts, which integrate systems and synthetic biology into strain engineering, has upgraded C. glutamicum into one of the most successful industrial microorganisms in the world.

  4. Dual production of poly(3-hydroxybutyrate) and glutamate using variable biotin concentrations in Corynebacterium glutamicum.

    Science.gov (United States)

    Jo, Sung-Jin; Leong, Chean Ring; Matsumoto, Ken'ichiro; Taguchi, Seiichi

    2009-04-01

    We previously synthesized poly(3-hydroxybutyrate) [P(3HB)] in recombinant Corynebacterium glutamicum, a prominent producer of amino acids. In this study, a two-step cultivation was established for the dual production of glutamate and P(3HB) due to the differences in the optimal concentration of biotin. Glutamate was extracellularly produced first under the biotin-limited condition of 0.3 microg/L. Production was then shifted to P(3HB) by addition of biotin to a total concentration of 9 microg/L. The final products obtained were 18 g/L glutamate and 36 wt% of P(3HB).

  5. Recurrent Breast Abscesses due to Corynebacterium kroppenstedtii, a Human Pathogen Uncommon in Caucasian Women

    Directory of Open Access Journals (Sweden)

    Anne Le Flèche-Matéos

    2012-01-01

    Full Text Available Background. Corynebacterium kroppenstedtii (Ck was first described in 1998 from human sputum. Contrary to what is observed in ethnic groups such as Maori, Ck is rarely isolated from breast abscesses and granulomatous mastitis in Caucasian women. Case Presentation. We herein report a case of recurrent breast abscesses in a 46-year-old Caucasian woman. Conclusion. In the case of recurrent breast abscesses, even in Caucasian women, the possible involvement of Ck should be investigated. The current lack of such investigations, probably due to the difficulty to detect Ck, may cause the underestimation of such an aetiology.

  6. una comunidad

    Directory of Open Access Journals (Sweden)

    Adriana Hernández García

    2006-01-01

    embargo, el desarrollo generó mayores desigualdades económicas entre las poblaciones urbanas y las rurales, así como efectos de contaminación del medio ambiente y escasez de los recursos naturales. En este trabajo se presentan los puntos de encuentros locales, la historia, identidad y simbolismos que mantienen una visión de la vida comunal; los desencuentros frente al desarrollo aplicado en la localidad; los cambios en los patrones de cultivo y de la pesca, así como la migración como uno de los principales efectos del cambio.

  7. Immobilazation of aerobic microorganisms on glassy sintered material, illustrated by the example of the production of L leucine using Corynebacterium glutamicum. Immobilisierung von aeroben Mikroorganismen an Glassintermaterial am Beispiel der L-Leucin-Produktion mit Corynebacterium glutamicum

    Energy Technology Data Exchange (ETDEWEB)

    Buechs, J.

    1988-12-01

    The aim of this study was to develop the carrier fixation of aerobic microorganisms on open-pore sintered glass material. The fermentative production of L-leucine from {alpha} cetonic isocaproic acid with Corynebacterium glutamicum was chosen as an example of a microbial process with a high demand of oxygen. (orig.).

  8. Flux through the tetrahydrodipicolinate succinylase pathway is dispensable for L-lysine production in Corynebacterium glutamicum.

    Science.gov (United States)

    Shaw-Reid, C A; McCormick, M M; Sinskey, A J; Stephanopoulos, G

    1999-03-01

    The N-succinyl-LL-diaminopimelate desuccinylase gene (dapE) in the four-step succinylase branch of the L-lysine biosynthetic pathway of Corynebacterium glutamicum was disrupted via marker-exchange mutagenesis to create a mutant strain that uses only the one-step meso-diaminopimelate dehydrogenase branch to overproduce lysine. This mutant strain grew and utilized glucose from minimal medium at the same rate as the parental strain. In addition, the dapE- strain produced lysine at the same rate as its parent strain. Transformation of the parental and dapE- strains with the amplified meso-diaminopimelate dehydrogenase gene (ddh) on a plasmid did not affect lysine production in either strain, despite an eightfold amplification of the activity of the enzyme. These results indicate that the four-step succinylase pathway is dispensable for lysine overproduction in shake-flask culture. In addition, the one-step meso-diaminopimelate dehydrogenase pathway does not limit lysine flux in Corynebacterium under these conditions.

  9. First report of Corynebacterium pseudotuberculosis from caseous lymphadenitis lesions in Black Alentejano pig (Sus scrofa domesticus).

    Science.gov (United States)

    Oliveira, Manuela; Barroco, Cynthia; Mottola, Carla; Santos, Raquel; Lemsaddek, Abdelhak; Tavares, Luis; Semedo-Lemsaddek, Teresa

    2014-09-21

    Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis, a common disease in small ruminant populations throughout the world and responsible for a significant economic impact for producers. To our knowledge, this is the first characterization of C. pseudotuberculosis from caseous lymphadenitis lesions in Black Alentejano pig (Sus scrofa domesticus). In this study, phenotypic and genotypic identification methods allocated the swine isolates in C. pseudotuberculosis biovar ovis. The vast majority of the isolates were able to produce phospholipase D and were susceptible to most of the antimicrobial compounds tested. Macrorestriction patterns obtained by Pulsed Field Gel Electrophoresis (PFGE) grouped the C. pseudotuberculosis in two clusters with a high similarity index, which reveals their clonal relatedness. Furthermore, swine isolates were compared with C. pseudotuberculosis from caprines and PFGE patterns also showed high similarity, suggesting the prevalence of dominant clones and a potential cross-dissemination between these two animal hosts. This work represents the first report of Corynebacterium pseudotuberculosis from caseous lymphadenitis lesions in Black Alentejano pig and alerts for the importance of the establishment of suitable control and sanitary management practices to control the infection and avoid further dissemination of this important pathogen to other animal hosts.

  10. Characterization of Staphylococcus and Corynebacterium clusters in the human axillary region.

    Directory of Open Access Journals (Sweden)

    Chris Callewaert

    Full Text Available The skin microbial community is regarded as essential for human health and well-being, but likewise plays an important role in the formation of body odor in, for instance, the axillae. Few molecular-based research was done on the axillary microbiome. This study typified the axillary microbiome of a group of 53 healthy subjects. A profound view was obtained of the interpersonal, intrapersonal and temporal diversity of the human axillary microbiota. Denaturing gradient gel electrophoresis (DGGE and next generation sequencing on 16S rRNA gene region were combined and used as extent to each other. Two important clusters were characterized, where Staphylococcus and Corynebacterium species were the abundant species. Females predominantly clustered within the Staphylococcus cluster (87%, n = 17, whereas males clustered more in the Corynebacterium cluster (39%, n = 36. The axillary microbiota was unique to each individual. Left-right asymmetry occurred in about half of the human population. For the first time, an elaborate study was performed on the dynamics of the axillary microbiome. A relatively stable axillary microbiome was noticed, although a few subjects evolved towards another stable community. The deodorant usage had a proportional linear influence on the species diversity of the axillary microbiome.

  11. Improved L-ornithine production in Corynebacterium crenatum by introducing an artificial linear transacetylation pathway.

    Science.gov (United States)

    Shu, Qunfeng; Xu, Meijuan; Li, Jing; Yang, Taowei; Zhang, Xian; Xu, Zhenghong; Rao, Zhiming

    2018-05-04

    L-Ornithine is a non-protein amino acid with extensive applications in the food and pharmaceutical industries. In this study, we performed metabolic pathway engineering of an L-arginine hyper-producing strain of Corynebacterium crenatum for L-ornithine production. First, we amplified the L-ornithine biosynthetic pathway flux by blocking the competing branch of the pathway. To enhance L-ornithine synthesis, we performed site-directed mutagenesis of the ornithine-binding sites to solve the problem of L-ornithine feedback inhibition for ornithine acetyltransferase. Alternatively, the genes argA from Escherichia coli and argE from Serratia marcescens, encoding the enzymes N-acetyl glutamate synthase and N-acetyl-L-ornithine deacetylase, respectively, were introduced into Corynebacterium crenatum to mimic the linear pathway of L-ornithine biosynthesis. Fermentation of the resulting strain in a 5-L bioreactor allowed a dramatically increased production of L-ornithine, 40.4 g/L, with an overall productivity of 0.673 g/L/h over 60 h. This demonstrates that an increased level of transacetylation is beneficial for L-ornithine biosynthesis.

  12. Pyruvate:Quinone Oxidoreductase in Corynebacterium glutamicum: Molecular Analysis of the pqo Gene, Significance of the Enzyme, and Phylogenetic Aspects

    Czech Academy of Sciences Publication Activity Database

    Schreiner, M. E.; Riedel, Ch.; Holátko, Jiří; Pátek, Miroslav; Eikmanns, B. J.

    2006-01-01

    Roč. 188, č. 4 (2006), s. 1341-1350 ISSN 0021-9193 R&D Projects: GA ČR GA525/04/0548 Institutional research plan: CEZ:AV0Z50200510 Keywords : corynebacterium glutamicum * pqo * molecular analysis Subject RIV: EE - Microbiology, Virology Impact factor: 3.993, year: 2006

  13. Genome sequence of Corynebacterium pseudotuberculosis biovar equi strain 258 and prediction of antigenic targets to improve biotechnological vaccine production

    DEFF Research Database (Denmark)

    Soares, Siomar C; Trost, Eva; Ramos, Rommel T J

    2013-01-01

    Corynebacterium pseudotuberculosis is the causative agent of several veterinary diseases in a broad range of economically important hosts, which can vary from caseous lymphadenitis in sheep and goats (biovar ovis) to ulcerative lymphangitis in cattle and horses (biovar equi). Existing vaccines ag...

  14. Brain and lung cryptococcoma and concurrent corynebacterium pseudotuberculosis infection in a goat: a case report

    Directory of Open Access Journals (Sweden)

    MCR Luvizotto

    2009-01-01

    Full Text Available A four-year-old male goat with a history of neurological disorder was euthanized. It presented uncommon nodules in the brain and lungs associated with multiple abscesses, predominantly in the spleen and liver. Histological examination of brain and lung sections revealed yeast forms confirmed to be Cryptococcus gattii after a combination of isolation and polymerase chain reaction (PCR procedures. Moreover, Corynebacterium pseudotuberculosis infection was diagnosed by PCR of samples from the lung, spleen and liver. The present report highlights the rare concurrent infection of C. gatti and C. pseudotuberculosis in an adult goat from São Paulo state, Brazil, and indicates the necessity of surveillance in the treatment of goats with atypical pulmonary infections associated with neurological disorders.

  15. In Silico Genome-Scale Reconstruction and Validation of the Corynebacterium glutamicum Metabolic Network

    DEFF Research Database (Denmark)

    Kjeldsen, Kjeld Raunkjær; Nielsen, J.

    2009-01-01

    A genome-scale metabolic model of the Gram-positive bacteria Corynebacterium glutamicum ATCC 13032 was constructed comprising 446 reactions and 411 metabolite, based on the annotated genome and available biochemical information. The network was analyzed using constraint based methods. The model...... was extensively validated against published flux data, and flux distribution values were found to correlate well between simulations and experiments. The split pathway of the lysine synthesis pathway of C. glutamicum was investigated, and it was found that the direct dehydrogenase variant gave a higher lysine...... yield than the alternative succinyl pathway at high lysine production rates. The NADPH demand of the network was not found to be critical for lysine production until lysine yields exceeded 55% (mmol lysine (mmol glucose)(-1)). The model was validated during growth on the organic acids acetate...

  16. Global Transcriptomic Analysis of the Response of Corynebacterium glutamicum to Vanillin.

    Directory of Open Access Journals (Sweden)

    Can Chen

    Full Text Available Lignocellulosic biomass is an abundant and renewable resource for biofuels and bio-based chemicals. Vanillin is one of the major phenolic inhibitors in biomass production using lignocellulose. To assess the response of Corynebacterium glutamicum to vanillin stress, we performed a global transcriptional response analysis. The transcriptional data showed that the vanillin stress not only affected the genes involved in degradation of vanillin, but also differentially regulated several genes related to the stress response, ribosome/translation, protein secretion, and the cell envelope. Moreover, deletion of the sigH or msrA gene in C. glutamicum resulted in a decrease in cell viability under vanillin stress. These insights will promote further engineering of model industrial strains, with enhanced tolerance or degradation ability to vanillin to enable suitable production of biofuels and bio-based chemicals from lignocellulosic biomass.

  17. Global Transcriptomic Analysis of the Response of Corynebacterium glutamicum to Vanillin.

    Science.gov (United States)

    Chen, Can; Pan, Junfeng; Yang, Xiaobing; Guo, Chenghao; Ding, Wei; Si, Meiru; Zhang, Yi; Shen, Xihui; Wang, Yao

    2016-01-01

    Lignocellulosic biomass is an abundant and renewable resource for biofuels and bio-based chemicals. Vanillin is one of the major phenolic inhibitors in biomass production using lignocellulose. To assess the response of Corynebacterium glutamicum to vanillin stress, we performed a global transcriptional response analysis. The transcriptional data showed that the vanillin stress not only affected the genes involved in degradation of vanillin, but also differentially regulated several genes related to the stress response, ribosome/translation, protein secretion, and the cell envelope. Moreover, deletion of the sigH or msrA gene in C. glutamicum resulted in a decrease in cell viability under vanillin stress. These insights will promote further engineering of model industrial strains, with enhanced tolerance or degradation ability to vanillin to enable suitable production of biofuels and bio-based chemicals from lignocellulosic biomass.

  18. Molecular cloning and expression of Corynebacterium glutamicum genes for amino acid synthesis in Escherichia coli cells

    International Nuclear Information System (INIS)

    Beskrovnaya, O.Yu.; Fonshtein, M.Yu.; Kolibaba, L.G.; Yankovskii, N.K.; Debabov, V.G.

    1989-01-01

    Molecular cloning of Corynebacterium glutamicum genes for threonine and lysine synthesis has been done in Escherichia coli cells. The clonal library of EcoRI fragments of chromosomal DNA of C. glutamicum was constructed on the plasmid vector λpSL5. The genes for threonine and lysine synthesis were identified by complementation of E. coli mutations in thrB and lysA genes, respectively. Recombinant plasmids, isolated from independent ThrB + clone have a common 4.1-kb long EcoRI DNA fragment. Hybrid plasmids isolated from LysA + transductants of E. coli have common 2.2 and 3.3 kb long EcoRI fragments of C. glutamicum DNA. The hybrid plasmids consistently transduced the markers thrB + and lysA + . The Southern hybridization analysis showed that the cloned DNA fragments hybridized with the fragments of identical length in C. glutamicum chromosomes

  19. Bioconversion of sugar cane molasses into glutamic acid by gamma irradiated corynebacterium glutamicum

    International Nuclear Information System (INIS)

    El-Batal, A.I.

    1996-01-01

    Corynebacterium glutamicum (ATCC 13058) was used for glutamic acid production from sugar cane molasses which contain sufficient. The addition of 5 units ml 4 of penicillin G was superior in glutamic acid production (11.5 g L 4 ). Tweens and their saturated fatty acids were effective on the accumulation of glutamic acid in the culture medium and the maximum yield (16.6 g L 4 ) was the addition of 5 mg ml 4 Tween 40. Gamma irradiation prior to Tween-40 treatment of bacterial cells resulted in an obvious increase in glutamic acid production and it was maximum (23.72 g L 4 ) at 0.1 k Gy exposure dose of inocula. 5 tabs

  20. BIOCHEMICAL AND PHYLOGENETIC STUDIES OF CreD OF Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Muhammad Tausif Chaudhry

    2015-06-01

    Full Text Available CreD characterized as Mg2+-dependent phosphohydrolase with conserved HD domain was involved in 4-cresol metabolism in Corynebacterium glutamicum. Native molecular mass of 54 kDa suggested that the biological unit is a dimer. No deoxynucleotide triphosphate triphosphohydrolase (dNTPase activity was detected for CreD. The apparent Km and Vmax values for 4-nitrophenyl phosphate were 0.35 mM and 16.23 M min-1 mg-1, respectively, while calculated values for kcat and kcat/Km were 0.4 s-1 and 1.14103 M-1 s-1, respectively. Among thiol group inhibitors, iodoacetic acid significantly inhibited phosphohydrolase activity. Sequence identity and phylogenetic analysis suggested universal existence of CreD homologues. Involvement of HD-domain hydrolase in aromatic degradation has not been reported before.

  1. In silico identification of essential proteins in Corynebacterium pseudotuberculosis based on protein

    DEFF Research Database (Denmark)

    Folador, Edson Luiz; de Carvalho, Paulo Vinícius Sanches Daltro; Silva, Wanderson Marques

    2016-01-01

    BACKGROUND: Corynebacterium pseudotuberculosis (Cp) is a gram-positive bacterium that is classified into equi and ovis serovars. The serovar ovis is the etiological agent of caseous lymphadenitis, a chronic infection affecting sheep and goats, causing economic losses due to carcass condemnation...... of the potential Cp interactome and to identify potentially essential proteins serving as putative drug targets. On average, we predict 16,669 interactions for each of the nine strains (with 15,495 interactions shared among all strains). An in silico sanity check suggests that the potential networks were...... not formed by spurious interactions but have a strong biological bias. With the inferred Cp networks we identify 181 essential proteins, among which 41 are non-host homologous. CONCLUSIONS: The list of candidate interactions of the Cp strains lay the basis for developing novel hypotheses and designing...

  2. Influence of Corynebacterium parvum on the phagocytosis of /sup 198/Au colloids in rats

    Energy Technology Data Exchange (ETDEWEB)

    Bergoc, R.M.; Bianchin, A.M.; Caro, R.A.; Ihlo, J.E.; Rivera, E.S. (Buenos Aires Univ. Nacional (Argentina). Facultad de Farmacia y Bioquimica)

    1982-07-01

    The kinetics of the phagocytosis of gelatin-protected /sup 198/Au colloids in Wistar rats treated with Corynebacterium Parvum (CBP), was studied in order to explain its mechanism of immunomodulation. A previously developed extracorporeal blood circulation technique was used. The changes in the rate of phagocytosis, v, after the administration of CBP, for a dose of the /sup 198/Au colloid smaller or higher than the substratum constant, were studied. In the first case, no significant changes of v were observed; in the second case, significant increases of v were determined, which reached a maximum 6 days after the CBP administration. The kinetic analysis of the obtained data indicates that the action of CBP is exerted on the stage of the entrance of the colloidal particle into the reticuloendothelial cell.

  3. Influence of Corynebacterium parvum on the phagocytosis of 198Au colloids in rats

    International Nuclear Information System (INIS)

    Bergoc, R.M.; Bianchin, A.M.; Caro, R.A.; Ihlo, J.E.; Rivera, E.S.

    1982-01-01

    The kinetics of the phagocytosis of gelatin-protected 198 Au colloids in Wistar rats treated with Corynebacterium Parvum (CBP), was studied in order to explain its mechanism of immunomodulation. A previously developed extracorporeal blood circulation technique was used. The changes in the rate of phagocytosis, v, after the administration of CBP, for a dose of the 198 Au colloid smaller or higher than the substratum constant, were studied. In the first case, no significant changes of v were observed; in the second case, significant increases of v were determined, which reached a maximum 6 days after the CBP administration. The kinetic analysis of the obtained data indicates that the action of CBP is exerted on the stage of the entrance of the colloidal particle into the reticuloendothelial cell. (author) [es

  4. Pathogenicity and genetic variation of 3 strains of Corynebacterium bovis in immunodeficient mice.

    Science.gov (United States)

    Dole, Vandana S; Henderson, Kenneth S; Fister, Richard D; Pietrowski, Michael T; Maldonado, Geomaris; Clifford, Charles B

    2013-07-01

    Corynebacterium bovis has been associated with hyperkeratotic dermatitis and acanthosis in mice. We studied 3 different strains of C. bovis: one previously described to cause hyperkeratotic dermatitis (HAC), one that infected athymic nude mice without leading to the classic clinical signs, and one of bovine origin (ATCC 7715). The 3 strains showed a few biochemical and genetic differences. Immunodeficient nude mice were housed in 3 independent isolators and inoculated with pure cultures of the 3 strains. We studied the transmission of these C. bovis studies to isolator-bedding and contact sentinels housed for 5 to 12 wk in filter-top or wire-top cages in the respective isolators. Using a 16S rRNA-based qPCR assay, we did not find consistent differences in growth and transmission among the 3 C. bovis strains, and neither the incidence nor severity of hyperkeratosis or acanthosis differed between strains. Housing in filter-top compared with wire-top cages did not alter the morbidity associated with any of the strains. Our findings confirmed the variability in the gross and histologic changes associated with C. bovis infection of mice. Although bacteriology was a sensitive method for the detection of Corynebacterium spp., standard algorithms occasionally misidentified C. bovis and several related species. Our study demonstrates that PCR of skin swabs or feces is a sensitive and specific method for the detection of C. bovis infection in mice. An rpoB-based screen of samples from North American vivaria revealed that HAC is the predominant C. bovis strain in laboratory mice.

  5. Corynebacterium striatum infecting a malignant cutaneous lesion: the emergence of an opportunistic pathogen Corynebacterium striatum infectando lesão cutânea maligna: a emergência de um patógeno oportunista

    Directory of Open Access Journals (Sweden)

    Silvana Vargas Superti

    2009-04-01

    Full Text Available We described a case of a 27-year old male patient with skin and soft tissue infection of a neoplastic lesion caused by Corynebacterium striatum, an organism which has been rarely described as a human pathogen. Identification was confirmed by DNA sequencing. Successful treatment with penicillin was achieved. The role of the C. striatum as an emerging opportunistic pathogen is discussed.Descrevemos infecção de lesão neoplásica em paciente masculino de 27 anos, envolvendo pele e partes moles, causada por Corynebacterium striatum, um microrganismo raramente descrito como patógeno humano. A identificação foi confirmada por seqüenciamento de DNA. O paciente foi tratado com penicilina, com sucesso. O papel do C. striatum como patógeno oportunista é discutido.

  6. Mutations of the Corynebacterium glutamicum NCgl1221 Gene, Encoding a Mechanosensitive Channel Homolog, Induce l-Glutamic Acid Production▿

    OpenAIRE

    Nakamura, Jun; Hirano, Seiko; Ito, Hisao; Wachi, Masaaki

    2007-01-01

    Corynebacterium glutamicum is a biotin auxotroph that secretes l-glutamic acid in response to biotin limitation; this process is employed in industrial l-glutamic acid production. Fatty acid ester surfactants and penicillin also induce l-glutamic acid secretion, even in the presence of biotin. However, the mechanism of l-glutamic acid secretion remains unclear. It was recently reported that disruption of odhA, encoding a subunit of the 2-oxoglutarate dehydrogenase complex, resulted in l-gluta...

  7. Determination of the Presence of crpgenes in Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus delbrueckii and Corynebacterium veraSuş

    OpenAIRE

    BELDÜZ, Ali Osman; DEMİRBAĞ, Zihni; DÜLGER, Sabriye

    2014-01-01

    Polymerase chain reaction (PCR) was employed to detect the presence of cyclic AMP receptor protein (CPR) in a number of diverse organisms. In PCR, two primers specific to the crp gene of Escherichia coli were used. Staphylococcus aureus, Staphylococcus epidermidis, Lactobacillus delbrueckii and Corynebacterium veraSuş all showed the same size of PCR frağments (708 bp) and same restriction frağment length polymorphizm (RFLP).

  8. CRISPR/Cas9-coupled recombineering for metabolic engineering of Corynebacterium glutamicum.

    Science.gov (United States)

    Cho, Jae Sung; Choi, Kyeong Rok; Prabowo, Cindy Pricilia Surya; Shin, Jae Ho; Yang, Dongsoo; Jang, Jaedong; Lee, Sang Yup

    2017-07-01

    Genome engineering of Corynebacterium glutamicum, an important industrial microorganism for amino acids production, currently relies on random mutagenesis and inefficient double crossover events. Here we report a rapid genome engineering strategy to scarlessly knock out one or more genes in C. glutamicum in sequential and iterative manner. Recombinase RecT is used to incorporate synthetic single-stranded oligodeoxyribonucleotides into the genome and CRISPR/Cas9 to counter-select negative mutants. We completed the system by engineering the respective plasmids harboring CRISPR/Cas9 and RecT for efficient curing such that multiple gene targets can be done iteratively and final strains will be free of plasmids. To demonstrate the system, seven different mutants were constructed within two weeks to study the combinatorial deletion effects of three different genes on the production of γ-aminobutyric acid, an industrially relevant chemical of much interest. This genome engineering strategy will expedite metabolic engineering of C. glutamicum. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  9. Metabolic engineering of Corynebacterium glutamicum for fermentative production of chemicals in biorefinery.

    Science.gov (United States)

    Baritugo, Kei-Anne; Kim, Hee Taek; David, Yokimiko; Choi, Jong-Il; Hong, Soon Ho; Jeong, Ki Jun; Choi, Jong Hyun; Joo, Jeong Chan; Park, Si Jae

    2018-05-01

    Bio-based production of industrially important chemicals provides an eco-friendly alternative to current petrochemical-based processes. Because of the limited supply of fossil fuel reserves, various technologies utilizing microbial host strains for the sustainable production of platform chemicals from renewable biomass have been developed. Corynebacterium glutamicum is a non-pathogenic industrial microbial species traditionally used for L-glutamate and L-lysine production. It is a promising species for industrial production of bio-based chemicals because of its flexible metabolism that allows the utilization of a broad spectrum of carbon sources and the production of various amino acids. Classical breeding, systems, synthetic biology, and metabolic engineering approaches have been used to improve its applications, ranging from traditional amino-acid production to modern biorefinery systems for production of value-added platform chemicals. This review describes recent advances in the development of genetic engineering tools and techniques for the establishment and optimization of metabolic pathways for bio-based production of major C2-C6 platform chemicals using recombinant C. glutamicum.

  10. Difteria pelo Corynebacterium ulcerans: uma zoonose emergente no Brasil e no mundo

    Directory of Open Access Journals (Sweden)

    Alexandre Alves de Souza de Oliveira Dias

    2011-12-01

    Full Text Available O artigo revisa a literatura sobre a emergência de infecções humanas causadas por Corynebacterium ulcerans em diversos países, incluindo o Brasil. Foi realizada análise de artigos publicados entre 1926 e 2011 nas bases Medline/PubMed e SciELO, bem como artigos e informes do Ministério da Saúde. Apresenta-se um esquema de triagem, rápido, econômico e de fácil execução, capaz de permitir a realização do diagnóstico presuntivo de C. ulcerans e C. diphtheriae na maioria dos laboratórios brasileiros públicos e privados. A circulação de C. ulcerans em vários países, aliada aos recentes casos de isolamento do patógeno no Rio de Janeiro, é um alerta a clínicos, veterinários e microbiologistas sobre a ocorrência de difteria zoonótica e a circulação do C. ulcerans em regiões urbanas e rurais do território nacional e/ou da América Latina.

  11. Physico-chemical parameter for production of lactic acid or ethanol of (corynebacterium glutamicum) bacteria

    International Nuclear Information System (INIS)

    Castellanos, Angelica; Garcia, Lina Marcela; Astudillo, Myriam; Lopez Galan, Jorge Enrique; Florez Pardo, Luz Marina.

    2011-01-01

    The interest to obtain products for the bio-fuel industry from renewable resources has directed research to find resistant and costs-effective biotechnological systems. Corynebacterium glutamicum, is a microorganism used to produce amino acids, that grows in wide variety of substrates and its resistance during fermentation to pH, temperature, osmotic pressure variations and alcohol aggregate, renders this organism a suitable candidate to improve by genetic modifications lactic acid and ethanol synthesis. However, some aspects of its physiology remain unknown, such us increase lactic acid and ethanol production from C5 and C6 sugars. For this reason, the main aim in our work was to identify the most important variables with impact on culture and the best culture conditions to produce lactic acid or ethanol in batch culture. To achieve this objective, eight variables were tested in culture using a statistical model. The best culture conditions were obtained and tested in a bacth bioreactor system. Temperature, biotin and glucose concentration were the variables with most impact (p - 1 , 16 g/l of lactic acid was obtained after 15 h of culture with an efficiency of 32%. High glucose consumption was observed during bacterial growth, which leads to low concentration of substrate for the production process; this suggests a culture feeding at the end of exponential growth phase, which can increase the production yield.

  12. Surgical Site Infection by Corynebacterium macginleyi in a Patient with Neurofibromatosis Type 1

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    Bruno Cacopardo

    2013-01-01

    Full Text Available Corynebacterium (C. macginleyi is a gram positive, lipophilic rod, usually considered a colonizer of skin and mucosal surfaces. Several reports have associated C. macginleyi with ocular infections, such as conjunctivitis and endophthalmitis. However, even if rare, extraocular infections from C. macginleyi may occur, especially among immunocompromised patients and patients with indwelling medical devices. We report herein the first case of surgical site infection by C. macginleyi after orthopaedic surgery for the correction of kyphoscoliosis in a patient with neurofibromatosis type 1. Our patient developed a nodular granulomatous lesion of about two centimetres along the surgical scar, at the level of C4-C5, with purulent discharge and formation of a fistulous tract. Cervical magnetic resonance imaging showed the presence of a two-centimetre fluid pocket in the subcutaneous tissue. Several swabs were collected from the borders of the lesion as well as from the exudate, with isolation of C. macginleyi. The isolate was susceptible to beta-lactams, cotrimoxazole, linezolid, and glycopeptides but resistant to quinolones, third-generation cephalosporins, and erythromycin. Two 30-day courses of antibiotic therapy with amoxicillin/clavulanate (1 g three times/day and cotrimoxazole (800/160 mg twice a day were administered, obtaining a complete healing of the lesion.

  13. Detoxification of furfural in Corynebacterium glutamicum under aerobic and anaerobic conditions.

    Science.gov (United States)

    Tsuge, Yota; Hori, Yoshimi; Kudou, Motonori; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2014-10-01

    The toxic fermentation inhibitors in lignocellulosic hydrolysates raise serious problems for the microbial production of fuels and chemicals. Furfural is considered to be one of the most toxic compounds among these inhibitors. Here, we describe the detoxification of furfural in Corynebacterium glutamicum ATCC13032 under both aerobic and anaerobic conditions. Under aerobic culture conditions, furfuryl alcohol and 2-furoic acid were produced as detoxification products of furfural. The ratio of the products varied depending on the initial furfural concentration. Neither furfuryl alcohol nor 2-furoic acid showed any toxic effect on cell growth, and both compounds were determined to be the end products of furfural degradation. Interestingly, unlike under aerobic conditions, most of the furfural was converted to furfuryl alcohol under anaerobic conditions, without affecting the glucose consumption rate. Both the NADH/NAD(+) and NADPH/NADP(+) ratio decreased in the accordance with furfural concentration under both aerobic and anaerobic conditions. These results indicate the presence of a single or multiple endogenous enzymes with broad and high affinity for furfural and co-factors in C. glutamicum ATCC13032.

  14. FudC, a protein primarily responsible for furfural detoxification in Corynebacterium glutamicum.

    Science.gov (United States)

    Tsuge, Yota; Kudou, Motonori; Kawaguchi, Hideo; Ishii, Jun; Hasunuma, Tomohisa; Kondo, Akihiko

    2016-03-01

    Lignocellulosic hydrolysates contain compounds that inhibit microbial growth and fermentation, thereby decreasing the productivity of biofuel and biochemical production. In particular, the heterocyclic aldehyde furfural is one of the most toxic compounds found in these hydrolysates. We previously demonstrated that Corynebacterium glutamicum converts furfural into the less toxic compounds furfuryl alcohol and 2-furoic acid. To date, however, the genes involved in these oxidation and reduction reactions have not been identified in the C. glutamicum genome. Here, we show that Cgl0331 (designated FudC) is mainly responsible for the reduction of furfural into furfuryl alcohol in C. glutamicum. Deletion of the gene encoding FudC markedly diminished the in vivo reduction of furfural to furfuryl alcohol. Purified His-tagged FudC protein from Escherichia coli was also shown to convert furfural into furfuryl alcohol in an in vitro reaction utilizing NADPH, but not NADH, as a cofactor. Kinetic measurements demonstrated that FudC has a high affinity for furfural but has a narrow substrate range for other aldehydes compared to the protein responsible for furfural reduction in E. coli.

  15. Evaluation of three methods for DNA fingerprinting of Corynebacterium pseudotuberculosis strains isolated from goats in Poland.

    Science.gov (United States)

    Stefańska, Ilona; Rzewuska, Magdalena; Binek, Marian

    2008-01-01

    Phenotypic approaches based on metabolic and biological characteristics of Corynebacterium pseudotuberculosis have been limited due to insufficient discrimination between closely related isolates. In this paper we present performance and convenience of three molecular typing methods: BOX-PCR, random amplification of polymorphic DNA (RAPD) and amplification of DNA fragments surrounding rare restriction site (ADSRRS-fingerprinting) in genome analysis of these bacteria. Among examined 61 strains there were distinguished four, eight and 10 different genotypes by BOX-PCR, RAPD and ADSRRS-fingerprinting, respectively. The value of discrimination index was the lowest for BOX-PCR (D = 0.265), much bigger for RAPD (D = 0.539) and the highest for ADSRRS-fingerprinting (D = 0.604). The good discriminatory ability and reproducibility of RAPD and ADSRRS-fingerprinting indicates that those techniques may be particularly applied for epidemiological studies of C. pseudotuberculosis isolates. We found that ADSRRS-fingerprinting is a rapid method offering good discrimination power, excellent reproducibility and may be applied for epidemiological studies of intraspecific genetic relatedness of C. pseudotuberculosis strains.

  16. Heterologous expression of the Halothiobacillus neapolitanus carboxysomal gene cluster in Corynebacterium glutamicum.

    Science.gov (United States)

    Baumgart, Meike; Huber, Isabel; Abdollahzadeh, Iman; Gensch, Thomas; Frunzke, Julia

    2017-09-20

    Compartmentalization represents a ubiquitous principle used by living organisms to optimize metabolic flux and to avoid detrimental interactions within the cytoplasm. Proteinaceous bacterial microcompartments (BMCs) have therefore created strong interest for the encapsulation of heterologous pathways in microbial model organisms. However, attempts were so far mostly restricted to Escherichia coli. Here, we introduced the carboxysomal gene cluster of Halothiobacillus neapolitanus into the biotechnological platform species Corynebacterium gluta-micum. Transmission electron microscopy, fluorescence microscopy and single molecule localization microscopy suggested the formation of BMC-like structures in cells expressing the complete carboxysome operon or only the shell proteins. Purified carboxysomes consisted of the expected protein components as verified by mass spectrometry. Enzymatic assays revealed the functional production of RuBisCO in C. glutamicum both in the presence and absence of carboxysomal shell proteins. Furthermore, we could show that eYFP is targeted to the carboxysomes by fusion to the large RuBisCO subunit. Overall, this study represents the first transfer of an α-carboxysomal gene cluster into a Gram-positive model species supporting the modularity and orthogonality of these microcompartments, but also identified important challenges which need to be addressed on the way towards biotechnological application. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Comparison of two biochemical methods for identifying Corynebacterium pseudotuberculosis isolated from sheep and goats.

    Science.gov (United States)

    Huerta, Belén; Gómez-Gascón, Lidia; Vela, Ana I; Fernández-Garayzábal, José F; Casamayor, Almudena; Tarradas, Carmen; Maldonado, Alfonso

    2013-06-01

    The biochemical pattern of Cowan and Steel (BPCS) was compared with a commercial biochemical strip for the identification of Corynebacterium pseudotuberculosis isolated from small ruminants. On 16S rRNA gene sequencing, 40/78 coryneform isolates from the lymph nodes of sheep and goats with lesions resembling caseous lymphadenitis were identified as C. pseudotuberculosis. The sensitivities of the BPCS and the commercial biochemical strip relative to 16S rRNA sequencing were 80% and 85%, and their specificities were 92.1% and 94.7%, respectively; the level of agreement between the BPCS and the commercial biochemical strip was high (κ=0.82). Likelihood ratios for positive and negative results were 10.0 and 0.22 for the BPCS, and 16.0 and 0.16 for the commercial biochemical strip, respectively. These results indicate that the BPCS and the commercial biochemical strip are both useful for identifying C. pseudotuberculosis in veterinary microbiology laboratories. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Expression, crystallization and preliminary crystallographic study of GluB from Corynebacterium glutamicum

    International Nuclear Information System (INIS)

    Liu, Qingbo; Li, Defeng; Hu, Yonglin; Wang, Da-Cheng

    2013-01-01

    GluB, a substrate-binding protein from C. glutamicum, was expressed, purified and crystallized, followed by X-ray diffraction data collection and preliminary crystallographic analysis. GluB is a substrate-binding protein (SBP) which participates in the uptake of glutamic acid in Corynebacterium glutamicum, a Gram-positive bacterium. It is part of an ATP-binding cassette (ABC) transporter system. Together with the transmembrane proteins GluC and GluD and the cytoplasmic protein GluA, which couples the hydrolysis of ATP to the translocation of glutamate, they form a highly active glutamate-uptake system. As part of efforts to study the amino-acid metabolism, especially the metabolism of glutamic acid by C. glutamicum, a bacterium that is widely used in the industrial production of glutamic acid, the GluB protein was expressed, purified and crystallized, an X-ray diffraction data set was collected to a resolution of 1.9 Å and preliminary crystallographic analysis was performed. The crystal belonged to space group P3 1 21 or P3 2 21, with unit-cell parameters a = b = 82.50, c = 72.69 Å

  19. Transcriptomic Changes in Response to Putrescine Production in Metabolically Engineered Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Zhen Li

    2017-10-01

    Full Text Available Putrescine is widely used in industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Although engineered Corynebacterium glutamicum has been successfully used to produce high levels of putrescine, the overall cellular physiological and metabolic changes caused by overproduction of putrescine remains unclear. To reveal the transcriptional changes that occur in response to putrescine production in an engineered C. glutamicum strain, a comparative transcriptomic analysis was carried out. Overproduction of putrescine resulted in transcriptional downregulation of genes involved in glycolysis; the TCA cycle, pyruvate degradation, biosynthesis of some amino acids, oxidative phosphorylation; vitamin biosynthesis (thiamine and vitamin 6, metabolism of purine, pyrimidine and sulfur, and ATP-, NAD-, and NADPH-consuming enzymes. The transcriptional levels of genes involved in ornithine biosynthesis and NADPH-forming related enzymes were significantly upregulated in the putrescine producing C. glutamicum strain PUT-ALE. Comparative transcriptomic analysis provided some genetic modification strategies to further improve putrescine production. Repressing ATP- and NADPH-consuming enzyme coding gene expression via CRISPRi enhanced putrescine production.

  20. Analysis of different DNA fragments of Corynebacterium glutamicum complementing dapE of Escherichia coli.

    Science.gov (United States)

    Wehrmann, A; Eggeling, L; Sahm, H

    1994-12-01

    In Corynebacterium glutamicum L-lysine is synthesized simultaneously via the succinylase and dehydrogenase variant of the diaminopimelate pathway. Starting from a strain with a disrupted dehydrogenase gene, three different-sized DNA fragments were isolated which complemented defective Escherichia coli mutants in the succinylase pathway. Enzyme studies revealed that in one case the dehydrogenase gene had apparently been reconstituted in the heterologous host. The two other fragments resulted in desuccinylase activity; one of them additionally in succinylase activity. However, the physical analysis showed that structural changes had taken place in all fragments. Using a probe derived from one of the fragments we isolated a 3.4 kb BamHI DNA fragment without selective pressure (by colony hybridization). This was structurally intact and proved functionally to result in tenfold desuccinylase overexpression. The nucleotide sequence of a 1966 bp fragment revealed the presence of one truncated open reading frame of unknown function and that of dapE encoding N-succinyl diaminopimelate desuccinylase (EC 3.5.1.18). The deduced amino acid sequence of the dapE gene product shares 23% identical residues with that from E. coli. The C. glutamicum gene now available is the first gene from the succinylase branch of lysine synthesis of this biotechnologically important organism.

  1. Aggregative adherent strains of Corynebacterium pseudodiphtheriticum enter and survive within HEp-2 epithelial cells

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    Monica Cristina de Souza

    2012-06-01

    Full Text Available Corynebacterium pseudodiphtheriticum is a well-known human pathogen that mainly causes respiratory disease and is associated with high mortality in compromised hosts. Little is known about the virulence factors and pathogenesis of C. pseudodiphtheriticum. In this study, cultured human epithelial (HEp-2 cells were used to analyse the adherence pattern, internalisation and intracellular survival of the ATCC 10700 type strain and two additional clinical isolates. These microorganisms exhibited an aggregative adherence-like pattern to HEp-2 cells characterised by clumps of bacteria with a "stacked-brick" appearance. The differences in the ability of these microorganisms to invade and survive within HEp-2 cells and replicate in the extracellular environment up to 24 h post infection were evaluated. The fluorescent actin staining test demonstrated that actin polymerisation is involved in the internalisation of the C. pseudodiphtheriticum strains. The depolymerisation of microfilaments by cytochalasin E significantly reduced the internalisation of C. pseudodiphtheriticum by HEp-2 cells. Bacterial internalisation and cytoskeletal rearrangement seemed to be partially triggered by the activation of tyrosine kinase activity. Although C. pseudodiphtheriticum strains did not demonstrate an ability to replicate intracellularly, HEp-2 cells were unable to fully clear the pathogen within 24 h. These characteristics may explain how some C. pseudodiphtheriticum strains cause severe infection in human patients.

  2. Mural endocarditis caused by Corynebacterium mustelae in a dog with a VSD.

    Science.gov (United States)

    Winter, Randolph L; Gordon, Sonya G; Zhang, Shuping; Hariu, Crystal D; Miller, Matthew W

    2014-01-01

    A 6 yr old female spayed large Munsterlander was evaluated following a 3 wk history of lethargy, inappetence, intermittent fever, and a recent change to the timing of her previously diagnosed heart murmur. Physical examination revealed marked dehydration, lethargy, and a grade 5/6 to-and-fro heart murmur that was auscultated best at the right sternal border. The dog was febrile, and echocardiography revealed a large, mobile, vegetative lesion in the right ventricular outflow tract associated with a ventricular septal defect (VSD). Mild aortic insufficiency was present. Corynebacterium mustelae (C. mustelae) was isolated from a pooled blood culture. Treatment of infective endocarditis (IE) was initiated along with supportive care, and the patient was discharged 9 days later. The dog remained without clinical signs 132 days after discharge. VSD is rarely mentioned as a predisposing factor for development of IE in veterinary literature; however, this report highlights that dogs with a VSD may be at risk for IE. To the authors' knowledge, this is the first documented case of a canine infection with C. mustelae. Infection with C. mustelae in this case represents a novel agent for IE in the dog.

  3. Transcriptomic Changes in Response to Putrescine Production in Metabolically Engineered Corynebacterium glutamicum

    Science.gov (United States)

    Li, Zhen; Liu, Jian-Zhong

    2017-01-01

    Putrescine is widely used in industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Although engineered Corynebacterium glutamicum has been successfully used to produce high levels of putrescine, the overall cellular physiological and metabolic changes caused by overproduction of putrescine remains unclear. To reveal the transcriptional changes that occur in response to putrescine production in an engineered C. glutamicum strain, a comparative transcriptomic analysis was carried out. Overproduction of putrescine resulted in transcriptional downregulation of genes involved in glycolysis; the TCA cycle, pyruvate degradation, biosynthesis of some amino acids, oxidative phosphorylation; vitamin biosynthesis (thiamine and vitamin 6), metabolism of purine, pyrimidine and sulfur, and ATP-, NAD-, and NADPH-consuming enzymes. The transcriptional levels of genes involved in ornithine biosynthesis and NADPH-forming related enzymes were significantly upregulated in the putrescine producing C. glutamicum strain PUT-ALE. Comparative transcriptomic analysis provided some genetic modification strategies to further improve putrescine production. Repressing ATP- and NADPH-consuming enzyme coding gene expression via CRISPRi enhanced putrescine production. PMID:29089930

  4. Crystallization and preliminary X-ray diffraction studies of FAD synthetase from Corynebacterium ammoniagenes

    International Nuclear Information System (INIS)

    Herguedas, Beatriz; Martínez-Júlvez, Marta; Frago, Susana; Medina, Milagros; Hermoso, Juan A.

    2009-01-01

    Native and selenomethionine-labelled FAD synthetase from C. ammoniagenes have been crystallized by the hanging-drop vapour-diffusion method. A MAD data set for SeMet-labelled FAD synthetase was collected to 2.42 Å resolution, while data sets were collected to 1.95 Å resolution for the native crystals. FAD synthetase from Corynebacterium ammoniagenes (CaFADS), a prokaryotic bifunctional enzyme that catalyses the phosphorylation of riboflavin as well as the adenylylation of FMN, has been crystallized using the hanging-drop vapour-diffusion method at 277 K. Diffraction-quality cubic crystals of native and selenomethionine-labelled (SeMet-CaFADS) protein belonged to the cubic space group P2 1 3, with unit-cell parameters a = b = c = 133.47 Å and a = b = c = 133.40 Å, respectively. Data sets for native and SeMet-containing crystals were collected to 1.95 and 2.42 Å resolution, respectively

  5. Engineering biotin prototrophic Corynebacterium glutamicum strains for amino acid, diamine and carotenoid production.

    Science.gov (United States)

    Peters-Wendisch, P; Götker, S; Heider, S A E; Komati Reddy, G; Nguyen, A Q; Stansen, K C; Wendisch, V F

    2014-12-20

    The Gram-positive Corynebacterium glutamicum is auxotrophic for biotin. Besides the biotin uptake system BioYMN and the transcriptional regulator BioQ, this bacterium possesses functional enzymes for the last three reactions of biotin synthesis starting from pimeloyl-CoA. Heterologous expression of bioF from the Gram-negative Escherichia coli enabled biotin synthesis from pimelic acid added to the medium, but expression of bioF together with bioC and bioH from E. coli did not entail biotin prototrophy. Heterologous expression of bioWAFDBI from Bacillus subtilis encoding another biotin synthesis pathway in C. glutamicum allowed for growth in biotin-depleted media. Stable growth of the recombinant was observed without biotin addition for eight transfers to biotin-depleted medium while the empty vector control stopped growth after the first transfer. Expression of bioWAFDBI from B. subtilis in C. glutamicum strains overproducing the amino acids l-lysine and l-arginine, the diamine putrescine, and the carotenoid lycopene, respectively, enabled formation of these products under biotin-depleted conditions. Thus, biotin-prototrophic growth and production by recombinant C. glutamicum were achieved. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Metabolic engineering of Corynebacterium glutamicum aimed at alternative carbon sources and new products

    Directory of Open Access Journals (Sweden)

    Volker Fritz Wendisch

    2012-10-01

    Full Text Available Corynebacterium glutamicum is well known as the amino acid-producing workhorse of fermentation industry, being used for multi-million-ton scale production of glutamate and lysine for more than 60 years. However, it is only recently that extensive research has focused on engineering it beyond the scope of amino acids. Meanwhile, a variety of corynebacterial strains allows access to alternative carbon sources and/or allows production of a wide range of industrially relevant compounds. Some of these efforts set new standards in terms of titers and productivities achieved whereas others represent a proof-of-principle. These achievements manifest the position of C. glutamicum as an important industrial microorganism with capabilities far beyond the traditional amino acid production. In this review we focus on the state of the art of metabolic engineering of C. glutamicum for utilization of alternative carbon sources, (e.g. coming from wastes and unprocessed sources, and construction of C. glutamicum strains for production of new products such as diamines, organic acids and alcohols.

  7. Corynebacterium diphtheriae methionine sulfoxide reductase a exploits a unique mycothiol redox relay mechanism.

    Science.gov (United States)

    Tossounian, Maria-Armineh; Pedre, Brandán; Wahni, Khadija; Erdogan, Huriye; Vertommen, Didier; Van Molle, Inge; Messens, Joris

    2015-05-01

    Methionine sulfoxide reductases are conserved enzymes that reduce oxidized methionines in proteins and play a pivotal role in cellular redox signaling. We have unraveled the redox relay mechanisms of methionine sulfoxide reductase A of the pathogen Corynebacterium diphtheriae (Cd-MsrA) and shown that this enzyme is coupled to two independent redox relay pathways. Steady-state kinetics combined with mass spectrometry of Cd-MsrA mutants give a view of the essential cysteine residues for catalysis. Cd-MsrA combines a nucleophilic cysteine sulfenylation reaction with an intramolecular disulfide bond cascade linked to the thioredoxin pathway. Within this cascade, the oxidative equivalents are transferred to the surface of the protein while releasing the reduced substrate. Alternatively, MsrA catalyzes methionine sulfoxide reduction linked to the mycothiol/mycoredoxin-1 pathway. After the nucleophilic cysteine sulfenylation reaction, MsrA forms a mixed disulfide with mycothiol, which is transferred via a thiol disulfide relay mechanism to a second cysteine for reduction by mycoredoxin-1. With x-ray crystallography, we visualize two essential intermediates of the thioredoxin relay mechanism and a cacodylate molecule mimicking the substrate interactions in the active site. The interplay of both redox pathways in redox signaling regulation forms the basis for further research into the oxidative stress response of this pathogen. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Mastitis in dairy cattle caused by Corynebacterium pseudotuberculosis and the feasibility of transmission by houseflies. I.

    Science.gov (United States)

    Yeruham, I; Braverman, Y; Shpigel, N Y; Chizov-Ginzburg, A; Saran, A; Winkler, M

    1996-09-01

    Morbidity due to Corynebacterium pseudotuberculosis infection occurred in 29 dairy herds. The disease appeared basically in three clinical forms: cutaneous, mastitic, and visceral. The appearance of the disease showed a marked seasonality: in 23 herds it occurred during the spring and summer months (dry season) (March-October). The mastitic form occurred in only 10 herds and the causative bacterium was isolated from 33 cows (5.8%). All the strains of C. pseudotuberculosis isolated from the milk samples were found not to be nitrate reducers. The bacterium was excreted in the milk of six cows from herd B during a period of 11 months. In the mastitic cows, a decrease in milk production and considerable increases in the somatic cell count were noted. C. pseudotuberculosis was isolated from houseflies collected over a cow lesion. Laboratory-reared houseflies were successfully infected with C. pseudotuberculosis-contaminated milk, broth and sugar cubes. Flies infected with the bacterium from contaminated milk excreted the bacterium in their droppings for up to 4 h and from their saliva for up to 3 h post infection. The bacterium survived on the external organs of houseflies for no longer than 10 min post infection, after the flies had been dipped in contaminated broth.

  9. 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.

  10. Carrier state of Haemophilus influenzae type b (Hib, Streptococcus pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children in Pokhara, Nepal

    Directory of Open Access Journals (Sweden)

    Dharm Raj Bhatta

    2014-02-01

    Full Text Available Objective: To determine the incidence of carrier state of Haemophilus influenzae type b, Streptococcus pneumoniae (S. pneumoniae, Streptococcus pyogenes, Neisseria meningitidis and Corynebacterium diphtheriae among school children. Methods: Specimen from posterior pharyngeal wall and tonsils were collected on calcium alginate coated swabs from 1 02 participants. Processing of specimen and antimicrobial susceptibility testing was done by standard procedures. Results: Potential pathogens isolated in our study were S. pneumoniae (14.7%, Staphylococcus aureus (12.7%, Corynebacterium diphtheriae (3.9%, Streptococcus pyogenes (3.9% and Haemophilus influenzae (1.9%. Important findings in antibiogram include high resistance of S. pneumoniae to penicillin (73% and resistance of Staphylococcus aureus to oxacillin (23%. Conclusions: Pharyngeal colonization by S. pneumoniae among school children was found high and there is need of introduction of pneumococcal vaccines among children. Despite expected universal vaccination, pharyngeal colonization by Corynebacterium diphtheriae is possible and there is possibility of transmission.

  11. Cystic Neutrophilic Granulomatous Mastitis: Further Characterization of a Distinctive Histopathologic Entity Not Always Demonstrably Attributable to Corynebacterium Infection.

    Science.gov (United States)

    D'Alfonso, Timothy M; Moo, Tracy-Ann; Arleo, Elizabeth K; Cheng, Esther; Antonio, Lilian B; Hoda, Syed A

    2015-10-01

    Granulomatous lobular mastitis (GLM) is an uncommon condition that typically occurs in parous, reproductive-aged women and can simulate malignancy on the basis of clinical and imaging features. A distinctive histologic pattern termed cystic neutrophilic granulomatous mastitis (CNGM) is seen in some cases of GLM and has been associated with Corynebacterium infection. We sought to further characterize the clinical, imaging, and histopathologic features of CNGM by studying 12 cases and attempted to establish the relationship of this disease with Corynebacterium infection. Patients were women ranging in age from 25 to 49 years (median: 34 y), and all presented with a palpable mass that was painful in half of the cases. In 2 of 9 cases, imaging was highly suspicious for malignancy (BI-RADS 5). CNGM was characterized by lobulocentric granulomas with mixed inflammation and clear vacuoles lined by neutrophils within granulomas. Gram-positive bacilli were identified in 5/12 cases. In 4 patients, the disease process worsened after the diagnostic core biopsy, with the development of a draining sinus in 2 cases. No growth of bacteria was seen in any microbial cultures. No bacterial DNA was identified by 16S rDNA polymerase chain reaction for 1 case that showed gram-positive bacilli on histology. Patients were treated with variable combinations of surgery, antibiotics, and steroids. The time to significant resolution of symptoms ranged from 2 weeks to 6 months. Similar to other forms of GLM, CNGM can mimic malignancy clinically and on imaging. When encountered in a needle core biopsy sample, recognition of the characteristic histologic pattern and its possible association with Corynebacterium infection can help guide treatment.

  12. PcaO Positively Regulates pcaHG of the β-Ketoadipate Pathway in Corynebacterium glutamicum▿

    OpenAIRE

    Zhao, Ke-Xin; Huang, Yan; Chen, Xi; Wang, Nan-Xi; Liu, Shuang-Jiang

    2010-01-01

    We identified a new regulator, PcaO, which is involved in regulation of the protocatechuate (PCA) branch of the β-ketoadipate pathway in Corynebacterium glutamicum. PcaO is an atypical large ATP-binding LuxR family (LAL)-type regulator and does not have a Walker A motif. A mutant of C. glutamicum in which pcaO was disrupted (RES167ΔpcaO) was unable to grow on PCA, and growth on PCA was restored by complementation with pcaO. Both an enzymatic assay of PCA 3,4-dioxygenase activity (encoded by p...

  13. Systems metabolic engineering of Corynebacterium glutamicum for production of the chemical chaperone ectoine.

    Science.gov (United States)

    Becker, Judith; Schäfer, Rudolf; Kohlstedt, Michael; Harder, Björn J; Borchert, Nicole S; Stöveken, Nadine; Bremer, Erhard; Wittmann, Christoph

    2013-11-15

    The stabilizing and function-preserving effects of ectoines have attracted considerable biotechnological interest up to industrial scale processes for their production. These rely on the release of ectoines from high-salinity-cultivated microbial producer cells upon an osmotic down-shock in rather complex processor configurations. There is growing interest in uncoupling the production of ectoines from the typical conditions required for their synthesis, and instead design strains that naturally release ectoines into the medium without the need for osmotic changes, since the use of high-salinity media in the fermentation process imposes notable constraints on the costs, design, and durability of fermenter systems. Here, we used a Corynebacterium glutamicum strain as a cellular chassis to establish a microbial cell factory for the biotechnological production of ectoines. The implementation of a mutant aspartokinase enzyme ensured efficient supply of L-aspartate-beta-semialdehyde, the precursor for ectoine biosynthesis. We further engineered the genome of the basic C. glutamicum strain by integrating a codon-optimized synthetic ectABCD gene cluster under expressional control of the strong and constitutive C. glutamicum tuf promoter. The resulting recombinant strain produced ectoine and excreted it into the medium; however, lysine was still found as a by-product. Subsequent inactivation of the L-lysine exporter prevented the undesired excretion of lysine while ectoine was still exported. Using the streamlined cell factory, a fed-batch process was established that allowed the production of ectoine with an overall productivity of 6.7 g L(-1) day(-1) under growth conditions that did not rely on the use of high-salinity media. The present study describes the construction of a stable microbial cell factory for recombinant production of ectoine. We successfully applied metabolic engineering strategies to optimize its synthetic production in the industrial workhorse C

  14. Development of a CRISPR/Cas9 genome editing toolbox for Corynebacterium glutamicum.

    Science.gov (United States)

    Liu, Jiao; Wang, Yu; Lu, Yujiao; Zheng, Ping; Sun, Jibin; Ma, Yanhe

    2017-11-16

    Corynebacterium glutamicum is an important industrial workhorse and advanced genetic engineering tools are urgently demanded. Recently, the clustered regularly interspaced short palindromic repeats (CRISPR) and their CRISPR-associated proteins (Cas) have revolutionized the field of genome engineering. The CRISPR/Cas9 system that utilizes NGG as protospacer adjacent motif (PAM) and has good targeting specificity can be developed into a powerful tool for efficient and precise genome editing of C. glutamicum. Herein, we developed a versatile CRISPR/Cas9 genome editing toolbox for C. glutamicum. Cas9 and gRNA expression cassettes were reconstituted to combat Cas9 toxicity and facilitate effective termination of gRNA transcription. Co-transformation of Cas9 and gRNA expression plasmids was exploited to overcome high-frequency mutation of cas9, allowing not only highly efficient gene deletion and insertion with plasmid-borne editing templates (efficiencies up to 60.0 and 62.5%, respectively) but also simple and time-saving operation. Furthermore, CRISPR/Cas9-mediated ssDNA recombineering was developed to precisely introduce small modifications and single-nucleotide changes into the genome of C. glutamicum with efficiencies over 80.0%. Notably, double-locus editing was also achieved in C. glutamicum. This toolbox works well in several C. glutamicum strains including the widely-used strains ATCC 13032 and ATCC 13869. In this study, we developed a CRISPR/Cas9 toolbox that could facilitate markerless gene deletion, gene insertion, precise base editing, and double-locus editing in C. glutamicum. The CRISPR/Cas9 toolbox holds promise for accelerating the engineering of C. glutamicum and advancing its application in the production of biochemicals and biofuels.

  15. L-Serine overproduction with minimization of by-product synthesis by engineered Corynebacterium glutamicum.

    Science.gov (United States)

    Zhu, Qinjian; Zhang, Xiaomei; Luo, Yuchang; Guo, Wen; Xu, Guoqiang; Shi, Jinsong; Xu, Zhenghong

    2015-02-01

    The direct fermentative production of L-serine by Corynebacterium glutamicum from sugars is attractive. However, superfluous by-product accumulation and low L-serine productivity limit its industrial production on large scale. This study aimed to investigate metabolic and bioprocess engineering strategies towards eliminating by-products as well as increasing L-serine productivity. Deletion of alaT and avtA encoding the transaminases and introduction of an attenuated mutant of acetohydroxyacid synthase (AHAS) increased both L-serine production level (26.23 g/L) and its productivity (0.27 g/L/h). Compared to the parent strain, the by-products L-alanine and L-valine accumulation in the resulting strain were reduced by 87 % (from 9.80 to 1.23 g/L) and 60 % (from 6.54 to 2.63 g/L), respectively. The modification decreased the metabolic flow towards the branched-chain amino acids (BCAAs) and induced to shift it towards L-serine production. Meanwhile, it was found that corn steep liquor (CSL) could stimulate cell growth and increase sucrose consumption rate as well as L-serine productivity. With addition of 2 g/L CSL, the resulting strain showed a significant improvement in the sucrose consumption rate (72 %) and the L-serine productivity (67 %). In fed-batch fermentation, 42.62 g/L of L-serine accumulation was achieved with a productivity of 0.44 g/L/h and yield of 0.21 g/g sucrose, which was the highest production of L-serine from sugars to date. The results demonstrated that combined metabolic and bioprocess engineering strategies could minimize by-product accumulation and improve L-serine productivity.

  16. Promoter library-based module combination (PLMC) technology for optimization of threonine biosynthesis in Corynebacterium glutamicum.

    Science.gov (United States)

    Wei, Liang; Xu, Ning; Wang, Yiran; Zhou, Wei; Han, Guoqiang; Ma, Yanhe; Liu, Jun

    2018-05-01

    Due to the lack of efficient control elements and tools, the fine-tuning of gene expression in the multi-gene metabolic pathways is still a great challenge for engineering microbial cell factories, especially for the important industrial microorganism Corynebacterium glutamicum. In this study, the promoter library-based module combination (PLMC) technology was developed to efficiently optimize the expression of genes in C. glutamicum. A random promoter library was designed to contain the putative - 10 (NNTANANT) and - 35 (NNGNCN) consensus motifs, and refined through a three-step screening procedure to achieve numerous genetic control elements with different strength levels, including fluorescence-activated cell sorting (FACS) screening, agar plate screening, and 96-well plate screening. Multiple conventional strategies were employed for further precise characterizations of the promoter library, such as real-time quantitative PCR, sodium dodecyl sulfate polyacrylamide gel electrophoresis, FACS analysis, and the lacZ reporter system. These results suggested that the established promoter elements effectively regulated gene expression and showed varying strengths over a wide range. Subsequently, a multi-module combination technology was created based on the efficient promoter elements for combination and optimization of modules in the multi-gene pathways. Using this technology, the threonine biosynthesis pathway was reconstructed and optimized by predictable tuning expression of five modules in C. glutamicum. The threonine titer of the optimized strain was significantly improved to 12.8 g/L, an approximate 6.1-fold higher than that of the control strain. Overall, the PLMC technology presented in this study provides a rapid and effective method for combination and optimization of multi-gene pathways in C. glutamicum.

  17. Biosynthesis of rare ketoses through constructing a recombination pathway in an engineered Corynebacterium glutamicum.

    Science.gov (United States)

    Yang, Jiangang; Zhu, Yueming; Li, Jitao; Men, Yan; Sun, Yuanxia; Ma, Yanhe

    2015-01-01

    Rare sugars have various known biological functions and potential for applications in pharmaceutical, cosmetics, and food industries. Here we designed and constructed a recombination pathway in Corynebacterium glutamicum, in which dihydroxyacetone phosphate (DHAP), an intermediate of the glycolytic pathway, and a variety of aldehydes were condensed to synthesize rare ketoses sequentially by rhamnulose-1-phosphate aldolase (RhaD) and fructose-1-phosphatase (YqaB) obtained from Escherichia coli. A wild-type strain harboring this artificial pathway had the ability to produce D-sorbose and D-psicose using D-glyceraldehyde and glucose as the substrates. The tpi gene, encoding triose phosphate isomerase was further deleted, and the concentration of DHAP increased to nearly 20-fold relative to that of the wild-type. After additional optimization of expression levels from rhaD and yqaB genes and of the fermentation conditions, the engineered strain SY6(pVRTY) exhibited preferable performance for rare ketoses production. Its yield increased to 0.59 mol/mol D-glyceraldehyde from 0.33 mol/mol D-glyceraldehyde and productivity to 2.35 g/L h from 0.58 g/L h. Moreover, this strain accumulated 19.5 g/L of D-sorbose and 13.4 g/L of D-psicose using a fed-batch culture mode under the optimal conditions. In addition, it was verified that the strain SY6(pVRTY) meanwhile had the ability to synthesize C4, C5, C6, and C7 rare ketoses when a range of representative achiral and homochiral aldehydes were applied as the substrates. Therefore, the platform strain exhibited the potential for microbial production of rare ketoses and deoxysugars. © 2014 Wiley Periodicals, Inc.

  18. C1 Metabolism in Corynebacterium glutamicum: an Endogenous Pathway for Oxidation of Methanol to Carbon Dioxide

    Science.gov (United States)

    Witthoff, Sabrina; Mühlroth, Alice

    2013-01-01

    Methanol is considered an interesting carbon source in “bio-based” microbial production processes. Since Corynebacterium glutamicum is an important host in industrial biotechnology, in particular for amino acid production, we performed studies of the response of this organism to methanol. The C. glutamicum wild type was able to convert 13C-labeled methanol to 13CO2. Analysis of global gene expression in the presence of methanol revealed several genes of ethanol catabolism to be upregulated, indicating that some of the corresponding enzymes are involved in methanol oxidation. Indeed, a mutant lacking the alcohol dehydrogenase gene adhA showed a 62% reduced methanol consumption rate, indicating that AdhA is mainly responsible for methanol oxidation to formaldehyde. Further studies revealed that oxidation of formaldehyde to formate is catalyzed predominantly by two enzymes, the acetaldehyde dehydrogenase Ald and the mycothiol-dependent formaldehyde dehydrogenase AdhE. The Δald ΔadhE and Δald ΔmshC deletion mutants were severely impaired in their ability to oxidize formaldehyde, but residual methanol oxidation to CO2 was still possible. The oxidation of formate to CO2 is catalyzed by the formate dehydrogenase FdhF, recently identified by us. Similar to the case with ethanol, methanol catabolism is subject to carbon catabolite repression in the presence of glucose and is dependent on the transcriptional regulator RamA, which was previously shown to be essential for expression of adhA and ald. In conclusion, we were able to show that C. glutamicum possesses an endogenous pathway for methanol oxidation to CO2 and to identify the enzymes and a transcriptional regulator involved in this pathway. PMID:24014532

  19. Utilization of fermentation waste (Corynebacterium glutamicum) for biosorption of Reactive Black 5 from aqueous solution

    International Nuclear Information System (INIS)

    Vijayaraghavan, K.; Yun, Yeoung-Sang

    2007-01-01

    A fermentation waste, Corynebacterium glutamicum, was successfully employed as a biosorbent for Reactive Black 5 (RB5) from aqueous solution. This paper initially studied the effect of pretreatment on the biosorption capacity of C. glutamicum toward RB5, using several chemical agents, such as HCl, H 2 SO 4 , HNO 3 , NaOH, Na 2 CO 3 , CaCl 2 and NaCl. Among these reagents, 0.1 M HNO 3 gave the maximum enhancement of the RB5 uptake, exhibiting 195 mg/g at pH 1 with an initial RB5 concentration of 500 mg/l. The solution pH and temperature were found to affect the biosorption capacity, and the biosorption isotherms derived at different pHs and temperatures revealed that a low pH (pH 1) and high temperature (35 deg. C) favored biosorption. The biosorption isotherm was well represented using three-parameter models (Redlich-Peterson and Sips) compared to two-parameter models (Langmuir and Freundlich models). As a result, high correlation coefficients and low average percentage error values were observed for three-parameter models. A maximum RB5 uptake of 419 mg/g was obtained at pH 1 and a temperature of 35 deg. C, according to the Langmuir model. The kinetics of the biosorption process with different initial concentrations (500-2000 mg/l) was also monitored, and the data were analyzed using pseudo-first and pseudo-second order models, with the latter describing the data well. Various thermodynamic parameters, such as ΔG o , ΔH o and ΔS o , were calculated, indicating that the present system was a spontaneous and endothermic process. The use of a 0.1 M NaOH solution successfully desorbed almost all the dye molecules from dye-loaded C. glutamicum biomass at different solid-to-liquid ratios examined

  20. Transcriptome and Multivariable Data Analysis of Corynebacterium glutamicum under Different Dissolved Oxygen Conditions in Bioreactors

    Science.gov (United States)

    Sun, Yang; Guo, Wenwen; Wang, Fen; Peng, Feng; Yang, Yankun; Dai, Xiaofeng; Liu, Xiuxia; Bai, Zhonghu

    2016-01-01

    Dissolved oxygen (DO) is an important factor in the fermentation process of Corynebacterium glutamicum, which is a widely used aerobic microbe in bio-industry. Herein, we described RNA-seq for C. glutamicum under different DO levels (50%, 30% and 0%) in 5 L bioreactors. Multivariate data analysis (MVDA) models were used to analyze the RNA-seq and metabolism data to investigate the global effect of DO on the transcriptional distinction of the substance and energy metabolism of C. glutamicum. The results showed that there were 39 and 236 differentially expressed genes (DEGs) under the 50% and 0% DO conditions, respectively, compared to the 30% DO condition. Key genes and pathways affected by DO were analyzed, and the result of the MVDA and RNA-seq revealed that different DO levels in the fermenter had large effects on the substance and energy metabolism and cellular redox balance of C. glutamicum. At low DO, the glycolysis pathway was up-regulated, and TCA was shunted by the up-regulation of the glyoxylate pathway and over-production of amino acids, including valine, cysteine and arginine. Due to the lack of electron-acceptor oxygen, 7 genes related to the electron transfer chain were changed, causing changes in the intracellular ATP content at 0% and 30% DO. The metabolic flux was changed to rebalance the cellular redox. This study applied deep sequencing to identify a wealth of genes and pathways that changed under different DO conditions and provided an overall comprehensive view of the metabolism of C. glutamicum. The results provide potential ways to improve the oxygen tolerance of C. glutamicum and to modify the metabolic flux for amino acid production and heterologous protein expression. PMID:27907077

  1. The Druggable Pocketome of Corynebacterium diphtheriae: A New Approach for in silico Putative Druggable Targets

    Science.gov (United States)

    Hassan, Syed S.; Jamal, Syed B.; Radusky, Leandro G.; Tiwari, Sandeep; Ullah, Asad; Ali, Javed; Behramand; de Carvalho, Paulo V. S. D.; Shams, Rida; Khan, Sabir; Figueiredo, Henrique C. P.; Barh, Debmalya; Ghosh, Preetam; Silva, Artur; Baumbach, Jan; Röttger, Richard; Turjanski, Adrián G.; Azevedo, Vasco A. C.

    2018-01-01

    Diphtheria is an acute and highly infectious disease, previously regarded as endemic in nature but vaccine-preventable, is caused by Corynebacterium diphtheriae (Cd). In this work, we used an in silico approach along the 13 complete genome sequences of C. diphtheriae followed by a computational assessment of structural information of the binding sites to characterize the “pocketome druggability.” To this end, we first computed the “modelome” (3D structures of a complete genome) of a randomly selected reference strain Cd NCTC13129; that had 13,763 open reading frames (ORFs) and resulted in 1,253 (∼9%) structure models. The amino acid sequences of these modeled structures were compared with the remaining 12 genomes and consequently, 438 conserved protein sequences were obtained. The RCSB-PDB database was consulted to check the template structures for these conserved proteins and as a result, 401 adequate 3D models were obtained. We subsequently predicted the protein pockets for the obtained set of models and kept only the conserved pockets that had highly druggable (HD) values (137 across all strains). Later, an off-target host homology analyses was performed considering the human proteome using NCBI database. Furthermore, the gene essentiality analysis was carried out that gave a final set of 10-conserved targets possessing highly druggable protein pockets. To check the target identification robustness of the pipeline used in this work, we crosschecked the final target list with another in-house target identification approach for C. diphtheriae thereby obtaining three common targets, these were; hisE-phosphoribosyl-ATP pyrophosphatase, glpX-fructose 1,6-bisphosphatase II, and rpsH-30S ribosomal protein S8. Our predicted results suggest that the in silico approach used could potentially aid in experimental polypharmacological target determination in C. diphtheriae and other pathogens, thereby, might complement the existing and new drug-discovery pipelines

  2. Technetium-99m labeling and fibronectin binding ability of Corynebacterium diphtheriae

    International Nuclear Information System (INIS)

    Souza, S.M.S.; Nagao, P.E.; Bernardo-Filho, M.; Pereira, G.A.; Napoleao, F.; Andrade, A.F.B.; Hirata Junior, R.; Mattos-Guaraldi, A.L.

    2004-01-01

    The use of radionuclides has permitted advances in areas of clinical and scientific knowledge. Several molecules and cells have been labelled with Technetium-99m ( 99m Tc). The stannous chloride (SnCl 2 ) has a significant influence on the labeling and stability of 99m Tc radiotracers. The frequent risk of diphtheria epidemics has intensified interest in the virulence factors of Corynebacterium diphtheriae. Although studies have looked at potential adhesins including haemagglutinins and exposed sugar residues, the molecular basis of mechanisms of adherence remains unclear. Adherence of pathogens to mammalian tissues may be mediated by fibronectin (FN) found in body fluids, matrix of connective tissues, and cell surfaces. In the present study we evaluated the binding ability to human plasma FN by 99m Tc labeled-C.diphtheriae. Due to adverse effects of stannous ions, microorganisms were submitted to survival and filamentation induction assays. Data showed a dose dependent susceptibility to SnCl 2 bactericidal effects. Cell filamentation was observed for concentrations of SnCl 2 > 110 μg/ml. Adherence levels of 99m Tc labelled 241strain to coverslips coated with 20 μg/ml FN were higher (P = 0.0037) than coated with bovine serum albumin. FN binding by the sucrose fermenting 241 C. diphtheriae strain (8.9% + 2.6) was significantly lower (P=0.0139) than Staphylococcus aureus Cowan I strain (34.1% ± 1.2). Therefore, bacterial 99m Tc labeling represents an additional tool that may contribute to the comprehension of C. diphtheriae interactions with host receptors such as FN that act as biological organizers by holding bacterial cells in position and guiding their migration. (author)

  3. Effects of phosphoenolpyruvate carboxylase desensitization on glutamic acid production in Corynebacterium glutamicum ATCC 13032.

    Science.gov (United States)

    Wada, Masaru; Sawada, Kazunori; Ogura, Kotaro; Shimono, Yuta; Hagiwara, Takuya; Sugimoto, Masakazu; Onuki, Akiko; Yokota, Atsushi

    2016-02-01

    Phosphoenolpyruvate carboxylase (PEPC) in Corynebacterium glutamicum ATCC13032, a glutamic-acid producing actinobacterium, is subject to feedback inhibition by metabolic intermediates such as aspartic acid and 2-oxoglutaric acid, which implies the importance of PEPC in replenishing oxaloacetic acid into the TCA cycle. Here, we investigated the effects of feedback-insensitive PEPC on glutamic acid production. A single amino-acid substitution in PEPC, D299N, was found to relieve the feedback control by aspartic acid, but not by 2-oxoglutaric acid. A simple mutant, strain R1, having the D299N substitution in PEPC was constructed from ATCC 13032 using the double-crossover chromosome replacement technique. Strain R1 produced glutamic acid at a concentration of 31.0 g/L from 100 g/L glucose in a jar fermentor culture under biotin-limited conditions, which was significantly higher than that of the parent, 26.0 g/L (1.19-fold), indicative of the positive effect of desensitized PEPC on glutamic acid production. Another mutant, strain DR1, having both desensitized PEPC and PYK-gene deleted mutations, was constructed in a similar manner using strain D1 with a PYK-gene deleted mutation as the parent. This mutation had been shown to enhance glutamic acid production in our previous study. Although marginal, strain D1 produced higher glutamic acid, 28.8 g/L, than ATCC13032 (1.11-fold). In contrast, glutamic acid production by strain DR-1 was elevated up to 36.9 g/L, which was 1.42-fold higher than ATCC13032 and significantly higher than the other three strains. The results showed a synergistic effect of these two mutations on glutamic acid production in C. glutamicum. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  4. Enhanced production of recombinant proteins with Corynebacterium glutamicum by deletion of insertion sequences (IS elements).

    Science.gov (United States)

    Choi, Jae Woong; Yim, Sung Sun; Kim, Min Jeong; Jeong, Ki Jun

    2015-12-29

    In most bacteria, various jumping genetic elements including insertion sequences elements (IS elements) cause a variety of genetic rearrangements resulting in harmful effects such as genome and recombinant plasmid instability. The genetic stability of a plasmid in a host is critical for high-level production of recombinant proteins, and in this regard, the development of an IS element-free strain could be a useful strategy for the enhanced production of recombinant proteins. Corynebacterium glutamicum, which is a workhorse in the industrial-scale production of various biomolecules including recombinant proteins, also has several IS elements, and it is necessary to identify the critical IS elements and to develop IS element deleted strain. From the cultivation of C. glutamicum harboring a plasmid for green fluorescent protein (GFP) gene expression, non-fluorescent clones were isolated by FACS (fluorescent activated cell sorting). All the isolated clones had insertions of IS elements in the GFP coding region, and two major IS elements (ISCg1 and ISCg2 families) were identified. By co-cultivating cells harboring either the isolated IS element-inserted plasmid or intact plasmid, it was clearly confirmed that cells harboring the IS element-inserted plasmids became dominant during the cultivation due to their growth advantage over cells containing intact plasmids, which can cause a significant reduction in recombinant protein production during cultivation. To minimize the harmful effects of IS elements on the expression of heterologous genes in C. glutamicum, two IS element free C. glutamicum strains were developed in which each major IS element was deleted, and enhanced productivity in the engineered C. glutamicum strain was successfully demonstrated with three models: GFP, poly(3-hydroxybutyrate) [P(3HB)] and γ-aminobutyrate (GABA). Our findings clearly indicate that the hopping of IS elements could be detrimental to the production of recombinant proteins in C

  5. Metabolic engineering of Corynebacterium glutamicum to produce GDP-L-fucose from glucose and mannose.

    Science.gov (United States)

    Chin, Young-Wook; Park, Jin-Byung; Park, Yong-Cheol; Kim, Kyoung Heon; Seo, Jin-Ho

    2013-06-01

    Wild-type Corynebacterium glutamicum was metabolically engineered to convert glucose and mannose into guanosine 5'-diphosphate (GDP)-L-fucose, a precursor of fucosyl-oligosaccharides, which are involved in various biological and pathological functions. This was done by introducing the gmd and wcaG genes of Escherichia coli encoding GDP-D-mannose-4,6-dehydratase and GDP-4-keto-6-deoxy-D-mannose-3,5-epimerase-4-reductase, respectively, which are known as key enzymes in the production of GDP-L-fucose from GDP-D-mannose. Coexpression of the genes allowed the recombinant C. glutamicum cells to produce GDP-L-fucose in a minimal medium containing glucose and mannose as carbon sources. The specific product formation rate was much higher during growth on mannose than on glucose. In addition, the specific product formation rate was further increased by coexpressing the endogenous phosphomanno-mutase gene (manB) and GTP-mannose-1-phosphate guanylyl-transferase gene (manC), which are involved in the conversion of mannose-6-phosphate into GDP-D-mannose. However, the overexpression of manA encoding mannose-6-phosphate isomerase, catalyzing interconversion of mannose-6-phosphate and fructose-6-phosphate showed a negative effect on formation of the target product. Overall, coexpression of gmd, wcaG, manB and manC in C. glutamicum enabled production of GDP-L-fucose at the specific rate of 0.11 mg g cell(-1) h(-1). The specific GDP-L-fucose content reached 5.5 mg g cell(-1), which is a 2.4-fold higher than that of the recombinant E. coli overexpressing gmd, wcaG, manB and manC under comparable conditions. Well-established metabolic engineering tools may permit optimization of the carbon and cofactor metabolisms of C. glutamicum to further improve their production capacity.

  6. Selection and Characterization of a Lysine Yielding Mutant of Corynebacterium glutamicum - a Soil Isolate from Pakistan

    Directory of Open Access Journals (Sweden)

    Habib-ur-Rehman§٭, Abdul Hameed and Safia Ahmed

    2012-01-01

    Full Text Available L-lysine is the second limiting amino acid for poultry and supplemented in broiler feed for optimal performance. Lysine can be produced by inducing mutation in glutamate producing bacteria. The study was conducted to enhance lysine production from a local strain of Corynebacterium glutamicum. The bacterium was mutated by exposure to UV. Mutants resistant to s-2-aminoethyle L-cystein (AEC and showing auxotrophy for L-homoserine were screened for lysine production qualitatively and quantitatively. A mutant showing highest production of lysine (8.2 mg/mL was selected for optimization of physical and nutritional parameters for maximum production of lysine in shake flask. An initial pH 7.6, 30˚C temperature, 300 rpm and 60 h incubation time were the optimized values of physical requirements. Cane molasses and corn starch hydrolysate were required at 15% (w/v in the fermentation media which provided around 9% total sugars to produce maximum lysine (17 to 18 mg/mL. When amonium sulphate was used at 3.5% (w/v level in molasses or corn starch hydrolysate based fermentation media, production of lysine slightly increased above 18 mg/mL. It is concluded that industrial by products like cane molasses, corn steep liquor, and corn starch hydrolysate can be used as carbon and organic nitrogen sources in fermentation medium for scale up process of lysine production and this lysine enriched broth may be used in broiler feed later. However, more potent lysine producing mutant and additional in vivo trials would be required to commercialize this product.

  7. Metabolic evolution and a comparative omics analysis of Corynebacterium glutamicum for putrescine production.

    Science.gov (United States)

    Li, Zhen; Shen, Yu-Ping; Jiang, Xuan-Long; Feng, Li-Shen; Liu, Jian-Zhong

    2018-02-01

    Putrescine is widely used in the industrial production of bioplastics, pharmaceuticals, agrochemicals, and surfactants. Because the highest titer of putrescine is much lower than that of its precursor L-ornithine reported in microorganisms to date, further work is needed to increase putrescine production in Corynebacterium glutamicum. We first compared 7 ornithine decarboxylase genes and found that the Enterobacter cloacae ornithine decarboxylase gene speC1 was most suitable for putrescine production in C. glutamicum. Increasing NADPH availability and blocking putrescine oxidation and acetylation were chosen as targets for metabolic engineering. The putrescine producer C. glutamicum PUT4 was first constructed by deleting puo, butA and snaA genes, and replacing the fabG gene with E. cloacae speC1. After adaptive evolution with C. glutamicum PUT4, the evolved strain C. glutamicum PUT-ALE, which produced an 96% higher amount of putrescine compared to the parent strain, was obtained. The whole genome resequencing indicates that the SNPs located in the odhA coding region may be associated with putrescine production. The comparative proteomic analysis reveals that the pentose phosphate and anaplerotic pathway, the glyoxylate cycle, and the ornithine biosynthetic pathway were upregulated in the evolved strain C. glutamicum PUT-ALE. The aspartate family, aromatic, and branched chain amino acid and fatty acid biosynthetic pathways were also observed to be downregulated in C. glutamicum PUT-ALE. Reducing OdhA activity by replacing the odhA native start codon GTG with TTG and overexpression of cgmA or pyc458 further improved putrescine production. Repressing the carB, ilvH, ilvB and aroE expression via CRISPRi also increased putrescine production by 5, 9, 16 and 19%, respectively.

  8. Systems-wide metabolic pathway engineering in Corynebacterium glutamicum for bio-based production of diaminopentane.

    Science.gov (United States)

    Kind, Stefanie; Jeong, Weol Kyu; Schröder, Hartwig; Wittmann, Christoph

    2010-07-01

    In the present work the Gram-positive bacterium Corynebacterium glutamicum was engineered into an efficient, tailor-made production strain for diaminopentane (cadaverine), a highly attractive building block for bio-based polyamides. The engineering comprised expression of lysine decarboxylase (ldcC) from Escherichia coli, catalyzing the conversion of lysine into diaminopentane, and systems-wide metabolic engineering of central supporting pathways. Substantially re-designing the metabolism yielded superior strains with desirable properties such as (i) the release from unwanted feedback regulation at the level of aspartokinase and pyruvate carboxylase by introducing the point mutations lysC311 and pycA458, (ii) an optimized supply of the key precursor oxaloacetate by amplifying the anaplerotic enzyme, pyruvate carboxylase, and deleting phosphoenolpyruvate carboxykinase which otherwise removes oxaloacetate, (iii) enhanced biosynthetic flux via combined amplification of aspartokinase, dihydrodipicolinate reductase, diaminopimelate dehydrogenase and diaminopimelate decarboxylase, and (iv) attenuated flux into the threonine pathway competing with production by the leaky mutation hom59 in the homoserine dehydrogenase gene. Lysine decarboxylase proved to be a bottleneck for efficient production, since its in vitro activity and in vivo flux were closely correlated. To achieve an optimal strain having only stable genomic modifications, the combination of the strong constitutive C. glutamicum tuf promoter and optimized codon usage allowed efficient genome-based ldcC expression and resulted in a high diaminopentane yield of 200 mmol mol(-1). By supplementing the medium with 1 mgL(-1) pyridoxal, the cofactor of lysine decarboxylase, the yield was increased to 300 mmol mol(-1). In the production strain obtained, lysine secretion was almost completely abolished. Metabolic analysis, however, revealed substantial formation of an as yet unknown by-product. It was identified as an

  9. Surveillance of a Ventilated Rack System for Corynebacterium bovis by Sampling Exhaust-Air Manifolds.

    Science.gov (United States)

    Manuel, Christopher A; Pugazhenthi, Umarani; Leszczynski, Jori K

    2016-01-01

    Corynebacterium bovis causes an opportunistic infection of nude (Foxn1, nu/nu) mice, leading to nude mouse hyperkeratotic dermatitis (scaly skin disease). Enzootic in many nude mouse colonies, C. bovis spreads rapidly to naive nude mice, despite modern husbandry practices, and is very difficult to eradicate. To facilitate rapid detection in support of eradication efforts, we investigated a surveillance method based on quantitative real-time PCR (qPCR) evaluation of swabs collected from the horizontal exhaust manifold (HEM) of an IVC rack system. We first evaluated the efficacy of rack sanitation methods for removing C. bovis DNA from the HEM of racks housing endemic colonies of infected nude mice. Pressurized water used to flush the racks' air exhaust system followed by a standard rack-washer cycle was ineffective in eliminating C. bovis DNA. Only after autoclaving did all sanitized racks test negative for C. bovis DNA. We then measured the effects of stage of infection (early or established), cage density, and cage location on the rack on time-to-detection at the HEM. Stage of infection significantly affected time-to-detection, independent of cage location. Early infections required 7.3 ± 1.2 d whereas established infections required 1 ± 0 d for detection of C. bovis at the HEM. Cage density influenced the quantity of C. bovis DNA detected but not time-to-detection. The location of the cage on the rack affected the time-to-detection only during early C. bovis infections. We suggest that qPCR swabs of HEM are useful during the routine surveillance of nude mouse colonies for C. bovis infection.

  10. An integrative in-silico approach for therapeutic target identification in the human pathogen Corynebacterium diphtheriae.

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    Syed Babar Jamal

    Full Text Available Corynebacterium diphtheriae (Cd is a Gram-positive human pathogen responsible for diphtheria infection and once regarded for high mortalities worldwide. The fatality gradually decreased with improved living standards and further alleviated when many immunization programs were introduced. However, numerous drug-resistant strains emerged recently that consequently decreased the efficacy of current therapeutics and vaccines, thereby obliging the scientific community to start investigating new therapeutic targets in pathogenic microorganisms. In this study, our contributions include the prediction of modelome of 13 C. diphtheriae strains, using the MHOLline workflow. A set of 463 conserved proteins were identified by combining the results of pangenomics based core-genome and core-modelome analyses. Further, using subtractive proteomics and modelomics approaches for target identification, a set of 23 proteins was selected as essential for the bacteria. Considering human as a host, eight of these proteins (glpX, nusB, rpsH, hisE, smpB, bioB, DIP1084, and DIP0983 were considered as essential and non-host homologs, and have been subjected to virtual screening using four different compound libraries (extracted from the ZINC database, plant-derived natural compounds and Di-terpenoid Iso-steviol derivatives. The proposed ligand molecules showed favorable interactions, lowered energy values and high complementarity with the predicted targets. Our proposed approach expedites the selection of C. diphtheriae putative proteins for broad-spectrum development of novel drugs and vaccines, owing to the fact that some of these targets have already been identified and validated in other organisms.

  11. Distinct roles of two anaplerotic pathways in glutamate production induced by biotin limitation in Corynebacterium glutamicum.

    Science.gov (United States)

    Sato, Hiroki; Orishimo, Keita; Shirai, Tomokazu; Hirasawa, Takashi; Nagahisa, Keisuke; Shimizu, Hiroshi; Wachi, Masaaki

    2008-07-01

    Corynebacterium glutamicum is a biotin auxotrophic bacterium in which glutamate production is induced under biotin-limited conditions. During glutamate production, anaplerotic reactions catalyzed by phosphoenolpyruvate carboxylase (PEPC) and a biotin-containing enzyme pyruvate carboxylase (PC) are believed to play an important role in supplying oxaloacetate in the tricarboxylic acid cycle. To understand the distinct roles of PEPC and PC on glutamate production by C. glutamicum, we observed glutamate production induced under biotin-limited conditions in the disruptants of the genes encoding PEPC (ppc) and PC (pyc), respectively. The pyc disruptant retained the ability to produce high amounts of glutamate, and lactate was simultaneously produced probably due to the increased intracellular pyruvate levels. On the other hand, the ppc knockout mutant could not produce glutamate. Additionally, glutamate production in the pyc disruptant was enhanced by overexpression of ppc rather than disruption of the lactate dehydrogenase gene (ldh), which is involved in lactate production. Metabolic flux analysis based on the 13C-labeling experiment and measurement of 13C-enrichment in glutamate using nuclear magnetic resonance spectroscopy revealed that the flux for anaplerotic reactions in the pyc disruptant was lower than that in the wild type, concomitantly increasing the flux for lactate formation. Moreover, overexpression of ppc increased this flux in both the pyc disruptant and the wild type. Our results suggest that the PEPC-catalyzed anaplerotic reaction is necessary for glutamate production induced under biotin-limited conditions, because PC is not active during glutamate production, and overexpression of ppc effectively enhances glutamate production under biotin-limited conditions.

  12. Biotin protein ligase from Corynebacterium glutamicum: role for growth and L: -lysine production.

    Science.gov (United States)

    Peters-Wendisch, P; Stansen, K C; Götker, S; Wendisch, V F

    2012-03-01

    Corynebacterium glutamicum is a biotin auxotrophic Gram-positive bacterium that is used for large-scale production of amino acids, especially of L-glutamate and L-lysine. It is known that biotin limitation triggers L-glutamate production and that L-lysine production can be increased by enhancing the activity of pyruvate carboxylase, one of two biotin-dependent proteins of C. glutamicum. The gene cg0814 (accession number YP_225000) has been annotated to code for putative biotin protein ligase BirA, but the protein has not yet been characterized. A discontinuous enzyme assay of biotin protein ligase activity was established using a 105aa peptide corresponding to the carboxyterminus of the biotin carboxylase/biotin carboxyl carrier protein subunit AccBC of the acetyl CoA carboxylase from C. glutamicum as acceptor substrate. Biotinylation of this biotin acceptor peptide was revealed with crude extracts of a strain overexpressing the birA gene and was shown to be ATP dependent. Thus, birA from C. glutamicum codes for a functional biotin protein ligase (EC 6.3.4.15). The gene birA from C. glutamicum was overexpressed and the transcriptome was compared with the control strain revealing no significant gene expression changes of the bio-genes. However, biotin protein ligase overproduction increased the level of the biotin-containing protein pyruvate carboxylase and entailed a significant growth advantage in glucose minimal medium. Moreover, birA overexpression resulted in a twofold higher L-lysine yield on glucose as compared with the control strain.

  13. Isoprenoid Pyrophosphate-Dependent Transcriptional Regulation of Carotenogenesis in Corynebacterium glutamicum

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    Petra Peters-Wendisch

    2017-04-01

    Full Text Available Corynebacterium glutamicum is a natural producer of the C50 carotenoid decaprenoxanthin. The crtEcg0722crtBIYEb operon comprises most of its genes for terpenoid biosynthesis. The MarR-type regulator encoded upstream and in divergent orientation of the carotenoid biosynthesis operon has not yet been characterized. This regulator, named CrtR in this study, is encoded in many actinobacterial genomes co-occurring with terpenoid biosynthesis genes. CrtR was shown to repress the crt operon of C. glutamicum since DNA microarray experiments revealed that transcript levels of crt operon genes were increased 10 to 70-fold in its absence. Transcriptional fusions of a promoter-less gfp gene with the crt operon and crtR promoters confirmed that CrtR represses its own gene and the crt operon. Gel mobility shift assays with purified His-tagged CrtR showed that CrtR binds to a region overlapping with the −10 and −35 promoter sequences of the crt operon. Isoprenoid pyrophosphates interfered with binding of CrtR to its target DNA, a so far unknown mechanism for regulation of carotenogenesis. The molecular details of protein-ligand interactions remain to be studied. Decaprenoxanthin synthesis by C. glutamicum wild type was enhanced 10 to 30-fold upon deletion of crtR and was decreased 5 to 6-fold as result of crtR overexpression. Moreover, deletion of crtR was shown as metabolic engineering strategy to improve production of native and non-native carotenoids including lycopene, β-carotene, C.p. 450 and sarcinaxanthin.

  14. Implantation of Corynebacterium pseudodiphtheriticum for elimination of Staphylococcus aureus from the nasal cavity in volunteers

    Science.gov (United States)

    Viacheslav, Ilyin; Kiryukhina, Nataliya

    Nasal carriage of Staphylococcus aureus is a well-documented risk factor of infection and inflammation of the skin, soft tissues and bacteremia. It is also known that most often etiology of these disorders is associated with autoinfection. The present-day methods of opportunistic pathogens eradication from the nasal cavity are based principally on the use of antiseptic and antibacterial agents. For instance, a local antibiotic mupirocin in the form of nasal ointment is considered to be the gold standard for the treatment of S. aureus carriage. The literature describes investigations showing how mupirocin can strengthen antibiotic resistance in S. aureus strains, including those with methicillin resistance (MRSA). It is also common knowledge that recolonization of the nasal mucous membrane takes place within several months after mupirocin treatment. This circumstance dictates the necessity to look for alternative ways of preventing the S. aureus carriage and methods of elimination. One of the methods of nasal S. aureus elimination is implantation of nonpathogenic microorganisms which will extrude opportunistic pathogens without impinging the symbiotic microbiota. Effectiveness of saline suspension of Corynebacterium pseudodiphtheriticum containing spray was assessed in a several chamber experiments with simulation of some spaceflight factors (dry immersion, isolation). Various schemes of application of preparations were applied. In all cases of corynebacteria application the strong inhibiting effect against S. aureus was detected. This fact opens a prospect of using nonpathogenic corynebacteria as a nasal probiotic. Administration of the nasal corynebacteria spray possibly prevented cross-infection by MRSA and appearance of staphylococcal infection. Further pre-clinical and clinical study of this bacterial therapy method is under development.

  15. Identification of clinically relevant Corynebacterium strains by Api Coryne, MALDI-TOF-mass spectrometry and molecular approaches.

    Science.gov (United States)

    Alibi, S; Ferjani, A; Gaillot, O; Marzouk, M; Courcol, R; Boukadida, J

    2015-09-01

    We evaluated the Bruker Biotyper matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) for the identification of 97 Corynebacterium clinical in comparison to identification strains by Api Coryne and MALDI-TOF-MS using 16S rRNA gene and hypervariable region of rpoB genes sequencing as a reference method. C. striatum was the predominant species isolated followed by C. amycolatum. There was an agreement between Api Coryne strips and MALDI-TOF-MS identification in 88.65% of cases. MALDI-TOF-MS was unable to differentiate C. aurimucosum from C. minutissimum and C. minutissimum from C. singulare but reliably identify 92 of 97 (94.84%) strains. Two strains remained incompletely identified to the species level by MALDI-TOF-MS and molecular approaches. They belonged to Cellulomonas and Pseudoclavibacter genus. In conclusion, MALDI-TOF-MS is a rapid and reliable method for the identification of Corynebacterium species. However, some limits have been noted and have to be resolved by the application of molecular methods. Copyright © 2015. Published by Elsevier SAS.

  16. Functional analysis of sequences adjacent to dapE of Corynebacterium glutamicum reveals the presence of aroP, which encodes the aromatic amino acid transporter.

    Science.gov (United States)

    Wehrmann, A; Morakkabati, S; Krämer, R; Sahm, H; Eggeling, L

    1995-10-01

    An initially nonclonable DNA locus close to a gene of L-lysine biosynthesis in Corynebacterium glutamicum was analyzed in detail. Its stepwise cloning and its functional identification by monitoring the amino acid uptakes of defined mutants, together with mechanistic studies, identified the corresponding structure as aroP, the general aromatic amino acid uptake system.

  17. Corynebacterium fournierii,’ a new bacterial species isolated from the vaginal sample of a patient with bacterial vaginosis

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    K. Diop

    2017-07-01

    Full Text Available Here we describe briefly ‘Corynebacterium fournierii’ strain Marseille P2948 (= CSUR P2948 = DSM103271, a new bacterium that was isolated from the vaginal sample of a 21-year-old woman with bacterial vaginosis.

  18. The pan-genome of the animal pathogen Corynebacterium pseudotuberculosis reveals differences in genome plasticity between the biovar ovis and equi strains

    DEFF Research Database (Denmark)

    Soares, Siomar C; Silva, Artur; Trost, Eva

    2013-01-01

    , Corynebacterium pseudotuberculosis infections pose a rising worldwide economic problem in ruminants. The complete genome sequences of 15 C. pseudotuberculosis strains isolated from different hosts and countries were comparatively analyzed using a pan-genomic strategy. Phylogenomic, pan-genomic, core genomic...

  19. Rational Design of a Corynebacterium glutamicum Pantothenate Production Strain and Ins Characterization by Metabolic Flux Analysis and Genome-Wide Transcriptional Profiling

    Czech Academy of Sciences Publication Activity Database

    Hüser, A.T.; Chassagnole, Ch.; Lindley, N.D.; Merkamm, M.; Guyonvarch, A.; Elišáková, Veronika; Pátek, Miroslav; Kalinowski, J.; Brune, I.; Pühler, A.; Tauch, A.

    2005-01-01

    Roč. 71, č. 6 (2005), s. 3255-3268 ISSN 0099-2240 Institutional research plan: CEZ:AV0Z50200510 Keywords : corynebacterium glutamicum * metabolic flux Subject RIV: EE - Microbiology, Virology Impact factor: 3.818, year: 2005

  20. Multiplex polymerase chain reaction to identify and determine the toxigenicity of Corynebacterium spp with zoonotic potential and an overview of human and animal infections

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    Luciene de Fátima Costa Torres

    2013-05-01

    Full Text Available Corynebacterium diphtheriae, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis constitute a group of potentially toxigenic microorganisms that are related to different infectious processes in animal and human hosts. Currently, there is a lack of information on the prevalence of disease caused by these pathogens, which is partially due to a reduction in the frequency of routine laboratory testing. In this study, a multiplex polymerase chain reaction (mPCR assay that can simultaneously identify and determine the toxigenicity of these corynebacterial species with zoonotic potential was developed. This assay uses five primer pairs targeting the following genes: rpoB (Corynebacterium spp, 16S rRNA (C. ulcerans and C. pseudotuberculosis, pld (C. pseudotuberculosis, dtxR (C. diphtheriae and tox [diphtheria toxin (DT ]. In addition to describing this assay, we review the literature regarding the diseases caused by these pathogens. Of the 213 coryneform strains tested, the mPCR results for all toxigenic and non-toxigenic strains of C . diphtheriae, C. ulcerans and C. pseudotuberculosis were in 100% agreement with the results of standard biochemical tests and PCR-DT. As an alternative to conventional methods, due to its advantages of specificity and speed, the mPCR assay used in this study may successfully be applied for the diagnosis of human and/or animal diseases caused by potentially toxigenic corynebacterial species.

  1. Metabolic responses to pyruvate kinase deletion in lysine producing Corynebacterium glutamicum

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    Wittmann Christoph

    2008-03-01

    Full Text Available Abstract Background Pyruvate kinase is an important element in flux control of the intermediate metabolism. It catalyzes the irreversible conversion of phosphoenolpyruvate into pyruvate and is under allosteric control. In Corynebacterium glutamicum, this enzyme was regarded as promising target for improved production of lysine, one of the major amino acids in animal nutrition. In pyruvate kinase deficient strains the required equimolar ratio of the two lysine precursors oxaloacetate and pyruvate can be achieved through concerted action of the phosphotransferase system (PTS and phosphoenolpyruvate carboxylase (PEPC, whereby a reduced amount of carbon may be lost as CO2 due to reduced flux into the tricarboxylic acid (TCA cycle. In previous studies, deletion of pyruvate kinase in lysine-producing C. glutamicum, however, did not yield a clear picture and the exact metabolic consequences are not fully understood. Results In this work, deletion of the pyk gene, encoding pyruvate kinase, was carried out in the lysine-producing strain C. glutamicum lysCfbr, expressing a feedback resistant aspartokinase, to investigate the cellular response to deletion of this central glycolytic enzyme. Pyk deletion was achieved by allelic replacement, verified by PCR analysis and the lack of in vitro enzyme activity. The deletion mutant showed an overall growth behavior (specific growth rate, glucose uptake rate, biomass yield which was very similar to that of the parent strain, but differed in slightly reduced lysine formation, increased formation of the overflow metabolites dihydroxyacetone and glycerol and in metabolic fluxes around the pyruvate node. The latter involved a flux shift from pyruvate carboxylase (PC to PEPC, by which the cell maintained anaplerotic supply of the TCA cycle. This created a metabolic by-pass from PEP to pyruvate via malic enzyme demonstrating its contribution to metabolic flexibility of C. glutamicum on glucose. Conclusion The metabolic

  2. Corynebacterium jeikeium jk0268 constitutes for the 40 amino acid long PorACj, which forms a homooligomeric and anion-selective cell wall channel.

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    Narges Abdali

    Full Text Available Corynebacterium jeikeium, a resident of human skin, is often associated with multidrug resistant nosocomial infections in immunodepressed patients. C. jeikeium K411 belongs to mycolic acid-containing actinomycetes, the mycolata and contains a channel-forming protein as judged from reconstitution experiments with artificial lipid bilayer experiments. The channel-forming protein was present in detergent treated cell walls and in extracts of whole cells using organic solvents. A gene coding for a 40 amino acid long polypeptide possibly responsible for the pore-forming activity was identified in the known genome of C. jeikeium by its similar chromosomal localization to known porH and porA genes of other Corynebacterium strains. The gene jk0268 was expressed in a porin deficient Corynebacterium glutamicum strain. For purification temporarily histidine-tailed or with a GST-tag at the N-terminus, the homogeneous protein caused channel-forming activity with an average conductance of 1.25 nS in 1M KCl identical to the channels formed by the detergent extracts. Zero-current membrane potential measurements of the voltage dependent channel implied selectivity for anions. This preference is according to single-channel analysis caused by some excess of cationic charges located in the channel lumen formed by oligomeric alpha-helical wheels. The channel has a suggested diameter of 1.4 nm as judged from the permeability of different sized hydrated anions using the Renkin correction factor. Surprisingly, the genome of C. jeikeium contained only one gene coding for a cell wall channel of the PorA/PorH type found in other Corynebacterium species. The possible evolutionary relationship between the heterooligomeric channels formed by certain Corynebacterium strains and the homooligomeric pore of C. jeikeium is discussed.

  3. Prediction of DtxR regulon: Identification of binding sites and operons controlled by Diphtheria toxin repressor in Corynebacterium diphtheriae

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    Hasnain Seyed

    2004-09-01

    Full Text Available Abstract Background The diphtheria toxin repressor, DtxR, of Corynebacterium diphtheriae has been shown to be an iron-activated transcription regulator that controls not only the expression of diphtheria toxin but also of iron uptake genes. This study aims to identify putative binding sites and operons controlled by DtxR to understand the role of DtxR in patho-physiology of Corynebacterium diphtheriae. Result Positional Shannon relative entropy method was used to build the DtxR-binding site recognition profile and the later was used to identify putative regulatory sites of DtxR within C. diphtheriae genome. In addition, DtxR-regulated operons were also identified taking into account the predicted DtxR regulatory sites and genome annotation. Few of the predicted motifs were experimentally validated by electrophoretic mobility shift assay. The analysis identifies motifs upstream to the novel iron-regulated genes that code for Formamidopyrimidine-DNA glycosylase (FpG, an enzyme involved in DNA-repair and starvation inducible DNA-binding protein (Dps which is involved in iron storage and oxidative stress defense. In addition, we have found the DtxR motifs upstream to the genes that code for sortase which catalyzes anchoring of host-interacting proteins to the cell wall of pathogenic bacteria and the proteins of secretory system which could be involved in translocation of various iron-regulated virulence factors including diphtheria toxin. Conclusions We have used an in silico approach to identify the putative binding sites and genes controlled by DtxR in Corynebacterium diphtheriae. Our analysis shows that DtxR could provide a molecular link between Fe+2-induced Fenton's reaction and protection of DNA from oxidative damage. DtxR-regulated Dps prevents lethal combination of Fe+2 and H2O2 and also protects DNA by nonspecific DNA-binding. In addition DtxR could play an important role in host interaction and virulence by regulating the levels of sortase

  4. Identification and characterization of smallest pore-forming protein in the cell wall of pathogenic Corynebacterium urealyticum DSM 7109.

    Science.gov (United States)

    Abdali, Narges; Younas, Farhan; Mafakheri, Samaneh; Pothula, Karunakar R; Kleinekathöfer, Ulrich; Tauch, Andreas; Benz, Roland

    2018-05-09

    Corynebacterium urealyticum, a pathogenic, multidrug resistant member of the mycolata, is known as causative agent of urinary tract infections although it is a bacterium of the skin flora. This pathogenic bacterium shares with the mycolata the property of having an unusual cell envelope composition and architecture, typical for the genus Corynebacterium. The cell wall of members of the mycolata contains channel-forming proteins for the uptake of solutes. In this study, we provide novel information on the identification and characterization of a pore-forming protein in the cell wall of C. urealyticum DSM 7109. Detergent extracts of whole C. urealyticum cultures formed in lipid bilayer membranes slightly cation-selective pores with a single-channel conductance of 1.75 nS in 1 M KCl. Experiments with different salts and non-electrolytes suggested that the cell wall pore of C. urealyticum is wide and water-filled and has a diameter of about 1.8 nm. Molecular modelling and dynamics has been performed to obtain a model of the pore. For the search of the gene coding for the cell wall pore of C. urealyticum we looked in the known genome of C. urealyticum for a similar chromosomal localization of the porin gene to known porH and porA genes of other Corynebacterium strains. Three genes are located between the genes coding for GroEL2 and polyphosphate kinase (PKK2). Two of the genes (cur_1714 and cur_1715) were expressed in different constructs in C. glutamicum ΔporAΔporH and in porin-deficient BL21 DE3 Omp8 E. coli strains. The results suggested that the gene cur_1714 codes alone for the cell wall channel. The cell wall porin of C. urealyticum termed PorACur was purified to homogeneity using different biochemical methods and had an apparent molecular mass of about 4 kDa on tricine-containing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Biophysical characterization of the purified protein (PorACur) suggested indeed that cur_1714 is the gene

  5. 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.

  6. Lactate production as representative of the fermentation potential of Corynebacterium glutamicum 2262 in a one-step process.

    Science.gov (United States)

    Khuat, Hoang Bao Truc; Kaboré, Abdoul Karim; Olmos, Eric; Fick, Michel; Boudrant, Joseph; Goergen, Jean-Louis; Delaunay, Stéphane; Guedon, Emmanuel

    2014-01-01

    The fermentative properties of thermo-sensitive strain Corynebacterium glutamicum 2262 were investigated in processes coupling aerobic cell growth and the anaerobic fermentation phase. In particular, the influence of two modes of fermentation on the production of lactate, the fermentation product model, was studied. In both processes, lactate was produced in significant amount, 27 g/L in batch culture, and up to 55.8 g/L in fed-batch culture, but the specific production rate in the fed-batch culture was four times lower than that in the batch culture. Compared to other investigated fermentation processes, our strategy resulted in the highest yield of lactic acid from biomass. Lactate production by C. glutamicum 2262 thus revealed the capability of the strain to produce various fermentation products from pyruvate.

  7. Osmolality, temperature, and membrane lipid composition modulate the activity of betaine transporter BetP in Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Ozcan, Nuran; Ejsing, Christer S.; Shevchenko, Andrej

    2007-01-01

    The gram-positive soil bacterium Corynebacterium glutamicum, a major amino acid-producing microorganism in biotechnology, is equipped with several osmoregulated uptake systems for compatible solutes, which is relevant for the physiological response to osmotic stress. The most significant carrier......P activity. We further correlated the change in BetP regulation properties in cells grown at different temperatures to changes in the lipid composition of the plasma membrane. For this purpose, the glycerophospholipidome of C. glutamicum grown at different temperatures was analyzed by mass spectrometry using...... quantitative multiple precursor ion scanning. The molecular composition of glycerophospholipids was strongly affected by the growth temperature. The modulating influence of membrane lipid composition on BetP function was further corroborated by studying the influence of artificial modulation of membrane...

  8. A comparative study on phyllosphere nitrogen fixation by newly isolated Corynebacterium sp. & Flavobacterium sp. and their potentialities as biofertilizer.

    Science.gov (United States)

    Giri, S; Pati, B R

    2004-01-01

    A number of nitrogen fixing bacteria has been isolated from forest phyllosphere on the basis of nitrogenase activity. Among them two best isolates are selected and identified as Corynebacterium sp. AN1 & Flavobacterium sp. TK2 able to reduce 88 and 132 n mol of acetylene (10(8)cells(-1)h(-1)) respectively. They were grown in large amount and sprayed on the phyllosphere of maize plants as a substitute for nitrogenous fertilizer. Marked improvements in growth and total nitrogen content of the plant have been observed by the application of these nitrogen-fixing bacteria. An average 30-37% increase in yield was obtained, which is nearer to chemical fertilizer treatment. Comparatively better effect was obtained by application of Flavobacterium sp.

  9. High-resolution detection of DNA binding sites of the global transcriptional regulator GlxR in Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Jungwirth, Britta; Sala, Claudia; Kohl, Thomas A

    2013-01-01

    of the 6C non-coding RNA gene and to non-canonical DNA binding sites within protein-coding regions. The present study underlines the dynamics within the GlxR regulon by identifying in vivo targets during growth on glucose and contributes to the expansion of knowledge of this important transcriptional......The transcriptional regulator GlxR has been characterized as a global hub within the gene-regulatory network of Corynebacterium glutamicum. Chromatin immunoprecipitation with a specific anti-GlxR antibody and subsequent high-throughput sequencing (ChIP-seq) was applied to C. glutamicum to get new...... mapping of these data on the genome sequence of C. glutamicum, 107 enriched DNA fragments were detected from cells grown with glucose as carbon source. GlxR binding sites were identified in the sequence of 79 enriched DNA fragments, of which 21 sites were not previously reported. Electrophoretic mobility...

  10. Historia de una histeria

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    Jorge Luis Gómez

    2015-01-01

    Full Text Available Una versión ecuatoriana de la novela "La guerra de los mundos" de H. G. Wells, en audición radiofónica de Radio Quito, en 1949, inauguró formalmente en el Ecuador la historia de las histerias colectivas. En este breve texto, el autor hace una reflexión sobre este fenómeno de masas.

  11. Rich biotin content in lignocellulose biomass plays the key role in determining cellulosic glutamic acid accumulation by Corynebacterium glutamicum.

    Science.gov (United States)

    Wen, Jingbai; Xiao, Yanqiu; Liu, Ting; Gao, Qiuqiang; Bao, Jie

    2018-01-01

    Lignocellulose is one of the most promising alternative feedstocks for glutamic acid production as commodity building block chemical, but the efforts by the dominant industrial fermentation strain Corynebacterium glutamicum failed for accumulating glutamic acid using lignocellulose feedstock. We identified the existence of surprisingly high biotin concentration in corn stover hydrolysate as the determining factor for the failure of glutamic acid accumulation by Corynebacterium glutamicum . Under excessive biotin content, induction by penicillin resulted in 41.7 ± 0.1 g/L of glutamic acid with the yield of 0.50 g glutamic acid/g glucose. Our further investigation revealed that corn stover contained 353 ± 16 μg of biotin per kg dry solids, approximately one order of magnitude greater than the biotin in corn grain. Most of the biotin remained stable during the biorefining chain and the rich biotin content in corn stover hydrolysate almost completely blocked the glutamic acid accumulation. This rich biotin existence was found to be a common phenomenon in the wide range of lignocellulose biomass and this may be the key reason why the previous studies failed in cellulosic glutamic acid fermentation from lignocellulose biomass. The extended recording of the complete members of all eight vitamin B compounds in lignocellulose biomass further reveals that the major vitamin B members were also under the high concentration levels even after harsh pretreatment. The high content of biotin in wide range of lignocellulose biomass feedstocks and the corresponding hydrolysates was discovered and it was found to be the key factor in determining the cellulosic glutamic acid accumulation. The highly reserved biotin and the high content of their other vitamin B compounds in biorefining process might act as the potential nutrients to biorefining fermentations. This study creates a new insight that lignocellulose biorefining not only generates inhibitors, but also keeps nutrients

  12. una sociedad emergente

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    Derlisiret Rincón M.

    2006-01-01

    Full Text Available Este trabajo busca reflexionar por una parte acerca del papel de la ciencia, la tecnología y la educación, como factores de desarrollo de las naciones e intenta responder la interrogante en torno al cómo estas variables contribuirán a la transformación de la realidad social venezolana. Los planteamientos expuestos en este artículo forman parte de una investigación cualitativa que se sustenta en una revisión teórica cuyos resultados indican que existe la posibilidad cierta de construir y alcanzar una Venezuela virtual en los próximos años; es decir, se vislumbra un país interconectado y funcionando a través de redes cuyos individuos estarían capacitados y entrenados en el uso y usufructo de las nuevas tecnologías. Esta visión de país, se basa en la premisa de que la oportuna implementación de la Planificación de Ciencia y Tecnología resultaría instrumento de vinculación de las variables tecnológicas, educativas y científicas, que permiten obtener conocimientos especializados y orientados a la solución de problemas de creciente dimensión global. Tales conocimientos, pudieran generar los cambios sustanciales necesarios en el contexto nacional, para lograr modificar o disminuir el sentido de crecimiento de la brecha o divisoria digital en este entorno

  13. Comprehensive update of dalbavancin activity when tested against uncommonly isolated streptococci, Corynebacterium spp., Listeria monocytogenes, and Micrococcus spp. (1357 strains).

    Science.gov (United States)

    Jones, Ronald N; Stilwell, Matthew G

    2013-06-01

    Dalbavancin is an investigational lipoglycopeptide having an extended serum elimination half-life allowing once-weekly dosing. Data from testing 1357 strains of uncommonly isolated species expand the dalbavancin spectrum details as follows (MIC50/90): β-haemolytic streptococcal serogroups C, F, and G (≤0.03/≤0.03 μg/mL), 7 viridans group of streptococci (≤0.03/≤0.03-0.06 μg/mL), 5 Corynebacterium spp. (0.06/0.12 μg/mL), Listeria monocytogenes (0.06/0.12 μg/mL), and Micrococcus spp. (≤0.03/≤0.03 μg/mL). Among all reported isolates, 99.8% of tested strains were inhibited at dalbavancin MIC values at ≤0.12 μg/mL. Dalbavancin remains very potent against rarer Gram-positive pathogens, using in vitro test experience with organisms cultured through 2011. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Novel Polyoxyethylene-Containing Glycolipids Are Synthesized in Corynebacterium matruchotii and Mycobacterium smegmatis Cultured in the Presence of Tween 80

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    Cindy Wang

    2011-01-01

    Full Text Available The addition of polyoxyethylene sorbitan monooleate (Tween 80 to a culture of mycobacteria greatly influences cell permeability and sensitivity to antibiotics but very little is known regarding the underlying mechanism. Here we show that Corynebacterium matruchotii (surrogate of mycobacteria converts Tween 80 to a structural series of polyoxyethylenic acids which are then used to form novel series-2A and series-2B glycolipids. Minor series-3 glycolipids were also synthesized. The polyoxyethylenic acids replaced corynomycolic acids in the cell wall. Correspondingly the trehalose dicorynomycolate content was reduced. MALDI mass spectrometry, MS-MS, 1H-NMR, and 13C-NMR were used to characterize the series-2 glycolipids. Series-2A glycolipid is trehalose 6-C36:2-corynomycolate-6′-polyoxyethylenate and series-2B glycolipid is trehalose 6-C36:2-corynomycolate-6′-furan ring-containing polyoxyethylenate. Mycobacterium smegmatis grown in the presence of Tween 80 also synthesizes series-2 type glycolipids. The synthesis of these novel glycolipids in corynebacteria and mycobacteria should result in gross changes in the cell wall permeability and drug sensitivity.

  15. Corynebacterium diphtheriae in a free-roaming red fox: case report and historical review on diphtheria in animals.

    Science.gov (United States)

    Sing, Andreas; Konrad, Regina; Meinel, Dominik M; Mauder, Norman; Schwabe, Ingo; Sting, Reinhard

    2016-08-01

    Corynebacterium diphtheriae, the classical causative agent of diphtheria, is considered to be nearly restricted to humans. Here we report the first finding of a non-toxigenic C. diphtheriae biovar belfanti strain in a free-roaming wild animal. The strain obtained from the subcutis and mammary gland of a dead red fox (Vulpes vulpes) was characterized by biochemical and molecular methods including MALDI-TOF and Multi Locus Sequence Typing. Since C. diphtheriae infections of animals, usually with close contact to humans, are reported only very rarely, an intense review comprising also scientific literature from the beginning of the 20th century was performed. Besides the present case, only 11 previously reported C. diphtheriae animal infections could be verified using current scientific criteria. Our report is the first on the isolation of C. diphtheriae from a wildlife animal without any previous human contact. In contrast, the very few unambiguous publications on C. diphtheriae in animals referred to livestock or pet animals with close human contact. C. diphtheriae carriage in animals has to be considered as an exceptionally rare event.

  16. Different modes of diaminopimelate synthesis and their role in cell wall integrity: a study with Corynebacterium glutamicum.

    Science.gov (United States)

    Wehrmann, A; Phillipp, B; Sahm, H; Eggeling, L

    1998-06-01

    In eubacteria, there are three slightly different pathways for the synthesis of m-diaminopimelate (m-DAP), which is one of the key linking units of peptidoglycan. Surprisingly, for unknown reasons, some bacteria use two of these pathways together. An example is Corynebacterium glutamicum, which uses both the succinylase and dehydrogenase pathways for m-DAP synthesis. In this study, we clone dapD and prove by enzyme experiments that this gene encodes the succinylase (M(r) = 24082), initiating the succinylase pathway of m-DAP synthesis. By using gene-directed mutation, dapD, as well as dapE encoding the desuccinylase, was inactivated, thereby forcing C. glutamicum to use only the dehydrogenase pathway of m-DAP synthesis. The mutants are unable to grow on organic nitrogen sources. When supplied with low ammonium concentrations but excess carbon, their morphology is radically altered and they are less resistant to mechanical stress than the wild type. Since the succinylase has a high affinity toward its substrate and uses glutamate as the nitrogen donor, while the dehydrogenase has a low affinity and incorporates ammonium directly, the m-DAP synthesis is another example of twin activities present in bacteria for access to important metabolites such as the well-known twin activities for the synthesis of glutamate or for the uptake of potassium.

  17. Identification of membrane-associated proteins with pathogenic potential expressed by Corynebacterium pseudotuberculosis grown in animal serum.

    Science.gov (United States)

    Raynal, José Tadeu; Bastos, Bruno Lopes; Vilas-Boas, Priscilla Carolinne Bagano; Sousa, Thiago de Jesus; Costa-Silva, Marcos; de Sá, Maria da Conceição Aquino; Portela, Ricardo Wagner; Moura-Costa, Lília Ferreira; Azevedo, Vasco; Meyer, Roberto

    2018-01-25

    Previous works defining antigens that might be used as vaccine targets against Corynebacterium pseudotuberculosis, which is the causative agent of sheep and goat caseous lymphadenitis, have focused on secreted proteins produced in a chemically defined culture media. Considering that such antigens might not reflect the repertoire of proteins expressed during infection conditions, this experiment aimed to investigate the membrane-associated proteins with pathogenic potential expressed by C. pseudotuberculosis grown directly in animal serum. Its membrane-associated proteins have been extracted using an organic solvent enrichment methodology, followed by LC-MS/MS and bioinformatics analysis for protein identification and classification. The results revealed 22 membrane-associated proteins characterized as potentially pathogenic. An interaction network analysis indicated that the four potentially pathogenic proteins ciuA, fagA, OppA4 and OppCD were biologically connected within two distinct network pathways, which were both associated with the ABC Transporters KEGG pathway. These results suggest that C. pseudotuberculosis pathogenesis might be associated with the transport and uptake of nutrients; other seven identified potentially pathogenic membrane proteins also suggest that pathogenesis might involve events of bacterial resistance and adhesion. The proteins herein reported potentially reflect part of the protein repertoire expressed during real infection conditions and might be tested as vaccine antigens.

  18. Production of carbon-13-labeled cadaverine by engineered Corynebacterium glutamicum using carbon-13-labeled methanol as co-substrate.

    Science.gov (United States)

    Leßmeier, Lennart; Pfeifenschneider, Johannes; Carnicer, Marc; Heux, Stephanie; Portais, Jean-Charles; Wendisch, Volker F

    2015-12-01

    Methanol, a one-carbon compound, can be utilized by a variety of bacteria and other organisms as carbon and energy source and is regarded as a promising substrate for biotechnological production. In this study, a strain of non-methylotrophic Corynebacterium glutamicum, which was able to produce the polyamide building block cadaverine as non-native product, was engineered for co-utilization of methanol. Expression of the gene encoding NAD+-dependent methanol dehydrogenase (Mdh) from the natural methylotroph Bacillus methanolicus increased methanol oxidation. Deletion of the endogenous aldehyde dehydrogenase genes ald and fadH prevented methanol oxidation to carbon dioxide and formaldehyde detoxification via the linear formaldehyde dissimilation pathway. Heterologous expression of genes for the key enzymes hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase of the ribulose monophosphate (RuMP) pathway in this strain restored growth in the presence of methanol or formaldehyde, which suggested efficient formaldehyde detoxification involving RuMP key enzymes. While growth with methanol as sole carbon source was not observed, the fate of 13C-methanol added as co-substrate to sugars was followed and the isotopologue distribution indicated incorporation into central metabolites and in vivo activity of the RuMP pathway. In addition, 13C-label from methanol was traced to the secreted product cadaverine. Thus, this synthetic biology approach led to a C. glutamicum strain that converted the non-natural carbon substrate methanol at least partially to the non-native product cadaverine.

  19. Construction of in vitro transcription system for Corynebacterium glutamicum and its use in the recognition of promoters of different classes.

    Science.gov (United States)

    Holátko, Jiří; Silar, Radoslav; Rabatinová, Alžbeta; Sanderová, Hana; Halada, Petr; Nešvera, Jan; Krásný, Libor; Pátek, Miroslav

    2012-10-01

    To facilitate transcription studies in Corynebacterium glutamicum, we have developed an in vitro transcription system for this bacterium used as an industrial producer of amino acids and a model organism for actinobacteria. This system consists of C. glutamicum RNA polymerase (RNAP) core (α2, β, β'), a sigma factor and a promoter-carrying DNA template, that is specifically recognized by the RNAP holoenzyme formed. The RNAP core was purified from the C. glutamicum strain with the modified rpoC gene, which produced His-tagged β' subunit. The C. glutamicum sigA and sigH genes were cloned and overexpressed using the Escherichia coli plasmid vector, and the sigma subunits σ(A) and σ(H) were purified by affinity chromatography. Using the reconstituted C. glutamicum holo-RNAPs, recognition of the σ(A)- and σ(H)-dependent promoters and synthesis of the specific transcripts was demonstrated. The developed in vitro transcription system is a novel tool that can be used to directly prove the specific recognition of a promoter by the particular σ factor(s) and to analyze transcriptional control by various regulatory proteins in C. glutamicum.

  20. Metabolic Design of Corynebacterium glutamicum for Production of l-Cysteine with Consideration of Sulfur-Supplemented Animal Feed.

    Science.gov (United States)

    Joo, Young-Chul; Hyeon, Jeong Eun; Han, Sung Ok

    2017-06-14

    l-Cysteine is a valuable sulfur-containing amino acid widely used as a nutrition supplement in industrial food production, agriculture, and animal feed. However, this amino acid is mostly produced by acid hydrolysis and extraction from human or animal hairs. In this study, we constructed recombinant Corynebacterium glutamicum strains that overexpress combinatorial genes for l-cysteine production. The aims of this work were to investigate the effect of the combined overexpression of serine acetyltransferase (CysE), O-acetylserine sulfhydrylase (CysK), and the transcriptional regulator CysR on l-cysteine production. The CysR-overexpressing strain accumulated approximately 2.7-fold more intracellular sulfide than the control strain (empty pMT-tac vector). Moreover, in the resulting CysEKR recombinant strain, combinatorial overexpression of genes involved in l-cysteine production successfully enhanced its production by approximately 3.0-fold relative to that in the control strain. This study demonstrates a biotechnological model for the production of animal feed supplements such as l-cysteine using metabolically engineered C. glutamicum.

  1. Mutational analysis to identify the residues essential for the inhibition of N-acetyl glutamate kinase of Corynebacterium glutamicum.

    Science.gov (United States)

    Huang, Yuanyuan; Zhang, Hao; Tian, Hongming; Li, Cheng; Han, Shuangyan; Lin, Ying; Zheng, Suiping

    2015-09-01

    N-acetyl glutamate kinase (NAGK) is a key enzyme in the synthesis of L-arginine that is inhibited by its end product L-arginine in Corynebacterium glutamicum (C. glutamicum). In this study, the potential binding sites of arginine and the residues essential for its inhibition were identified by homology modeling, inhibitor docking, and site-directed mutagenesis. The allosteric inhibition of NAGK was successfully alleviated by a mutation, as determined through analysis of mutant enzymes, which were overexpressed in vivo in C. glutamicum ATCC14067. Analysis of the mutant enzymes and docking analysis demonstrated that residue W23 positions an arginine molecule, and the interaction between arginine and residues L282, L283, and T284 may play an important role in the remote inhibitory process. Based on the results of the docking analysis of the effective mutants, we propose a linkage mechanism for the remote allosteric regulation of NAGK activity, in which residue R209 may play an essential role. In this study, the structure of the arginine-binding site of C. glutamicum NAGK (CgNAGK) was successfully predicted and the roles of the relevant residues were identified, providing new insight into the allosteric regulation of CgNAGK activity and a solid platform for the future construction of an optimized L-arginine producing strain.

  2. Disruption of pknG enhances production of gamma-aminobutyric acid by Corynebacterium glutamicum expressing glutamate decarboxylase.

    Science.gov (United States)

    Okai, Naoko; Takahashi, Chihiro; Hatada, Kazuki; Ogino, Chiaki; Kondo, Akihiko

    2014-01-01

    Gamma-aminobutyric acid (GABA), a building block of the biodegradable plastic polyamide 4, is synthesized from glucose by Corynebacterium glutamicum that expresses Escherichia coli glutamate decarboxylase (GAD) B encoded by gadB. This strain was engineered to produce GABA more efficiently from biomass-derived sugars. To enhance GABA production further by increasing the intracellular concentration of its precursor glutamate, we focused on engineering pknG (encoding serine/threonine protein kinase G), which controls the activity of 2-oxoglutarate dehydrogenase (Odh) in the tricarboxylic acid cycle branch point leading to glutamate synthesis. We succeeded in expressing GadB in a C. glutamicum strain harboring a deletion of pknG. C. glutamicum strains GAD and GAD ∆pknG were cultured in GP2 medium containing 100 g L(-1) glucose and 0.1 mM pyridoxal 5'-phosphate. Strain GAD∆pknG produced 31.1 ± 0.41 g L(-1) (0.259 g L(-1) h(-1)) of GABA in 120 hours, representing a 2.29-fold higher level compared with GAD. The production yield of GABA from glucose by GAD∆pknG reached 0.893 mol mol(-1).

  3. Phenotypic, molecular characterization, antimicrobial susceptibility and draft genome sequence of Corynebacterium argentoratense strains isolated from clinical samples

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    I. Fernández-Natal

    2016-03-01

    Full Text Available During a 12-year period we isolated five Corynebacterium argentoratense strains identified by phenotypic methods, including the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF and 16S rRNA gene sequencing. In addition, antimicrobial susceptibility was determined, and genome sequencing for the detection of antibiotic resistance genes was performed. The organisms were isolated from blood and throat cultures and could be identified by all methods used. All strains were resistant to cotrimoxazole, and resistance to β-lactams was partly present. Two strains were resistant to erythromycin and clindamycin. The draft genome sequences of theses isolates revealed the presence of the erm(X resistance gene that is embedded in the genetic structure of the transposable element Tn5423. Although rarely reported as a human pathogen, C. argentoratense can be involved in bacteraemia and probably in other infections. Our results also show that horizontal transfer of genes responsible for antibiotic resistance is occurring in this species.

  4. Diphtheria in the Republic of Georgia: Use of Molecular Typing Techniques for Characterization of Corynebacterium diphtheriae Strains

    Science.gov (United States)

    Sulakvelidze, Alexander; Kekelidze, Merab; Gomelauri, Tsaro; Deng, Yingkang; Khetsuriani, Nino; Kobaidze, Ketino; De Zoysa, Aruni; Efstratiou, Androulla; Morris, J. Glenn; Imnadze, Paata

    1999-01-01

    Sixty-six Corynebacterium diphtheriae strains (62 of the gravis biotype and 4 of the mitis biotype) isolated during the Georgian diphtheria epidemic of 1993 to 1998 and 13 non-Georgian C. diphtheriae strains (10 Russian and 3 reference isolates) were characterized by (i) biotyping, (ii) toxigenicity testing with the Elek assay and PCR, (iii) the randomly amplified polymorphic DNA (RAPD) technique, and (iv) pulsed-field gel electrophoresis (PFGE). Fifteen selected strains were ribotyped. Six RAPD types and 15 PFGE patterns were identified among all strains examined, and 12 ribotypes were found among the 15 strains that were ribotyped. The Georgian epidemic apparently was caused by one major clonal group of C. diphtheriae (PFGE type A, ribotype R1), which was identical to the predominant epidemic strain(s) isolated during the concurrent diphtheria epidemic in Russia. A dendrogram based on the PFGE patterns revealed profound differences between the minor (nonpredominant) epidemic strains found in Georgia and Russia. The methodologies for RAPD typing, ribotyping, and PFGE typing of C. diphtheriae strains were improved to enable rapid and convenient molecular typing of the strains. The RAPD technique was adequate for biotype differentiation; however, PFGE and ribotyping were better (and equal to each other) at discriminating between epidemiologically related and unrelated isolates. PMID:10488190

  5. Expression, purification, crystallization and preliminary crystallographic analysis of SpaA, a major pilin from Corynebacterium diphtheriae

    International Nuclear Information System (INIS)

    Kang, Hae Joo; Paterson, Neil G.; Baker, Edward N.

    2009-01-01

    SpaA, one of the major pilins of C. diphtheriae, has been expressed, purified and crystallized and X-ray diffraction data have been collected to 1.6 Å resolution. Bacterial pili are cell-surface organelles that are critically involved in adhesion to host cells, leading to the colonization of host tissues and the establishment of infections. Whereas the pili of Gram-negative bacteria have been extensively studied, those of Gram-positive bacteria came to light only recently after the discovery and characterization of Corynebacterium diphtheriae pili. These newly discovered pili are formed by the covalent polymerization of pilin subunits catalyzed by sortase enzymes, making them fundamentally different from the noncovalent pilin assemblies of Gram-negative bacteria. Here, the expression, crystallization and preliminary crystallographic analysis of SpaA, which forms the shaft of one of the three types of pili expressed by C. diphtheriae, are reported. SpaA 53–486 crystals diffracted to 1.6 Å resolution and belonged to space group P2 1 2 1 2 1 , with unit-cell parameters a = 34.9, b = 64.1, c = 198.7 Å, α = β = γ = 90°

  6. Characterization and chromosomal organization of the murD-murC-ftsQ region of Corynebacterium glutamicum ATCC 13869.

    Science.gov (United States)

    Ramos, Angelina; Honrubia, Maria P; Vega, Daniel; Ayala, Juan A; Bouhss, Ahmed; Mengin-Lecreulx, Dominique; Gil, José A

    2004-04-01

    The sequence of a 4.6-kb region of DNA from Corynebacterium glutamicum ATCC 13869 lying upstream from the ftsQ-ftsZ region has been determined. The region contains four genes with high similarity to the murD, ftsW, murG, and murC genes from different microorganisms. The products of these mur genes probably catalyse several steps in the formation of the precursors for peptidoglycan synthesis in C. glutamicum, whereas ftsW might play also a role in the stabilisation of the FtsZ ring during cell division. The murC gene product was purified to near homogeneity and its UDP-N-acetylmuramate: L-alanine adding activity was demonstrated. Northern analysis indicated that ftsW, murG and ftsQ are poorly expressed in C. glutamicum whereas murC and ftsZ are expressed at higher levels at the beginning of the exponential phase. Dicistronic (ftsQ-ftsZ) and monocistronic (murC and ftsZ) transcripts can be detected using specific probes and are in agreement with the lack of transcriptional terminators in the partially analysed dcw cluster. Disruption experiments performed in C. glutamicum using internal fragments of the ftsW, murG and murC genes allowed us to conclude that FtsW, MurG, and MurC are essential gene products in C. glutamicum.

  7. Reprogramming One-Carbon Metabolic Pathways To Decouple l-Serine Catabolism from Cell Growth in Corynebacterium glutamicum.

    Science.gov (United States)

    Zhang, Yun; Shang, Xiuling; Lai, Shujuan; Zhang, Yu; Hu, Qitiao; Chai, Xin; Wang, Bo; Liu, Shuwen; Wen, Tingyi

    2018-02-16

    l-Serine, the principal one-carbon source for DNA biosynthesis, is difficult for microorganisms to accumulate due to the coupling of l-serine catabolism and microbial growth. Here, we reprogrammed the one-carbon unit metabolic pathways in Corynebacterium glutamicum to decouple l-serine catabolism from cell growth. In silico model-based simulation showed a negative influence on glyA-encoding serine hydroxymethyltransferase flux with l-serine productivity. Attenuation of glyA transcription resulted in increased l-serine accumulation, and a decrease in purine pools, poor growth and longer cell shapes. The gcvTHP-encoded glycine cleavage (Gcv) system from Escherichia coli was introduced into C. glutamicum, allowing glycine-derived 13 CH 2 to be assimilated into intracellular purine synthesis, which resulted in an increased amount of one-carbon units. Gcv introduction not only restored cell viability and morphology but also increased l-serine accumulation. Moreover, comparative proteomic analysis indicated that abundance changes of the enzymes involved in one-carbon unit cycles might be responsible for maintaining one-carbon unit homeostasis. Reprogramming of the one-carbon metabolic pathways allowed cells to reach a comparable growth rate to accumulate 13.21 g/L l-serine by fed-batch fermentation in minimal medium. This novel strategy provides new insights into the regulation of cellular properties and essential metabolite accumulation by introducing an extrinsic pathway.

  8. CRIPTOSPORIDIOSIS: UNA ZOONOSIS PARASITARIA

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    Claudia Vergara

    2004-07-01

    Full Text Available La criptosporidiosis es una enfermedad parasitariaproducida por protozoos coccidios pertenecientes algénero Cryptosporidium. Su importancia se puso demanifiesto a comienzos de los años 1980 por lo quepuede considerarse una patología de conocimientorelativamente reciente, aunque actualmente se hademostrado que es una de las infecciones entéricasmás frecuentes en humanos y animales y un problemade salud pública en todo el mundo (Casemore et al.1997. La especie de mayor interés dentro del género,y a la cual nos referiremos a lo largo de esta revisión,es C. parvum, que se multiplica preferentemente enlas células epiteliales del intestino delgado de losmamíferos desencadenando diarrea por absorción ydigestión deficientes y que debido a su escasaespecificidad de hospedador, puede transmitirseindistintamente entre los mamíferos domésticos y elhombre

  9. Hacia una vejez útil

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    Hernández Amparo

    1992-12-01

    Full Text Available

    Con lleva un interés bien particular encontrarnos con una población tan heterogénea en cuanto a caracterización se refiere, ya porque miremos en ella sus hábitos, sus costumbres, procedencia, nivel socio-cultural, etc., dicha comunidad de ancianos plantea, de inmediato la necesidad de ponerse en un contacto generacional que rompiera y dejara atrás la rutina y la monotonía, propia de su cotidianidad, es entonces cuando tres profesionales altamente motivadas en el trabajo comunitario, inician un proceso vivo y dinámico con el anciano institucionalizado a fin de que ellos recobraran el protagonismo, elevaran su autoestima, tomaran parte en la toma de decisiones frente a su vida, y volvieran a sentirse en capacidad de dar respuesta a sus conflictos, buscando alternativas de solución en una tarea mancomunada que exigió madurez, diálogo y comunicación permanente entre cada una de las partes involucradas en dicho proceso.

  10. Una metropolitana chiamata "tram"

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    Mariella Zoppi

    2012-08-01

    Full Text Available Perché il caso-Firenze della tramvia ha avuto un rilievo così forte sui media nazionali? Perché la tramvia (se vogliamo continuare a chiamare così una metropolitana di superficie è parte di un sovvertimento dei valori storici, estetici ed economici della città di cui il sistema di trasporto è solo un frammento. La grande operazione di trasformazione, come viene chiamata dall’Amministrazione comunale, passa per il cambiamento di destinazione e la nuova edificazione di molte aree urbane: dall’area Fiat e da quella dell’ex-officine ferroviarie di Porta a Prato (ormai in fase conclusiva, dall’avvio dell’edificazione privata a Castello (vicenda nota negli anni Ottanta come “Fondiaria” a quelle di aree di minori dimensioni che interessano ex-cinema o teatri (è di questi giorni il destino dell’attuale Teatro comunale che si mutano in abitazioni pregiate o di fabbriche dismesse che si trasformano, con il loro carico volumetrico pressoché intatto (a pareggiare i conti ci pensa la “perequazione”, in parcheggi in struttura (semi-vuoti perché mal collocati, residenze, uffici, alberghi e quant’altro possa essere “utile” ad una città invecchiata che ha perso, centomila abitanti fra il 1971 ed il 2001, passando da una popolazione di 457.803 a una di 356.118. Come nel resto del Paese, anche a Firenze, non esiste più un dibattito pubblico che riporti gli umori della città all’interno delle vicende politiche e amministrative, e dunque tutto avviene fra l’indifferenza delle cronache locali che sembrano più interessate alle dichiarazioni di questo o quel personaggio che alla effettiva trasmissione delle informazioni. Le notizie circolano sulla rete, veicolate dai comitati (ormai c’è un comitato di cittadini per ogni strada o problema, che vive separatamente dagli amministratori e diventano patrimonio di quanti abbiano una sia pur minima alfabetizzazione informatica.

  11. Ecuador: una democracia inestable

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    Juan J. Paz y Miño Cepeda

    2009-12-01

    Full Text Available En 1979, tras una década de dictaduras militares, se inició la fase constitucional más larga en la historia del Ecuador. Ésta se levantó sobre las herencias del pasado y se caracterizó, de manera fundamental, por el tránsito desde un modelo estatal-desarrollista hacia uno de tipo empresarial, por el aparecimiento de nuevos agentes sociales, el multipartidismo político, la regionalización nacional, la presencia multicultural y la inserción del país en nuevas relaciones internacionales. Pero esos procesos trajeron como consecuencias centrales: la edificación de una economía inequitativa, una sociedad tensionada, la desestructuración institucional, la precarización del trabajo y la debilidad con la que la nación ha enfrentado el nuevo mundo unipolar. Todo ello ha configurado un cuadro de riesgos para la incipiente democracia. El Ecuador contemporáneo tiene, por tanto, una serie de desafíos económicos, sociales y políticos para escapar a la inestabilidad que ha acompañado a la construcción de su modernización democrática.___________________ABSTRACT:In 1979, after one decade of military dictatorships, the longest constitutional phase in the history of Ecuador was initiated. It was built upon the inheritance of the past and can be fundamentally characterized by the transition from a model that focused on the state as developing the economy (State-model to a model that focused on private business (enterprise-model. The appearance of new social agents, a multiparty system, national regionalization, multicultural presence and the country´s new international relationships are processes which show some important consequences: the establishment of an unequal economy, a society under tension, the breakdown of institutional structures, the vulnerability of working conditions and the weakness with which the nation faced the new polarized world. All this might put into danger this incipient democracy. And this is why Ecuador in these

  12. una propuesta de indicadores

    Directory of Open Access Journals (Sweden)

    Noemí Luján Ponce

    2007-01-01

    Full Text Available La tecnología reviste características de neutralidad, eficiencia, transparencia y regularidad. Factores que hoy día resultan relevantes para realizar procesos electorales confiables. Las redistritaciones electorales en México 1996 y 2005 resultan casos paradigmáticos en relación a la cristalización de la tecnología como una mediación para la construcción de acuerdos entre los partidos y las autoridades electorales. Se ofrecen cinco indicadores para comparar ambos procesos de distritación.

  13. Construir una literatura

    OpenAIRE

    Sánchez Wilde, Ariel Oscar

    1998-01-01

    La consideración de las relaciones entre los textos producidos en el centro yen la periferia del sistema es insoslayable a la hora de abordar la lectura crítica de una literatura, analizándola tanto en su proceso histórico (diacronía), como en un estado determinado de dicho proceso (sincronía). El presente trabajo, a partir de un corpus de diez textos publicados entre 1921 y 1931 en distintos lugares de Latinoamérica (Argentina, Brasil, Cuba, México, Nicaragua, Perú, Puerto Rico y República D...

  14. Technetium-99m labeling and fibronectin binding ability of Corynebacterium diphtheriae; Marcacao de Corynebacterium diphtheriae com Tecnecio-99m e avaliacao da capacidade de ligacao a fibronectina de plasma humano

    Energy Technology Data Exchange (ETDEWEB)

    Souza, S.M.S.; Nagao, P.E.; Bernardo-Filho, M. [Universidade do Estado do Rio de Janeiro, RJ (Brazil). Inst. de Biologia Roberto Alcantara Gomes; Pereira, G.A.; Napoleao, F.; Andrade, A.F.B.; Hirata Junior, R.; Mattos-Guaraldi, A.L. [Universidade do Estado do Rio de Janeiro, RJ (Brazil). Faculdade de Ciencias Medicas

    2004-04-15

    The use of radionuclides has permitted advances in areas of clinical and scientific knowledge. Several molecules and cells have been labelled with Technetium-99m ({sup 99m}Tc). The stannous chloride (SnCl{sub 2}) has a significant influence on the labeling and stability of {sup 99m}Tc radiotracers. The frequent risk of diphtheria epidemics has intensified interest in the virulence factors of Corynebacterium diphtheriae. Although studies have looked at potential adhesins including haemagglutinins and exposed sugar residues, the molecular basis of mechanisms of adherence remains unclear. Adherence of pathogens to mammalian tissues may be mediated by fibronectin (FN) found in body fluids, matrix of connective tissues, and cell surfaces. In the present study we evaluated the binding ability to human plasma FN by {sup 99m}Tc labeled-C.diphtheriae. Due to adverse effects of stannous ions, microorganisms were submitted to survival and filamentation induction assays. Data showed a dose dependent susceptibility to SnCl{sub 2} bactericidal effects. Cell filamentation was observed for concentrations of SnCl{sub 2} > 110 {mu}g/ml. Adherence levels of {sup 99m}Tc labelled 241strain to coverslips coated with 20 {mu}g/ml FN were higher (P = 0.0037) than coated with bovine serum albumin. FN binding by the sucrose fermenting 241 C. diphtheriae strain (8.9% + 2.6) was significantly lower (P=0.0139) than Staphylococcus aureus Cowan I strain (34.1% {+-} 1.2). Therefore, bacterial {sup 99m}Tc labeling represents an additional tool that may contribute to the comprehension of C. diphtheriae interactions with host receptors such as FN that act as biological organizers by holding bacterial cells in position and guiding their migration. (author)

  15. Una finestra sul polo

    Directory of Open Access Journals (Sweden)

    Graziella Busso

    2015-07-01

    Full Text Available Rabbia, dolore, incredulità si mescolano in un turbinio di emozioni quando, dalle affissioni che quasi quotidianamente si danno il cambio, si legge il necrologio di un “qualcuno” che sappiamo ucciso dal cancro. E pensiamo che, ancora e forse per tanto tempo, potremmo essere più fortunati. E non c’è pace, non c’è consolazione per quei giorni di vita vissuta, strappata, stropicciata, rubata da un mostro che non sempre è possibile sconfiggere finché non subentra la stanchezza, la rassegnazione, la secchezza delle ghiandole lacrimali. Unico strumento per cercare di “cambiare le cose”, per quanto difficile possa sembrare farlo, è combattere, perché la lotta per un ambiente più vivibile sarà una conquista per noi e per i nostri figli, un’eredità che non ha prezzo. La voglia di “gridare” la sofferenza di chi vive la realtà di uno sviluppo insostenibile si è da tempo trasformata ad Augusta in una battaglia di sensibilizzazione alla ormai annosa problematica e nel profondo desiderio di raccontare, far conoscere, testimoniare emozioni, desideri, sogni di chi vive in prima persona o ha vissuto la malattia di un proprio caro perché tutto questo possa servire a spingere verso quel mutamento culturale, storico, ambientale a cui tutti noi agogniamo.

  16. [Corynebacterium imitans isolated from blood culture in a patient with suspected bacteremia - the first isolation from human clinical material in the Czech Republic].

    Science.gov (United States)

    JeŽek, Petr; Zavadilová, Jana; Kolínská, Renáta; Švec, Pavel; Guttwirth, Jiří; Petráš, Petr

    2014-09-01

    The current view of the clinical importance of nondiphtherial corynebacteria recovered from human clinical material has changed considerably in recent decades; in many cases, a direct etiological role is assumed or has already been demonstrated. Presented is a case of suspected bacteremia in a hospitalized elderly woman with isolation of the very rare species Corynebacterium imitans from blood culture. However, the etiological significance of the isolated microorganism remains unclear. The aim was not to demonstrate the etiological significance of the isolated C. imitans strain but to report the occurrence of this very rare species which is considered to be the first isolation from humans in the Czech Republic.

  17. The two-component signal transduction system CopRS of Corynebacterium glutamicum is required for adaptation to copper-excess stress

    OpenAIRE

    Schelder, S.; Zaade, D.; Litsanov, B.; Bott, M.; Brocker, M.

    2011-01-01

    Copper is an essential cofactor for many enzymes but at high concentrations it is toxic for the cell. Copper ion concentrations ≥50 µM inhibited growth of Corynebacterium glutamicum. The transcriptional response to 20 µM Cu(2+) was studied using DNA microarrays and revealed 20 genes that showed a ≥ 3-fold increased mRNA level, including cg3281-cg3289. Several genes in this genomic region code for proteins presumably involved in the adaption to copper-induced stress, e. g. a multicopper oxidas...

  18. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L. Assisted by Corynebacterium variabile.

    Directory of Open Access Journals (Sweden)

    Sen Yang

    Full Text Available The accumulation of a considerable quantity of gibberellin fermentation residue (GFR during gibberellic acid A3 (GA3 production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL and microbes (Corynebacterium variabile to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26 °C. A total of 371 g housefly larvae meal and 2,064 g digested residue were bio-converted from 3,500 g raw GFR mixture contaning1, 400 g rice straw in the unit of (calculated dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources.

  19. From zero to hero - production of bio-based nylon from renewable resources using engineered Corynebacterium glutamicum.

    Science.gov (United States)

    Kind, Stefanie; Neubauer, Steffi; Becker, Judith; Yamamoto, Motonori; Völkert, Martin; Abendroth, Gregory von; Zelder, Oskar; Wittmann, Christoph

    2014-09-01

    Polyamides are important industrial polymers. Currently, they are produced exclusively from petrochemical monomers. Herein, we report the production of a novel bio-nylon, PA5.10 through an integration of biological and chemical approaches. First, systems metabolic engineering of Corynebacterium glutamicum was used to create an effective microbial cell factory for the production of diaminopentane as the polymer building block. In this way, a hyper-producer, with a high diaminopentane yield of 41% in shake flask culture, was generated. Subsequent fed-batch production of C. glutamicum DAP-16 allowed a molar yield of 50%, a productivity of 2.2gL(-1)h(-1), and a final titer of 88gL(-1). The streamlined producer accumulated diaminopentane without generating any by-products. Solvent extraction from alkalized broth and two-step distillation provided highly pure diaminopentane (99.8%), which was then directly accessible for poly-condensation. Chemical polymerization with sebacic acid, a ten-carbon dicarboxylic acid derived from castor plant oil, yielded the bio-nylon, PA5.10. In pure form and reinforced with glass fibers, the novel 100% bio-polyamide achieved an excellent melting temperature and the mechanical strength of the well-established petrochemical polymers, PA6 and PA6.6. It even outperformed the oil-based products in terms of having a 6% lower density. It thus holds high promise for applications in energy-friendly transportation. The demonstration of a novel route for generation of bio-based nylon from renewable sources opens the way to production of sustainable bio-polymers with enhanced material properties and represents a milestone in industrial production. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Bioconversion of Gibberellin Fermentation Residue into Feed Supplement and Organic Fertilizer Employing Housefly (Musca domestica L.) Assisted by Corynebacterium variabile

    Science.gov (United States)

    Yang, Sen; Xie, Jiufeng; Hu, Nan; Liu, Yixiong; Zhang, Jiner; Ye, Xiaobin; Liu, Ziduo

    2015-01-01

    The accumulation of a considerable quantity of gibberellin fermentation residue (GFR) during gibberellic acid A3 (GA3) production not only results in the waste of many resources, but also poses a potential hazard to the environment, indicating that the safe treatment of GFR has become an urgent issue for GA3 industry. The key to recycle GFR is converting it into an available resource and removing the GA3 residue. To this end, we established a co-bioconversion process in this study using house fly larvae (HFL) and microbes (Corynebacterium variabile) to convert GFR into insect biomass and organic fertilizer. About 85.5% GA3 in the GFR was removed under the following optimized solid-state fermentation conditions: 60% GFR, 40% rice straw powder, pH 8.5 and 6 days at 26°C. A total of 371g housefly larvae meal and 2,064g digested residue were bio-converted from 3,500g raw GFR mixture contaning1, 400g rice straw in the unit of (calculated) dry matter. HFL meal derived from GFR contained 56.4% protein, 21.6% fat, and several essential amino acids, suggesting that it is a potential alternative animal feed protein source. Additionally, the digested GFR could be utilized as an organic fertilizer with a content of 3.2% total nitrogen, 2.0% inorganic phosphorus, 1.3% potassium and 91.5% organic matter. This novel GFR bio-conversion method can mitigate potential environmental pollution and recycle the waste resources. PMID:25992605

  1. Analysis of SOS-Induced Spontaneous Prophage Induction in Corynebacterium glutamicum at the Single-Cell Level

    Science.gov (United States)

    Nanda, Arun M.; Heyer, Antonia; Krämer, Christina; Grünberger, Alexander; Kohlheyer, Dietrich

    2014-01-01

    The genome of the Gram-positive soil bacterium Corynebacterium glutamicum ATCC 13032 contains three integrated prophage elements (CGP1 to -3). Recently, it was shown that the large lysogenic prophage CGP3 (∼187 kbp) is excised spontaneously in a small number of cells. In this study, we provide evidence that a spontaneously induced SOS response is partly responsible for the observed spontaneous CGP3 induction. Whereas previous studies focused mainly on the induction of prophages at the population level, we analyzed the spontaneous CGP3 induction at the single-cell level using promoters of phage genes (Pint2 and Plysin) fused to reporter genes encoding fluorescent proteins. Flow-cytometric analysis revealed a spontaneous CGP3 activity in about 0.01 to 0.08% of the cells grown in standard minimal medium, which displayed a significantly reduced viability. A PrecA-eyfp promoter fusion revealed that a small fraction of C. glutamicum cells (∼0.2%) exhibited a spontaneous induction of the SOS response. Correlation of PrecA to the activity of downstream SOS genes (PdivS and PrecN) confirmed a bona fide induction of this stress response rather than stochastic gene expression. Interestingly, the reporter output of PrecA and CGP3 promoter fusions displayed a positive correlation at the single-cell level (ρ = 0.44 to 0.77). Furthermore, analysis of the PrecA-eyfp/Pint2-e2-crimson strain during growth revealed the highest percentage of spontaneous PrecA and Pint2 activity in the early exponential phase, when fast replication occurs. Based on these studies, we postulate that spontaneously occurring DNA damage induces the SOS response, which in turn triggers the induction of lysogenic prophages. PMID:24163339

  2. Assessment of heavy metal tolerance and hexavalent chromium reducing potential of Corynebacterium paurometabolum SKPD 1204 isolated from chromite mine seepage

    Directory of Open Access Journals (Sweden)

    Amal Kanti Paul

    2016-07-01

    Full Text Available Corynebacterium paurometabolum SKPD 1204 (MTCC 8730, a heavy metal tolerant and chromate reducing bacterium isolated from chromite mine seepage of Odisha, India has been evaluated for chromate reduction under batch culture. The isolate was found to tolerate metals like Co(II, Cu(II, Ni(II, Mn(II, Zn(II, Fe(III and Hg(II along with Cr(VI and was resistant to different antibiotics as evaluated by disc-diffusion method. The isolate, SKPD 1204 was found to reduce 62.5% of 2 mM Cr(VI in Vogel Bonner broth within 8 days of incubation. Chromate reduction capability of SKPD 1204 decreased with increase in Cr(VI concentration, but increased with increase in cell density and attained its maximum at 1010 cells/mL. Chromate reducing efficiency of SKPD 1204 was promoted in the presence of glycerol and glucose, while the highest reduction was recorded at pH 7.0 and 35 °C. The reduction process was inhibited by divalent cations Zn(II, Cd(II, Cu(II, and Ni(II, but not by Mn(II. Anions like nitrate, phosphate, sulphate and sulphite was found to be inhibitory to the process of Cr(VI reduction. Similarly, sodium fluoride, carbonyl cyanide m-chlorophenylhydrazone, sodium azide and N, N,-Di cyclohexyl carboiimide were inhibitory to chromate reduction, while 2,4-dinitrophenol appeared to be neither promotive nor inhibitory to the process.

  3. Integrated Analysis of the Transcriptome and Metabolome of Corynebacterium glutamicum during Penicillin-Induced Glutamic Acid Production.

    Science.gov (United States)

    Hirasawa, Takashi; Saito, Masaki; Yoshikawa, Katsunori; Furusawa, Chikara; Shmizu, Hiroshi

    2018-05-01

    Corynebacterium glutamicum is known for its ability to produce glutamic acid and has been utilized for the fermentative production of various amino acids. Glutamic acid production in C. glutamicum is induced by penicillin. In this study, the transcriptome and metabolome of C. glutamicum is analyzed to understand the mechanism of penicillin-induced glutamic acid production. Transcriptomic analysis with DNA microarray revealed that expression of some glycolysis- and TCA cycle-related genes, which include those encoding the enzymes involved in conversion of glucose to 2-oxoglutaric acid, is upregulated after penicillin addition. Meanwhile, expression of some TCA cycle-related genes, encoding the enzymes for conversion of 2-oxoglutaric acid to oxaloacetic acid, and the anaplerotic reactions decreased. In addition, expression of NCgl1221 and odhI, encoding proteins involved in glutamic acid excretion and inhibition of the 2-oxoglutarate dehydrogenase, respectively, is upregulated. Functional category enrichment analysis of genes upregulated and downregulated after penicillin addition revealed that genes for signal transduction systems are enriched among upregulated genes, whereas those for energy production and carbohydrate and amino acid metabolisms are enriched among the downregulated genes. As for the metabolomic analysis using capillary electrophoresis time-of-flight mass spectrometry, the intracellular content of most metabolites of the glycolysis and the TCA cycle decreased dramatically after penicillin addition. Overall, these results indicate that the cellular metabolism and glutamic acid excretion are mainly optimized at the transcription level during penicillin-induced glutamic acid production by C. glutamicum. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Formation of xylitol and xylitol-5-phosphate and its impact on growth of d-xylose-utilizing Corynebacterium glutamicum strains.

    Science.gov (United States)

    Radek, Andreas; Müller, Moritz-Fabian; Gätgens, Jochem; Eggeling, Lothar; Krumbach, Karin; Marienhagen, Jan; Noack, Stephan

    2016-08-10

    Wild-type Corynebacterium glutamicum has no endogenous metabolic activity for utilizing the lignocellulosic pentose d-xylose for cell growth. Therefore, two different engineering approaches have been pursued resulting in platform strains harbouring a functional version of either the Isomerase (ISO) or the Weimberg (WMB) pathway for d-xylose assimilation. In a previous study we found for C. glutamicum WMB by-product formation of xylitol during growth on d-xylose and speculated that the observed lower growth rates are due to the growth inhibiting effect of this compound. Based on a detailed phenotyping of the ISO, WMB and the wild-type strain of C. glutamicum, we here show that this organism has a natural capability to synthesize xylitol from d-xylose under aerobic cultivation conditions. We furthermore observed the intracellular accumulation of xylitol-5-phosphate as a result of the intracellular phosphorylation of xylitol, which was particularly pronounced in the C. glutamicum ISO strain. Interestingly, low amounts of supplemented xylitol strongly inhibit growth of this strain on d-xylose, d-glucose and d-arabitol. These findings demonstrate that xylitol is a suitable substrate of the endogenous xylulokinase (XK, encoded by xylB) and its overexpression in the ISO strain leads to a significant phosphorylation of xylitol in C. glutamicum. Therefore, in order to circumvent cytotoxicity by xylitol-5-phosphate, the WMB pathway represents an interesting alternative route for engineering C. glutamicum towards efficient d-xylose utilization. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. A thioredoxin-dependent peroxiredoxin Q from Corynebacterium glutamicum plays an important role in defense against oxidative stress.

    Directory of Open Access Journals (Sweden)

    Tao Su

    Full Text Available Peroxiredoxin Q (PrxQ that belonged to the cysteine-based peroxidases has long been identified in numerous bacteria, but the information on the physiological and biochemical functions of PrxQ remain largely lacking in Corynebacterium glutamicum. To better systematically understand PrxQ, we reported that PrxQ from model and important industrial organism C. glutamicum, encoded by the gene ncgl2403 annotated as a putative PrxQ, played important roles in adverse stress resistance. The lack of C. glutamicum prxQ gene resulted in enhanced cell sensitivity, increased ROS accumulation, and elevated protein carbonylation levels under adverse stress conditions. Accordingly, PrxQ-mediated resistance to adverse stresses mainly relied on the degradation of ROS. The physiological roles of PrxQ in resistance to adverse stresses were corroborated by its induced expression under adverse stresses, regulated directly by the stress-responsive ECF-sigma factor SigH. Through catalytical kinetic activity, heterodimer formation, and bacterial two-hybrid analysis, we proved that C. glutamicum PrxQ catalytically eliminated peroxides by exclusively receiving electrons from thioredoxin (Trx/thioredoxin reductase (TrxR system and had a broad range of oxidizing substrates, but a better efficiency for peroxynitrite and cumene hydroperoxide (CHP. Site-directed mutagenesis confirmed that the conserved Cys49 and Cys54 are the peroxide oxidation site and the resolving Cys residue, respectively. It was also discovered that C. glutamicum PrxQ mainly existed in monomer whether under its native state or functional state. Based on these results, a catalytic model of PrxQ is being proposed. Moreover, our result that C. glutamicum PrxQ can prevent the damaging effects of adverse stresses by acting as thioredoxin-dependent monomeric peroxidase could be further applied to improve the survival ability and robustness of the important bacterium during fermentation process.

  6. Overexpression of Genes Encoding Glycolytic Enzymes in Corynebacterium glutamicum Enhances Glucose Metabolism and Alanine Production under Oxygen Deprivation Conditions

    Science.gov (United States)

    Yamamoto, Shogo; Gunji, Wataru; Suzuki, Hiroaki; Toda, Hiroshi; Suda, Masako; Jojima, Toru; Inui, Masayuki

    2012-01-01

    We previously reported that Corynebacterium glutamicum strain ΔldhAΔppc+alaD+gapA, overexpressing glyceraldehyde-3-phosphate dehydrogenase-encoding gapA, shows significantly improved glucose consumption and alanine formation under oxygen deprivation conditions (T. Jojima, M. Fujii, E. Mori, M. Inui, and H. Yukawa, Appl. Microbiol. Biotechnol. 87:159–165, 2010). In this study, we employ stepwise overexpression and chromosomal integration of a total of four genes encoding glycolytic enzymes (herein referred to as glycolytic genes) to demonstrate further successive improvements in C. glutamicum glucose metabolism under oxygen deprivation. In addition to gapA, overexpressing pyruvate kinase-encoding pyk and phosphofructokinase-encoding pfk enabled strain GLY2/pCRD500 to realize respective 13% and 20% improved rates of glucose consumption and alanine formation compared to GLY1/pCRD500. Subsequent overexpression of glucose-6-phosphate isomerase-encoding gpi in strain GLY3/pCRD500 further improved its glucose metabolism. Notably, both alanine productivity and yield increased after each overexpression step. After 48 h of incubation, GLY3/pCRD500 produced 2,430 mM alanine at a yield of 91.8%. This was 6.4-fold higher productivity than that of the wild-type strain. Intracellular metabolite analysis showed that gapA overexpression led to a decreased concentration of metabolites upstream of glyceraldehyde-3-phosphate dehydrogenase, suggesting that the overexpression resolved a bottleneck in glycolysis. Changing ratios of the extracellular metabolites by overexpression of glycolytic genes resulted in reduction of the intracellular NADH/NAD+ ratio, which also plays an important role on the improvement of glucose consumption. Enhanced alanine dehydrogenase activity using a high-copy-number plasmid further accelerated the overall alanine productivity. Increase in glycolytic enzyme activities is a promising approach to make drastic progress in growth-arrested bioprocesses. PMID

  7. Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum

    Science.gov (United States)

    2012-01-01

    Background The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 might be involved in biotin uptake by C. glutamicum. Results By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation. Conclusions The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation. PMID:22243621

  8. Optimization of the IPP Precursor Supply for the Production of Lycopene, Decaprenoxanthin and Astaxanthin by Corynebacterium glutamicum

    International Nuclear Information System (INIS)

    Heider, Sabine A. E.; Wolf, Natalie; Hofemeier, Arne; Peters-Wendisch, Petra; Wendisch, Volker F.

    2014-01-01

    The biotechnologically relevant bacterium Corynebacterium glutamicum, currently used for the million ton-scale production of amino acids for the food and feed industries, is pigmented due to synthesis of the rare cyclic C50 carotenoid decaprenoxanthin and its glucosides. The precursors of carotenoid biosynthesis, isopenthenyl pyrophosphate (IPP) and its isomer dimethylallyl pyrophosphate, are synthesized in this organism via the methylerythritol phosphate (MEP) or non-mevalonate pathway. Terminal pathway engineering in recombinant C. glutamicum permitted the production of various non-native C50 and C40 carotenoids. Here, the role of engineering isoprenoid precursor supply for lycopene production by C. glutamicum was characterized. Overexpression of dxs encoding the enzyme that catalyzes the first committed step of the MEP-pathway by chromosomal promoter exchange in a prophage-cured, genome-reduced C. glutamicum strain improved lycopene formation. Similarly, an increased IPP supply was achieved by chromosomal integration of two artificial operons comprising MEP pathway genes under the control of a constitutive promoter. Combined overexpression of dxs and the other six MEP pathways genes in C. glutamicum strain LYC3-MEP was not synergistic with respect to improving lycopene accumulation. Based on C. glutamicum strain LYC3-MEP, astaxanthin could be produced in the milligrams per gram cell dry weight range when the endogenous genes crtE, crtB, and crtI for conversion of geranylgeranyl pyrophosphate to lycopene were coexpressed with the genes for lycopene cyclase and β-carotene hydroxylase from Pantoea ananatis and carotene C(4) oxygenase from Brevundimonas aurantiaca.

  9. Effect of biotin on transcription levels of key enzymes and glutamate efflux in glutamate fermentation by Corynebacterium glutamicum.

    Science.gov (United States)

    Cao, Yan; Duan, Zuoying; Shi, Zhongping

    2014-02-01

    Biotin is an important factor affecting the performance of glutamate fermentation by biotin auxotrophic Corynebacterium glutamicum and glutamate is over-produced only when initial biotin content is controlled at suitable levels or initial biotin is excessive but with Tween 40 addition during fermentation. The transcription levels of key enzymes at pyruvate, isocitrate and α-ketoglutarate metabolic nodes, as well as transport protein (TP) of glutamate were investigated under the conditions of varied biotin contents and Tween 40 supplementation. When biotin was insufficient, the genes encoding key enzymes and TP were down-regulated in the early production phase, in particular, the transcription level of isocitrate dehydrogenase (ICDH) which was only 2% of that of control. Although the cells' morphology transformation and TP level were not affected, low transcription level of ICDH led to lower final glutamate concentration (64 g/L). When biotin was excessive, the transcription levels of key enzymes were at comparable levels as those of control with ICDH as an exception, which was only 3-22% of control level throughout production phase. In this case, little intracellular glutamate accumulation (1.5 mg/g DCW) and impermeable membrane resulted in non glutamate secretion into broth, even though the quantity of TP was more than 10-folds of control level. Addition of Tween 40 when biotin was excessive stimulated the expression of all key enzymes and TP, intracellular glutamate content was much higher (10-12 mg/g DCW), and final glutamate concentration reached control level (75-80 g/L). Hence, the membrane alteration and TP were indispensable in glutamate secretion. Biotin and Tween 40 influenced the expression level of ICDH and glutamate efflux, thereby influencing glutamate production.

  10. Characterization of the biotin uptake system encoded by the biotin-inducible bioYMN operon of Corynebacterium glutamicum.

    Science.gov (United States)

    Schneider, Jens; Peters-Wendisch, Petra; Stansen, K Corinna; Götker, Susanne; Maximow, Stanislav; Krämer, Reinhard; Wendisch, Volker F

    2012-01-13

    The amino acid-producing Gram-positive Corynebacterium glutamicum is auxotrophic for biotin although biotin ring assembly starting from the precursor pimeloyl-CoA is still functional. It possesses AccBC, the α-subunit of the acyl-carboxylases involved in fatty acid and mycolic acid synthesis, and pyruvate carboxylase as the only biotin-containing proteins. Comparative genome analyses suggested that the putative transport system BioYMN encoded by cg2147, cg2148 and cg2149 might be involved in biotin uptake by C. glutamicum. By comparison of global gene expression patterns of cells grown with limiting or excess supply of biotin or with dethiobiotin as supplement replacing biotin revealed that expression of genes coding for enzymes of biotin ring assembly and for the putative uptake system was regulated according to biotin availability. RT-PCR and 5'-RACE experiments demonstrated that the genes bioY, bioM, and bioN are transcribed from one promoter as a single transcript. Biochemical analyses revealed that BioYMN catalyzes the effective uptake of biotin with a concentration of 60 nM biotin supporting a half-maximal transport rate. Maximal biotin uptake rates were at least five fold higher in biotin-limited cells as compared to cells grown with excess biotin. Overexpression of bioYMN led to an at least 50 fold higher biotin uptake rate as compared to the empty vector control. Overproduction of BioYMN alleviated biotin limitation and interfered with triggering L-glutamate production by biotin limitation. The operon bioYMN from C. glutamicum was shown to be induced by biotin limitation. Transport assays with radio-labeled biotin revealed that BioYMN functions as a biotin uptake system. Overexpression of bioYMN affected L-glutamate production triggered by biotin limitation.

  11. Chassis organism from Corynebacterium glutamicum--a top-down approach to identify and delete irrelevant gene clusters.

    Science.gov (United States)

    Unthan, Simon; Baumgart, Meike; Radek, Andreas; Herbst, Marius; Siebert, Daniel; Brühl, Natalie; Bartsch, Anna; Bott, Michael; Wiechert, Wolfgang; Marin, Kay; Hans, Stephan; Krämer, Reinhard; Seibold, Gerd; Frunzke, Julia; Kalinowski, Jörn; Rückert, Christian; Wendisch, Volker F; Noack, Stephan

    2015-02-01

    For synthetic biology applications, a robust structural basis is required, which can be constructed either from scratch or in a top-down approach starting from any existing organism. In this study, we initiated the top-down construction of a chassis organism from Corynebacterium glutamicum ATCC 13032, aiming for the relevant gene set to maintain its fast growth on defined medium. We evaluated each native gene for its essentiality considering expression levels, phylogenetic conservation, and knockout data. Based on this classification, we determined 41 gene clusters ranging from 3.7 to 49.7 kbp as target sites for deletion. 36 deletions were successful and 10 genome-reduced strains showed impaired growth rates, indicating that genes were hit, which are relevant to maintain biological fitness at wild-type level. In contrast, 26 deleted clusters were found to include exclusively irrelevant genes for growth on defined medium. A combinatory deletion of all irrelevant gene clusters would, in a prophage-free strain, decrease the size of the native genome by about 722 kbp (22%) to 2561 kbp. Finally, five combinatory deletions of irrelevant gene clusters were investigated. The study introduces the novel concept of relevant genes and demonstrates general strategies to construct a chassis suitable for biotechnological application. © 2014 The Authors. Biotechnology Journal published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence, which permits use and distribution in any medium, provided the original work is properly cited, the use is non- commercial and no modifications or adaptations are made.

  12. Mucormicosis: Una micosis emergente

    Directory of Open Access Journals (Sweden)

    Iris Tiraboschi

    2012-02-01

    Full Text Available El objetivo de este trabajo es presentar la incidencia, frecuencia, características clínicas y evolución de los pacientes con mucormicosis atendidos en el Hospital de Clínicas José de San Martín, Universidad de Buenos Aires, entre los años 1982 y 2010. Durante ese período se diagnosticaron 10 casos de mucormicosis. Los tres primeros entre 1982 y 2004 y los últimos 7 entre 2005 y 2010. La incidencia y frecuencia de esta enfermedad, para el período 1980-2004 fue 0.13 pacientes/año y 0.1 casos/10 000 egresos (IC 95%: 0.00 a 0.3 respectivamente. En el período 2005-2010 la incidencia fue 0.86 pacientes/año y la frecuencia de 1.1 casos/10 000 egresos (IC 95%: 0.5 a 2.4. Hubo nueve casos de mucormicosis rinosinuso-orbitaria, siete en pacientes con diabetes mellitus, uno en una paciente con una hemopatía maligna y neutropenia, y el restante en un paciente con HIV/sida que además estaba neutropénico y con un síndrome hemofagocítico. En una paciente se realizó el diagnóstico post mortem de mucormicosis pulmonar. El diagnóstico se efectuó por la observación de filamentos cenocíticos en los diez casos. Hubo desarrollo de mucorales en los cultivos de 8/9 pacientes; cinco Rhizopus spp y tres Mucor spp. Todos los pacientes recibieron un tratamiento inicial con anfotericina B deoxicolato, que en tres de ellos fue continuado con anfotericina B liposomal, y cirugía. Tres enfermos recibieron además un tratamiento adyuvante con oxigeno hiperbárico. La mortalidad fue 30%.

  13. El blindaje de una PC

    Directory of Open Access Journals (Sweden)

    Revista Chasqui

    2015-01-01

    Full Text Available La navegación en Internet y la consiguiente conexión a una red expone a una computadora a un sinfín de riesgos y peligros. Una PC que no sea utilizada para navegar en Internet o que no esté conectada a una red puede,incluso, ser también afectada por virus, por la utilización de disquetes contaminados que la contaminen con un virus. Para enfrentar esos problemas, la industria informática ha previsto una serie de protecciones y recaudos, de cuyo uso y utilización deben estar plenamente informados los usuarios de una PC.

  14. Leggere è una festa

    Directory of Open Access Journals (Sweden)

    Philippe Lejeune

    2011-04-01

    Full Text Available Come è possibile? Io, così agnostico, perché sono sollecitato da immagini religiose? Abbiamo inventato a poco a poco, dal 1992, poi ritualizzato, il nostro modo di fare. Una “liturgia” regola il corso delle nostre riunioni: è la “carta” dei gruppi di lettura. Le procedure devono essere le stesse in tutti i gruppi, al fine di garantire la coerenza di questo immenso lavoro. Vi è un’ortodossia, un’istanza di controllo che si preoccupa delle alterazioni delle regole, delle procedure d’invito … Come per gli ordini monastici c’è un noviziato (ogni nuovo partecipante è preso “in prova” in un gruppo e dei voti da pronunziare, in particolare quello di “leggere in simpatia” (su questo ci ritornerò dopo – voto di spoliazione di sé per aprirsi all’altro – scoprendo per gradi che non è facile come sembra.

  15. AVALIAÇÃO DE FONTES DE CARBONO PARA A PRODUÇÃO DE INIBIDOR DE CRESCIMENTO DE Aspergillus fumigatus USP2 por Corynebacterium sp.

    Directory of Open Access Journals (Sweden)

    Gabrielle Fernanda Zimmer

    2013-07-01

    Full Text Available O aumento significativo na incidência de infecções fúngicas invasivas e a resistência natural de agentes etiológicos a antifúngicos existentes têm motivado a constante pesquisa por novos agentes antifúngicos nos ultimos anos. Neste sentido, foi selcionada uma cepa de Corynebacterium sp. com potencial antagonista frente à Aspergilus fumigatus USP2. A cepa foi cultivada em fase submersa e em fase sólida, avaliando-se a variação das fontes de glicose, sacarose e glicerol em presença de peptona, bem como o meio sintético Czapek. Os caldos de cultivo submerso foram utilizados para o ensaio de antagonismo microbiano com o fungo Aspergillus fumigatus USP2. Os resultados apontam que o cultivo em fase sólida utilizando glicose como fonte de carbono apresenta maior potencial inibitório da cepa de Corynebacterium sp. sobre o fungo Aspergillus fumigatus USP2.

  16. Characterization and antimicrobial susceptibility of one antibiotic-sensitive and one multidrug-resistant Corynebacterium kroppenstedtii strain isolated from patients with granulomatous mastitis

    Directory of Open Access Journals (Sweden)

    I. Fernández-Natal

    2016-11-01

    Full Text Available Human infections associated with Corynebacterium kroppenstedtii are rarely reported, and this organism is usually described as antibiotic sensitive. Almost all published cases of C. kroppenstedtii infections have been associated with breast pathology in women and have been described in New Zealand, France, Canada, India and Japan. Here we describe the microbiologic characteristics of two strains isolated from two women diagnosed of granulomatous mastitis in Spain. One C. kroppenstedtii isolate was antibiotic sensitive while the other was multidrug resistant. Biochemical identification was possible using a wide battery of methods including API Coryne V2.0, API Strep, API NH, API NE, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and 16S rRNA gene amplification and sequencing. Antimicrobial susceptibility to 28 antibiotics as determined by Etest showed one isolate being sensitive to benzylpenicillin, ciprofloxacin, moxifloxacin, gentamicin, vancomycin, clindamycin, tetracycline, linezolid and rifampin. The second isolate showed resistance to ciprofloxacin, moxifloxacin, clindamycin, tetracycline and rifampin. The multidrug-resistant isolate contained the erm(X, tet(W, cmx, aphA1-IAB, strAB and sul1 resistance genes known from the R plasmid pJA144188 of Corynebacterium resistens. These genes were absent in the genome of the antibiotic-sensitive isolate. This report confirms the tropism of this microorganism for women's breasts and presents the first description of a multidrug-resistant C. kroppenstedtii strain.

  17. Transcriptional Analysis of the groES-groEL1, groEL2, and dnaK genes in Corynebacterium glutamicum: Characterization of Heat Shock-Induced Promoters

    Czech Academy of Sciences Publication Activity Database

    Barreiro, C.; González-Lavado, E.; Pátek, Miroslav; Martin, J. F.

    2004-01-01

    Roč. 186, č. 14 (2004), s. 4813-4817 ISSN 0021-9193 R&D Projects: GA AV ČR KSK5052113 Keywords : corynebacterium glutamicum * mrna Subject RIV: EE - Microbiology, Virology Impact factor: 4.146, year: 2004

  18. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum

    Czech Academy of Sciences Publication Activity Database

    Busche, T.; Šilar, Radoslav; Pičmanová, Martina; Pátek, Miroslav; Kalinowski, J.

    2012-01-01

    Roč. 13, č. 445 (2012), s. 445-464 ISSN 1471-2164 R&D Projects: GA ČR GC204/09/J015 Institutional research plan: CEZ:AV0Z50200510 Keywords : Corynebacterium glutamicum * ECF sigma factor * Anti-sigma factor Subject RIV: EE - Microbiology, Virology Impact factor: 4.397, year: 2012

  19. Una revista distinta: Ellas

    Directory of Open Access Journals (Sweden)

    Requena Hidalgo, Cora

    2014-06-01

    Full Text Available This article focuses on the women’s magazine Ellas, published in the mid-nineteenth century in Madrid, and discusses its relationship with other approximately contemporary magazines and newspapers in order to contribute to a reconstruction of the history of women’s publications in the Spanish press. The approach is based on an analysis of the text of each issue of the magazine and comparison with other publications, where applicable. Key features of the article include a reflection on the social rights of women, an attempt to analyse the main differences between women and men and defining features of sexual gender, the need for women’s education, etc. Studying the magazine’s content clearly reveals a continual tension between progressive and conservative ideas typical of the historical context in which gender studies emerged in Spain.Este artículo centra su atención en la revista para mujeres Ellas, publicada a mediados del siglo XIX en Madrid. Analiza, asimismo, la relación de esta publicación con algunas otras revistas y periódicos de su contexto histórico próximo, con el fin de contribuir a la reconstrucción de una Historia de las publicaciones para mujeres en la prensa española. Para ello se utiliza el análisis de textos que forman parte de los números que componen la revista, así como el análisis comparativo entre publicaciones, cuando es pertinente. Entre los aspectos de mayor interés que el artículo pone de relieve se encuentra la reflexión sobre los derechos sociales de las mujeres, el intento de análisis de las principales diferencias entre mujeres y hombres y de los rasgos definitorios de los géneros sexuales, la necesidad de educación de las mujeres, entre otros. El estudio del contenido de la publicación revela claramente una tensión contradictoria continua entre las ideas progresistas y las ideas conservadoras propias del momento histórico que dieron origen en España al nacimiento de los estudios de género.

  20. Una visita a Buero Vallejo

    Directory of Open Access Journals (Sweden)

    Luis Navarro

    1962-06-01

    Full Text Available Si usted, que ha visto representadas o ha leído "Historia de una escalera", "En la ardiente oscuridad", "Meninas", quiere conocer a su autor, véngase conmigo. Ande, apurémonos: la cita es para la una y media y ya son las dos.

  1. Gnomon una indagine sul numero

    CERN Document Server

    Zellini, Paolo

    1999-01-01

    Lo "gnomone" di cui si parla in questo libro non è quello stilo, più o meno monumentale, la cui ombra indica l'ora solare, ma un semplice strumento matematico: una figura geometrica, piana o solida, che aggiunta a un'altra ne genera una simile. Si tratta quindi di una tecnica, ampiamente diffusa nell'antichità, atta a ingrandire o rimpicciolire una forma conservandone l'aspetto. Lo gnomone non aveva solo importanza geometrica. Dalla semplice operazione di correzione "gnomonica" di una figura sono dipesi infatti la stessa nozione di numero, la definizione di vari concetti dell'Analisi e alcuni tra i principali algoritmi numerici e algebrici della matematica.

  2. Enhancing poly-γ-glutamic acid production in Bacillus amyloliquefaciens by introducing the glutamate synthesis features from Corynebacterium glutamicum.

    Science.gov (United States)

    Feng, Jun; Quan, Yufen; Gu, Yanyan; Liu, Fenghong; Huang, Xiaozhong; Shen, Haosheng; Dang, Yulei; Cao, Mingfeng; Gao, Weixia; Lu, Xiaoyun; Wang, Yi; Song, Cunjiang; Wang, Shufang

    2017-05-22

    Poly-γ-glutamic acid (γ-PGA) is a valuable polymer with glutamate as its sole precursor. Enhancement of the intracellular glutamate synthesis is a very important strategy for the improvement of γ-PGA production, especially for those glutamate-independent γ-PGA producing strains. Corynebacterium glutamicum has long been used for industrial glutamate production and it exhibits some unique features for glutamate synthesis; therefore introduction of these metabolic characters into the γ-PGA producing strain might lead to increased intracellular glutamate availability, and thus ultimate γ-PGA production. In this study, the unique glutamate synthesis features from C. glutamicum was introduced into the glutamate-independent γ-PGA producing Bacillus amyloliquefaciens NK-1 strain. After introducing the energy-saving NADPH-dependent glutamate dehydrogenase (NADPH-GDH) pathway, the NK-1 (pHT315-gdh) strain showed slightly increase (by 9.1%) in γ-PGA production. Moreover, an optimized metabolic toggle switch for controlling the expression of ɑ-oxoglutarate dehydrogenase complex (ODHC) was introduced into the NK-1 strain, because it was previously shown that the ODHC in C. glutamicum was completely inhibited when glutamate was actively produced. The obtained NK-PO1 (pHT01-xylR) strain showed 66.2% higher γ-PGA production than the NK-1 strain. However, the further combination of these two strategies (introducing both NADPH-GDH pathway and the metabolic toggle switch) did not lead to further increase of γ-PGA production but rather the resultant γ-PGA production was even lower than that in the NK-1 strain. We proposed new metabolic engineering strategies to improve the γ-PGA production in B. amyloliquefaciens. The NK-1 (pHT315-gdh) strain with the introduction of NADPH-GDH pathway showed 9.1% improvement in γ-PGA production. The NK-PO1 (pHT01-xylR) strain with the introduction of a metabolic toggle switch for controlling the expression of ODHC showed 66.2% higher

  3. Effect of Polyhydroxybutyrate (PHB) storage on L-arginine production in recombinant Corynebacterium crenatum using coenzyme regulation.

    Science.gov (United States)

    Xu, Meijuan; Qin, Jingru; Rao, Zhiming; You, Hengyi; Zhang, Xian; Yang, Taowei; Wang, Xiaoyuan; Xu, Zhenghong

    2016-01-19

    Corynebacterium crenatum SYPA 5 is the industrial strain for L-arginine production. Poly-β-hydroxybutyrate (PHB) is a kind of biopolymer stored as bacterial reserve materials for carbon and energy. The introduction of the PHB synthesis pathway into several strains can regulate the global metabolic pathway. In addition, both the pathways of PHB and L-arginine biosynthesis in the cells are NADPH-dependent. NAD kinase could upregulate the NADPH concentration in the bacteria. Thus, it is interesting to investigate how both PHB and NAD kinase affect the L-arginine biosynthesis in C. crenatum SYPA 5. C. crenatum P1 containing PHB synthesis pathway was constructed and cultivated in batch fermentation for 96 h. The enzyme activities of the key enzymes were enhanced comparing to the control strain C. crenatum SYPA 5. More PHB was found in C. crenatum P1, up to 12.7 % of the dry cell weight. Higher growth level and enhanced glucose consumptions were also observed in C. crenatum P1. With respect to the yield of L-arginine, it was 38.54 ± 0.81 g/L, increasing by 20.6 %, comparing to the control under the influence of PHB accumulation. For more NADPH supply, C. crenatum P2 was constructed with overexpression of NAD kinase based on C. crenatum P1. The NADPH concentration was increased in C. crenatum P2 comparing to the control. PHB content reached 15.7 % and 41.11 ± 1.21 g/L L-arginine was obtained in C. crenatum P2, increased by 28.6 %. The transcription levels of key L-arginine synthesis genes, argB, argC, argD and argJ in recombinant C. crenatum increased 1.9-3.0 times compared with the parent strain. Accumulation of PHB by introducing PHB synthesis pathway, together with up-regulation of coenzyme level by overexpressing NAD kinase, enables the recombinant C. crenatum to serve as high-efficiency cell factories in the long-time L-arginine fermentation. Furthermore, batch cultivation of the engineered C. crenatum revealed that it could accumulate both extracellular L

  4. Rational modification of Corynebacterium glutamicum dihydrodipicolinate reductase to switch the nucleotide-cofactor specificity for increasing l-lysine production.

    Science.gov (United States)

    Xu, Jian-Zhong; Yang, Han-Kun; Liu, Li-Ming; Wang, Ying-Yu; Zhang, Wei-Guo

    2018-03-25

    l-lysine is an important amino acid in animals and humans and NADPH is a vital cofactor for maximizing the efficiency of l-lysine fermentation. Dihydrodipicolinate reductase (DHDPR), an NAD(P)H-dependent enzyme, shows a variance in nucleotide-cofactor affinity in bacteria. In this study, we rationally engineered Corynebacterium glutamicum DHDPR (CgDHDPR) to switch its nucleotide-cofactor specificity resulting in an increase in final titer (from 82.6 to 117.3 g L -1 ), carbon yield (from 0.35 to 0.44 g [g glucose] -1 ) and productivity (from 2.07 to 2.93 g L -1  hr -1 ) of l-lysine in JL-6 ΔdapB::Ec-dapB C115G,G116C in fed-batch fermentation. To do this, we comparatively analyzed the characteristics of CgDHDPR and Escherichia coli DHDPR (EcDHDPR), indicating that hetero-expression of NADH-dependent EcDHDPR increased l-lysine production. Subsequently, we rationally modified the conserved structure of cofactor-binding motif, and results indicated that introducing the mutation K11A or R13A in CgDHDPR and introducing the mutation R16A or R39A in EcDHDPR modifies the nucleotide-cofactor affinity of DHDPR. Lastly, the effects of these mutated DHDPRs on l-lysine production were investigated. The highest increase (26.2%) in l-lysine production was observed for JL-6 ΔdapB::Ec-dapB C115G,G116C , followed by JL-6 Cg-dapB C37G,G38C (21.4%) and JL-6 ΔdapB::Ec-dapB C46G,G47C (15.2%). This is the first report of a rational modification of DHDPR that enhances the l-lysine production and yield through the modulation of nucleotide-cofactor specificity. © 2018 Wiley Periodicals, Inc.

  5. Una visita en Sud America

    Science.gov (United States)

    1982-09-01

    Oisfrute de una estadfa en el Hotel La Silla, el mejor hotel de Sud America con su tan unica atmosfera extraterrestre! Los espera su calificado personal de experimentados hoteleros, jefes de cocina, etc., ansiosos todos de satisfacer sus deseos hasta el mas mfnimo detalle. Naturalmente nuestro espacioso restaurant de tres estrellas ofrece un completo surtido de exquisitas comidas y deliciosos tragos (conocedores usualmente eligen "Oelicia Orion" 0 "Centauro Especial"). EI servicio cempleto durante 24 horas incluye nuestra ya mundialmente famosa "Cena de medianoche para los miradores de estrellas", por eso - no olvide: No pierda la oportunidad de una estadfa en EL HOTEL LA SILLA - una experiencia maravillosa!

  6. The uptake, distribution and translocation of 86Rb in alfalfa plants susceptible and resistant to the bacterial wilt and the effect of Corynebacterium insidiosum upon these processes

    International Nuclear Information System (INIS)

    Hanker, I.; Kudelova, A.

    1981-01-01

    Alfalfa (Medicago sativa L.) plants susceptible (S) and resistant (R) to bacterial wilt were fed via roots with a nutrient solution labelled with 86 Rb + , at different times after inoculation with Corynebacterium insidiosum (McCull.) H.L. Jens. The infection did not affect 86 Rb + uptake per plant in the course of a 14-day-period following inoculation; however, it affected its distribution differently in the S- and the R-plants. 86 Rb + uptake significantly decreased due to the infection in the S-plants on the day 49 after inoculation (a 4-h-exposure to 86 Rb + ), with the ions more slowly translocated to the shoots in diseased S-plants than in diseased R-plants. Likely factors causing these effects and their relationship to alfalfa resistance to bacterial wilt are discussed. (author)

  7. Isolation of Corynebacterium Xerosis from Jordanian Soil and a Study on its Antimicrobial Activity against a Range of Bacteria and Fungi

    International Nuclear Information System (INIS)

    El-Banna, Nasser

    2004-01-01

    A bacterial strain which has been identified as Corneybacterium Xerosis NB-2 was isolated from a soil sample from Jerash Private University, Jerash, Jordan. This isolate was found to produce an antimicrobial substance active only against filamentous fungi and yeasts (Aspergillus niger SQ 40, Fusarium oxysporium SQ11, Verticillium dahliae SQ 42, Saccharomyces SQ 46 and Candida albicans SQ 47). However, all tested gram-positive bacteria and gram negative bacteria (Bacillus megaterium SQ5, Bacillus cereus SQ6, Staphylococcus aureus SQ9, Streptococcus pyogens SQ10, Eschericshia coli SQ 22, Klepsiella spp SQ33 and SQ33 and Pseudonomas mallei SQ 34) were found to be resistant. In batch culture, the isolated NB-2 produced the antimicrobial substance late in the growth phase and antimicrobial activity of Corynebacterium Xerosis against filamentous fungi and yeasts which was not previously described. (author)

  8. The role of lipids and salts in two-dimensional crystallization of the glycine-betaine transporter BetP from Corynebacterium glutamicum

    DEFF Research Database (Denmark)

    Tsai, Ching-Ju; Ejsing, Christer S.; Shevchenko, Andrej

    2007-01-01

    The osmoregulated and chill-sensitive glycine-betaine transporter (BetP) from Corynebacterium glutamicum was reconstituted into lipids to form two-dimensional (2D) crystals. The sensitivity of BetP partly bases on its interaction with lipids. Here we demonstrate that lipids and salts influence...... crystal morphology and crystallinity of a C-terminally truncated BetP. The salt type and concentration during crystallization determined whether crystals grew in the form of planar-tubes, sheets or vesicles, while the lipid type influenced crystal packing and order. Three different lipid preparations...... for 2D crystallization were compared. Only the use of lipids extracted from C. glutamicum cells led to the formation of large, well-ordered crystalline areas. To understand the lipid-derived influence on crystallinity, lipid extracts from different stages of the crystallization process were analyzed...

  9. Quinone-dependent D-lactate dehydrogenase Dld (Cg1027 is essential for growth of Corynebacterium glutamicum on D-lactate

    Directory of Open Access Journals (Sweden)

    Oikawa Tadao

    2010-12-01

    Full Text Available Abstract Background Corynebacterium glutamicum is able to grow with lactate as sole or combined carbon and energy source. Quinone-dependent L-lactate dehydrogenase LldD is known to be essential for utilization of L-lactate by C. glutamicum. D-lactate also serves as sole carbon source for C. glutamicum ATCC 13032. Results Here, the gene cg1027 was shown to encode the quinone-dependent D-lactate dehydrogenase (Dld by enzymatic analysis of the protein purified from recombinant E. coli. The absorption spectrum of purified Dld indicated the presence of FAD as bound cofactor. Inactivation of dld resulted in the loss of the ability to grow with D-lactate, which could be restored by plasmid-borne expression of dld. Heterologous expression of dld from C. glutamicum ATCC 13032 in C. efficiens enabled this species to grow with D-lactate as sole carbon source. Homologs of dld of C. glutamicum ATCC 13032 are not encoded in the sequenced genomes of other corynebacteria and mycobacteria. However, the dld locus of C. glutamicum ATCC 13032 shares 2367 bp of 2372 bp identical nucleotides with the dld locus of Propionibacterium freudenreichii subsp. shermanii, a bacterium used in Swiss-type cheese making. Both loci are flanked by insertion sequences of the same family suggesting a possible event of horizontal gene transfer. Conclusions Cg1067 encodes quinone-dependent D-lactate dehydrogenase Dld of Corynebacterium glutamicum. Dld is essential for growth with D-lactate as sole carbon source. The genomic region of dld likely has been acquired by horizontal gene transfer.

  10. In Vivo Roles of Fatty Acid Biosynthesis Enzymes in Biosynthesis of Biotin and α-Lipoic Acid in Corynebacterium glutamicum.

    Science.gov (United States)

    Ikeda, Masato; Nagashima, Takashi; Nakamura, Eri; Kato, Ryosuke; Ohshita, Masakazu; Hayashi, Mikiro; Takeno, Seiki

    2017-10-01

    For fatty acid biosynthesis, Corynebacterium glutamicum uses two type I fatty acid synthases (FAS-I), FasA and FasB, in addition to acetyl-coenzyme A (CoA) carboxylase (ACC) consisting of AccBC, AccD1, and AccE. The in vivo roles of the enzymes in supplying precursors for biotin and α-lipoic acid remain unclear. Here, we report genetic evidence demonstrating that the biosynthesis of these cofactors is linked to fatty acid biosynthesis through the FAS-I pathway. For this study, we used wild-type C. glutamicum and its derived biotin vitamer producer BFI-5, which was engineered to express Escherichia coli bioBF and Bacillus subtilis bioI Disruption of either fasA or fasB in strain BFI-5 led to decreased production of biotin vitamers, whereas its amplification contributed to increased production, with a larger impact of fasA in both cases. Double disruptions of fasA and fasB resulted in no biotin vitamer production. The acc genes showed a positive effect on production when amplified simultaneously. Augmented fatty acid biosynthesis was also reflected in pimelic acid production when carbon flow was blocked at the BioF reaction. These results indicate that carbon flow down the FAS-I pathway is destined for channeling into the biotin biosynthesis pathway, and that FasA in particular has a significant impact on precursor supply. In contrast, fasB disruption resulted in auxotrophy for lipoic acid or its precursor octanoic acid in both wild-type and BFI-5 strains. The phenotypes were fully complemented by plasmid-mediated expression of fasB but not fasA These results reveal that FasB plays a specific physiological role in lipoic acid biosynthesis in C. glutamicum IMPORTANCE For the de novo biosynthesis of fatty acids, C. glutamicum exceptionally uses a eukaryotic multifunctional type I fatty acid synthase (FAS-I) system comprising FasA and FasB, in contrast to most bacteria, such as E. coli and B. subtilis , which use an individual nonaggregating type II fatty acid synthase

  11. Una experiencia de campo con una cooperativa de promotores ambientales

    OpenAIRE

    Bazán, Claudia I.; Ferrari, Liliana

    2014-01-01

    La presente ponencia describe el trabajo que se está realizando con una cooperativa de promotores ambientes, El CorreCamino, cuya propuesta no es pensada como una actividad marginal sino que toma el proceso de reciclado como contribución social y enfatiza el papel activo del trabajador en solidaridad con los vecinos y el espacio ambiental. La metodología utilizada es la Investigación Acción Participativa (IAP) cuyo principal objetivo es aunar los ...

  12. alumnos de una sola cultura?

    Directory of Open Access Journals (Sweden)

    Siegfried Boehm

    2006-01-01

    Full Text Available Dado que en la actualidad hay mayores posibilidades para practicar una lengua extranjera en su contexto natural con nativohablantes, es imprescindible poseer una cierta competencia intercultural a fin de que este diálogo pueda llevarse a cabo exitosamente. Sin embargo, los libros de texto convencionales editados en el país de origen de la lengua estudiada difícilmente pueden cubrir este requisito, puesto que las particularidades culturales de una sociedad sólo se vuelven interculturales al compararlas con la cultura de los alumnos. En el artículo presente se proponen varios ejercicios enfocados al aprendizaje intercultural en donde no sólo se aprenden las normas, reglas y actitudes de la cultura meta, en este caso de Alemania, Austria y Suiza, sino que también se estimula la reflexión sobre las de la cultura propia. Esta sensibilización cultural es indispensable para lograr una comunicación equitativa entre personas de diferentes culturas.

  13. Polynucleotide Phosphorylase, RNase E/G, and YbeY Are Involved in the Maturation of 4.5S RNA in Corynebacterium glutamicum.

    Science.gov (United States)

    Maeda, Tomoya; Tanaka, Yuya; Wachi, Masaaki; Inui, Masayuki

    2017-03-01

    Corynebacterium glutamicum has been applied for the industrial production of various metabolites, such as amino acids. To understand the biosynthesis of the membrane protein in this bacterium, we investigated the process of signal recognition particle (SRP) assembly. SRP is found in all three domains of life and plays an important role in the membrane insertion of proteins. SRP RNA is initially transcribed as precursor molecules; however, relatively little is known about its maturation. In C. glutamicum , SRP consists of the Ffh protein and 4.5S RNA lacking an Alu domain. In this study, we found that 3'-to-5' exoribonuclease, polynucleotide phosphorylase (PNPase), and two endo-type RNases, RNase E/G and YbeY, are involved in the 3' maturation of 4.5S RNA in C. glutamicum The mature form of 4.5S RNA was inefficiently formed in Δ rneG Δ pnp mutant cells, suggesting the existence of an alternative pathway for the 3' maturation of 4.5S RNA. Primer extension analysis also revealed that the 5' mature end of 4.5S RNA corresponds to that of the transcriptional start site. Immunoprecipitated Ffh protein contained immature 4.5S RNA in Δ pnp , Δ rneG , and Δ ybeY mutants, suggesting that 4.5S RNA precursors can interact with Ffh. These results imply that the maturation of 4.5S RNA can be performed in the 4.5S RNA-Ffh complex. IMPORTANCE Overproduction of a membrane protein, such as a transporter, is useful for engineering of strains of Corynebacterium glutamicum , which is a workhorse of amino acid production. To understand membrane protein biogenesis in this bacterium, we investigated the process of signal recognition particle (SRP) assembly. SRP contains the Ffh protein and SRP RNA and plays an important role in the membrane insertion of proteins. Although SRP RNA is highly conserved among the three domains of life, relatively little is known about its maturation. We show that PNPase, RNase E/G, and YbeY are involved in the 3' maturation of the SRP RNA (4.5S RNA) in

  14. Complete genome sequence, lifestyle, and multi-drug resistance of the human pathogen Corynebacterium resistens DSM 45100 isolated from blood samples of a leukemia patient

    Science.gov (United States)

    2012-01-01

    Background Corynebacterium resistens was initially recovered from human infections and recognized as a new coryneform species that is highly resistant to antimicrobial agents. Bacteremia associated with this organism in immunocompromised patients was rapidly fatal as standard minocycline therapies failed. C. resistens DSM 45100 was isolated from a blood culture of samples taken from a patient with acute myelocytic leukemia. The complete genome sequence of C. resistens DSM 45100 was determined by pyrosequencing to identify genes contributing to multi-drug resistance, virulence, and the lipophilic lifestyle of this newly described human pathogen. Results The genome of C. resistens DSM 45100 consists of a circular chromosome of 2,601,311 bp in size and the 28,312-bp plasmid pJA144188. Metabolic analysis showed that the genome of C. resistens DSM 45100 lacks genes for typical sugar uptake systems, anaplerotic functions, and a fatty acid synthase, explaining the strict lipophilic lifestyle of this species. The genome encodes a broad spectrum of enzymes ensuring the availability of exogenous fatty acids for growth, including predicted virulence factors that probably contribute to fatty acid metabolism by damaging host tissue. C. resistens DSM 45100 is able to use external L-histidine as a combined carbon and nitrogen source, presumably as a result of adaptation to the hitherto unknown habitat on the human skin. Plasmid pJA144188 harbors several genes contributing to antibiotic resistance of C. resistens DSM 45100, including a tetracycline resistance region of the Tet W type known from Lactobacillus reuteri and Streptococcus suis. The tet(W) gene of pJA144188 was cloned in Corynebacterium glutamicum and was shown to confer high levels of resistance to tetracycline, doxycycline, and minocycline in vitro. Conclusions The detected gene repertoire of C. resistens DSM 45100 provides insights into the lipophilic lifestyle and virulence functions of this newly recognized

  15. Metabolic engineering of an ATP-neutral Embden-Meyerhof-Parnas pathway in Corynebacterium glutamicum: growth restoration by an adaptive point mutation in NADH dehydrogenase.

    Science.gov (United States)

    Komati Reddy, Gajendar; Lindner, Steffen N; Wendisch, Volker F

    2015-03-01

    Corynebacterium glutamicum uses the Embden-Meyerhof-Parnas pathway of glycolysis and gains 2 mol of ATP per mol of glucose by substrate-level phosphorylation (SLP). To engineer glycolysis without net ATP formation by SLP, endogenous phosphorylating NAD-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was replaced by nonphosphorylating NADP-dependent glyceraldehyde-3-phosphate dehydrogenase (GapN) from Clostridium acetobutylicum, which irreversibly converts glyceraldehyde-3-phosphate (GAP) to 3-phosphoglycerate (3-PG) without generating ATP. As shown recently (S. Takeno, R. Murata, R. Kobayashi, S. Mitsuhashi, and M. Ikeda, Appl Environ Microbiol 76:7154-7160, 2010, http://dx.doi.org/10.1128/AEM.01464-10), this ATP-neutral, NADPH-generating glycolytic pathway did not allow for the growth of Corynebacterium glutamicum with glucose as the sole carbon source unless hitherto unknown suppressor mutations occurred; however, these mutations were not disclosed. In the present study, a suppressor mutation was identified, and it was shown that heterologous expression of udhA encoding soluble transhydrogenase from Escherichia coli partly restored growth, suggesting that growth was inhibited by NADPH accumulation. Moreover, genome sequence analysis of second-site suppressor mutants that were able to grow faster with glucose revealed a single point mutation in the gene of non-proton-pumping NADH:ubiquinone oxidoreductase (NDH-II) leading to the amino acid change D213G, which was shared by these suppressor mutants. Since related NDH-II enzymes accepting NADPH as the substrate possess asparagine or glutamine residues at this position, D213G, D213N, and D213Q variants of C. glutamicum NDH-II were constructed and were shown to oxidize NADPH in addition to NADH. Taking these findings together, ATP-neutral glycolysis by the replacement of endogenous NAD-dependent GAPDH with NADP-dependent GapN became possible via oxidation of NADPH formed in this pathway by mutant NADPH

  16. In vitro activities of the new semisynthetic glycopeptide telavancin (TD-6424), vancomycin, daptomycin, linezolid, and four comparator agents against anaerobic gram-positive species and Corynebacterium spp.

    Science.gov (United States)

    Goldstein, Ellie J C; Citron, Diane M; Merriam, C Vreni; Warren, Yumi A; Tyrrell, Kerin L; Fernandez, Helen T

    2004-06-01

    Telavancin is a new semisynthetic glycopeptide anti-infective with multiple mechanisms of action, including inhibition of bacterial membrane phospholipid synthesis and inhibition of bacterial cell wall synthesis. We determined the in vitro activities of telavancin, vancomycin, daptomycin, linezolid, quinupristin-dalfopristin, imipenem, piperacillin-tazobactam, and ampicillin against 268 clinical isolates of anaerobic gram-positive organisms and 31 Corynebacterium strains using agar dilution methods according to National Committee for Clinical Laboratory Standards procedures. Plates with daptomycin were supplemented with Ca(2+) to 50 mg/liter. The MICs at which 90% of isolates tested were inhibited (MIC(90)s) for telavancin and vancomycin were as follows: Actinomyces spp. (n = 45), 0.25 and 1 microg/ml, respectively; Clostridium difficile (n = 14), 0.25 and 1 microg/ml, respectively; Clostridium ramosum (n = 16), 1 and 4 microg/ml, respectively; Clostridium innocuum (n = 15), 4 and 16 microg/ml, respectively; Clostridium clostridioforme (n = 15), 8 and 1 microg/ml, respectively; Eubacterium group (n = 33), 0.25 and 2 microg/ml, respectively; Lactobacillus spp. (n = 26), 0.5 and 4 microg/ml, respectively; Propionibacterium spp. (n = 34), 0.125 and 0.5 microg/ml, respectively; Peptostreptococcus spp. (n = 52), 0.125 and 0.5 microg/ml, respectively; and Corynebacterium spp. (n = 31), 0.03 and 0.5 microg/ml, respectively. The activity of TD-6424 was similar to that of quinupristin-dalfopristin for most strains except C. clostridioforme and Lactobacillus casei, where quinupristin-dalfopristin was three- to fivefold more active. Daptomycin had decreased activity (MIC > 4 microg/ml) against 14 strains of Actinomyces spp. and all C. ramosum, Eubacterium lentum, and Lactobacillus plantarum strains. Linezolid showed decreased activity (MIC > 4 microg/ml) against C. ramosum, two strains of C. difficile, and 15 strains of Lactobacillus spp. Imipenem and piperacillin

  17. Una minga para el posdesarrollo

    Directory of Open Access Journals (Sweden)

    Arturo Escobar

    2011-01-01

    Full Text Available El artículo sintetiza algunas conclusiones a las que han llegado movimientos sociales y académicos en las últimas dos décadas al reflexionar sobre la globalización y sus implicaciones; el modelo dominante, basado en las nociones de "desarrollo" y "modernidad", ha entrado en crisis. Por lo tanto, se hace necesario avanzar en una transición cultural que se pueda comprender como un cambio de época y no sólo como una época de cambios. Para llevar a cabo esta transformación, se deben resolver las con-tradicciones existentes entre el neodesarrollismo y el postdesarrollo, por supuesto, a favor de éste último.

  18. Una entrada popular al Internet

    Directory of Open Access Journals (Sweden)

    Bruce Girard

    2015-01-01

    Full Text Available El Internet ofrece la posibilidad de una comunicación rápida y económica. El proyecto de AMARC y CEDEP (Ecuador financiado, en parte, por el Buró Canadiense de Educación Internacional, busca aprovechar esta posibilidad para proporcionar un servicio de noticias a las radios comunitarias de la región.

  19. "Rera": historia de una palabra

    OpenAIRE

    Fradejas Lebrero, José

    2011-01-01

    Se analiza una palabra que es un hapax legomenon que solo se documenta en la Vita Beata de Juan de Lucena y se establece, a partir de ella, que el étimo propuesto para algunos derivados es erróneo. It is analyzed a word that is only attested in Juan de Lucena's Vita Beata, and it is established that the proposed etymon for some of it reflexes is mistaken.

  20. Sevilla, una encrucijada de caminos

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    Manuel Martín Martin

    2009-01-01

    Full Text Available El mundo del flamenco, tan acostumbrado a contemplar la historia del género como una sucesión de nombres distinguidos que, por su significación expresiva o por su carácter de maestría incontestable, simbolizan una época, olvida con frecuencia el universo en que esa constelación de estrellas irradia su luminosidad más intensa, esto es, relega a un rol de menor importancia el ámbito en que se desarrollaron unos talentos especiales que, a lapostre, describirían situaciones y formas que el tiempo estimaría de verdadera trascendencia. Sin ánimo de caer en un determinismo localista demasiado forzoso, justo es decir que uno de los más grandes milagros de la música flamenca, se llama Sevilla, su barrio de Triana y muchos pueblos de la provincia. Una unidad demográfica que ofrece en grado sumo el origen de la complacencia en los goces de los sentidos.

  1. Una Utopia Factible: Latin Vision

    Directory of Open Access Journals (Sweden)

    Peter Schenkel

    2015-01-01

    Full Text Available Que la información de noticiero de radio y televisión oficiales en la mayoría de los países latinoamericanos, no brilla precisamente por su imparcialidad. Además los noticieros con información sobre actividades, políticas y criterios de entidades públicas difunden un punto de vista que no es necesariamente compartido por sectores políticos y económicos de la sociedad civil y que tampoco refleja necesariamente lo que ocurre en un país. Este es un hecho comprobado hasta la saciedad y constituye un problema que exigirá que las contribuciones al programa común se distingan por una excelente selección representativa del multifacético acontecer diario de una nación. Las estadísticas de otros sistemas como EUROVISION y ASIAVISION muestran que una noticia se difunde más si es oportuna - "caliente"-, objetiva y presentada con calidad.

  2. [Construction of Corynebacterium crenatum AS 1.542 δ argR and analysis of transcriptional levels of the related genes of arginine biosynthetic pathway].

    Science.gov (United States)

    Chen, Xuelan; Tang, Li; Jiao, Haitao; Xu, Feng; Xiong, Yonghua

    2013-01-04

    ArgR, coded by the argR gene from Corynebacterium crenatum AS 1.542, acts as a negative regulator in arginine biosynthetic pathway. However, the effect of argR on transcriptional levels of the related biosynthetic genes has not been reported. Here, we constructed a deletion mutant of argR gene: C. crenatum AS 1.542 Delta argR using marker-less knockout technology, and compared the changes of transcriptional levels of the arginine biosynthetic genes between the mutant strain and the wild-type strain. We used marker-less knockout technology to construct C. crenatum AS 1.542 Delta argR and analyzed the changes of the relate genes at the transcriptional level using real-time fluorescence quantitative PCR. C. crenatum AS 1.542 Delta argR was successfully obtained and the transcriptional level of arginine biosynthetic genes in this mutant increased significantly with an average of about 162.1 folds. The arginine biosynthetic genes in C. crenatum are clearly controlled by the negative regulator ArgR. However, the deletion of this regulator does not result in a clear change in arginine production in the bacteria.

  3. Effect of biosurfactant and fertilizer on biodegradation of crude oil by marine isolates of Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa.

    Science.gov (United States)

    Thavasi, Rengathavasi; Jayalakshmi, Singaram; Banat, Ibrahim M

    2011-01-01

    This study was conducted to investigate the effects of fertilizers and biosurfactants on biodegradation of crude oil by three marine bacterial isolates; Bacillus megaterium, Corynebacterium kutscheri and Pseudomonas aeruginosa. Five sets of experiments were carried out in shake flask and microcosm conditions with crude oil as follows: Set 1-only bacterial cells added (no fertilizer and biosurfactant), Set 2-with additional fertilizer only, Set 3-with additional biosurfactant only, Set 4-with added biosurfactant+fertilizer, Set 5-with no bacterial cells added (control), all the above experimental sets were incubated for 168 h. The biosurfactant+fertilizer added Set 4, resulted in maximum crude oil degradation within shake flask and microcosm conditions. Among the three bacterial isolates, P. aeruginosa and biosurfactant produced by this strain resulted in maximum crude oil degradation compared to the other two bacterial strains investigated. Interestingly, when biosurfactant and bacterial cells were used (Set 3), significant oil biodegradation activity occurred and the difference between this treatment and that in Set 4 with added fertilizer+biosurfactant were only 4-5% higher degradation level in shake flask and 3.2-7% in microcosm experiments for all three bacterial strains used. It is concluded that, biosurfactants alone capable of promoting biodegradation to a large extent without added fertilizers, which will reduce the cost of bioremediation process and minimizes the dilution or wash away problems encountered when water soluble fertilizers used during bioremediation of aquatic environments. Copyright © 2010 Elsevier Ltd. All rights reserved.

  4. A thiol-disulfide oxidoreductase of the Gram-positive pathogen Corynebacterium diphtheriae is essential for viability, pilus assembly, toxin production and virulence.

    Science.gov (United States)

    Reardon-Robinson, Melissa E; Osipiuk, Jerzy; Jooya, Neda; Chang, Chungyu; Joachimiak, Andrzej; Das, Asis; Ton-That, Hung

    2015-12-01

    The Gram-positive pathogen Corynebacterium diphtheriae exports through the Sec apparatus many extracellular proteins that include the key virulence factors diphtheria toxin and the adhesive pili. How these proteins attain their native conformations after translocation as unfolded precursors remains elusive. The fact that the majority of these exported proteins contain multiple cysteine residues and that several membrane-bound oxidoreductases are encoded in the corynebacterial genome suggests the existence of an oxidative protein-folding pathway in this organism. Here we show that the shaft pilin SpaA harbors a disulfide bond in vivo and alanine substitution of these cysteines abrogates SpaA polymerization and leads to the secretion of degraded SpaA peptides. We then identified a thiol-disulfide oxidoreductase (MdbA), whose structure exhibits a conserved thioredoxin-like domain with a CPHC active site. Remarkably, deletion of mdbA results in a severe temperature-sensitive cell division phenotype. This mutant also fails to assemble pilus structures and is greatly defective in toxin production. Consistent with these defects, the ΔmdbA mutant is attenuated in a guinea pig model of diphtheritic toxemia. Given its diverse cellular functions in cell division, pilus assembly and toxin production, we propose that MdbA is a component of the general oxidative folding machine in C. diphtheriae. © 2015 John Wiley & Sons Ltd.

  5. A de novo NADPH generation pathway for improving lysine production of Corynebacterium glutamicum by rational design of the coenzyme specificity of glyceraldehyde 3-phosphate dehydrogenase.

    Science.gov (United States)

    Bommareddy, Rajesh Reddy; Chen, Zhen; Rappert, Sugima; Zeng, An-Ping

    2014-09-01

    Engineering the cofactor availability is a common strategy of metabolic engineering to improve the production of many industrially important compounds. In this work, a de novo NADPH generation pathway is proposed by altering the coenzyme specificity of a native NAD-dependent glyceraldehyde 3-phosphate dehydrogenase (GAPDH) to NADP, which consequently has the potential to produce additional NADPH in the glycolytic pathway. Specifically, the coenzyme specificity of GAPDH of Corynebacterium glutamicum is systematically manipulated by rational protein design and the effect of the manipulation for cellular metabolism and lysine production is evaluated. By a combinatorial modification of four key residues within the coenzyme binding sites, different GAPDH mutants with varied coenzyme specificity were constructed. While increasing the catalytic efficiency of GAPDH towards NADP enhanced lysine production in all of the tested mutants, the most significant improvement of lysine production (~60%) was achieved with the mutant showing similar preference towards both NAD and NADP. Metabolic flux analysis with (13)C isotope studies confirmed that there was no significant change of flux towards the pentose phosphate pathway and the increased lysine yield was mainly attributed to the NADPH generated by the mutated GAPDH. The present study highlights the importance of protein engineering as a key strategy in de novo pathway design and overproduction of desired products. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  6. Production of L-glutamic Acid with Corynebacterium glutamicum (NCIM 2168) and Pseudomonas reptilivora (NCIM 2598): A Study on Immobilization and Reusability.

    Science.gov (United States)

    Shyamkumar, Rajaram; Moorthy, Innasi Muthu Ganesh; Ponmurugan, Karuppiah; Baskar, Rajoo

    2014-07-01

    L-glutamic acid is one of the major amino acids that is present in a wide variety of foods. It is mainly used as a food additive and flavor enhancer in the form of sodium salt. Corynebacterium glutamicum (C. glutamicum) is one of the major organisms widely used for glutamic acid production. The study was dealing with immobilization of C. glutamicum and mixed culture of C. glutamicum and Pseudomonas reptilivora (P. reptilivora) for L-glutamic acid production using submerged fermentation. 2, 3 and 5% sodium alginate concentrations were used for production and reusability of immobilized cells for 5 more trials. The results revealed that 2% sodium alginate concentration produced the highest yield (13.026±0.247 g/l by C. glutamicum and 16.026±0.475 g/l by mixed immobilized culture). Moreover, reusability of immobilized cells was evaluated in 2% concentration with 5 more trials. However, when the number of cycles increased, the production of L-glutamic acid decreased. Production of glutamic acid using optimized medium minimizes the time needed for designing the medium composition. It also minimizes external contamination. Glutamic acid production gradually decreased due to multiple uses of beads and consequently it reduces the shelf life.

  7. Metabolic flux distributions in Corynebacterium glutamicum during growth and lysine overproduction. Reprinted from Biotechnology and Bioengineering, Vol. 41, Pp 633-646 (1993).

    Science.gov (United States)

    Vallino, J J; Stephanopoulos, G

    2000-03-20

    The two main contributions of this article are the solidification of Corynebacterium glutamicum biochemistry guided by bioreaction network analysis, and the determination of basal metabolic flux distributions during growth and lysine synthesis. Employed methodology makes use of stoichiometrically based mass balances to determine flux distributions in the C. glutamicum metabolic network. Presented are a brief description of the methodology, a thorough literature review of glutamic acid bacteria biochemistry, and specific results obtained through a combination of fermentation studies and analysis-directed intracellular assays. The latter include the findings of the lack of activity of glyoxylate shunt, and that phosphoenolpyruvate carboxylase (PPC) is the only anaplerotic reaction expressed in C. glutamicum cultivated on glucose minimal media. Network simplifications afforded by the above findings facilitated the determination of metabolic flux distributions under a variety of culture conditions and led to the following conclusions. Both the pentose phosphate pathway and PPC support significant fluxes during growth and lysine overproduction, and that flux partitioning at the glucosa-6-phosphate branch point does not appear to limit lysine synthesis. Copyright 1993 John Wiley & Sons, Inc.

  8. Selective oxidation of trimethylolpropane to 2,2-bis(hydroxymethyl)butyric acid using growing cells of Corynebacterium sp. ATCC 21245.

    Science.gov (United States)

    Sayed, Mahmoud; Dishisha, Tarek; Sayed, Waiel F; Salem, Wesam M; Temerk, Hanan A; Pyo, Sang-Hyun

    2016-03-10

    Multifunctional chemicals including hydroxycarboxylic acids are gaining increasing interest due to their growing applications in the polymer industry. One approach for their production is a biological selective oxidation of polyols, which is difficult to achieve by conventional chemical catalysis. In the present study, trimethylolpropane (TMP), a trihydric alcohol, was subjected to selective oxidation using growing cells of Corynebacterium sp. ATCC 21245 as a biocatalyst and yielding the dihydroxy-monocarboxylic acid, 2,2-bis(hydroxymethyl)butyric acid (BHMB). The study revealed that co-substrates are crucial for this reaction. Among the different evaluated co-substrates, a mixture of glucose, xylose and acetate at a ratio of 5:5:2 was found optimum. The optimal conditions for biotransformation were pH 8, 1v/v/m airflow and 500rpm stirring speed. In batch mode of operation, 70.6% of 5g/l TMP was converted to BHMB in 10 days. For recovery of the product the adsorption pattern of BHMB to the anion exchange resin, Ambersep(®) 900 (OH(-)), was investigated in batch and column experiments giving maximum static and dynamic binding capacities of 135 and 144mg/g resin, respectively. BHMB was separated with 89.7% of recovery yield from the fermentation broth. The approach is applicable for selective oxidation of other highly branched polyols by biotransformation. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Transcriptome and Gene Ontology (GO) Enrichment Analysis Reveals Genes Involved in Biotin Metabolism That Affect L-Lysine Production in Corynebacterium glutamicum.

    Science.gov (United States)

    Kim, Hong-Il; Kim, Jong-Hyeon; Park, Young-Jin

    2016-03-09

    Corynebacterium glutamicum is widely used for amino acid production. In the present study, 543 genes showed a significant change in their mRNA expression levels in L-lysine-producing C. glutamicum ATCC21300 than that in the wild-type C. glutamicum ATCC13032. Among these 543 differentially expressed genes (DEGs), 28 genes were up- or downregulated. In addition, 454 DEGs were functionally enriched and categorized based on BLAST sequence homologies and gene ontology (GO) annotations using the Blast2GO software. Interestingly, NCgl0071 (bioB, encoding biotin synthase) was expressed at levels ~20-fold higher in the L-lysine-producing ATCC21300 strain than that in the wild-type ATCC13032 strain. Five other genes involved in biotin metabolism or transport--NCgl2515 (bioA, encoding adenosylmethionine-8-amino-7-oxononanoate aminotransferase), NCgl2516 (bioD, encoding dithiobiotin synthetase), NCgl1883, NCgl1884, and NCgl1885--were also expressed at significantly higher levels in the L-lysine-producing ATCC21300 strain than that in the wild-type ATCC13032 strain, which we determined using both next-generation RNA sequencing and quantitative real-time PCR analysis. When we disrupted the bioB gene in C. glutamicum ATCC21300, L-lysine production decreased by approximately 76%, and the three genes involved in biotin transport (NCgl1883, NCgl1884, and NCgl1885) were significantly downregulated. These results will be helpful to improve our understanding of C. glutamicum for industrial amino acid production.

  10. Efficient production of α-ketoglutarate in the gdh deleted Corynebacterium glutamicum by novel double-phase pH and biotin control strategy.

    Science.gov (United States)

    Li, Yanjun; Sun, Lanchao; Feng, Jia; Wu, Ruifang; Xu, Qingyang; Zhang, Chenglin; Chen, Ning; Xie, Xixian

    2016-06-01

    Production of L-glutamate using a biotin-deficient strain of Corynebacterium glutamicum has a long history. The process is achieved by controlling biotin at suboptimal dose in the initial fermentation medium, meanwhile feeding NH4OH to adjust pH so that α-ketoglutarate (α-KG) can be converted to L-glutamate. In this study, we deleted glutamate dehydrogenase (gdh1 and gdh2) of C. glutamicum GKG-047, an L-glutamate overproducing strain, to produce α-KG that is the direct precursor of L-glutamate. Based on the method of L-glutamate fermentation, we developed a novel double-phase pH and biotin control strategy for α-KG production. Specifically, NH4OH was added to adjust the pH at the bacterial growth stage and NaOH was used when the cells began to produce acid; besides adding an appropriate amount of biotin in the initial medium, certain amount of additional biotin was supplemented at the middle stage of fermentation to maintain a high cell viability and promote the carbon fixation to the flux of α-KG production. Under this control strategy, 45.6 g/L α-KG accumulated after 30-h fermentation in a 7.5-L fermentor and the productivity and yield achieved were 1.52 g/L/h and 0.42 g/g, respectively.

  11. Development of an indirect ELISA to detect Corynebacterium pseudotuberculosis specific antibodies in sheep employing T1 strain culture supernatant as antigen

    Directory of Open Access Journals (Sweden)

    Miriam F. Rebouças

    2013-11-01

    Full Text Available Corynebacterium pseudotuberculosis is the etiologic agent of caseous lymphadenitis (CLA, a chronic disease that affects goats and sheep, characterized by granuloma formation in subcutaneous and internal lymph nodes. CLA causes significant economic losses to commercial goat herds. In this study, we aimed to test secreted antigens secreted from T1 strain bacteria grown in brain heart infusion (BHI broth in an indirect ELISA system to determine the presence of specific immunoglobulins against C. pseudotuberculosis. We analyzed the BHI antigen electrophoretic profile and the recognition pattern by infected sheep sera samples. The ELISA results were compared with multiplex PCR assay and IFN-gamma production. The ELISA was able to discriminate between negative and positive animals, with a sensitivity of 89% and a specificity of 99%, using microbiological isolation as gold standard. When this assay was compared with multiplex PCR and specific IFN-gamma quantification, six discrepant results were found among thirty-two samples. We concluded that the ELISA using antigens secreted from C. pseudotuberculosis T1 strain growth in BHI broth culture can be used for the serodiagnosis of CLA in sheep.

  12. Conservación por congelación de Bordetella pertussis y Corynebacterium diphtheriae, empleados en la producción de vacunas para uso humano

    Directory of Open Access Journals (Sweden)

    Yilian Plasencia,

    2000-11-01

    Full Text Available En el presente estudio se evaluó el método de congelación a –70ºC para la preservación de Bordetella pertussis y Corynebacterium diphtheriae. Para verificar el sustento de los cultivos se realizó un adecuado control de calidad, que incluyó comprobación de pureza, viabilidad y estabilidad de las propiedades de interés. En este trabajo se probaron diferentes formulaciones. Se seleccionó la que arrojó los mejores resultados y se realizó un estudio de mantenimiento de las características evaluadas durante el tiempo. Para medir determinados parámetros se realizaron procesos a escala industrial, empleándose para esto un biorreactor Chemap de 35 L. Se tomaron como referencia los valores obtenidos por las cepas conservadas por liofilización. De esta forma se buscaron alternativas y soluciones a problemas presentados en su conservación. Los resultados obtenidos sugieren la posible inclusión en el Programa de Mantenimiento establecido.

  13. Una nueva ópera

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    José Sánchez Sanz

    2016-05-01

    Full Text Available Si algo ha marcado al género operístico desde sus inicios ha sido el público que ha asistido a los espectáculos que se representaban en sus teatros. En el siglo XX, con la aparición del cine, la ópera sufre una crisis de audiencia, el público tiene un espectáculo masivo al que asistir, más económico y más cercano al consumo cultural dominante. La ópera pasa a convertirse en un espacio para una élite capaz de pagar los altos precios de los abonos. En la actualidad diversas decisiones tomadas por teatros de ópera están provocando que el interés por el género crezca en una sociedad posmoderna en la que la tecnología parece haber agotado los límites espaciales y temporales. Óperas con libretos basados en películas o en personajes de la contemporaneidad, que exhiben prodigios técnicos visuales y sonoros, realizados éstos por grandes figuras del arte y del diseño. Un concepto de la ópera que vuelve a ser un espectáculo que abarca todas las disciplinas, y que ha asumido la evolución que la tecnología ha aportado a éstas con total naturalidad. 

  14. Diario de una infancia. Mariana

    OpenAIRE

    Casal, Silvana

    2017-01-01

    Resumen: Este artículo está centrado en el análisis del diario de infancia que una de mis entrevistadas, Mariana, escribió durante su niñez en la dictatorial República Argentina a partir del secuestro de su padre, producido en 1977, situación que dio pie al exilio familiar en México. Mariana nos permite entrar en su universo, conocer sus sentimientos y emociones, y acercarnos -a través de sus palabras plasmadas en las cartas que le escribe a su padre desaparecido- a su vida cotidiana y a trav...

  15. Atresia biliar: una enfermedad grave

    OpenAIRE

    Ramonet, Margarita; Ciocca, Mirta; Alvarez, Fernando

    2014-01-01

    La atresia biliar es una grave enfermedad que se manifiesta en los recién nacidos, y se desconoce su causa. La inflamación y destrucciónprogresiva de los conductos biliares conducen a la aparición de ictericia, coluria y acolia entre la segunda y sexta semana de vida. Como existen múltiples causas de colestasis neonatal en esta etapa de la vida, es necesario realizar un diagnóstico y derivación precoz para ofrecer un tratamiento quirúrgico, con el fin de restablecer el flujo biliar. Alrededor...

  16. Feronia Inc : una diosa desnuda

    OpenAIRE

    Muntané Puig, Joaquim

    2015-01-01

    El informe cuenta con la colaboración de Devlin Kuyek (GRAIN), Carles Soler (Revista SABC), Liliane Spendeler (Amigos de la Tierra), Guadalupe Rodríguez (Salva la Selva) y Jean-François Mombia (RIAO-RDC). Este informe sigue el hilo de las actividades de la compañía Feronia Inc. para descubrir cómo unas plantaciones congoleñas de palma de aceite conectan de forma muy directa con la alimentación y los bolsillos de la ciudadanía española. El caso se muestra como un ejemplo concreto de un fenó...

  17. Pesquisas, recuerdos y una entrevista

    OpenAIRE

    Blasco, Selina

    2009-01-01

    Estudio del trabajo desarrollado por los arquitectos Luis M. Feduchi, Javier Feduchi y Pedro Feduchi en el ámbito del diseño. Sus trayectorias profesionales, a veces entrecruzadas, son el punto de partida de una reflexión, situada histórica y espacialmente en el Madrid del siglo XX, acerca de diversos ámbitos disciplinares (diseño de mobiliario, interiorismo, decorados cinematográficos, montajes de exposiciones, museografías, dispositivos para la exposición y venta en centros comerciales, ent...

  18. Seguridad en una red universitaria

    OpenAIRE

    Bernal España, Juan Antonio

    2014-01-01

    Las redes de comunicaciones son muy importantes para las empresas. Se solicita una red de altas prestaciones que pueda llevar muchos sistemas sobre ella (cámaras de seguridad, video, voz, datos, SCADA, wifi). Ahora también necesitamos que la red sea segura. Cuando hablamos de seguridad no solo nos referimos a evitar ataques o virus, también hablamos de cómo puede afectarnos el incendio de un centro de proceso de datos. Basándonos en la ISO 27001:2013 daremos las principales pau...

  19. Una nueva forma de conflicto

    Directory of Open Access Journals (Sweden)

    SALUSTIANO DEL CAMPO

    2002-01-01

    Full Text Available Con el ataque del 11 de septiembre al World Trade Center, el siglo XXI ha empezado con una nueva forma de conflicto y un realineamiento global. Samuel P. Huntington (1993 describió esto como un choque de civilizaciones entre el islam y occidente, pero se argumenta que esto es una simplificación. Otros factores a tener en cuenta son la coexistencia de las sociedades modernas y postmodernas, la desigual distribución de la riqueza, los conflictos internacionales insolubles de larga duración y la condición del islam en diferentes países. Se discute el impacto de la futura diseminación de la tecnología de la información en la resolución de algunas de estas diferencias. Recientemente se han desmantelado anteriores redes internacionales e instituciones. Coexisten redes legales e ilegales de negocios y organizaciones. En el caso de las redes terroristas, es muy complicado identifcarlas, atacarlas y desactivarlas. En el proceso de combatir al terrorismo no deberían sacrificarse los derechos fundamentales democráticos.

  20. Diario de una infancia. Mariana

    Directory of Open Access Journals (Sweden)

    Silvana Beatriz Casal

    2017-09-01

    Full Text Available Este artículo está centrado en el análisis del diario de infancia que una de mis entrevistadas, Mariana, escribió durante su niñez en la dictatorial República Argentina a partir del secuestro de su padre, producido en 1977, situación que dio pie al exilio familiar en México. Mariana nos permite entrar en su universo, conocer sus sentimientos y emociones, y acercarnos –a través de sus palabras plasmadas en las cartas que le escribe a su padre desaparecido– a su vida cotidiana y a través de ella a la de muchos otros niños que vivieron situaciones de violencia similares. Mi propósito es enfatizar que los niños son actores sociales y su aporte es vital en la construcción de una historia que los incluya como agentes activos. Abordaré la importancia histórica de escuchar la voz de los niños y el significado de acceder a escritos elaborados por ellos mismos durante la infancia.

  1. Diseño de una red WAN

    OpenAIRE

    Labella Sanz, Gabriel

    2010-01-01

    Disseny d'una xarxa WAN, formada per una xarxa d'Accés HFC, una xarxa de Commutació ATM i una xarxa de Transport SDH. Diseño de una red WAN, formada por una red de Acceso HFC, una red de Conmutación ATM y una red de Transporte SDH. WAN network design consisting of a HFC access network, an ATM switching network and a SDH transport network.

  2. Santiago, una ciudad con temor

    Directory of Open Access Journals (Sweden)

    Enrique Oviedo S.

    1999-04-01

    Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

  3. Santiago, una ciudad con temor

    Directory of Open Access Journals (Sweden)

    Oviedo S. Enrique

    1999-01-01

    Full Text Available El objetivo general de este artículo es evaluar los efectos de la inseguridad ciudadana en el uso del espacio público. Dicha evaluación exige analizar dos relaciones que se establecen en el ámbito de la violencia: la relación entre victimización y percepción de inseguridad; y la que se establece entre actitudes sociales y resolución pacífica de conflictos nacionales. Para ello, se analizaron las variables victimización, percepción de inseguridad, uso del espacio físico, actitudes hacia el sistema institucional político y social y hacia la resolución de conflictos nacionales, y las posibles relaciones entre ellas. Los datos para realizar el estudio se obtuvieron por medio de una encuesta que se llevó a cabo con 1 200 personas de 18 y 70 años de edad residentes en la ciudad de Santiago. Los resultados indican que Santiago es una ciudad de habitantes con temor y que el aumento de la percepción de inseguridad de sus habitantes contrasta con el hecho de que las tasas de victimización se hayan mantenido, más o menos, constantes en los años que precedieron a la encuesta. El temor se relaciona con el abandono del espacio público físico y sociopolítico, así como con el refugio en los espacios y la vida privados. La actitud de resolver los conflictos por medios no pacíficos es frecuente y se asocia en mayor medida con la inseguridad, la actitud negativa hacia la democracia y la falta de expectativas sobre el futuro del país. Los resultados de este estudio respaldan la idea de que para superar el temor la gente tiende a adaptarse a la realidad adoptando una postura conformista, homogeneizando las creencias y los comportamientos, y sobreestimando la fuerza como medio para resolver las diferencias.

  4. El derecho a una vivienda

    Directory of Open Access Journals (Sweden)

    John GLEDHILL

    2010-11-01

    Full Text Available El derecho a la vivienda es un derecho humano básico recogido en las declaraciones internacionales y muchas constituciones nacionales. Del él puede hacerse también una lectura “burguesa”, como fundamento de la democracia liberal basada en la propiedad privada, con interesantes consecuencias cuando los ciudadanos ven que sus derechos son violados. Este artículo explora cómo va cambiando la definición del derecho a la vivienda a través de la agenda de ONU–Hábitat, y discute los puntos fuertes y débiles de este programa desde una perspectiva antropológica. El análisis incide sobre el hecho de que gran parte de la población mundial ha tenido que encontrar sus propias soluciones a los problemas de vivienda, y aborda los debates en torno a la “regularización” de los asentamientos, la tierra y las viviendas “informales”, a los mercados de la vivienda, y a las implicaciones sociales de los diferentes enfoques al respecto. Se sostiene que el enfoque de las Naciones Unidas, a pesar de su énfasis en la planificación participativa y la universalización del derecho a la ciudad, sigue marginando aspectos más complejos que surgen de las relaciones entre la vivienda, el hábitat y los patrones de sociabilidad. El artículo concluye con la consideración de las condiciones a las que se enfrentan los movimientos sociales que luchan por el derecho a la ciudad, en un contexto de regeneración urbana y gentrificación basado en la clase social, incorporando la comprensión de los procesos microsociales que ofrece la investigación etnográfica, desde una perspectiva multidimensional, sobre las relaciones de poder que han estructurado el reciente desarrollo de las ciudades metropolitanas.

  5. Double mutation of cell wall proteins CspB and PBP1a increases secretion of the antibody Fab fragment from Corynebacterium glutamicum

    Science.gov (United States)

    2014-01-01

    Background Among other advantages, recombinant antibody-binding fragments (Fabs) hold great clinical and commercial potential, owing to their efficient tissue penetration compared to that of full-length IgGs. Although production of recombinant Fab using microbial expression systems has been reported, yields of active Fab have not been satisfactory. We recently developed the Corynebacterium glutamicum protein expression system (CORYNEX®) and demonstrated improved yield and purity for some applications, although the system has not been applied to Fab production. Results The Fab fragment of human anti-HER2 was successfully secreted by the CORYNEX® system using the conventional C. glutamicum strain YDK010, but the productivity was very low. To improve the secretion efficiency, we investigated the effects of deleting cell wall-related genes. Fab secretion was increased 5.2 times by deletion of pbp1a, encoding one of the penicillin-binding proteins (PBP1a), mediating cell wall peptidoglycan (PG) synthesis. However, this Δpbp1a mutation did not improve Fab secretion in the wild-type ATCC13869 strain. Because YDK010 carries a mutation in the cspB gene encoding a surface (S)-layer protein, we evaluated the effect of ΔcspB mutation on Fab secretion from ATCC13869. The Δpbp1a mutation showed a positive effect on Fab secretion only in combination with the ΔcspB mutation. The ΔcspBΔpbp1a double mutant showed much greater sensitivity to lysozyme than either single mutant or the wild-type strain, suggesting that these mutations reduced cell wall resistance to protein secretion. Conclusion There are at least two crucial permeability barriers to Fab secretion in the cell surface structure of C. glutamicum, the PG layer, and the S-layer. The ΔcspBΔpbp1a double mutant allows efficient Fab production using the CORYNEX® system. PMID:24731213

  6. Restoration of prostaglandin E2-producing splenic macrophages in 89Sr-treated mice with bone marrow from Corynebacterium parvum primed donors

    International Nuclear Information System (INIS)

    Shibata, Y.

    1989-01-01

    Administration of Corynebacterium parvum (CP), 56 mg/kg ip to CBA/J mice effected the induction of prostaglandin E2 (PGE2) producing macrophages (M phi) in the bone marrow and the spleen. Maximal release of PGE2 from M phi cultured in vitro with calcium ionophore A23187 for 2 h was reached by marrow M phi removed on 5 days after CP (450 ng/mg cell protein), and by splenic M phi 9 days after CP (400 ng/mg). Neither M phi population, however, yielded more than 6.0 ng/mg leukotriene C4. To assess ontogenic relationships mice were depleted of bone marrow and blood monocytes by iv injection of the bone-seeking isotope, 89Sr. CP was given at several points before or after bone marrow cell depletion. PGE2 production by splenic M phi harvested on day 9 after CP was profoundly impaired when CP was administered either concurrently with or 3 days after 89Sr. When CP was administered 1, 3, 5, and 7 days before 89Sr, however, the induction of PGE2-producing M phi in the spleen was unaffected. To determine whether bone marrow cells from CP-injected donors can restore PGE2-producing splenic M phi (PGSM) in 89Sr-mice, recipient mice which had and had not received CP 3 days after 89Sr were transfused with 5 x 10(6) syngeneic bone marrow cells from donor mice prepared at varying intervals after CP administration. The results clearly indicate the capacity of bone marrow cells harvested on either day 1 or 2 following CP to restore PGSM in CP-primed, but not unprimed, recipients

  7. Rapid hybrid de novo assembly of a microbial genome using only short reads: Corynebacterium pseudotuberculosis I19 as a case study.

    Science.gov (United States)

    Cerdeira, Louise Teixeira; Carneiro, Adriana Ribeiro; Ramos, Rommel Thiago Jucá; de Almeida, Sintia Silva; D'Afonseca, Vivian; Schneider, Maria Paula Cruz; Baumbach, Jan; Tauch, Andreas; McCulloch, John Anthony; Azevedo, Vasco Ariston Carvalho; Silva, Artur

    2011-08-01

    Due to the advent of the so-called Next-Generation Sequencing (NGS) technologies the amount of monetary and temporal resources for whole-genome sequencing has been reduced by several orders of magnitude. Sequence reads can be assembled either by anchoring them directly onto an available reference genome (classical reference assembly), or can be concatenated by overlap (de novo assembly). The latter strategy is preferable because it tends to maintain the architecture of the genome sequence the however, depending on the NGS platform used, the shortness of read lengths cause tremendous problems the in the subsequent genome assembly phase, impeding closing of the entire genome sequence. To address the problem, we developed a multi-pronged hybrid de novo strategy combining De Bruijn graph and Overlap-Layout-Consensus methods, which was used to assemble from short reads the entire genome of Corynebacterium pseudotuberculosis strain I19, a bacterium with immense importance in veterinary medicine that causes Caseous Lymphadenitis in ruminants, principally ovines and caprines. Briefly, contigs were assembled de novo from the short reads and were only oriented using a reference genome by anchoring. Remaining gaps were closed using iterative anchoring of short reads by craning to gap flanks. Finally, we compare the genome sequence assembled using our hybrid strategy to a classical reference assembly using the same data as input and show that with the availability of a reference genome, it pays off to use the hybrid de novo strategy, rather than a classical reference assembly, because more genome sequences are preserved using the former. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. The transcriptional regulatory network of Corynebacterium jeikeium K411 and its interaction with metabolic routes contributing to human body odor formation.

    Science.gov (United States)

    Barzantny, Helena; Schröder, Jasmin; Strotmeier, Jasmin; Fredrich, Eugenie; Brune, Iris; Tauch, Andreas

    2012-06-15

    Lipophilic corynebacteria are involved in the generation of volatile odorous products in the process of human body odor formation by degrading skin lipids and specific odor precursors. Therefore, these bacteria represent appropriate model systems for the cosmetic industry to examine axillary malodor formation on the molecular level. To understand the transcriptional control of metabolic pathways involved in this process, the transcriptional regulatory network of the lipophilic axilla isolate Corynebacterium jeikeium K411 was reconstructed from the complete genome sequence. This bioinformatic approach detected a gene-regulatory repertoire of 83 candidate proteins, including 56 DNA-binding transcriptional regulators, nine two-component systems, nine sigma factors, and nine regulators with diverse physiological functions. Furthermore, a cross-genome comparison among selected corynebacterial species of the taxonomic cluster 3 revealed a common gene-regulatory repertoire of 44 transcriptional regulators, including the MarR-like regulator Jk0257, which is exclusively encoded in the genomes of this taxonomical subline. The current network reconstruction comprises 48 transcriptional regulators and 674 gene-regulatory interactions that were assigned to five interconnected functional modules. Most genes involved in lipid degradation are under the combined control of the global cAMP-sensing transcriptional regulator GlxR and the LuxR-family regulator RamA, probably reflecting the essential role of lipid degradation in C. jeikeium. This study provides the first genome-scale in silico analysis of the transcriptional regulation of metabolism in a lipophilic bacterium involved in the formation of human body odor. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Outbreak investigation for toxigenic Corynebacterium diphtheriae wound infections in refugees from Northeast Africa and Syria in Switzerland and Germany by whole genome sequencing.

    Science.gov (United States)

    Meinel, D M; Kuehl, R; Zbinden, R; Boskova, V; Garzoni, C; Fadini, D; Dolina, M; Blümel, B; Weibel, T; Tschudin-Sutter, S; Widmer, A F; Bielicki, J A; Dierig, A; Heininger, U; Konrad, R; Berger, A; Hinic, V; Goldenberger, D; Blaich, A; Stadler, T; Battegay, M; Sing, A; Egli, A

    2016-12-01

    Toxigenic Corynebacterium diphtheriae is an important and potentially fatal threat to patients and public health. During the current dramatic influx of refugees into Europe, our objective was to use whole genome sequencing for the characterization of a suspected outbreak of C. diphtheriae wound infections among refugees. After conventional culture, we identified C. diphtheriae using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and investigated toxigenicity by PCR. Whole genome sequencing was performed on a MiSeq Illumina with >70×coverage, 2×250 bp read length, and mapping against a reference genome. Twenty cases of cutaneous C. diphtheriae in refugees from East African countries and Syria identified between April and August 2015 were included. Patients presented with wound infections shortly after arrival in Switzerland and Germany. Toxin production was detected in 9/20 (45%) isolates. Whole genome sequencing-based typing revealed relatedness between isolates using neighbour-joining algorithms. We detected three separate clusters among epidemiologically related refugees. Although the isolates within a cluster showed strong relatedness, isolates differed by >50 nucleotide polymorphisms. Toxigenic C. diphtheriae associated wound infections are currently observed more frequently in Europe, due to refugees travelling under poor hygienic conditions. Close genetic relatedness of C. diphtheriae isolates from 20 refugees with wound infections indicates likely transmission between patients. However, the diversity within each cluster and phylogenetic time-tree analysis suggest that transmissions happened several months ago, most likely outside Europe. Whole genome sequencing offers the potential to describe outbreaks at very high resolution and is a helpful tool in infection tracking and identification of transmission routes. Copyright © 2016. Published by Elsevier Ltd.

  10. Boosting Anaplerotic Reactions by Pyruvate Kinase Gene Deletion and Phosphoenolpyruvate Carboxylase Desensitization for Glutamic Acid and Lysine Production in Corynebacterium glutamicum.

    Science.gov (United States)

    Yokota, Atsushi; Sawada, Kazunori; Wada, Masaru

    In the 1980s, Shiio and coworkers demonstrated using random mutagenesis that the following three phenotypes were effective for boosting lysine production by Corynebacterium glutamicum: (1) low-activity-level citrate synthase (CS L ), (2) phosphoenolpyruvate carboxylase (PEPC) resistant to feedback inhibition by aspartic acid (PEPC R ), and (3) pyruvate kinase (PYK) deficiency. Here, we reevaluated these phenotypes and their interrelationship in lysine production using recombinant DNA techniques.The pyk deletion and PEPC R (D299N in ppc) independently showed marginal effects on lysine production, but both phenotypes synergistically increased lysine yield, demonstrating the importance of PEPC as an anaplerotic enzyme in lysine production. Similar effects were also found for glutamic acid production. CS L (S252C in gltA) further increased lysine yield. Thus, using molecular techniques, the combination of these three phenotypes was reconfirmed to be effective for lysine production. However, a simple CS L mutant showed instabilities in growth and lysine yield.Surprisingly, the pyk deletion was found to increase biomass production in wild-type C. glutamicum ATCC13032 under biotin-sufficient conditions. The mutant showed a 37% increase in growth (based on OD 660 ) compared with the ATCC13032 strain in a complex medium containing 100 g/L glucose. Metabolome analysis revealed the intracellular accumulation of excess precursor metabolites. Thus, their conversion into biomass was considered to relieve the metabolic distortion in the pyk-deleted mutant. Detailed physiological studies of various pyk-deleted mutants also suggested that malate:quinone oxidoreductase (MQO) is important to control both the intracellular oxaloacetic acid (OAA) level and respiration rate. These findings may facilitate the rational use of C. glutamicum in fermentation industries.

  11. Elucidation of the regulatory role of the fructose operon reveals a novel target for enhancing the NADPH supply in Corynebacterium glutamicum.

    Science.gov (United States)

    Wang, Zhihao; Chan, Siu Hung Joshua; Sudarsan, Suresh; Blank, Lars M; Jensen, Peter Ruhdal; Solem, Christian

    2016-11-01

    The performance of Corynebacterium glutamicum cell factories producing compounds which rely heavily on NADPH has been reported to depend on the sugar being metabolized. While some aspects of this phenomenon have been elucidated, there are still many unresolved questions as to how sugar metabolism is linked to redox and to the general metabolism. We here provide new insights into the regulation of the metabolism of this important platform organism by systematically characterizing mutants carrying various lesions in the fructose operon. Initially, we found that a strain where the dedicated fructose uptake system had been inactivated (KO-ptsF) was hampered in growth on sucrose minimal medium, and suppressor mutants appeared readily. Comparative genomic analysis in conjunction with enzymatic assays revealed that suppression was linked to inactivation of the pfkB gene, encoding a fructose-1-phosphate kinase. Detailed characterization of KO-ptsF, KO-pfkB and double knock-out (DKO) derivatives revealed a strong role for sugar-phosphates, especially fructose-1-phosphate (F1P), in governing sugar as well as redox metabolism due to effects on transcriptional regulation of key genes. These findings allowed us to propose a simple model explaining the correlation between sugar phosphate concentration, gene expression and ultimately the observed phenotype. To guide us in our analysis and help us identify bottlenecks in metabolism we debugged an existing genome-scale model onto which we overlaid the transcriptome data. Based on the results obtained we managed to enhance the NADPH supply and transform the wild-type strain into delivering the highest yield of lysine ever obtained on sucrose and fructose, thus providing a good example of how regulatory mechanisms can be harnessed for bioproduction. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  12. Enhancement of γ-aminobutyric acid production in recombinant Corynebacterium glutamicum by co-expressing two glutamate decarboxylase genes from Lactobacillus brevis.

    Science.gov (United States)

    Shi, Feng; Jiang, Junjun; Li, Yongfu; Li, Youxin; Xie, Yilong

    2013-11-01

    γ-Aminobutyric acid (GABA), a non-protein amino acid, is a bioactive component in the food, feed and pharmaceutical fields. To establish an effective single-step production system for GABA, a recombinant Corynebacterium glutamicum strain co-expressing two glutamate decarboxylase (GAD) genes (gadB1 and gadB2) derived from Lactobacillus brevis Lb85 was constructed. Compared with the GABA production of the gadB1 or gadB2 single-expressing strains, GABA production by the gadB1-gadB2 co-expressing strain increased more than twofold. By optimising urea supplementation, the total production of L-glutamate and GABA increased from 22.57 ± 1.24 to 30.18 ± 1.33 g L⁻¹, and GABA production increased from 4.02 ± 0.95 to 18.66 ± 2.11 g L⁻¹ after 84-h cultivation. Under optimal urea supplementation, L-glutamate continued to be consumed, GABA continued to accumulate after 36 h of fermentation, and the pH level fluctuated. GABA production increased to a maximum level of 27.13 ± 0.54 g L⁻¹ after 120-h flask cultivation and 26.32 g L⁻¹ after 60-h fed-batch fermentation. The conversion ratio of L-glutamate to GABA reached 0.60-0.74 mol mol⁻¹. By co-expressing gadB1 and gadB2 and optimising the urea addition method, C. glutamicum was genetically improved for de novo biosynthesis of GABA from its own accumulated L-glutamate.

  13. Immunoregulation of antitumor response; differential secretion of arachidonic acid metabolites by macrophages during stimulation ''in vitro'' with BCG and ''Corynebacterium parvum''

    International Nuclear Information System (INIS)

    Tomecki, Jaroslaw; Sukiennik, Jadwiga; Kordowiak, Anna

    1993-01-01

    The level of arachidonic acid (AA) metabolites in the supernatants of cultures peritoneal exudate cells (PEC) were studied under various conditions using BCG and ''Corynebacterium parvum'' as stimulators. The metabolite levels were analyzed by thin layer chromatography (TLC). The degree of macrophage cytotoxic/cytostatic activity was dependent on the dose and character of stimulators used and the source of macrophages. The application of micro cytotoxicity assay for the evaluation of tumor cell lysis (lung sarcoma SaL-1) ''in vitro'' revealed that peritoneal macrophages from healthy and tumor bearing BALB/c mice may affect the degree of antitumor response. In the supernatants of cultured PEC from tumor bearing mice AA level increased (by 10-fold) in comparison with PEC from healthy mice. Stimulation with BCG induced over a double level of AA in PEC isolated from tumor bearing mice non-stimulated or stimulated with ''C.parvum''. A lower level of prostaglandins (PGs) was found in the supernatants of cultured PEC isolated from healthy mice (stimulated and non-stimulated), but the highest level of PGs was observed in the supernatants of cultured PEC isolated from tumor bearing mice stimulated with BCG. The unique metabolite of AA was found only in the supernatants form non-stimulated PEC from tumor bearing mice. PEC from tumor bearing mice produced metabolites of AA which were not detected in control group. These results suggest that macrophages also play a regulatory role by secretion of AA. This process can be modified by bacterial antigens. (author). 21 refs, 7 figs

  14. A slow-forming isopeptide bond in the structure of the major pilin SpaD from Corynebacterium diphtheriae has implications for pilus assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hae Joo; Paterson, Neil G. [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Kim, Chae Un [Cornell University, Ithaca, NY 14853 (United States); Middleditch, Martin [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand); Chang, Chungyu; Ton-That, Hung [University of Texas–Houston Medical School, Houston, TX 77030 (United States); Baker, Edward N., E-mail: ted.baker@auckland.ac.nz [University of Auckland, Private Bag 92019, Auckland 1142 (New Zealand)

    2014-05-01

    Two crystal structures of the major pilin SpaD from C. diphtheriae have been determined at 1.87 and 2.5 Å resolution. The N-terminal domain is found to contain an isopeptide bond that forms slowly over time in the recombinant protein. Given its structural context, this provides insight into the relationship between internal isopeptide-bond formation and pilus assembly. The Gram-positive organism Corynebacterium diphtheriae, the cause of diphtheria in humans, expresses pili on its surface which it uses for adhesion and colonization of its host. These pili are covalent protein polymers composed of three types of pilin subunit that are assembled by specific sortase enzymes. A structural analysis of the major pilin SpaD, which forms the polymeric backbone of one of the three types of pilus expressed by C. diphtheriae, is reported. Mass-spectral and crystallographic analysis shows that SpaD contains three internal Lys–Asn isopeptide bonds. One of these, shown by mass spectrometry to be located in the N-terminal D1 domain of the protein, only forms slowly, implying an energy barrier to bond formation. Two crystal structures, of the full-length three-domain protein at 2.5 Å resolution and of a two-domain (D2-D3) construct at 1.87 Å resolution, show that each of the three Ig-like domains contains a single Lys–Asn isopeptide-bond cross-link, assumed to give mechanical stability as in other such pili. Additional stabilizing features include a disulfide bond in the D3 domain and a calcium-binding loop in D2. The N-terminal D1 domain is more flexible than the others and, by analogy with other major pilins of this type, the slow formation of its isopeptide bond can be attributed to its location adjacent to the lysine used in sortase-mediated polymerization during pilus assembly.

  15. The MurC ligase essential for peptidoglycan biosynthesis is regulated by the serine/threonine protein kinase PknA in Corynebacterium glutamicum.

    Science.gov (United States)

    Fiuza, Maria; Canova, Marc J; Patin, Delphine; Letek, Michal; Zanella-Cléon, Isabelle; Becchi, Michel; Mateos, Luís M; Mengin-Lecreulx, Dominique; Molle, Virginie; Gil, José A

    2008-12-26

    The Mur ligases play an essential role in the biosynthesis of bacterial cell-wall peptidoglycan and thus represent attractive targets for the design of novel antibacterials. These enzymes catalyze the stepwise formation of the peptide moiety of the peptidoglycan disaccharide peptide monomer unit. MurC is responsible of the addition of the first residue (L-alanine) onto the nucleotide precursor UDP-MurNAc. Phosphorylation of proteins by Ser/Thr protein kinases has recently emerged as a major physiological mechanism of regulation in prokaryotes. Herein, the hypothesis of a phosphorylation-dependent mechanism of regulation of the MurC activity was investigated in Corynebacterium glutamicum. We showed that MurC was phosphorylated in vitro by the PknA protein kinase. An analysis of the phosphoamino acid content indicated that phosphorylation exclusively occurred on threonine residues. Six phosphoacceptor residues were identified by mass spectrometry analysis, and we confirmed that mutagenesis to alanine residues totally abolished PknA-dependent phosphorylation of MurC. In vitro and in vivo ligase activity assays showed that the catalytic activity of MurC was impaired following mutation of these threonine residues. Further in vitro assays revealed that the activity of the MurC-phosphorylated isoform was severely decreased compared with the non-phosphorylated protein. To our knowledge, this is the first demonstration of a MurC ligase phosphorylation in vitro. The finding that phosphorylation is correlated with a decrease in MurC enzymatic activity could have significant consequences in the regulation of peptidoglycan biosynthesis.

  16. The MurC Ligase Essential for Peptidoglycan Biosynthesis Is Regulated by the Serine/Threonine Protein Kinase PknA in Corynebacterium glutamicum*

    Science.gov (United States)

    Fiuza, Maria; Canova, Marc J.; Patin, Delphine; Letek, Michal; Zanella-Cléon, Isabelle; Becchi, Michel; Mateos, Luís M.; Mengin-Lecreulx, Dominique; Molle, Virginie; Gil, José A.

    2008-01-01

    The Mur ligases play an essential role in the biosynthesis of bacterial cell-wall peptidoglycan and thus represent attractive targets for the design of novel antibacterials. These enzymes catalyze the stepwise formation of the peptide moiety of the peptidoglycan disaccharide peptide monomer unit. MurC is responsible of the addition of the first residue (l-alanine) onto the nucleotide precursor UDP-MurNAc. Phosphorylation of proteins by Ser/Thr protein kinases has recently emerged as a major physiological mechanism of regulation in prokaryotes. Herein, the hypothesis of a phosphorylation-dependent mechanism of regulation of the MurC activity was investigated in Corynebacterium glutamicum. We showed that MurC was phosphorylated in vitro by the PknA protein kinase. An analysis of the phosphoamino acid content indicated that phosphorylation exclusively occurred on threonine residues. Six phosphoacceptor residues were identified by mass spectrometry analysis, and we confirmed that mutagenesis to alanine residues totally abolished PknA-dependent phosphorylation of MurC. In vitro and in vivo ligase activity assays showed that the catalytic activity of MurC was impaired following mutation of these threonine residues. Further in vitro assays revealed that the activity of the MurC-phosphorylated isoform was severely decreased compared with the non-phosphorylated protein. To our knowledge, this is the first demonstration of a MurC ligase phosphorylation in vitro. The finding that phosphorylation is correlated with a decrease in MurC enzymatic activity could have significant consequences in the regulation of peptidoglycan biosynthesis. PMID:18974047

  17. Complete genome sequence of Corynebacterium variabile DSM 44702 isolated from the surface of smear-ripened cheeses and insights into cheese ripening and flavor generation

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    Trost Eva

    2011-11-01

    Full Text Available Abstract Background Corynebacterium variabile is part of the complex microflora on the surface of smear-ripened cheeses and contributes to the development of flavor and textural properties during cheese ripening. Still little is known about the metabolic processes and microbial interactions during the production of smear-ripened cheeses. Therefore, the gene repertoire contributing to the lifestyle of the cheese isolate C. variabile DSM 44702 was deduced from the complete genome sequence to get a better understanding of this industrial process. Results The chromosome of C. variabile DSM 44702 is composed of 3, 433, 007 bp and contains 3, 071 protein-coding regions. A comparative analysis of this gene repertoire with that of other corynebacteria detected 1, 534 predicted genes to be specific for the cheese isolate. These genes might contribute to distinct metabolic capabilities of C. variabile, as several of them are associated with metabolic functions in cheese habitats by playing roles in the utilization of alternative carbon and sulphur sources, in amino acid metabolism, and fatty acid degradation. Relevant C. variabile genes confer the capability to catabolize gluconate, lactate, propionate, taurine, and gamma-aminobutyric acid and to utilize external caseins. In addition, C. variabile is equipped with several siderophore biosynthesis gene clusters for iron acquisition and an exceptional repertoire of AraC-regulated iron uptake systems. Moreover, C. variabile can produce acetoin, butanediol, and methanethiol, which are important flavor compounds in smear-ripened cheeses. Conclusions The genome sequence of C. variabile provides detailed insights into the distinct metabolic features of this bacterium, implying a strong adaption to the iron-depleted cheese surface habitat. By combining in silico data obtained from the genome annotation with previous experimental knowledge, occasional observations on genes that are involved in the complex

  18. Functional architecture and global properties of the Corynebacterium glutamicum regulatory network: Novel insights from a dataset with a high genomic coverage.

    Science.gov (United States)

    Freyre-González, Julio A; Tauch, Andreas

    2017-09-10

    Corynebacterium glutamicum is a Gram-positive, anaerobic, rod-shaped soil bacterium able to grow on a diversity of carbon sources like sugars and organic acids. It is a biotechnological relevant organism because of its highly efficient ability to biosynthesize amino acids, such as l-glutamic acid and l-lysine. Here, we reconstructed the most complete C. glutamicum regulatory network to date and comprehensively analyzed its global organizational properties, systems-level features and functional architecture. Our analyses show the tremendous power of Abasy Atlas to study the functional organization of regulatory networks. We created two models of the C. glutamicum regulatory network: all-evidences (containing both weak and strong supported interactions, genomic coverage=73%) and strongly-supported (only accounting for strongly supported evidences, genomic coverage=71%). Using state-of-the-art methodologies, we prove that power-law behaviors truly govern the connectivity and clustering coefficient distributions. We found a non-previously reported circuit motif that we named complex feed-forward motif. We highlighted the importance of feedback loops for the functional architecture, beyond whether they are statistically over-represented or not in the network. We show that the previously reported top-down approach is inadequate to infer the hierarchy governing a regulatory network because feedback bridges different hierarchical layers, and the top-down approach disregards the presence of intermodular genes shaping the integration layer. Our findings all together further support a diamond-shaped, three-layered hierarchy exhibiting some feedback between processing and coordination layers, which is shaped by four classes of systems-level elements: global regulators, locally autonomous modules, basal machinery and intermodular genes. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. A role of the transcriptional regulator LldR (NCgl2814) in glutamate metabolism under biotin-limited conditions in Corynebacterium glutamicum.

    Science.gov (United States)

    Supkulsutra, Tanyanut; Maeda, Tomoya; Kumagai, Kosuke; Wachi, Masaaki

    2013-01-01

    Corynebacterium glutamicum is a Gram-positive, rod-shaped, aerobic bacterium used for the fermentative production of L-glutamate. LldR (NCgl2814) is known as a repressor for ldhA and lldD encoding lactate dehydrogenases. LdhA is responsible for production of L-lactate, while LldD is for its assimilation. Since L-lactate production was observed as a by-product of glutamate production under biotin-limited conditions, LldR might play a regulatory role in the glutamate metabolism. Here for the first time, we investigated effects of overproduction or deletion of LldR on the glutamate metabolism under biotin-limited conditions in C. glutamicum. It was found that glutamate production under biotin-limited conditions was decreased by overproduction of LldR. In the wild-type cells, L-lactate was produced in the first 24 h and it was re-consumed thereafter. On the other hand, in the overproduced cells, L-lactate was produced like the wild type, but it was not re-consumed. This means that L-lactate assimilation, which is catalyzed by LldD, was suppressed by the overproduction of LldR, but L-lactate production, which is catalyzed by LdhA, was not affected, indicating that LldR mainly controls the expression of lldD but not of ldhA under biotin-limited conditions. This was confirmed by quantitative real-time RT-PCR. From these results, it is suggested that L-lactate metabolism, which is controlled by LldR, has a buffering function of the pyruvate pool for glutamate production.

  20. Integration of ARTP mutagenesis with biosensor-mediated high-throughput screening to improve L-serine yield in Corynebacterium glutamicum.

    Science.gov (United States)

    Zhang, Xin; Zhang, Xiaomei; Xu, Guoqiang; Zhang, Xiaojuan; Shi, Jinsong; Xu, Zhenghong

    2018-05-03

    L-Serine is widely used in the pharmaceutical, food, and cosmetics industries. Although direct fermentative production of L-serine from sugar in Corynebacterium glutamicum has been achieved, the L-serine yield remains relatively low. In this study, atmospheric and room temperature plasma (ARTP) mutagenesis was used to improve the L-serine yield based on engineered C. glutamicum ΔSSAAI strain. Subsequently, we developed a novel high-throughput screening method using a biosensor constructed based on NCgl0581, a transcriptional factor specifically responsive to L-serine, so that L-serine concentration within single cell of C. glutamicum can be monitored via fluorescence-activated cell sorting (FACS). Novel L-serine-producing mutants were isolated from a large library of mutagenized cells. The mutant strain A36-pDser was screened from 1.2 × 10 5 cells, and the magnesium ion concentration in the medium was optimized specifically for this mutant. C. glutamicum A36-pDser accumulated 34.78 g/L L-serine with a yield of 0.35 g/g sucrose, which were 35.9 and 66.7% higher than those of the parent C. glutamicum ΔSSAAI-pDser strain, respectively. The L-serine yield achieved in this mutant was the highest of all reported L-serine-producing strains of C. glutamicum. Moreover, the whole-genome sequencing identified 11 non-synonymous mutations of genes associated with metabolic and transport pathways, which might be responsible for the higher L-serine production and better cell growth in C. glutamicum A36-pDser. This study explored an effective mutagenesis strategy and reported a novel high-throughput screening method for the development of L-serine-producing strains.

  1. una aproximación

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    Roberto González Arana

    2007-01-01

    Full Text Available Este trabajo se propone analizar la dinámica actual de las relaciones entre Colombia y los Estados Unidos, las negociaciones de cara al Tratado de Libre Comercio y la influencia del conflicto colombiano en el tipo de relaciones políticas y económicas bilaterales. Los recientes cambios políticos en la región afectan no sólo las relaciones bilaterales entre Colombia y sus vecinos sino también tienen una incidencia en las relaciones con los Estados Unidos. Para ello, se evalúan las particularidades de la política de Seguridad Democrática y el estado de las relaciones entre Colombia y Estados Unidos durante la administración del presidente Álvaro Uribe.

  2. Una mirada a las competencias

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    Germán Albeiro Castaño Duque

    2013-07-01

    Full Text Available El concepto de competencias cobra cada vez más fuerza y se extiende cada vez más en diferentes ámbitos y niveles. El presente artículo efectúa un breve recorrido por algunos autores de renombre que han hablado sobre el tema, hace referencia a la necesidad que tiene la universidad de flexibilizar sus currículos para responder a las nuevas demandas de la sociedad del conocimiento y la globalización, de manera que favorezcan el perfil ocupacional de sus egresados mediante la formación en competencias y, además, da una muestra clara de cómo se está llevando a cabo este proceso en la Universidad Nacional de Colombia e indica, finalmente, un breve esbozo de cómo será la educación del futuro.

  3. La Tuberculosis, Una Enfermedad Modificada*

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    Valentin Malagón Castro

    1993-12-01

    Full Text Available

    Con ocasión de un estudio de revisión que hemos llevado a cabo recientemente sobre la tuberculosis osteoarticular, *** se ha apreciado un cambio notable en las características y manifestaciones de esta enfermedad.

    Hemos sido testigos del comportamiento de la tuberculosis en los últimos 40 años. Realizamos la tesis profesional en el Hospital de niños de la Misericordia de Bogotá en el año 1950 (86, basada en el análisis de más de 300 enfermos de Mal de Pott tratados con pobres resultados en esa institución en la época prequimioterápica. Efectuamos estudios de control del tratamiento quirúrgico de esa afección en el Hospital Infantil Lorencita Villegas de Santos y publicamos sus resultados en los años 1975,1980 Y1987 (85-87-88. Los pacientes correspondientes a estas nuevas series, ya en la época de la quimioterapia moderna, presentaban un mejor pronóstico vital y funcional. Cuadro 1A.

    En el decenio 1978-1988 asistimos al descenso espectacular de la frecuencia de tuberculosis osteoarticular en las salas de nuestros hospitales. Posteriormente hemos sido igualmente testigos de su lenta y progresiva reaparición.

    El estudio actual nos ha mostrado profundos cambios, como ya se ha dicho, en el comportamiento de la entidad, por lo que estamos de acuerdo en denominarla: La tuberculosis, una enfermedad modificada, diferente a la que hasta hace un década parecía derrotada, vencida por las nuevas drogas y las recientes técnicas quirúrgicas.

    La actual es una enfermedad diferente que ha tomado una fuerza avasalladora que amenaza con volverse resistente al tratamiento específico y dar lugar a una pandemia de incalculables proporciones y de terribles consecuencias para la humanidad.

    El objeto de publicar este estudio es recordar a nuestros colegas, en especial a aquellos de las nuevas promociones que quizás no han tenido la oportunidad de estar en contacto con pacientes de tuberculosis osteoarticular, de

  4. Wolbachia, una pandemia con posibilidades

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    Marcela S. RODRIGUERO

    2013-01-01

    Full Text Available La infección causada por Wolbachia es la más extendida entre los animales. La capacidad de esta bacteria para manipular la reproducción de sus hospedadores la posicionan en el centro de la biología de los organismos, influyendo en procesos tan capitales como la determinación del sexo, el ciclo celular, la formación y extinción de especies y el comportamiento de artrópodos entre los que se cuentan varias plagas y vectores de enfermedades. Cualidades tales como la herencia vertical de Wolbachia, la velocidad a la que se propaga en las poblaciones que afecta, la capacidad de bloquear la actividad patogénica de diversos microorganismos o de acortar el ciclo de vida de sus hospedadores la señalan como un potencial instrumento para el control de poblaciones de insec - tos y nematodos perjudiciales. ¿Cuáles son las posibilidades que nos ofrece esta pandemia? En la presente contribución se presenta una revisión de los aspectos fundamen - tales de esta infección y sus implicancias prácticas para el manejo de insectos plaga. Esta revisión está basada en el simposio del mismo nombre acontecido en el VIII Congreso Argentino de Entomología.

  5. TERMODINAMICA DE ECOSISTEMAS UNA APROXIMACION

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    Gómez Palacio Germán Raúl

    1998-06-01

    Full Text Available La ecología actual no es ya una ciencia puramente descriptiva y autosuficiente. Dada la naturaleza compleja de los ecosistemas, ha sido necesario recurrir a disciplinas como la física, la química, y a herramientas matemáticas como la teoría de catástrofes, la teoría de fractales, la cibernética y la teoría de redes, para el estudio y predicción de su comportamiento. La termodinámica -en sus distintos estadios -también aporta a esa visión pluralista, tal vez la única aproximada al comportamiento real de un ecosistema. Se presentan algunas ideas sobre la importancia que pueden tener conceptos como la energía, la entropía, la exergía, la información, el no equilibrio en el análisis de los procesos que tienen lugar en ecosistemas.

  6. Una red para la gente

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    Raúl Trejo Delarbre

    2004-02-01

    Full Text Available La próxima Cumbre Mundial de la Sociedad de la Información ha revitalizado, en numerosos países, el debate acerca de las nuevas tecnologías de la comunicación y los usos que pueden tener. Lamentablemente en México hemos estado casi del todo ajenos a esa intensa, extensa y en otras latitudes fructífera discusión. Ni los especialistas interesados en estos temas, ni la sociedad que es a la postre beneficiaria o damnificada según sea el empleo de tales tecnologías, ni los organismos del Estado a cargo de tales asuntos, han propiciado la reflexión colectiva que nos podría permitir tanto afinar las posiciones de nuestro país rumbo a la cumbre de Ginebra y Túnez como deliberar, en ese contexto, acerca de lo mucho que nos falta para tener un país auténticamente imbricado en la construcción de una auténtica Sociedad de la Información.

  7. No queremos una sola voz

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    Lourdes Barrezueta

    2015-01-01

    Full Text Available Comunicación y Género, acopia trabajos que vinculan a la mujer y la comunicación y sus esfuerzos por no ser consideradas inferiores. Del libro a la pantalla, acerca a algunas reflexiones sobre el proceso que lleva del libro a la pantalla por la polémica que despierta la adaptación de las novelas, puesto que muchos señalan que la trama se ve desfigurada. Se agregan varios temas sobre el cine. En "Días de Radio", se plantea el que a pesar de la censura y los problemas económicos que deben enfrentar, las radios populares de América Latina, siguen ganando espacios, de su desarrollo depende una mayor profundización de la democracia. Tema de debate es Estrategias comunicativas en Chiapas y Haití. Se añaden dos entrevistas a un caricaturista brasileño y a un corresponsal de guerra muy prestigiado.

  8. Una Amistad y una Vocacion: Carlos Sanmartin Barberi

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    Carlos Sanmartin Barberi

    1998-12-01

    Full Text Available

    Discurso Pronunciado por el Dr. EGON LICHTENBERGER en su recepción como Miembro Honorario de la Academia Nacional de Medicina.

    Con motivo de haber sido distinguido para presentarme en este recinto respetable para recibir la medalla de Miembro Honorario, revisé la lista de los académicos honorarios y demás miembros de la Academia Nacional de Medicina. Que la persona, que les dirige la palabra, pase a engrosar la lista de figuras tan eminentes de la Medicina Colombiana, me causa sentimientos de temor, de humildad y de satisfacción.

    De temor porque soy consciente de lo que significa ser y de lo que se espera de un Miembro Honorario de la Academia. De humildad por figurar al lado de profesionales tan eminentes y que han hecho contribuciones tan significativas en todas la ramas de la Medicina. Y de satisfacción por haber sido elegido por unanimidad para pertenecer a esta casa, después de mas de treinta años de labor académica y de casi quince frente al Instituto Nacional de Medicina Legal y Ciencias Forenses.

    Me perdonarán ustedes, si de la lista de Académico Honorarios deseo mencionar en esta ocasión solamente el nombre del Doctor Carlos Sanmartín Barberi, cuya ausencia de esta sesión solemne es extremadamente dolorosa. Con Carlos tuvimos una larga y estrecha amistad que comenzó con los estudios en la Facultad de Medicina de la Universidad Nacional, cuyos cicuenta años de egresados como médicos, se celebró recientemente con un acto académico, en el cual, el Doctor Sanmartín deleitó a los asistentes con una disertación sobre los progresos de la Medicina durante los últimos cincuenta años, disertación profunda y amena como todas las que pronunció durante su vida académica y profesional.

    Recuerdo cuando por los años 1943-1944, nos reuníamos por la noche en su casa, ubicada en Teusaquillo y en el microscopio heredado de su padre, Doctor Roberto Sanmartín Latorre, tempranamente

  9. Una vida con una válvula: vivencias de una joven operada de corazón

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    María Correa Rodríguez

    2013-09-01

    Full Text Available La informante del relato es una joven que tuvo que ser sometida a una intervención quirúrgica a corazón abierto. Este relato biográfico presenta sus vivencias, sentimientos y experiencias a lo largo del proceso, abarcando desde sus estancias hospitalarias, manejo de la enfermedad y situación actual. El objetivo del relato es describir el significado las experiencias relacionadas con la enfermedad que ha desarrollado la joven en las distintas etapas de su vida. Es una historia marcada por el enorme amor que siente hacia sus padres que la han apoyado en todo momento.

  10. Una vida con una válvula: vivencias de una joven operada de corazón

    OpenAIRE

    María Correa Rodríguez; José Antonio Gutiérrez Romero; Juan Manuel Martínez Guerrero

    2013-01-01

    La informante del relato es una joven que tuvo que ser sometida a una intervención quirúrgica a corazón abierto. Este relato biográfico presenta sus vivencias, sentimientos y experiencias a lo largo del proceso, abarcando desde sus estancias hospitalarias, manejo de la enfermedad y situación actual. El objetivo del relato es describir el significado las experiencias relacionadas con la enfermedad que ha desarrollado la joven en las distintas etapas de su vida. Es una historia marcada por el e...

  11. Hematologic interactions of endotoxin, tumor necrosis factor alpha (TNF alpha), interleukin 1, and adrenal hormones and the hematologic effects of TNF alpha in Corynebacterium parvum-primed rats.

    Science.gov (United States)

    Ulich, T R; del Castillo, J; Ni, R X; Bikhazi, N

    1989-06-01

    Endotoxin reduces the release among other cytokines of tumor necrosis factor (TNF) and interleukin 1 (IL-1) and causes peripheral lymphopenia and a dose-response-dependent initial neutropenia followed by a monophasic neutrophilia. TNF alone induces lymphopenia and an initial neutropenia followed by a biphasic neutrophilia. IL-1 alone induces lymphopenia and a monophasic neutrophilia. TNF-plus-IL-1 caused a greater lymphopenia than either monokine alone, suggesting that both monokines contribute to LPS-induced lymphopenia. TNF-plus-IL-1 induced neutropenia similar in magnitude to that induced by TNF alone and induced a neutrophilia significantly greater than that induced by either monokine alone, suggesting that LPS-induced neutropenia is caused by TNF, while LPS-induced neutrophilia is due to the combined effects of TNF and II-1. TNF and IL-1 were administered together with LPS to simulate the in vivo condition of endogenous monokine release during gram-negative bacteremia. TNF combined with LPS increased both the duration and magnitude of LPS-induced lymphopenia, LPS-induced neutropenia, and LPS-induced neutrophilia. TNF-plus-LPS treated rats at 2 hours after injection exhibited a striking 93% decrease in bone marrow neutrophils even though no peripheral neutrophilia was yet apparent, suggesting that the subsequent neutrophilia was due to demargination and recirculation of neutrophils sequestered in the peripheral vasculature immediately after their release from the bone marrow. Epinephrine, which causes neutrophilia by demargination but not by release of marrow neutrophils, reversed the initial neutropenia in TNF-plus-LPS-treated rats and increased the neutrophilia. IL-1 combined with LPS increased LPS-induced neutrophilia, suggesting that endogenous IL-1 also contributed to LPS-induced neutrophilia. Corynebacterium parvum-primed rats with hyperplasia of the monocyte-macrophage system and treated with TNF differed from naive rats treated with TNF in that the

  12. Random mutagenesis in Corynebacterium glutamicum ATCC 13032 using an IS6100-based transposon vector identified the last unknown gene in the histidine biosynthesis pathway

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    Gaigalat Lars

    2006-08-01

    Full Text Available Abstract Background Corynebacterium glutamicum, a Gram-positive bacterium of the class Actinobacteria, is an industrially relevant producer of amino acids. Several methods for the targeted genetic manipulation of this organism and rational strain improvement have been developed. An efficient transposon mutagenesis system for the completely sequenced type strain ATCC 13032 would significantly advance functional genome analysis in this bacterium. Results A comprehensive transposon mutant library comprising 10,080 independent clones was constructed by electrotransformation of the restriction-deficient derivative of strain ATCC 13032, C. glutamicum RES167, with an IS6100-containing non-replicative plasmid. Transposon mutants had stable cointegrates between the transposon vector and the chromosome. Altogether 172 transposon integration sites have been determined by sequencing of the chromosomal inserts, revealing that each integration occurred at a different locus. Statistical target site analyses revealed an apparent absence of a target site preference. From the library, auxotrophic mutants were obtained with a frequency of 2.9%. By auxanography analyses nearly two thirds of the auxotrophs were further characterized, including mutants with single, double and alternative nutritional requirements. In most cases the nutritional requirement observed could be correlated to the annotation of the mutated gene involved in the biosynthesis of an amino acid, a nucleotide or a vitamin. One notable exception was a clone mutagenized by transposition into the gene cg0910, which exhibited an auxotrophy for histidine. The protein sequence deduced from cg0910 showed high sequence similarities to inositol-1(or 4-monophosphatases (EC 3.1.3.25. Subsequent genetic deletion of cg0910 delivered the same histidine-auxotrophic phenotype. Genetic complementation of the mutants as well as supplementation by histidinol suggests that cg0910 encodes the hitherto unknown

  13. Association of Corynebacterium pseudotuberculosis recombinant proteins rCP09720 or rCP01850 with rPLD as immunogens in caseous lymphadenitis immunoprophylaxis.

    Science.gov (United States)

    Silva, Mara Thais de Oliveira; Bezerra, Francisco Silvestre Brilhante; de Pinho, Rodrigo Barros; Begnini, Karine Rech; Seixas, Fabiana Kommling; Collares, Tiago; Portela, Ricardo Dias; Azevedo, Vasco; Dellagostin, Odir; Borsuk, Sibele

    2018-01-02

    Caseous lymphadenitis (CLA) is a chronic disease responsible for significant economic losses in sheep and goat breeding worldwide. The treatment for this disease is not effective, and an intense vaccination schedule would be the best control strategy. In this study, we evaluated the associations of rCP09720 or rCP01850 proteins from Corynebacterium pseudotuberculosis with recombinant exotoxin phospholipase D (rPLD) as subunit vaccines in mice. Four experimental groups (10 animals each) were immunized with a sterile 0.9% saline solution (G1), rPLD (G2), rPLD + rCP09720 (G3), and rPLD + rCP01850 (G4). The mice received two doses of each vaccine at a 21-day interval and were challenged 21 days after the last immunization. The animals were evaluated daily for 40 days after the challenge, and mortality rate was recorded. The total IgG production level increased significantly in the experimental groups on day 42 after the first vaccination. Similarly, higher levels of specific IgG2a were observed in experimental groups G2, G3, and G4 compared to the IgG1 levels on day 42. G4 showed a significant (p < .05) humoral response against both antigens of the antigenic formulations. The cellular immune response induced by immunization was characterized by a significant (p < .05) production of interferon-γ compared to that in the control, while the concentrations of interleukin (IL)-4 and IL-12 were not significant in any group. A significant increase of tumor necrosis factor was observed only in G4. The survival rates after the challenge were 30% (rPLD), 40% (rPLD + rCP09720), and 50% (rPLD + rCP01850). Thus, the association of rCP01850 with rPLD resulted in the best protection against the challenge with C. pseudotuberculosis and induced a more intense type 1 T-helper cell immune response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Metabolome analysis-based design and engineering of a metabolic pathway in Corynebacterium glutamicum to match rates of simultaneous utilization of D-glucose and L-arabinose.

    Science.gov (United States)

    Kawaguchi, Hideo; Yoshihara, Kumiko; Hara, Kiyotaka Y; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

    2018-05-17

    L-Arabinose is the second most abundant component of hemicellulose in lignocellulosic biomass, next to D-xylose. However, few microorganisms are capable of utilizing pentoses, and catabolic genes and operons enabling bacterial utilization of pentoses are typically subject to carbon catabolite repression by more-preferred carbon sources, such as D-glucose, leading to a preferential utilization of D-glucose over pentoses. In order to simultaneously utilize both D-glucose and L-arabinose at the same rate, a modified metabolic pathway was rationally designed based on metabolome analysis. Corynebacterium glutamicum ATCC 31831 utilized D-glucose and L-arabinose simultaneously at a low concentration (3.6 g/L each) but preferentially utilized D-glucose over L-arabinose at a high concentration (15 g/L each), although L-arabinose and D-glucose were consumed at comparable rates in the absence of the second carbon source. Metabolome analysis revealed that phosphofructokinase and pyruvate kinase were major bottlenecks for D-glucose and L-arabinose metabolism, respectively. Based on the results of metabolome analysis, a metabolic pathway was engineered by overexpressing pyruvate kinase in combination with deletion of araR, which encodes a repressor of L-arabinose uptake and catabolism. The recombinant strain utilized high concentrations of D-glucose and L-arabinose (15 g/L each) at the same consumption rate. During simultaneous utilization of both carbon sources at high concentrations, intracellular levels of phosphoenolpyruvate declined and acetyl-CoA levels increased significantly as compared with the wild-type strain that preferentially utilized D-glucose. These results suggest that overexpression of pyruvate kinase in the araR deletion strain increased the specific consumption rate of L-arabinose and that citrate synthase activity becomes a new bottleneck in the engineered pathway during the simultaneous utilization of D-glucose and L-arabinose. Metabolome analysis

  15. Una trayectoria de nuestro tiempo

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    Roberto Schwarz

    2014-12-01

    Full Text Available La lectura crítica de la autobiografía de CaetanoVeloso, Verdade tropical, analiza la posición cultural y política de la Tropicália, movimiento en que este artista tuvo un papel decisivo con su música y sus shows. Se problematiza su distanciamiento de la izquierda tradicional y las críticas que hace de ésta: por un lado, su ilusión sobre la existencia de un ‘populismo’ y, por el otro, su complacencia con medidas dictatoriales tomadas en el nombre del pueblo. El artículo sostiene que esta actitud prepara el descompromiso social que caracteriza el post-modernismo, no obstante admite que tampoco la izquierda –hasta hoy– ha encontrado una respuesta sobre el periodo que apunte a una reevaluación de lo popular y del pueblo como sujeto políticamente viable. A leitura crítica da autobiografia de Caetano Veloso, Verdade tropical, analisa a perspectiva cultural e política da Tropicália, movimento no qual este artista teve um papel decisivo com sua música e seus shows. Problematiza-se o seu afastamento a respeito da esquerda tradicional e as críticas que faz dela: de um lado, a sua ilusão com a existência de um ‘populismo’ e, do outro, a sua complacência com medidas ditatoriais tomadas em nome do povo. O ensaio assinala que a atitude da Tropicália antecipa a desobrigação social que caracteriza o pós-modernismo, não obstante admite que a esquerda não foi capaz até hoje de propor uma nova avaliação tanto do período quanto do popular e do povo como sujeito politicamente viável. This critical approach to Caetano Veloso’s autobiographic book Verdade Tropical, analyzes the cultural and political dimensions of Tropicália, a movement in which this artist played a decisive role with his music and shows. This article questions the distance Tropicália took from traditional left-wing positions, as well as its criticism of the latter: on the one hand, Tropicália’s misleading depiction about populism and, on the other

  16. Paso superior en una ladera

    Directory of Open Access Journals (Sweden)

    Bender, O.

    1965-07-01

    Full Text Available The Redwood highway, through the Californian forest, runs on a viaduct, as it crosses a mountain slope of about 45° inclination. The firm ground is fairly deep, and as an additional constructional difficulty, it was necessary to respect the natural beauty of the countryside. A structure of portal frames were built, forming a number of short spans. These spans were bridged with metal girders, on which a 19 m wide deck was placed. The columns are hollow and have a transversal cross beam, to join each pair. There was difficulty in excavating the foundations for the columns, as it was necessary to dig through the soft top soil, and also prevent this soil from hurting the trunks of the forest trees. Another significant difficulty in the construction of this viaduct was the access to the working site, since there were no suitable platforms from which to operate the appropriate machinery. This made it necessary to do a lot of the work by manual operation. As one of the edges of the deck is very close to the mountain side, a supporting beam was erected on this side. It was made of concrete, on metal piles. The formwork for the deck structure was placed on the concrete stems of the supporting piles.La autopista denominada Redwood (California salva, con un paso superior, la ladera de un bosque cuya pendiente es del 1/1. El terreno firme se halla a bastante profundidad, añadiéndose, a los naturales problemas de la construcción, el imperativo de respetar la belleza agreste del paraje. La solución adoptada consiste en una estructura porticada, con varios tramos de pequeñas luces, salvados con vigas metálicas, sobre los que se coloca la losa del tablero, de 19 m de anchura total. Los soportes están constituidos por pórticos de dos montantes huecos (con bases de hormigón en masa por debajo del suelo, hasta el firme coronados por un cabezal. La perforación de pozos para el hormigonado de los montantes presentaba la dificultad de atravesar el terreno

  17. EI pensamiento organizacional estrategico: una perspectiva diacronica

    Directory of Open Access Journals (Sweden)

    Mauricio Sanabria

    2004-12-01

    Full Text Available El artículo recorre los principales elementos que han permitido configurar el pensamiento organizacional estratégico. Este campo, inscrito en la disciplina administrativa, cuenta con destacadas contribuciones fundamentalmente durante las últimas cinco décadas. Se reconstruye su desarrollo conceptual, ubicándolo en un contexto histórico particular; más que una crítica profunda, se presenta un panorama general, resultado de una aproximación diacrónica, en la que es imposible no postular una serie de ideas, planteamientos y reflexiones específicas.

  18. HACIA UNA PEDAGOGÍA FRANCISCANA

    Directory of Open Access Journals (Sweden)

    Benjamín Soto Forero

    2008-12-01

    Full Text Available El artículo busca presentar como mediante toda una manera de actuar, de ver y de pensar, se va construyendo una propuesta pedagógica franciscana; inspirada en el Evangelio y en la manera como Francisco de Asís vivió el mismo, buscando siempre la importancia de la persona humana, la fraternidad universal, el respeto por lo diferente, viviendo la cotidianidad de una manera alegre y festiva, donde la propuesta pedagógica franciscana se va dando en el caminar con el otro desde la fraternidad y el servicio.

  19. Desarrollo social y personalidad. Una perspectiva interdisciplinar

    OpenAIRE

    Riesco González, Manuel

    2012-01-01

    En las siguientes páginas se pretende establecer un diálogo interdisciplinar y abierto sobre cuestiones relevantes acerca del desarrollo social y de la personalidad. A partir de una breve reseña histórica del tema desde una perspectiva psicológica, se trata de comprender, con una visión amplia, el progreso humano como marco general del desarrollo social y de las personas. Finalmente, se muestra un bosquejo de la sociedad actual, definida como “sociedad del conocimiento”, “sociedad abierta” y ...

  20. Plan de viabilidad de una casa rural

    OpenAIRE

    Nieto González, Óscar

    2011-01-01

    Este proyecto consiste en la puesta en marcha de una casa rural en la localidad de Argés, próxima a la ciudad de Toledo, se llamará “La Casona de Argés”, la casa tendrá 4 habitaciones dobles y una suite, todas ellas con cuarto de baño y además de las estancias habituales como cocina y salón dispondrá de un semisótano destinado a zona de juegos, una piscina, y una amplia parcela acondicionada para juegos y disfrute de los huéspedes. El negocio va estar enfocado a un público que viaje con niños...

  1. Educando una nueva ética global

    Directory of Open Access Journals (Sweden)

    Juliana Ferrer

    2003-09-01

    Full Text Available Desde el trasfondo global, se han configurado espacios de poder diferenciados, que motivan a la educación de un mínimo de ética global, por la aspiración de una sociedad mas justa y humana. El presente artículo analiza las implícaciones en la formación ética global, bajo el enfoque de contribuir al reforzamiento de la interdependencia de valores éticos universales. Se realiza una contrastación teórica de las corrientes epistemológicas, desde la perspectiva postmodema. Se concluye sobre la necesidad de educar para una ética global, expandiendo sinergias entre dinamismo productivo, bien social e institucionalidad democrática, por la búsqueda de una convivencia social de futuro.

  2. Notas sobre una escuela circular prefabricada

    Directory of Open Access Journals (Sweden)

    Neutra, Richard J.

    1961-09-01

    Full Text Available En 1930, la idea de una planta circular para escuela, abarcando un espacio exterior frente a un edificio de usos varios, era ya antigua por lo menos en diez años. El Museo de Arte Moderno de Nueva York, que por aquellos tiempos instaló y preparó en sus nuevas dependencias la primera exposición masiva de Arquitectura moderna, dispuso una magnífica maqueta de este proyecto de Richard J. Neutra.

  3. Previous Experience a Model of Practice UNAE

    OpenAIRE

    Ormary Barberi Ruiz; María Dolores Pesántez Palacios

    2017-01-01

    The statements presented in this article represents a preliminary version of the proposed model of pre-professional practices (PPP) of the National University of Education (UNAE) of Ecuador, an urgent institutional necessity is revealed in the descriptive analyzes conducted from technical support - administrative (reports, interviews, testimonials), pedagogical foundations of UNAE (curricular directionality, transverse axes in practice, career plan, approach and diagnostic examination as subj...

  4. El budismo como una espiritualidad no religiosa

    Directory of Open Access Journals (Sweden)

    Marta Granés Bayona

    2014-09-01

    Full Text Available El budismo plantea acceder a una visión de la realidad desligada de creencias y supuestos de todo tipo. Para conseguirlo plantea una indagación libre en referencia al enclaustramiento de nuestro pensar y sentir al que nos somete el ego. El ego con sus necesidades y deseos genera un acceso a la realidad relativo a nosotros. Lo que se propone es una liberación de esta lectura para que la realidad pueda aparecer frente a nosotros de manera independiente de las imposiciones del ego, es decir, un acceso a ella ab-soluto (suelto de nosotros. El budismo es, pues, una propuesta de ‘espiritualidad no religiosa’, para la que el mismo término espiritualidad  resultaría inadecuado porque en él subyace la creencia en el ‘espíritu’. Vemos que por todo ello el mensaje budista resulta muy apropiado para las sociedades hoy presentes, bien para aquellas que están transitando de una sociedad agrícola a una industrial, que conlleva a debilitar las convicciones religiosas hasta disolverlas; bien para aquellas que están próximas o han entrado ya en las sociedades llamadas de conocimiento, innovación y cambio continuo cuya condición de movilidad impide  las creencias, porque son fijadoras, lo que arrastra como consecuencia la imposibilidad de tener religión ni espiritualidad. 

  5. Una matriz de contabilidad social para Asturias

    Directory of Open Access Journals (Sweden)

    Margarita Argüelles

    2003-01-01

    Full Text Available Una Matriz de Contabilidad Social es un sistema integrado de cuentas que presenta en un cuadro de doble entrada todas las transacciones que tienen lugar en una economía entre sectores productivos, factores de producción, sectores institucionales y resto del mundo. En comparación con una Tabla Input-Output, ofrece una mayor cantidad de información y presenta de forma plena el proceso circular de la renta, captando con mayor precisión los efectos de cambios exógenos. Una de las principales utilidades de una Matriz de Contabilidad Social es servir como base de datos para el desarrollo y aplicación de un modelo de equilibrio general computable. Este es, precisamente, el objetivo último que se persigue con la elaboración de la Matriz de Contabilidad Social de la economía asturiana que aquí se presenta. Esta Matriz ha sido construida con datos procedentes de las Cuentas Regionales de Asturias correspondientes al año 1995 y su estructura se ha adaptado a su futura utilización como base de datos para el modelo que se pretende aplicar en esta economía regional.

  6. Mito: memoria y legado de una sensibilidad

    Directory of Open Access Journals (Sweden)

    Rafael Humberto Moreno Durán

    1989-01-01

    Full Text Available Evocar con entusiasmo los logros de una revista cultural es una forma de hacer autobiografía. Una forma descaradamente amable de entronizar el propio gusto y de afiliarse a una tradición con pedigree. La revista, por esta vía, deja de ser lo que sociológicamente significa -o debe significar- en el contexto cultural de una época y un país y accede a un rango nuevo y singular: a su valor perse cabe añadir otro aporte: lo que cuenta en la vida espiritual y artística del lector qué la evoca y al cual ha cautivado. La revista adquiere entonces implicaciones antropológicas, en todo superiores a las meramente didácticas y formativas. Si es cierto eso de que el estilo es el hombre, hay estilos que sólo canalizan y concilian sus intereses a través de un tipo particular de revista, lo que de alguna forma constata la existencia de destinos unidos a la suerte de una publicación , y ese es el caso de Jorge Gaitán Durán y de un grupo de escritores , comúnmente designados en el panorama de las letras continentales bajo el nombre de Generación del Cincuenta.

  7. Estudo da difteria na cidade do Recife. I. Nota sôbre levantamento de portadores de Corynebacterium diphtheriae no bairro dos Coelhos Survey on diphtheriae carriers in "Bairro dos Coelhos" Recife, Brazil

    Directory of Open Access Journals (Sweden)

    Dalva A. Mello

    1969-06-01

    Full Text Available De uma amostra probabilística do bairro dos Coelhos da cidade do Recife, 410 indivíduos foram examinados para verificação de portadores de difteria. Sòmente duas amostras de C. diphtheriae foram isoladas de duas crianças de 8 a 9 anos, as quais não apresentaram sintomatologia compatível com o quadro diftérico.From a limited population living around the University Hospital in Recife, Brazil a randomic sample was examined in order to identify diphtheria carriers. Swabs were made from 410 persons in a house-to-house survey. Two strains of Corynebacterium diphtheriae were isolated from healthy 8 and 9-year old children.

  8. Sequence-based identification of inositol monophosphatase-like histidinol-phosphate phosphatases (HisN) in Corynebacterium glutamicum, Actinobacteria, and beyond.

    Science.gov (United States)

    Kulis-Horn, Robert Kasimir; Rückert, Christian; Kalinowski, Jörn; Persicke, Marcus

    2017-07-18

    The eighth step of L-histidine biosynthesis is carried out by an enzyme called histidinol-phosphate phosphatase (HolPase). Three unrelated HolPase families are known so far. Two of them are well studied: HAD-type HolPases known from Gammaproteobacteria like Escherichia coli or Salmonella enterica and PHP-type HolPases known from yeast and Firmicutes like Bacillus subtilis. However, the third family of HolPases, the inositol monophosphatase (IMPase)-like HolPases, present in Actinobacteria like Corynebacterium glutamicum (HisN) and plants, are poorly characterized. Moreover, there exist several IMPase-like proteins in bacteria (e.g. CysQ, ImpA, and SuhB) which are very similar to HisN but most likely do not participate in L-histidine biosynthesis. Deletion of hisN, the gene encoding the IMPase-like HolPase in C. glutamicum, does not result in complete L-histidine auxotrophy. Out of four hisN homologs present in the genome of C. glutamicum (impA, suhB, cysQ, and cg0911), only cg0911 encodes an enzyme with HolPase activity. The enzymatic properties of HisN and Cg0911 were determined, delivering the first available kinetic data for IMPase-like HolPases. Additionally, we analyzed the amino acid sequences of potential HisN, ImpA, SuhB, CysQ and Cg0911 orthologs from bacteria and identified six conserved sequence motifs for each group of orthologs. Mutational studies confirmed the importance of a highly conserved aspartate residue accompanied by several aromatic amino acid residues present in motif 5 for HolPase activity. Several bacterial proteins containing all identified HolPase motifs, but showing only moderate sequence similarity to HisN from C. glutamicum, were experimentally confirmed as IMPase-like HolPases, demonstrating the value of the identified motifs. Based on the confirmed IMPase-like HolPases two profile Hidden Markov Models (HMMs) were build using an iterative approach. These HMMs allow the fast, reliable detection and differentiation of the two

  9. diphtheriae in a child Corynebacterium

    African Journals Online (AJOL)

    isolated from blood cultures in suspected cases of. lE. Hpwever, his .... dextrin -, maltose +, sucrose -, catalase +,glucose +, mannitol-, trehalose -, nitrate ... by Abbott.9 Whether in acquired or congenital heart disease, the bacteraemia of lE is ...

  10. UNA ESCUELA RURAL EN TRANSFORMACIÓN: DE UNA CIUDADANÍA LOCAL A UNA CIUDADANÍA GLOBAL

    Directory of Open Access Journals (Sweden)

    Laura Rayón Rumayor

    2012-01-01

    Full Text Available A continuación presentamos parte de los resultados obtenidos en una investigación colaborativa,desarrollada en una escuela de una localidad rural de la provincia de Guadalajara. El estudio se ha centrado en comprender cómo viven y experimentan la convivencia escolar profesoradoyalumnado, y cuáles son las creencias de las familias sobre ésta. Mediante un diseño de investigación que se gesta en sus inicios con una acción de transformación y mejora, se va construyendo un relato de la vida escolar que tiene en cuenta al alumnado como sujeto escolary sujeto social.Tras una breve presentación de cuándo y cómo se gesta el estudio, exponemos los referentes teóricos y algunos rasgos importantes en relación con el contexto en el que está inserta la escuelaPosteriormente, abordamos el proceso metodológico seguido, resaltando los aspectos críticos quedan muestras de la fecundidad y el enriquecimiento que la investigación colaborativa tiene para la construcción de un conocimiento intersubjetivo y contrastado de la convivencia en la escuela. A continuación presentamos los resultados obtenidos y los sometemos a discusión, valorando surelevancia en relación con las ideas y planteamientos de otros autores. Terminamos con unas conclusiones en las que señalamos las ideas más relevantes extraídas del estudio.

  11. de una relación fallida?

    Directory of Open Access Journals (Sweden)

    César Mureddu Torres

    2008-01-01

    Full Text Available Los autores presentan los resultados de una investigación de campo realizada en dos instituciones pertenecientes al Sistema de Educación Superior en México, una pública y otra privada. Destacan en ella los tópicos referentes a la actitud política de los estudiantes y relevan la semejanza de ambos grupos, cuya tendencia es, fundamentalmente, hacia la incertidumbre. La conclusión del análisis de los datos los lleva a declarar que no hay suficiente evidencia empírica por la cual pueda asignarse una correlación significativa entre el tipo de institución y la actitud predominante entre los alumnos. Concluyen que en casos como el mexicano, frente a una situación política cambiante, la repuesta de los alumnos depende más de circunstancias que afectan a toda la estructura social y no necesariamente a una parte de ellas, como la acción de la universidad, por muy importante que ésta sea.

  12. ¿Madre hay una sola?

    Directory of Open Access Journals (Sweden)

    Bravi, Claudio

    2005-01-01

    Full Text Available Un patrón de herencia uniparental libre de recombinación unido a una alta tasa de evolución molecular han hecho del ADNmt una herramienta de alta resolución en el estudio del origen y evolución de las poblaciones humanas. La existencia de una robusta filogenia global, basada en >2.000 genomas mitocondriales completos, y de más de 30.000 secuencias de la Región Hipervariable I (RHV-I publicadas a la fecha permiten evaluar los patrones de distribución étnico/geográfica y las afinidades extra-continentales de los linajes maternos presentes en América. El análisis de ∼4.000 RHV-I publicadas para Nativos Americanos permite describir: a una distribución recíprocamente excluyente para varios grupos monofiléticos de linajes maternos; b un origen "híbrido" para las poblaciones peri-árticas; c una notable pérdida de diversidad respecto de Asia: en todo el continente americano, desde Alaska a la Patagonia, coexisten hoy menor cantidad de haplogrupos y sub-haplogrupos mitocondriales que en cualquier población indígena siberiana.

  13. Mujeres sufridoras: Una realidad en el tiempo

    Directory of Open Access Journals (Sweden)

    Paloma Calero Martín de Villodres

    Full Text Available A través de las vivencias de una persona podemos comprender y conocer mejor sus experiencias. El nombre de nuestra informante es Ana, una mujer de 84 años, ella va a compartir con nosotros una vida llena de desgracias, sufrimientos, soledad y desconsuelo que provocaría un cuadro clínico de hipertensión arterial y azúcar elevada que desencadenarían en crisis asmáticas futuras, insuficiencia cardiaca, una embolia e innumerables caídas fortuitas. Es una mujer luchadora, que ha sido educada para servir sin protestar, con un gran sentido de la responsabilidad familiar, sometida al machismo de la época. Cansada de callar, nos relata cómo ha sido su vida desde su niñez, su matrimonio, sus hijos, la enfermedad de Alzheimer de su marido, la desaparición de su sintomatología y el largo camino de obstáculos que ha tenido que superar hasta llegar a nuestros días.

  14. Emprendimiento social, una mirada a la equidad

    Directory of Open Access Journals (Sweden)

    Ignacio Barrios Parejo

    2017-07-01

    Full Text Available Este artículo comprende una revisión teórica acerca del emprendimiento social, entendido como una iniciativa de negocio con o sin fin de lucro, cuyo objetivo es la generación de valor social. Siendo este un campo de investigación reciente y atractivo, el objetivo de esta revisión consiste a su vez en identificar y generar una transformación social real, a partir de la reducción de los índices de pobreza, de la percepción de injusticia entre los ciudadanos y del aumento de la capacidad del país para darle a cada uno de sus ciudadanos lo que se merece en función de sus méritos y condiciones.

  15. Implementación de una red WAN en una escudería de F1

    OpenAIRE

    García Muñoz, Luis Eduardo

    2013-01-01

    TFC en el que se detalla la implementación de una red WAN en una escudería de Fórmula 1. TFC en què es detalla la implementació d'una xarxa WAN en una escuderia de Fórmula 1. Bachelor thesis for the Telecommunication Technologies program on Telematics.

  16. Editorial. Una Sabiduría Humanista

    Directory of Open Access Journals (Sweden)

    Angel Rodrigo Velez Bedoya

    2010-12-01

    Full Text Available La construcción de una sociedad justa, equitativa, solidaria y, ante todo, humana, sigue siendo una tarea de nunca acabar; parece ser que la racionalización moderna, la instrumentalización científica y tecnológica, la pérdida del sujeto, el impersonalismo y la masificación de las organizaciones, así como la pérdida paulatina del mundo de la vida, emergen cada vez mayor fuerza como problemas de difícil solución.

  17. Para tener entre manos una revista

    OpenAIRE

    Gabriel Giannone

    2017-01-01

    Consideramos importante rescatar el trabajo colectivo y acumulado que precede y sucede a la labor de intermediación académica que realiza una revista. Para ello recordamos una clásica frase prologal: el texto que usted tiene en sus manos. Con cierta ironía, porque quizás muy pocos de los lectores puedan tener entre manos y oler el papel impreso de Chasqui. Desde sus pantallas, sus tablets o sus teléfonos la intención es que se comprenda este número como un solo cuerpo. Y al mismo tiempo, como...

  18. Toponimia: una preziosa eredità

    OpenAIRE

    Crivelli, Ruggero

    2013-01-01

    Nel 2008, Mauro Corona pubblica un libro il cui titolo è I fantasmi di pietra. In questo suo libro, l’autore racconta storie di vita del suo villaggio, Erto, nella regione del Vajont, distrutto dall’alluvione del 1963 e praticamente abbandonato da allora. Con il pretesto di una visita sui luoghi della sua infanzia, di cui non restano che le rovine delle case e delle piazze, lo scrittore si sofferma in questo o in quel luogo e racconta: racconta spezzoni di una vita passata i cui protagonisti ...

  19. En busca de una escuela posible

    Directory of Open Access Journals (Sweden)

    Gloria Domínguez Chillón

    2003-01-01

    Full Text Available La historia de las reformas educativas promovidas desde el poder político es una historia de sucesivas frustraciones. No obstante muchos profesores siguen buscando las formas de construir una escuela mejor. Se presenta la experiencia personal de la autora, comprometida en esta búsqueda, partiendo de su planteamiento educativo en relación con la Educación Infantil. Ese planteamiento se concreta entre otras cosas, en la organización de las actividades en torno a Proyectos de Trabajo, de los que se nos muestra un ejemplo detallando los pasos seguidos en su desarrollo.

  20. Una politica dell’open access

    Directory of Open Access Journals (Sweden)

    Marco Pasini

    2008-12-01

    Full Text Available L’accesso libero al sapere è lo strumento principale per l’attuazione della democrazia del sapere. Per quello che ho potuto intuire fin dalle prime letture e comprendere poi meglio attraverso lo studio, vista la mia attività di traduzione, ho sempre notato la completezza nelle tematiche trattate e la varietà scientifica degli autori degli articoli. Questa caratteristica rappresenta certamente una garanzia di confronto e allo stesso tempo aumenta gli stimoli all’essere propositivo nel misurarsi in nuovi campi di applicazione, è una continua ricerca.

  1. El prematuro: una esperanza de vida

    OpenAIRE

    Betancur R., Diana Helena; Fundación Valle de Lili; Garzón F., Lucía

    1999-01-01

    Factores prenatales de riesgo para el feto/Alteraciones inherentes a la prematuréz/Manejo del niño prematuro/ ¿Existe relación entre la actividad física y los partos prematuros?/ ¿Cómo se puede prevenir la prematuréz?/ ¿El recién nacido prematuro puede llevar una vida normal una vez es dado de alta?/ ¿Qué tipo de alimentación deberá recibir el prematuro?/ ¿Cuándo debe usted consultar a su pediatra?

  2. PERSPECTIVAS PARA UNA TEOLOGIA LATINO AMERICANA

    Directory of Open Access Journals (Sweden)

    Juan Luis Segundo

    1977-01-01

    Full Text Available La teologia es parte de Ia cultura general, no un fenômeno aparte. Y Io que podríamos Mamar "nuestra" cultura es una determinada mezcla de elementos autóctones y de elementos importados. Lo que no eqüivale a decir; elementos autênticos e inauténticos.

  3. Enrico Fermi significato di una scoperta

    CERN Document Server

    2001-01-01

    Questo volume è la riedizione, rinnovata ed ampliata, del volume "Enrico Fermi. Significato di una scoperta" edito dal FIEN (Forum Italiano dell'Energia Nucleare) nel 1982 e nel 1992 in occasione, rispettivamente, del 40mo e del 50mo anniversario della pila di Fermi.

  4. Evolución de una casa

    Directory of Open Access Journals (Sweden)

    Mac L. Johansen, John

    1958-02-01

    Full Text Available La forma, aspecto, estructura, concepción y realización de una casa están en estrecha relación con el ambiente cultural, social y técnico que la rodean y con ellos evolucionan.

  5. La discapacidad: una imagen del paradigma.

    Directory of Open Access Journals (Sweden)

    Gloria Lucía Sierra.

    2002-03-01

    Full Text Available La educación especial ha refinado por siglos una intervención dirigida a la funcionalidad del organismo que aloja al sujeto discapacitado. Esta tendencia nos señala un apuntalamiento a lo real, que ignora a lo simbólico y a lo imaginario como dimensiones constituyentes del sujeto.

  6. Cubierta de madera para una nave industrial

    Directory of Open Access Journals (Sweden)

    Hossdorf, Heinz

    1958-05-01

    Full Text Available Para la ampliación de los talleres de Hans Schmidlin, de Basilea, Suiza, dedicados a la prefabricación de elementos de construcción de madera y metales ligeros para fachadas, se ha construido una nueva nave, rectangular, de 49x55,4 m en planta.

  7. Abrir una Venus: Hablar con ella

    Directory of Open Access Journals (Sweden)

    Ginnette Barrantes Sáenz

    2013-09-01

    Se propone a Alicia como la Venus abierta que  incita, mediante  la  cita cinematográfica del cine mudo en el cine de Almodóvar, la no tan conocida figura de  amar a una  dormida( Allouch, 2005

  8. Una descomposición convexa

    Directory of Open Access Journals (Sweden)

    Mario Lomelí - Haro

    2014-01-01

    Full Text Available Dada una colección P de puntos en el plano, una descomposición convexa de P es un conjunto Γ de polígonos convexos convértices en P que satisfacen lo siguiente: La unión de todos los elementos de Γ es el cierre convexo de P, cada elemento de Γ es vacío (no contiene a ningún otro elemento de P en su interior y para cualesquiera 2 elementos diferentes en Γ sus interiores son disjuntos (se intersecarán en a lo más una arista. Únicamente se sabe que existen descomposiciones convexas con a lo más 7n/5 elementos para toda colección de n puntos. En este trabajo diremos cómo obtener una descomposición convexa específica de P con a lo más 3n/ 2 elementos.

  9. The Woodlands: Una forma diferente de gobernar

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    Raquel Insa-Ciriza

    2010-06-01

    Full Text Available The Woodlands (Texas es uno de los mejores ejemplos de éxito de los partenariados público-privados entre el Departamento de Urbanismo y Vivienda Americano (Department of Housing and Urban Development, US - HUD y la empresa privada. The Woodlands, que fue creada como una «Nueva Ciudad» por la compañía Mitchell Energy & Development Corporation, ha ido creciendo y creando una masa crítica de residentes, trabajadores, su propio sentido de comunidad y lo más importante, su propia forma de gobierno. Es el único caso en Estados Unidos de ciudad gobernada por asociaciones privadas. Estas asociaciones, representadas por un Consejo de Administración, proveen la mayoría de los servicios públicos a los ciudadanos. En este artículo se muestra lo que llamo «complicidad ciudadana» basada en lo que el Nuevo Servicio Público define como gobierno basado en la comunidad. Ellos no están reinventando ninguna clase de gobierno, lo que están haciendo es crear una nueva forma de gobierno en la que los ciudadanos prefieren tomar el mando que servir. El estudio del caso que muestro nos ayuda a entender cómo una mayor participación de los ciudadanos en las tareas de la administración local puede hacer disminuir visiblemente el poder del promotor en el desarrollo de una Nueva Ciudad. Esta complicidad ciudadana se traduce en términos de implicación de los miembros de la comunidad en el crecimiento y en el Gobierno de la ciudad

  10. Complete genome sequence and lifestyle of black-pigmented Corynebacterium aurimucosum ATCC 700975 (formerly C. nigricans CN-1 isolated from a vaginal swab of a woman with spontaneous abortion

    Directory of Open Access Journals (Sweden)

    Gartemann Karl-Heinz

    2010-02-01

    Full Text Available Abstract Background Corynebacterium aurimucosum is a slightly yellowish, non-lipophilic, facultative anaerobic member of the genus Corynebacterium and predominantly isolated from human clinical specimens. Unusual black-pigmented variants of C. aurimucosum (originally named as C. nigricans continue to be recovered from the female urogenital tract and they are associated with complications during pregnancy. C. aurimucosum ATCC 700975 (C. nigricans CN-1 was originally isolated from a vaginal swab of a 34-year-old woman who experienced a spontaneous abortion during month six of pregnancy. For a better understanding of the physiology and lifestyle of this potential urogenital pathogen, the complete genome sequence of C. aurimucosum ATCC 700975 was determined. Results Sequencing and assembly of the C. aurimucosum ATCC 700975 genome yielded a circular chromosome of 2,790,189 bp in size and the 29,037-bp plasmid pET44827. Specific gene sets associated with the central metabolism of C. aurimucosum apparently provide enhanced metabolic flexibility and adaptability in aerobic, anaerobic and low-pH environments, including gene clusters for the uptake and degradation of aromatic amines, L-histidine and L-tartrate as well as a gene region for the formation of selenocysteine and its incorporation into formate dehydrogenase. Plasmid pET44827 codes for a non-ribosomal peptide synthetase that plays the pivotal role in the synthesis of the characteristic black pigment of C. aurimucosum ATCC 700975. Conclusions The data obtained by the genome project suggest that C. aurimucosum could be both a resident of the human gut and possibly a pathogen in the female genital tract causing complications during pregnancy. Since hitherto all black-pigmented C. aurimucosum strains have been recovered from female genital source, biosynthesis of the pigment is apparently required for colonization by protecting the bacterial cells against the high hydrogen peroxide concentration in

  11. Cuento: El último viernes de una guerra

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    Policarpo Varón

    1969-03-01

    Full Text Available La tarde en que Rosario Figueroa vda. de Rengifo murió, su vieja casa se llenó de gente falsamente condolida. Alguien recordó que la viuda formaba parte de algo que era como una institución. Al entierro la acompañaron no más de diez personas. Dos hijos varones con sus mujeres, una hija única con su marido, tres o cuatro nietos y un viejo que trabajosamente anduvo detrás del cortejo gesticulando y hablando solo y deteniéndose a veces para mirar algo a su espalda y limpiarse las lágrimas y el sudor de la cara y el cuello con un pañuelo floriado.

  12. Promocionar una franquicia española

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    Laura Pérez Sánchez

    2015-10-01

    Full Text Available Experiencia práctica dirigida a alumnos de niveles B1-B2 en la materia Español para los Negocios en la Universitat de València con una duración de 3 horas. El principal objetivo es que los alumnos aprendan a promocionar una franquicia española y repasar contenidos funcionales, gramaticales y culturales. Además, llevar al aula realias como material aplicable, el aprendizaje cooperativo y las diferentes agrupaciones formales e informales dependiendo de los roles asignados, el aprendizaje basado en proyectos (ABP de la promoción de la franquicia, el desarrollo de las Inteligencias Múltiples y diferentes tipos de evaluación: autoevaluación, coevaluación y heteroevaluación.

  13. Para tener entre manos una revista

    Directory of Open Access Journals (Sweden)

    Gabriel Giannone

    2017-12-01

    Full Text Available Consideramos importante rescatar el trabajo colectivo y acumulado que precede y sucede a la labor de intermediación académica que realiza una revista. Para ello recordamos una clásica frase prologal: el texto que usted tiene en sus manos. Con cierta ironía, porque quizás muy pocos de los lectores puedan tener entre manos y oler el papel impreso de Chasqui. Desde sus pantallas, sus tablets o sus teléfonos la intención es que se comprenda este número como un solo cuerpo. Y al mismo tiempo, como un esfuerzo colectivo. Alrededor de él están las propuestas, lecturas y análisis de cientos de autores, revisores externos y lectores.

  14. Estrategia organizacional: una propuesta de estudio

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    Ángela Lucía Noguera Hidalgo

    2014-01-01

    Full Text Available El concepto de estrategia en el contexto de las organizaciones empresariales es uno de los temas que genera gran interés en los asuntos del management. Sin embargo, la proposición de nuevos enfoques no ha aportado significativamente al avance en el estudio de este concepto. El estancamiento se hace evidente, razón por la cual el presente documento esboza una propuesta que reúne algunos de los retos para el estudio de la estrategia. En él se presenta una revisión que deja por sentados los posibles caminos a seguir, los cuales contribuyen a la perdurabilidad de las organizaciones.

  15. Voz, una nueva interfaz hombre- maquina

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    Jorge Augusto Jaramillo M.

    2015-05-01

    Full Text Available RESUMEN El siguiente escrito ha sido elaborado  con base en los documentos actuales en los esfuerzos hechos por diferentes personas y  entidades gubernamentales, en implementar sistemas que permitan incorporar el habla  humana en un computador, como una interface alternativa y más natural. Aquí se da un esbozo bastante global de lo que es esta interface, pues los estudios hechos al respecto van desde simples algoritmos para el análisis de las señales (determinación de las características implícitas en ellas hasta sistemas bastante complejos que desean establecer una comunicación continua con cualquier locutor.

  16. Una experiencia lexicográfica

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    José Aldemar Álvarez Valencia

    2006-01-01

    Full Text Available Las dinámicas actuales de las sociedades modernas y postmodernas hacen que haya una constante creación y flujo de unidades léxicas cuyo origen se hace cada vez más difícil de identificar. Este documento se propone reportar una experiencia investigativa en el área de la lexicografía que se llevó a cabo en algunos pueblos de la región de Cundinamarca. A través de grabaciones de audio de conversaciones informales, entrevistas y cuestionarios se buscó elaborar un glosario de naturaleza dialectal. Las conclusiones indican que debido a la movilidad de los habitantes de la ciudad de Bogotá hacia los pueblos de Cundinamarca y viceversa, es difuso determinar un vocabulario específico.

  17. en una especie mexicana de serpiente

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    Javier Manjarrez

    2005-01-01

    Full Text Available Este ensayo trata los determinantes de la dieta en serpientes y en particular se discute un fenómeno único entre las 29 especies del género Thamnophis: la ingestión de acociles por T. melanogaster como posible invasión del género dentro de un nicho alimentario nuevo. Se plantea la oportunidad de estudiar aspectos del proceso de entrada como la microevolución de la conducta y la morfología de la dentición y cráneo asociada a la incorporación de una nueva presa en la dieta. Finalmente se discute la posibilidad de la acocilofagia como un carácter conductual ancestral que ahora sólo permanece como una conducta homóloga.

  18. Oxitocina: nuevas perspectivas para una droga antigua

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    Steven L. CLARK

    2010-12-01

    Full Text Available La oxitocina es el medicamento más comúnmente asociada con la prevención de complicaciones perinatales y recientemente fue incluida por el Instituto para la Administración Medicamentosa Segura (Institute for Safe Medication Practices - ISMP en una pequeña lista de medicamentos “con alto grado de riesgos”, lo que puede “necesitar salvaguardas especiales para reducir el riesgo de error”. Las recomendaciones actuales para administrar este medicamento son vagas en relación a la indicación, tiempo de uso, dosis y el monitoreo de los efectos maternos y fetales. Una revisión de los datos clínicos y farmacológicos disponibles sugiere que las orientaciones específicas y basadas en evidencias para administrar oxitocina durante el parto puede derivarse de datos disponibles. Si implementadas, estas prácticas pueden reducir la probabilidad de daños al paciente. Esto sugiere el foco de las orientaciones para la administración electiva limitada de oxitocina, considerar estrategias que disminuyan la necesidad de usar oxitocina, confiar en terapéuticas de bajas dosis de oxitocina, la adhesión a definiciones semicuantitativas específicas sobre parto adecuado e inadecuado, y la aceptación de que, una vez que la actividad uterina adecuada sea alcanzada, es generalmente preferible esperar más tiempo que aumentar la infusión de oxitocina. El uso de protocolos conservadores y específicos para monitorear los efectos de la oxitocina en la madre y en el bebé tiende no sólo a aumentar los resultados, mas también a reducir los conflictos entre miembros del equipo obstétrico. Implementar estas orientaciones parece ser apropiada en una cultura cada vez más focalizada en la seguridad del paciente.

  19. Hacia una nueva Biología

    Directory of Open Access Journals (Sweden)

    Sandín, Máximo

    2002-05-01

    Full Text Available Not available

    «La victoria del darwinismo ha sido tan completa que es un shock darse cuenta de cuan vacía es realmente la visión darwiniana de la vida». Esta rotunda frase no parece significar solamente la manifestación de una opinión personal. Pertenece a un editorial publicado en Nature y fïrmado por Henry Gee, uno de sus comentaristas sobre evolución. El motivo de que una revista científica de las más prestigiosas (que se pueden considerar como las mantenedoras de la ortodoxia, haga suyo ese comentario es que las investigaciones más recientes (especialmente en el campo de la embriogénesis han revelado unos fenómenos que han puesto de manifiesto su absoluta incompatibilidad con la teoría darwinista de la evolución. Las consecuencias de esto son obvias, y las precisa otro editorialista de Nature, Philip Ball, en un comentario sobre la secuenciación del Genoma humano: «Los biólogos van a tener que construir una nueva Biología». Tenemos por delante un duro y largo trabajo científico por realizar, pero también tenemos una tarea previa: depurar la Biología de la, tan arraigada, terminología darwinista, cargada de conceptos y prejuicios deformadores de los fenómenos biológicos.

  20. Sobre una Rodoficea parasita de Gelidiaceas

    OpenAIRE

    Seoane Camba, Juan Antonio

    1982-01-01

    En este trabajo se hace un estudio de una Rodofícea parásita, encontrada sobre Gelidium cantabricum Seoane-Camba y Gelidium sesquipedale (Clemente) Thuret. Por sus características generales atribuímos esta planta al género Gelidiocolax. descrito por Gardner en 1927 para un parásito de Gelidium pulchrum Gardner de las costas americanas del Pacífico...

  1. Sardegna chiama Friuli: storia di una cooperazione

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    Sandra Bianchi

    2001-01-01

    Full Text Available Un progetto sperimentale, attuato nella scuola dell'obbligo, in cui l'esperienza di precedenti corsi di formazione a distanza da parte delle due insegnanti coordinatrici del lavoro e l'organizzazione di una virtual classroom si sono coniugate nella realizzazione di "Gli Eroi Dimenticati" e "La Meglio Gioventu'", iniziative prodotte all'interno del piu' ampio progetto di cooperazione telematica "Sardegna Chiama Friuli".

  2. Factores claves para iniciar una empresa

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    Irenarco Rueda Reyna

    2015-04-01

    Full Text Available RESUMEN El artículo presenta en forma esquemática los aspectos relevantes para la conformación de una empresa,  desde la planeación acertada, el mercado, los medios de producción,  personal y financiamiento. Resalta asimismo la importancia de las clasificaciones y características que debe tener el indicador  de negocios.

  3. The Woodlands: Una forma diferente de gobernar

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    Raquel Insa-Ciriza

    2010-01-01

    Unidos de ciudad gobernada por asociaciones privadas. Estas asociaciones, representadas por un Consejo de Administración, proveen la mayoría de los servicios públicos a los ciudadanos. En este artículo se muestra lo que llamo «complicidad ciudadana» basada en lo que el Nuevo Servicio Público define como gobierno basado en la comunidad. Ellos no están reinventando ninguna clase de gobierno, lo que están haciendo es crear una nueva forma de gobierno en la que los ciudadanos prefieren tomar el mando que servir. El estudio del caso que muestro nos ayuda a entender cómo una mayor participación de los ciudadanos en las tareas de la administración local puede hacer disminuir visiblemente el poder del promotor en el desarrollo de una Nueva Ciudad. Esta complicidad ciudadana se traduce en términos de implicación de los miembros de la comunidad en el crecimiento y en el Gobierno de la ciudad. Clasificación JEL: H1, H11, H70.

  4. Christine Angot: una hetero-homosexual incestuosa

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    María José Palma Borrego

    2008-01-01

    Full Text Available El proyecto literario de Christine Angot en L’inceste (1999 es el de desvelar no su historia incestuosa –ella misma afirma que su libro no es una autobiografía– sino el hacer visible lo más reprimido, lo más oculto y a la vez lo más originario de nuestra Cultura: el incesto con la madre. Un incesto que puede ser real o imaginario, y que el trabajo de escritura desvela y configura sus territorios que van desde la fusión con la madre, característica de toda situación preedípica, hasta una relación homosexual real con su doble narcisista, pasando por el deseo incestuoso por su hija. Mundo sin castración en donde todo puede ser posible, en ese juego de “ser” y “no-ser”, y en donde la temática del incesto está representada en el texto por una espacialidad vertical, de arriba abajo, generacional, madre/hija-Christine-Léonore, y horizontal, Christine-Marie Christine.

  5. Una imatge val per mil paraules

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    Jaume Cabré

    1999-11-01

    Full Text Available Una vegada hi havia un videoclub ple de pel·lícules i a l'entrada hi havia un rètol lluminós molt bonic que deia el lema d'aquesta casa, que és una imatge val per mil paraules. I vet aquí un dia que la clientela ja se n'havia anat, però encara no havien tancat els llums, van entrar al videoclub dues rates, l'Amàlia i l'Amèlia. I van dir: "Què fem avui?" Aleshores l'Amèlia se'n va anar de seguida cap al racó de la sèrie B i va agafar una pel·lícula poc coneguda, mentre que l'Amàlia va agafar Mort a Venècia. Llavors la va començar a rosegar i l'Amèlia li va dir: "Què, què te'n sembla?", i l'Amàlia li va contestar: "Mmm... Em va agradar més la novel·la."

  6. Computadores moleculares: una tecnología

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    Jorge Eduardo Ortiz Triviño

    1999-04-01

    Full Text Available En este artículo se explican algunos detalles básicos para la realización de computadores moleculares basados en ADN; describe el método general para realizar programas en un computador molecular. Se concluye, que la labor de construcción e implementación de esos computadores no es tarea exclusiva del Ingeniero de sistemas sino, y con una participación importante, de profesionales en genética, medicina, biología y ciencias relacionadas. De otro lado, aunque es una tecnología que se encuentra en su primera infancia, puede constituirse en una buena alternativa en los próximos años, si se tiene en cuenta que apoyaría en la solución de problemas, en distintas áreas, cuya solución mediante computación electrónica convencional pueda ser difícil, sino imposible.

  7. Una diferencia inquietante: diario de un aprendiz..

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    Fernando BÁRCENA ORBE

    2009-11-01

    Full Text Available La comunicación afectiva con la persona discapacitada —como social y pedagógicamente se ha convenido en denominar— introduce un tipo de relación asentada en un principio de diferencia. Sin embargo, esta diferencia no es posible pensarla bajo un marco teórico que pretendiese dejar resueltas todas las contradicciones que semejante relación de alteridad implica. Pues se trata de un acontecimiento cargado de suficientes consecuencias en todos los aspectos como para requerir una reflexión narrativa en vez de un frío análisis conceptual. El presente artículo no ha podido ser escrito, por tanto, bajo el régimen de una escritura científica, pero tampoco se trata de un testimonio personal. Procurando evitar las posibles arrogancias derivadas de ambos planteamientos, lo que aquí se presenta es el diario de un aprendiz, de alguien que en su trato diario con la «discapacidad» ha ido descubriendo la singularidad de las emociones del otro y ha tenido que transformar la relación misma en un lenguaje que permitiese habitar la intimidad de una relación inquietante.

  8. Hacia una definición de la medida

    OpenAIRE

    Parot, Jean Jacques

    2012-01-01

    Hacia una definición de la medida A. Primera situación Un granjero va al mercado para vender a) Una gallina (20 pesos) b) Un bulto de naranjas (45 pesos) c) Un pate (38 pesos) d) Una docena de huevos (12 pesos)

  9. Crisis vital desde una perspectiva de género

    OpenAIRE

    Castro, Eva; Flores López, Olga

    2004-01-01

    A continuación se presenta el caso de una mujer de 55 años que presenta una crisis de identidad, abordado desde una perspectiva de género y un modelo explicativo y terapéutico que incluye elementos del análisis transaccional y la terapia constructivista.

  10. Condiciones de posibilidad para una justicia global

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    Pereira, Gustavo

    2004-06-01

    Full Text Available Recognition, as a constitutive part of subjectivity, is a basic need for people as well as for States. The terms of international relationships imposed by a great number of international credit and commerce institutions contradict and undermine such recognition, by means of policies that result in segregation and poverty in the poorest countries. Breaking such logic seems to be the way to enable the existence of conditions of global justice based on terms of reciprocal recognition. A prudential argument is the first step in this process; mid and long-term benefit would be the only rational motivation for international institutions to enable such an openness that would ensure reciprocal recognition. However, this argument is not sufficient, and the objective of a radical inclusion affecting all regions of the planet requires a moral argument based on the idea of equal dignity, inherent to every person. Global justice and its counterpart, local justice, will only be possible through the combination of these two arguments, which would make the existence of a logic of reciprocal recognition possible, thus enabling justice.

    El reconocimiento, en tanto que constitutivo de la subjetividad, es una necesidad básica tanto de las personas como de los Estados. Los términos de relación internacional impuestos por buena parte de los organismos internacionales de crédito y comercio niegan y socavan este reconocimiento a través de políticas que generan exclusión y pobreza en los países más pobres. La ruptura de esta lógica se presenta como un camino que posibilita el surgimiento de condiciones de justicia global basadas en términos de reconocimiento recíproco. Un argumento prudencial oficia como primer paso en este proceso, el beneficio a medio y largo plazo sería la motivación racional para que los organismos internacionales generasen una apertura que permitiese asegurar el reconocimiento recíproco. Sin embargo, este argumento no es

  11. Genetic relationships of Corynebacterium diphtheriae strains isolated from a diphtheria case and carriers by restriction fragment length polymorphism of rRNA genes Relação genética de cepas de Corynebacterium diphtheriae isoladas de caso e seus contatos por RLFP de rRNA gene

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    Claudio Tavares Sacchi

    1995-08-01

    Full Text Available In the present study we report the results of an analysis, based on ribotyping of Corynebacterium diphtheriae intermedius strains isolated from a 9 years old child with clinical diphtheria and his 5 contacts. Quantitative analysis of RFLPs of rRNA was used to determine relatedness of these 7 C.diphtheriae strains providing support data in the diphtheria epidemiology. We have also tested those strains for toxigenicity in vitro by using the Elek's gel diffusion method and in vivo by using cell culture method on cultured monkey kidney cell (VERO cells. The hybridization results revealed that the 5 C.diphtheriae strains isolated from contacts and one isolated from the clinical case (nose case strain had identical RFLP patterns with all 4 restriction endonucleases used, ribotype B. The genetic distance from this ribotype and ribotype A (throat case strain, that we initially assumed to be responsible for the illness of the patient, was of 0.450 showing poor genetic correlation among these two ribotypes. We found no significant differences concerned to the toxin production by using the cell culture method. In conclusion, the use of RFLPs of rRNA gene was successful in detecting minor differences in closely related toxigenic C.diphtheriae intermedius strains and providing information about genetic relationships among them.No presente estudo, nós reportamos os resultados de uma análise, baseada na ribotipagem de cepas de C. diphtheriae intermedius isoladas de uma criança de 9 anos com difteria e seus 5 contatos. Análise quantitativa por RFLP de rRNA foi usada para determinar a relação destas 7 cepas de C. diphtheriae fornecendo dados de interesse epidemiológico. Nós também testamos estas cepas para toxicidade in vitro usando método de difusão de Elek e in vivo usando método de cultura celular com células VERO. Os resultados de hibridização revelaram que as 5 cepas de C. diphtheriae isoladas dos contatos e uma isolada do caso (cepa isolada

  12. Increased Production of Food-Grade d-Tagatose from d-Galactose by Permeabilized and Immobilized Cells of Corynebacterium glutamicum, a GRAS Host, Expressing d-Galactose Isomerase from Geobacillus thermodenitrificans.

    Science.gov (United States)

    Shin, Kyung-Chul; Sim, Dong-Hyun; Seo, Min-Ju; Oh, Deok-Kun

    2016-11-02

    The generally recognized as safe microorganism Corynebacterium glutamicum expressing Geobacillus thermodenitrificans d-galactose isomerase (d-GaI) was an efficient host for the production of d-tagatose, a functional sweetener. The d-tagatose production at 500 g/L d-galactose by the host was 1.4-fold higher than that by Escherichia coli expressing d-GaI. The d-tagatose-producing activity of permeabilized C. glutamicum (PCG) cells treated with 1% (w/v) Triton X-100 was 2.1-fold higher than that of untreated cells. Permeabilized and immobilized C. glutamicum (PICG) cells in 3% (w/v) alginate showed a 3.1-fold longer half-life at 50 °C and 3.1-fold higher total d-tagatose concentration in repeated batch reactions than PCG cells. PICG cells, which produced 165 g/L d-tagatose after 3 h, with a conversion of 55% (w/w) and a productivity of 55 g/L/h, showed significantly higher d-tagatose productivity than that reported for other cells. Thus, d-tagatose production by PICG cells may be an economical process to produce food-grade d-tagatose.

  13. Application of DEN refinement and automated model building to a difficult case of molecular-replacement phasing: the structure of a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum.

    Science.gov (United States)

    Brunger, Axel T; Das, Debanu; Deacon, Ashley M; Grant, Joanna; Terwilliger, Thomas C; Read, Randy J; Adams, Paul D; Levitt, Michael; Schröder, Gunnar F

    2012-04-01

    Phasing by molecular replacement remains difficult for targets that are far from the search model or in situations where the crystal diffracts only weakly or to low resolution. Here, the process of determining and refining the structure of Cgl1109, a putative succinyl-diaminopimelate desuccinylase from Corynebacterium glutamicum, at ∼3 Å resolution is described using a combination of homology modeling with MODELLER, molecular-replacement phasing with Phaser, deformable elastic network (DEN) refinement and automated model building using AutoBuild in a semi-automated fashion, followed by final refinement cycles with phenix.refine and Coot. This difficult molecular-replacement case illustrates the power of including DEN restraints derived from a starting model to guide the movements of the model during refinement. The resulting improved model phases provide better starting points for automated model building and produce more significant difference peaks in anomalous difference Fourier maps to locate anomalous scatterers than does standard refinement. This example also illustrates a current limitation of automated procedures that require manual adjustment of local sequence misalignments between the homology model and the target sequence.

  14. Corynebacterium glutamicum MTCC 2745 immobilized on granular activated carbon/MnFe2O4 composite: A novel biosorbent for removal of As(III) and As(V) ions.

    Science.gov (United States)

    Podder, M S; Majumder, C B

    2016-11-05

    The optimization of biosorption/bioaccumulation process of both As(III) and As(V) has been investigated by using the biosorbent; biofilm of Corynebacterium glutamicum MTCC 2745 supported on granular activated carbon/MnFe2O4 composite (MGAC). The presence of functional groups on the cell wall surface of the biomass that may interact with the metal ions was proved by FT-IR. To determine the most appropriate correlation for the equilibrium curves employing the procedure of the non-linear regression for curve fitting analysis, isotherm studies were performed for As(III) and As(V) using 30 isotherm models. The pattern of biosorption/bioaccumulation fitted well with Vieth-Sladek isotherm model for As(III) and Brouers-Sotolongo and Fritz-Schlunder-V isotherm models for As(V). The maximum biosorption/bioaccumulation capacity estimated using Langmuir model were 2584.668mg/g for As(III) and 2651.675mg/g for As(V) at 30°C temperature and 220min contact time. The results showed that As(III) and As(V) removal was strongly pH-dependent with an optimum pH value of 7.0. D-R isotherm studies specified that ion exchange might play a prominent role. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Una erótica del cuerpo narrado

    OpenAIRE

    Vigneron, Denis

    2013-01-01

    Este artículo estudia cómo Francisco Umbral, en una forma de autorretrato, propone una reflexión ontológica sobre su propio cuerpo y analiza los mecanismos literarios de una escritura del mismo basada en la erótica, entendiendo el erotismo en un sentido más creador que sexual. Con una escritura pulsional, al servicio de las manifestaciones del deseo, Mortal y rosa no es sólo el relato autobiográfico de una tragedia personal sino un estudio epistemológico de las alteraciones del cuerpo desde l...

  16. La escuela inclusiva: una oportunidad para humanizarnos

    Directory of Open Access Journals (Sweden)

    Miguel López Melero

    2012-01-01

    Full Text Available En este artículo mis reflexiones las centro en el amor y la educación como fundamentos de la escuela inclusiva. Un amor sin adjetivos, basado en el respeto al otro como legítimo otro en la convivencia. Es un modo de vida que se inicia en la confianza desde la edad más temprana. Más aun, el amor es un acto de confianza. La confianza es el fundamento de nuestra convivencia. Los seres humanos nos enfermamos en un ambiente de desconfianza, manipulación e instrumentalización de las relaciones. La ausencia de amor nos deshumaniza. Vivimos en un mundo en el que se habla mucho del amor pero lo negamos, continuamente, en nuestros comportamientos y acciones. Vivimos inmersos en la cultura patriarcal. El amor, en dicha cultura, es considerado como un bien inalcanzable o, acaso, una ilusión o una esperanza. Sin embargo, debemos recuperar la vida matrística de la infancia, viviendo en el amor, amando. Es decir, respetando a las personas como legítimas personas en su diferencia, independientemente del hándicap, del género, de la etnia, religión o procedencia, en la convivencia. Sólo en el respeto y en el reconocimiento de las personas como personas radica el sentido de lo humano. Lo que constituye al ser humano como tal es la dimensión social y no lo genético. La genética es la condición inicial, es un punto de partida, no de llegada. Somos lo que somos gracias a las oportunidades que hemos tenido y no a los genes. Ahora bien, lo más humano del ser humano es desvivirse por otro ser humano y en este desvivir surge el valor ético de la educación. Por tanto, hablar de inclusión es hablar de justicia y, parece lógico, que para construir una sociedad justa sea necesario desarrollar modelos educativos equitativos que afronten con justicia los desequilibrios existentes en la misma. Para ello es imprescindible que los responsables de las políticas educativas, el profesorado y los investigadores contraigamos el compromiso moral de orientar el

  17. Aprender a innovar: una experiencia on line

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    Joaquín MORENO MARCHAL

    2014-11-01

    Full Text Available La creatividad y la innovación se han convertido en recursos clave en la denominada sociedad del conocimiento, que bien podría ser también llamada sociedad de la innovación. Pero innovar es una actividad compleja, que integra la aplicación de múltiples capacidades, el pensamiento divergente y convergente, la gestión de equipos humanos, la comunicación. Ahora bien, a innovar se puede, y se debe, aprender. Aprender a innovar es un reto y también una obligación para el conjunto del sistema educativo en todos sus niveles. Partiendo de estas consideraciones este trabajo expone una experiencia de aprendizaje de la creatividad y de la innovación a través de un curso totalmente on line basado en la plataforma MOODLE, en el marco del Programa de Formación Permanente de la Universidad de Cádiz. Se presenta un modelo del proceso de innovación, denominado CREALAB, de elaboración propia. Este modelo se ha utilizado como base del proceso de aprendizaje de la creatividad y de la innovación y en el diseño del curso, está organizado en torno a actividades y tiene un carácter iterativo y realimentado. Se presentan además el conjunto del diseño metodológico y los resultados obtenidos en las dos ediciones celebradas hasta el momento. El diseño del curso totalmente on line y los resultados alcanzados permiten estimar un alto potencial de aplicación, tanto a nivel personal como a nivel organizacional.

  18. Per una lettura laica della teologia medievale

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    Dino Buzzetti

    2010-02-01

    Full Text Available È possibile operare una forma di epoché sui concetti di carattere teologico? Ed è possibile riflettere sulla loro importanza, prescindendo dalla loro portata religiosa? I concetti teologici riescono a dirci qualcosa, se si trascura il loro riferimento essenziale alla nostra relazione con un essere divino? La risposta a queste domande consente di comprendere che cosa significhi essere un studioso laico della filosofia medievale, mentre è impossibile discutere tale problema senza prendere in considerazione anche la teologia medievale. Tutto ciò dunque riguarda non solo la natura della teologia, ma anche l’idea stessa di laicità. Dunque una storiografia del pensiero medievale pienamente consapevole di se stessa deve studiare il discorso teologico e affrontare in profondità la portata teorica di questo problema. Si può concludere che per una lettura laica della teologia medievale è paradossalmente essenziale cogliere proprio il senso intimo del pensiero religioso e le forme storicamente determinate della sua effettiva concettualizzazione.  Is some form of epoché possible on theological concepts? In which way? Is it possible consider their importance leaving their religious scope aside? Can the theological concepts tell us something unless we consider their essential reference to our relationship with a divine being? The answer to these questions let us to understand what means to be a secular (laico scholar of medieval philosophy. It's impossible conversely to discuss this problem without dealing with medieval theology. And this concerns not only the nature of theology, but also and deeply the same idea of secularism (laicità. Therefore a fully aware historiography of medieval thought has to understand the theological speech and to encounter the depth of this theoretical question. So we can conclude that for a secular reading of the medieval theology is paradoxically essential to catch the intimate sense of religious thought and the

  19. LA LINGUA PER STUDIARE: UNA RASSEGNA BIBLIOGRAFICA

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    Marina Tassara

    2011-02-01

    Full Text Available I libri di testo adottati nelle scuole contengono parole sconosciute e costruzioni sintattiche e testuali complesse che rappresentano dei veri e propri “muri linguistici” per gli alunni stranieri che non possiedono una buona conoscenza della lingua italiana. Ciò facilmente determina un divario di competenze tra l’apprendente straniero e i suoi compagni e ritardi scolastici molto spesso incolmabili con conseguente perdita di motivazione e di autostima, senso di frustrazione e isolamento che a volte sfocia in un disagio psico-sociale. Tra gli strumenti adottati dalla scuola italiana per far fronte a questo problema vi sono i testi disciplinari ad alta comprensibilità che, pur mantenendo la maggior parte delle informazioni, le veicolano in una forma più semplice dal punto di vista linguistico. L’articolo fornisce una bibliografia di manuali ad alta comprensibilità il più possibile aggiornata suddivisa per ordine e grado di scuola e per materia scolastica, con l’intento di fornire agli insegnanti un aiuto nella scelta e nel reperimento dei testi.     Language for study:  a bibliography   Textbooks used in schools contain unknown words and complex sentence constructions that create real “linguistic barriers” for foreign students who do not know Italian well.  This creates an abyss between the competence of the foreign learner and his or her classmates and unsuccessful school performance which is often not made up for and leads to a loss of self-esteem, frustration, isolation, and ultimately to psycho-social malaise.  Among the tools utilized in the Italian school system to address this problem are highly comprehensible textbooks which, while containing most of the information, express the content in simpler language.  This article offers an up-dated bibliography of textbooks which are easily understandable, divided according to order and grade of school, for teachers to use in choosing the textbooks for their classes.

  20. Adaptación domótica de una vivienda para una persona con discapacidad

    OpenAIRE

    Sánchez Bermúdez, Francisca

    2015-01-01

    Este proyecto plantea la necesidad de adaptar viviendas para personas con discapacidad con el objetivo de que se garantice el confort y la accesibilidad, no solo del discapacitado, sinó de todas las personas integrantes en ese hogar. En concreto, está focalizado en un caso real de una niña de 3 años que vive con sus padres. Se contempla a partir de un sistema económico y sencillo para que las personas usuarias del mismo, puedan tener garantizado a largo plazo una me...

  1. Educación familiar para una afectividad, desde una antropología personalista

    OpenAIRE

    Pedreros Silva, Claudia A.

    2014-01-01

    Este trabajo pretende dar a conocer una propuesta de formación afectiva sexual para niños y adolescentes llamada “Aprendiendo a Querer”, un programa que abarca todo el arco de desarrollo del estudiante en el trascurso de la formación en los ciclos básica y media en Chile. Es una propuesta que encuentra cabida en la legislación vigente en el Estado de Chile bajo la ley general de educación 20.370 y la ley de salud 20.418 que establece la obligatoriedad de implementar...

  2. Implementació d'una Cache per a un processador MIPS d'una FPGA

    OpenAIRE

    Riera Villanueva, Marc

    2013-01-01

    [CATALÀ] Primer s'explicarà breument l'arquitectura d'un MIPS, la jerarquia de memòria i el funcionament de la cache. Posteriorment s'explicarà com s'ha dissenyat i implementat una jerarquia de memòria per a un MIPS implementat en VHDL en una FPGA. [ANGLÈS] First, the MIPS architecture, memory hierarchy and the functioning of the cache will be explained briefly. Then, the design and implementation of a memory hierarchy for a MIPS processor implemented in VHDL on an FPGA will be explained....

  3. Oxitocina: nuevas perspectivas para una droga antigua

    OpenAIRE

    Steven L. CLARK; Kathleen Rice SIMPSON; G. Eric KNOX; Thomas J. GARITE

    2010-01-01

    La oxitocina es el medicamento más comúnmente asociada con la prevención de complicaciones perinatales y recientemente fue incluida por el Instituto para la Administración Medicamentosa Segura (Institute for Safe Medication Practices - ISMP) en una pequeña lista de medicamentos “con alto grado de riesgos”, lo que puede “necesitar salvaguardas especiales para reducir el riesgo de error”. Las recomendaciones actuales para administrar este medicamento son vagas en relación a la indicación, tiemp...

  4. Una alternativa literaria para la literatura

    Directory of Open Access Journals (Sweden)

    Fernando Urueta Gutiérrez

    2010-01-01

    artistas: ellos, igual que quienes actúan en otros campos, también son objeto de determinaciones sociales y económicas. Las posiciones y disposiciones en el campo del arte han quedado así reducidas a las proporciones justas: los valores estéticos no son puramente estéticos, sino que responden a una búsqueda de prestigio, o a convicciones morales, o a intereses de poder económico y político.

  5. PLANIFICACION FAMILIAR: Un Derecho y una Necesidad

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    Miguel Trias

    1984-09-01

    Full Text Available

    La relación que existe entre el crecimiento poblacional y la situación socio-economica de una región, país o continente es algo que en forma intuitiva y vaga se conoce desde la más
    remota antigüedad. No menos conocido, en cada familia, ha sido el efecto nocivo de una
    reproducción superior a la deseada.
    Se ha necesitado del perfeccionismo de nuestros demógrafos y estadísticos para oscurecer la cuestión debajo y detrás de montañas de datos y de complejas ecuaciones.

    La generalizada y muy frecuente práctica del infanticidio entre tantos pueblos primitivos
    de ayer y de hoy, demuestra que a pesar de la elevada mortalidad natural, uno de los pocos insumos sobrantes del que se puede, cuando no se debe, disponer con facilidad es la vida humana acabada de nacer. Los superficiales ritos propiciatorios utilizados en algunos
    casos para su eliminación, le dan un escaso barniz religioso a la profunda preocupación
    ecológica y por consiguiente demográfica que los subyace.

    El infanticidio por simple abandono, practicado sin reatos de conciencia en la China Imperial el Imperio Romano o la Inglaterra pre-victoriana tenia una clara etiología social y económica. Los multitudinarios sacrificios juveniles de los Aztecas en un altiplano altamente erosionado por sobrecultivo, como el que encontraron los españoles a su llegada, parece no tener otra explicación razonable que el de ser una desesperada solución a un grave desequilibrio ecológico. Un desequilibrio que corrigió rápidamente la mortalidad mucho más eficiente que introducir los microbios europeos transportados por los conquistadores...

  6. Una experiencia del atletismo en Cantabria

    OpenAIRE

    Castillo Saornil, Santos

    2017-01-01

    Tesina titulada "Una experiencia del atletismo en Cantabria" del autor Santos Castillo Saornil y dirigida por el profesor Jesús Patricio Durán Piqueras. Instituto Nacional de Educación Física, curso 1983-1984. Consta de los siguientes capítulos: enseñanza del atletismo, iniciación al atletismo, la lección de iniciación al atletismo, iniciación a las carreras, experiencias personales, conclusiones y bibliografía.

  7. Praga, una suburbanización semidirigida

    OpenAIRE

    Welch Guerra, Max

    2011-01-01

    Índice Praga: breve perfil urbanístico. Nuevos factores para el desarrollo espacial desde 1989. Dos nuevos planes para la ciudad en su conjunto. Una suburbanización semidirigida. Entrevistas a expertos realizadas entre enero y julio de 2000. Bibliografía.ResumenDesde hace alrededor de 10 años se producen en Europa centrooriental transformaciones sociales profundas que abren un nuevo capítulo en la historia del urbanismo. A causa de muy diversos factores, en las estructuras urbanas de las gran...

  8. Tuberculosis una enfermedad prevenible y curable

    OpenAIRE

    García-Goez, José Fernando; Bedoya Quintero, Yamile

    2013-01-01

    La tuberculosis (TB) es una de las infecciones mas importante a nivel mundial, pues causa un número importante de muertes a pesar de ser prevenible y curable La Organización Mundial de la Salud (OMS) estima que 1/3 de la población mundial se encuentra infectada por el Mycobacterium tuberculosis causante de la TB y anualmente se reportan 8.8 millones de casos nuevos de TB, que fallecen 3 millones de personas a consecuencia de esta enfermedad y entre un 10% y 12% de los pac...

  9. Una reforma constitucional para la periferia europea

    OpenAIRE

    Gerardo Pissarello

    2011-01-01

    La intempestiva reforma del artículo 135 de la Constitución española puede leerse como una expresión más de la erosión en Europa de los elementos garantistas del constitucionalismo de posguerra. Tanto por su contenido como por el procedimiento empleado para acometerla, su aprobación aparece reñida con principios constitucionales básicos, como el democrático, el del Estado social o el de la autonomía territorial. Asimismo, supone un golpe a la legitimidad global de la Constitución cuya reversi...

  10. Marketing Experiencial: Una nueva tendencia del marketing

    OpenAIRE

    Magro Magdalena, Lara

    2013-01-01

    El reciente desarrollo de las tecnologías y su cada vez mayor implicación en la vida diaria de las personas, ha permitido en el mundo del marketing, la creación de nuevos modelos de negocio y promociones que buscan cautivar, interesar y sorprender, siempre de forma innovadora y distintiva a los usuarios finales. Durante todo el trabajo presentado a continuación, se va a explicar una nueva forma de marketing que está creando moda entre las firmas más prestigiosas, como pueden ser A...

  11. Arte Joven: 1901, una revista modernista

    OpenAIRE

    Flores Arroyuelo, Francisco José

    2002-01-01

    La revista Arte Joven, publicada en 1901, fue exponente del primer movimiento modernista y de sus afanes renovadores en el campo de las artes y de la literatura que se desarrollaron en España en el cambio del siglo XIX al siglo XX. Participaron en ella escritores y artistas de diversa forma de pensar y con distintas intenciones estéticas, desde Picasso a Unamuno, pero con una intención común de superar los esquemas establecidos por la estética realista anterior.

  12. Aprendizaje Servicio. Una experiencia en Gobierno TI

    OpenAIRE

    García-Peñalvo, F. J.

    2017-01-01

    La conferencia “Aprendizaje Servicio. Una experiencia en Gobierno TI” fue impartida el día 16 de octubre de 2017 en la II Jornada: Aprendizaje Servicio y otras experiencias de innovación educativa en la UPM, dentro del Ciclo de Jornadas 2017. Tendencias en Innovación Educativa y su implantación en UPM. Presenta cómo se ha aplicado el aprendizaje-servicio en el contexto de la asignatura Gobierno de Tecnologías de la Información, del Máster en Ingeniería Informática de la Universidad ...

  13. Leasing: una alternativa de financiamiento para PYMES

    OpenAIRE

    Bedjan, María Belén

    2008-01-01

    En la actualidad las pequeñas y medianas empresas encuentran dificultades para acceder a las líneas tradicionales de créditos bancarios. Por otro lado las empresas necesitan actualizarse constantemente para poder ser competitivas en el mercado. Es aquí donde el leasing nace como una alternativa de financiación para las PyMEs. Este trabajo pretendió demostrar la conveniencia financiera del leasing con respecto a los préstamos bancarios para la compra de maquinarias agrícolas ...

  14. Dimorfismo sexual mandibular en una coleccion formativa

    OpenAIRE

    Barboza, María Carolina; Mendonça, Osvaldo Juan; Bordach, María A.

    2005-01-01

    Muchas piezas óseas permiten la estimación sexual. En la mandíbula es mediante la observación de sectores morfoestructurales (gonion, mentón, rama, etc). La efectividad discriminatoria de esta estructura puede verse incremententada y/o complementada con nuevas propuestas técnico-metodológicas. Una de estas propuestas (Loth y Henneberg 1996), basada en la conformación anatómica de la inflexión del borde posterior de la rama mandibular, ha sido cuestionada en su eficiencia diagnóstica. Puesto q...

  15. Valores y preferencias televisivas: una experiencia universitaria

    OpenAIRE

    Palacios Navarro, Santiago; Medrano Samaniego, Concepción; Cortes Pascual, Alejandra

    2005-01-01

    El trabajo que se presenta forma parte, por un lado, de una investigación más amplia donde se ha recogido información sobre distintas variables: conocimientos previos, hábitos de estudio, estrategias motivacionales, estilos de aprendizaje, estilos de pensamiento, juicio moral, razonamiento personal, autoconcepto, madurez (adultez), valores y razonamiento lógico. Por otro lado, este trabajo es uno de los primeros pasos del proyecto de investigación en torno a la siempre problemática r...

  16. Publicidad, medio para crear una ventaja competitiva

    OpenAIRE

    Leyva Mancera, Jose Luis

    2014-01-01

    El caso muestra la manera en que surge una capacidad dinámica de reacción de la empresa líder del mercado en el sector automotriz en Colombia. GM Colmotores, genera estrategias para responder a los cambios, oportunidades y retos del mercado y los competidores. Así mismo se muestra la flexibilidad y evolución de la empresa que durante los últimos años siempre ha estado con la mayor porción de mercado en la industria. El desarrollo del caso permite ver como por medio de la capacidad de diri...

  17. Esofagitis necrotizante aguda: Una entidad inusual

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    Silvana E. Pramparo

    2010-12-01

    Full Text Available La esofagitis necrotizante aguda (ENA, también denominada esófago negro, es una rara enfermedad poco descripta en la literatura médica. Describimos el caso de un hombre de 80 años, con hemorragia digestiva alta quien desarrolló un esófago negro luego de un episodio de hipotensión. La necrosis fue confirmada histológicamente. Los pacientes se presentan con hematemesis y melena en más del 70% de los casos. Los hallazgos endoscópicos muestran una coloración negruzca de la mucosa esofágica. El diagnóstico se realiza con endoscopia y confirmación histológica. La mortalidad es alta (más del 50% aunque relacionada a las enfermedades de base del paciente. Por último, podemos decir que la sospecha es muy importante en el diagnóstico de ENA, particularmente en pacientes ancianos con enfermedades asociadas y evidencia de hemorragia digestiva alta. En este trabajo describimos las características clínicas, endoscópicas e histopatológicas de un paciente con ENA.

  18. Previous Experience a Model of Practice UNAE

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    Ormary Barberi Ruiz

    2017-02-01

    Full Text Available The statements presented in this article represents a preliminary version of the proposed model of pre-professional practices (PPP of the National University of Education (UNAE of Ecuador, an urgent institutional necessity is revealed in the descriptive analyzes conducted from technical support - administrative (reports, interviews, testimonials, pedagogical foundations of UNAE (curricular directionality, transverse axes in practice, career plan, approach and diagnostic examination as subject nature of the pre professional practice and the demand of socio educational contexts where the practices have been emerging to resize them. By relating these elements allowed conceiving the modeling of the processes of the pre-professional practices for the development of professional skills of future teachers through four components: contextual projective, implementation (tutoring, accompaniment (teaching couple and monitoring (meetings at the beginning, during and end of practice. The initial training of teachers is inherent to teaching (academic and professional training, research and links with the community, these are fundamental pillars of Ecuadorian higher education.

  19. Pantani di Marco Martinelli: una narrazione polifonica

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    Franco Nasi

    2014-05-01

    Full Text Available In questo articolo si analizza il testo drammaturgico Pantani di Marco Martinelli, una veglia epica teatrale di uno dei più noti eroi dello sport italiano degli ultimi anni. Il dramma rilegge anche la storia di Pantani e ricostruisce gli strani avvenimenti che portarono alla sospensione, alla estromissione del ciclista dal Giro d’Italia nel 1999, e in seguito alla sua profonda crisi psicologica e tragica morte in solitudine in un hotel, a soli 34 anni. Oltre alle modalità proprie della veglia rituale, il dramma utilizza anche i metodi del processo giudiziario, e offre testimonianze dettagliate che conducono a una riflessione critica sulla società italiana negli anni del potere politico di Berlusconi e della sua filosofia del consumismo. I tre diversi generi della retorica classica (epidittico, giudiziario e deliberativo si mescolano in questa complessa tessitura teatrale. Coniugando informazioni (processo e rito (veglia, Martinelli riesce a fondere la tragedia greca (forma mimetica e corale e il moderno teatro di narrazione (forma diegetica monologante. Combinando assieme scene intensamente drammatiche, ricordi di imprese sportive epiche, passaggi giocosi e parodici, e giustapponendo vari stili e registri (giornalistico, lirico, parodico, elegiaco, Martinelli crea momenti di forte “straniamento” e sorpresa, e rende particolarmente efficace il rito funebre, la ricostruzione storica della tragica vicenda di Pantani e la critica all’ideologia che ha dominato l’Italia negli anni di Berlusconi.

  20. Una vida ligada a La Floresta

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    Kintto Lucas

    2015-01-01

    Full Text Available En este número, el módulo Dibujos Animados, recoge las experiencias del primer curso realizado por el CIESPAL con apoyo de la UNICEF sobre la producción de programas educativos y culturales que utilizan este recurso como una opción comunicacional. Se trata de nuevas tecnologías aprovechadas en Cuba y que pueden ser aplicadas en nuestros países. El módulo relativo al medio ambiente habla del periodismo ecológico con importante desarrollo en América Latina, tema de actualidad que requiere preocupación por parte de los medios de comunicación. Incluye entrevistas a Gunter Grass y Jesús Polanco. Gabriel Alba adentra a los lectores en una novedosa forma de usar las computadoras. En el módulo Debate se trata la Economía, cultura y comunicación; La publicidad vía televisión, La evolución del merchandising en las novelas brasileñas ¿Exigir Ética solo al periodista?

  1. Una nuova piattaforma per i Dati Aperti

    Directory of Open Access Journals (Sweden)

    Ernesto Lastres

    2013-02-01

    Full Text Available In un panorama di continua evoluzione ed interesse da parte della opinione pubblica sul tema dei “dati open” moltienti della pubblica amministrazione e di governo stanno svolgendo azioni specifiche per la concretizzazione di queste iniziative in ottica di open government. Tuttavia, sono in pochi quelli che nel settore privato hanno intrapreso delle iniziative importanti in tale direzione. In questo articolo presentiamo una iniziativa indipendente per una nuova piattaforma software dedicata ai dati open su internet che, se confermasse i propri scopi, costituirebbe un punto di partenza a livello nazionale per l’accesso a questi dati.In a very evolving context and in a particular moment of public interest in theme of open data, many public organizations and government institutions are carrying out specific actions for the realization of initiatives in order to promote the open government ideas. However, very few private organizations have launched initiatives in this direction. In this paper we present an independent initiative for a new software platform for opendata on the internet that aims to be a starting point at the national level for the access to these kind of data.

  2. Una nuova piattaforma per i Dati Aperti

    Directory of Open Access Journals (Sweden)

    Ernesto Lastres

    2013-02-01

    Full Text Available In un panorama di continua evoluzione ed interesse da parte della opinione pubblica sul tema dei “dati open” moltienti della pubblica amministrazione e di governo stanno svolgendo azioni specifiche per la concretizzazione di queste iniziative in ottica di open government. Tuttavia, sono in pochi quelli che nel settore privato hanno intrapreso delle iniziative importanti in tale direzione. In questo articolo presentiamo una iniziativa indipendente per una nuova piattaforma software dedicata ai dati open su internet che, se confermasse i propri scopi, costituirebbe un punto di partenza a livello nazionale per l’accesso a questi dati. In a very evolving context and in a particular moment of public interest in theme of open data, many public organizations and government institutions are carrying out specific actions for the realization of initiatives in order to promote the open government ideas. However, very few private organizations have launched initiatives in this direction. In this paper we present an independent initiative for a new software platform for opendata on the internet that aims to be a starting point at the national level for the access to these kind of data.

  3. El asistente personal para una vida independiente: una figura en construcción

    OpenAIRE

    Carbonell Aparici, Gonzalo José

    2017-01-01

    La figura del Asistente Personal (AP), que hace posible la autonomía de una persona con diversidad funcional (PDF), puede ser considerada desde diversas perspectivas. La primera es la del Movimiento de Vida Independiente (MVI), que ofrece el sustento te�

  4. La enfermera escolar, ¿una utopía o una realidad?

    OpenAIRE

    Bayón Carrascal, María

    2013-01-01

    En la actualidad, los problemas de los alumnos que acuden a la escuela no se reducen sólamente a un examen difícil, unos deberes sin hacer o una asignatura suspensa, si no que a menudo sufren onsecuencias como alguna enfermedad, malos hábitos, trastornos alimenticios, problemas de drogodependencia o embarazos no deseados

  5. El método es una digresión. Una lectura benjaminiana de Goethe

    Directory of Open Access Journals (Sweden)

    María Filomena MOLDER

    2017-12-01

    Full Text Available El propio Benjamin nos dice que leer el trabajo de Simmel sobre el concepto de verdad en Goethe le ayudó a comprender que el concepto de origen propuesto en su libro sobre el Trauerspiel era una transposición del concepto goethiano de fenómeno original. Para discutir cómo los hechos económicos pueden convertirse en fenómenos originales, Benjamin se sirve de una analogía con el concepto de Goethe de la metamorfosis de las plantas. Por eso, aquí, intentaremos demostrar que comprender lo que es la filosofía en Benjamin implica una experiencia de umbral –en forma de salto, discontinuidad, interrupción, renuncia, disipación, obediencia y metamorfosis– cuya formulación suprema, concisa y enigmática es la siguiente: “El método es un desvio” [Methode is Umweg]. Algunos elementos del pensamiento morfológico de Goethe permitirán establecer una constelación de afinidades, algo bastante útil para la interpretación de este enigma.

  6. Impacto ambiental de una mina de mercurio abandonada

    OpenAIRE

    Álvarez Cuartas, María

    2016-01-01

    El objetivo principal de este Trabajo Fin de Máster es la evaluación del impacto ambiental de una explotación minera de mercurio en estado de abandono y de posible contaminación del medio ambiente. Una vez que se comprueba el elevado impacto debido al estado de abandono y a la alta contaminación, se ha elaborado una sencilla propuesta de restauración, barajado y comprando tres posibles alternativas.

  7. Leucoedema: una revisión de la literatura

    OpenAIRE

    Viñals Iglesias, Helena

    1999-01-01

    El leucoedema es una entidad de naturaleza benigna, que clinicamente se describe como un blanqueamiento difuso y opalino de la mucosa oral que le confiere un aspecto aterciopelado, generalmente bilateral, simétrico y de carácter crónico. Es más frecuente en negros americanos, aunque la prevalencia descrita en cada estudio es controvertida, al igual que su patogenia. Histologicamente se caracteriza por una hiperparaqueratosis, una acantosis con hiperplasia epitelial, espongiosis, edema intrace...

  8. Una respuesta a Linz desde el presidencialismo

    Directory of Open Access Journals (Sweden)

    Daniela Lucía Vargas Moreno

    2014-07-01

    Full Text Available Este artículo es una reflexión descriptiva de las relaciones e interacciones que se establecen entre los poderes Ejecutivo y Legislativo en el sistema presidencial. Su objetivo principal es responder a la crítica de Juan José Linz hacia el presidencialismo a través del examen de los dos argumentos centrales del autor: la legitimidad democrática dual y la rigidez de los mandatos. A su vez, este escrito incorpora el estudio del sistema electoral, del sistema de partidos y del liderazgo político, y las dinámicas que se generan entre estos elementos debido al tipo de régimen. La conclusión apunta a que no se puede establecer un fracaso rotundo del presidencialismo sin antes considerar distintas variables que han incidido, particularmente, en el escenario latinoamericano.

  9. Visual Virtual MT: relato de una pesquisa

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    LUDMILA BRANDÃO

    2015-01-01

    Full Text Available Con el fin de contribuir a la discusión acerca de las artes visuales en la sociedad contemporánea y de los dispositivos que operan la colonialidad del arte, sus mecanismos y efectos, cuya urgente desactivación nos impone enormes retos, en este artículo se presentan los resultados de la investigación titulada: “Artes Visuales en Mato Grosso: recopilación, difusión y crítica” encargada de crear el sitio Visual Virtual MT (VVMT. El VVMT reúne producciones aestésicas visuales de artistas individuales y colectivos que operan en diferentes soportes y medios, trabajando con una variedad de materiales que configuran, actualmente, la mayor colección catalogada y digital disponible en el Estado de Mato Grosso, en Brasil.

  10. Memoria y olvido de una ministra anarquista

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    Ángel Herrerín López

    1998-01-01

    Full Text Available Este artículo analiza como la imagen histórica de Federica Montseny ha ido variando con el paso del tiempo. Para dicho análisis se utiliza una doble óptica: por un lado, la visión que nos aportan, a través de sus memorias, sus compañeros libertarios; y por otro, como es tratada, esa imagen, por la empresa publicista.This article analyses Federica Montseny's historical image which has changed throughout time. A double point of view is used to do it: On one, hand the visión that her anarchist colleagues provide thorugh their memories, and on the other hand, we can see the way that her image has been treated by the standard press.

  11. Impuestos verdes: una meta de equidad

    Directory of Open Access Journals (Sweden)

    Lilliana Arrieta Quesada

    2011-09-01

    Full Text Available Al considerar necesario incorporar a los grupos económicos en el gran proyecto de alcanzar metas de desarrollo sostenible, que surge como un nuevo paradigma al tomarse en consciencia por parte de los organismos internacionales, entre ellos las Naciones Unidas, de la necesidad de hacer un planteamiento de desarrollo económico diferente al convencional que considera aspectos ambientales y de equidad social, se admite por primera vez que la explotación de los recursos naturales y su transformación en materia prima y fuente energética, tiene límites, los cuales deben ser considerados en cualquier planteamiento serio de desarrollo económico.Es así como surge la tesis de los impuestos verdes como una opción que permita a los gobiernos incidir tanto en el mercado como en el sector industrial y en los hábitos de los consumidores.

  12. Melanoma lentiginoso acral en una paciente adulta

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    Yoandra Seara Govea

    Full Text Available Se presenta el caso clínico de una paciente ecuatoriana de 58 años, blanca, con antecedentes de hernias discales en regiones cervical y lumbar, quien hace 2 años asistió a la Consulta de Dermatología por presentar cambio de coloración en la uña del tercer dedo de la mano derecha, síntomas que se correspondían con un lentigo simple. En esta ocasión acude con destrucción de la lámina ungueal y aumento de la coloración que se extiende a todo el pulpejo del dedo, por lo cual se le realizó otra biopsia y se confirmó el diagnóstico histológico de melanoma lentiginoso acral (in situ

  13. Plan de Empresa para una ONG

    OpenAIRE

    Hernández Pumarega, David

    2005-01-01

    Hace 5 años un grupo de jóvenes universitarios creamos la Asociación Juvenil Soñar Despierto, una asociación benéfica cuya finalidad es involucrar a jóvenes, familias e instituciones en programas y proyectos de ayuda a niños de familias desestructuradas y/o sin recursos de nuestra comunidad. La idea empezó como el sueño utópico de 4 amigos y ha ido tomando forma y calando entre la sociedad. Hasta el punto de que en el año 2005 son más de 900 los voluntarios que han colaborado con nosotros ...

  14. Mercadeo verde de una empresa dorada

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    Carlos Mario Uribe-Saldarriaga

    2014-01-01

    Full Text Available El caso presenta la campaña de mercadeo realizada por Ecopetrol entre 2009 y 2012 para la introducción en Colombia del diésel ultra bajo de azufre denominado diésel limpio. Se examina la campaña desde 2 puntos de vista: el primero, el posicionamiento de Ecopetrol como una de las empresas más admiradas de Colombia, tanto por sus resultados financieros como por sus actividades en la responsabilidad social empresarial; el segundo, desde las exigencias que se hacen al mercadeo ambiental en los países desarrollados, especialmente con respecto al lavado verde, teniendo en cuenta a la vez que Ecopetrol opera en un país en vía de desarrollo donde existe un menor avance en las exigencias ambientales hechas por los grupos de interés.

  15. Hacia una pedagogía pacicultora

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    ALEXANDER LUIS ORTIZ OCAÑA

    2013-11-01

    Full Text Available En este artículo se demuestra científicamente que el Bachillerato Pacicultor1 es un modelo didáctico innovador y pertinente dentro del contexto de las políticas de atención educativa a la población vulnerable y desplazada, sustentado en los modelos educativos de la Escuela Nueva y la Escuela del Desarrollo Integral, basado en enfoques constructivistas, tendencias humanistas, teorías sociocríticas o histórico – culturales y corrientes cognitivas de aprendizajes significativos. Este enfoque sistémico y configuracional del bachillerato aporta elementos esenciales que permitirán configurar una Pedagogía Pacicultora.   

  16. Mercadeo verde de una empresa dorada

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    Carlos Mario Uribe-Saldarriaga

    2014-01-01

    Full Text Available El caso presenta la campa ̃ na de mercadeo realizada por Ecopetrol entre 2009 y 2012 para la introducción en Colombia del diésel ultra bajo de azufre denominado diésel limpio. Se examina la campa ̃ na desde 2 puntos de vista: el primero, el posicionamiento de Ecopetrol como una de las empresas más admiradas de Colombia, tanto por sus resultados financieros como por sus actividades en la responsabilidad social empresarial; el segundo, desde las exigencias que se hacen al mercadeo ambiental en los países desarro- llados, especialmente con respecto al lavado verde, teniendo en cuenta a la vez que Ecopetrol opera en un país en vía de desarrollo donde existe un menor avance en las exigencias ambientales hechas por los grupos de interés.

  17. Fibroma de ovario en una gestante joven

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    Martha Lazo Pérez

    2015-02-01

    Full Text Available Se presenta el caso clínico de una gestante de 24 años de edad, quien acudió al Cuerpo de Guardia del Hospital Provincial Ginecoobstétrico Docente "Mariana Grajales Coello" de Santiago de Cuba, por presentar dolor en la parte baja del vientre, además de náuseas y estreñimiento. Se consideró el diagnóstico de fibroma de ovario, que fue definitivo luego de intervenirle quirúrgicamente y realizar el estudio anatomopatológico. Posteriormente se mantuvo el seguimiento clínico en consulta externa; la paciente evolucionó favorablemente y mantuvo su embarazo hasta tener a su hijo -- un recién nacido sano y a término -- a través de parto eutócico

  18. Una memoria consensuada : El Informe Rettig

    OpenAIRE

    Camacho Padilla, Fernando

    2004-01-01

    No cabe duda que hoy día la memoria de la dictadura militar (1973-1990) está presente en la vida cotidiana de Chile más que ningún otro periodo histórico. La razón se encuentra en los trágicos sucesos que se vivieron duran- te esos años en materia de derechos humanos. Don Patricio Aylwin, primer presidente electo democráticamente en tras 17 años de autoritarismo y una figura comprometida con los derechos humanos, era consciente de la necesi- dad de investigar la verdad de los crímenes de lesa...

  19. Una historia de Arlequín

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    Arturo Laguado

    1966-06-01

    Full Text Available Entre los personajes vivos del teatro universal y de la vida real existe una transmutación frecuente; de la misma manera que algunos hombres abandonan su identidad para convertirse en tipos ideales, ciertos personajes ficticios adquieren todas las características de los seres humanos. Unos y otros conforman esa teoría de valores que nos ayudan a juzgar, a compararnos, y a comprender la realidad. En el momento en que el personaje entra a constituír un mito, su existencia física parece innecesaria: vivo o muerto, real o ficticio, sabemos que su imagen no podrá variar, que pertenece al futuro, a ese tiempo que no habremos de conocer.

  20. La imagen: una venta en silencio

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    Harold Silva Guerra

    2014-01-01

    Full Text Available Uno de los aspectos más importantes y que más gravita en el éxito financiero de una empresa es su imagen. Por eso, el manejo de la misma, es trascendental, porque no solo se debe pretender que sea competitiva, sino que armonice con la responsabilidad social y ambiental del todo el entorno, y que siempre sea recordada por los clientes, con gratitud y que permanezca en el universo de suspreferencias. Para ello, deben comulgar tantas cosas positivas que van desde el buen servicio al cliente, pasando por la calidad de productos que se ofrecen, hasta el impacto que cause en los compradores los símbolos cuidadosamente elegidos los cuales contribuyan a una fijación mental positiva y duradera.Palabras clave: Imagen; identidad; reputación; cliente.The image: a sale in silenceAbstrac One of the most important aspects, which supports the financial success of a company, is its image. Therefore, the management of it, is transcendental, as it does not only pretend to be competitive, but also that harmonize with the social and environmental responsibility of the whole surroundings, and that it always will be remembered by customers, with gratitude and remain in the universe of their preferences. for that many positive things must coincide, ranging from good customer service, to the quality of products offered, to the impact cause on the buyers the carefully chosen symbols, which contribute to a positive and lasting mental fixation.Keywords: Image; identity; reputation; customer.

  1. UNA ACUSTEMOLOGÍA DE LA SELVA TROPICAL

    OpenAIRE

    FELD, STEVEN

    2013-01-01

    Este texto tiene por objeto darle voz a un tipo de realidad alterna, a un tipo de sensibilidad sonora que he encontrado a través de la investigación antropológica de una ecología del lenguaje, la música y la acústica. La esperanza es que, al dar a las voces marginadas espacios desde donde hablar, gritar y cantar, la antropología podrá contrarrestar en alguna medida la arraigada arrogancia de la autoridad colonial e imperial, de la historia escrita en una sola lengua, a una sola voz, como una ...

  2. Una parodia de lo adverso: Buena Vida (delivery.

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    Nicolás Ocaranza

    2006-08-01

    Full Text Available Hernán es un joven empleado en una pequeña empresa de reparto a domicilio (delivery. Mientras recorre los suburbios de la ciudad de Buenos Aires en su vieja motocicleta conoce a Patricia, quien trabaja en una estación de gasolina desde hace un tiempo. Hasta ese momento todo parece confluir en una esperada fórmula de amor de juventud entre un repartidor y su pretendiente. Pero cuando Hernán le ofrece a Patricia el alquiler de una habitación de su hogar la historia toma un destino insospechad...

  3. Un nuevo orden mundial, una ética universal, una nueva educación

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    Amparo MARTÍNEZ SÁNCHEZ

    2009-11-01

    Full Text Available RESUMEN: Este artículo ofrece unas reflexiones sobre la urgencia de establecer un nuevo orden mundial que exige: «una ética universal», «una nueva educación», «un mundo en paz». Se subraya que es necesaria una educación que esté al servicio: del desarrollo económico de los pueblos, particularmente de los pueblos del Sur; de la justicia cultural global y del diálogo de civilizaciones; de la democratización de todas las sociedades. Una educación que tenga como base un humanismo de carácter universal. Se concluye apuntando que la tarea social más urgente consiste en activar una nueva conciencia y unos nuevos actores sociales que fortalezcan los vínculos humanos en el nuevo escenario de la mundialización.ABSTRACT: This article offers some reflections on the urgency of establishing a new world order that calls for: «a universal ethic», «a new education», «a peaceful world». It emphasises the importance of education that serves: economic development of communities, particularly those in the South; global cultural justice and dialogue between civilisations; démocratisation of all societies. Education based on universal humanity. The conclusion demonstrates that the most urgent social task is to activate a new social conscience, and new social actors to strengthen human bonds in the current scenario of globalisation.RÉSUMÉ: Cet article offre une réflexion sur l'urgence d'établir un nouvel ordre mondial exigeant: une éthique universelle, une nouvelle éducation, un monde en paix. L'article met en évidence la nécessité d'une éducation au service du développement économique des peuples, en particulier des peuples du Sud; de la justice culturelle globale et du dialogue entre civilisations; de la démocratisation de toutes les sociétés. Une nouvelle éducation ayant comme base un humanisme universel. La conclusion démontre que la tâche sociale la plus urgente est celle d'activer une nouvelle conscience et des nouveaux

  4. The crystal structures of apo and cAMP-bound GlxR from Corynebacterium glutamicum reveal structural and dynamic changes upon cAMP binding in CRP/FNR family transcription factors.

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    Philip D Townsend

    Full Text Available The cyclic AMP-dependent transcriptional regulator GlxR from Corynebacterium glutamicum is a member of the super-family of CRP/FNR (cyclic AMP receptor protein/fumarate and nitrate reduction regulator transcriptional regulators that play central roles in bacterial metabolic regulatory networks. In C. glutamicum, which is widely used for the industrial production of amino acids and serves as a non-pathogenic model organism for members of the Corynebacteriales including Mycobacterium tuberculosis, the GlxR homodimer controls the transcription of a large number of genes involved in carbon metabolism. GlxR therefore represents a key target for understanding the regulation and coordination of C. glutamicum metabolism. Here we investigate cylic AMP and DNA binding of GlxR from C. glutamicum and describe the crystal structures of apo GlxR determined at a resolution of 2.5 Å, and two crystal forms of holo GlxR at resolutions of 2.38 and 1.82 Å, respectively. The detailed structural analysis and comparison of GlxR with CRP reveals that the protein undergoes a distinctive conformational change upon cyclic AMP binding leading to a dimer structure more compatible to DNA-binding. As the two binding sites in the GlxR homodimer are structurally identical dynamic changes upon binding of the first ligand are responsible for the allosteric behavior. The results presented here show how dynamic and structural changes in GlxR lead to optimization of orientation and distance of its two DNA-binding helices for optimal DNA recognition.

  5. Solution 1H NMR investigation of the active site molecular and electronic structures of substrate-bound, cyanide-inhibited HmuO, a bacterial heme oxygenase from Corynebacterium diphtheriae.

    Science.gov (United States)

    Li, Yiming; Syvitski, Ray T; Chu, Grace C; Ikeda-Saito, Masao; Mar, Gerd N La

    2003-02-28

    The molecular structure and dynamic properties of the active site environment of HmuO, a heme oxygenase (HO) from the pathogenic bacterium Corynebacterium diphtheriae, have been investigated by (1)H NMR spectroscopy using the human HO (hHO) complex as a homology model. It is demonstrated that not only the spatial contacts among residues and between residues and heme, but the magnetic axes that can be related to the direction and magnitude of the steric tilt of the FeCN unit are strongly conserved in the two HO complexes. The results indicate that very similar contributions of steric blockage of several meso positions and steric tilt of the attacking ligand are operative. A distal H-bond network that involves numerous very strong H-bonds and immobilized water molecules is identified in HmuO that is analogous to that previously identified in hHO (Li, Y., Syvitski, R. T., Auclair, K., Wilks, A., Ortiz de Montellano, P. R., and La Mar, G. N. (2002) J. Biol. Chem. 277, 33018-33031). The NMR results are completely consistent with the very recent crystal structure of the HmuO.substrate complex. The H-bond network/ordered water molecules are proposed to orient the distal water molecule near the catalytically key Asp(136) (Asp(140) in hHO) that stabilizes the hydroperoxy intermediate. The dynamic stability of this H-bond network in HmuO is significantly greater than in hHO and may account for the slower catalytic rate in bacterial HO compared with mammalian HO.

  6. Implementación de una solución de Business Intelligence en una unidad de negocios de cobranzas de una entidad financiera

    OpenAIRE

    Calderón Ccatamayo, Magaly; Calderón Ccatamayo, Magaly

    2014-01-01

    El presente informe describe la implementación de una solución de Business Intelligence en una unidad de negocios de Cobranzas de una entidad financiera, utilizando un conjunto de metodologías y herramientas automatizadas de Business Intelligence. Los objetivos del proyecto presentado en este informe son facilitar a los usuarios de Cobranzas el análisis de la información, la toma de decisiones y las definiciones de estrategias acertadas, mejorando de esta forma la gestión y seguimiento del...

  7. Ricavare un'opera viva da una soffitta: scrittura e teatro in balia di una cura

    Directory of Open Access Journals (Sweden)

    Elena Uber

    2008-04-01

    Full Text Available Il laboratorio di scrittura della Soffitta dura dall’autunno 2005 alla primavera 2006. In quell’anno l’Unità Operativa in cui lavoro, appartenendo diversi suoi operatori alla Società Italiana per lo Studio dei Comportamenti Alimentari (S.I.S.D.C.A., assume l’impegno di organizzare a Piacenza uno dei convegni nazionali annuali della Società stessa. Sulla scorta d’un consolidato piacere della mia équipe di valorizzare le risorse espressive dei suoi membri, progetto d’allestire con la collaborazione di un gruppo teatrale piacentino uno spettacolo a partire dal testo prodotto con il gruppo. Quest’ultimo viene rielaborato e ne viene ricavata una drammaturgia dove la soffitta diviene la stiva d’una nave nella quale A., la protagonista, compirà il suo viaggio “verso il mondo che l’aspetta là fuori”.

  8. Arqueología y cine: distorsiones de una ciencia y una profesión

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    Carlos Tejerizo García

    2011-06-01

    Full Text Available Sólo en los últimos años la investigación arqueológica se ha dirigido a analizar la relación de esta ciencia con el contexto social, político o económico actual. La grave distorsión que existe entre la imagen de la Arqueología de los profesionales y la imagen social es tratada a través de una treintena de películas analizando, igualmente, las consecuencias que en el mundo académico, educativo y profesional tienen este tipo de distorsiones. Finalmente, se propone una Arqueología “militante” basada en algunos postulados de la Teoría Crítica y el materialismo dialéctico como solución a este distanciamiento entre la Arqueología y la sociedad.

  9. MODELO MATEMÁTICO DEL TRANSPORTE DE UNA TOXINA EN UNA RED TRÓFICA MARINA

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    Daniel Arbeláez A.

    2014-07-01

    Full Text Available Algunos casos de intoxicación por consumo de peces contaminados, como la intoxicación por ciguatera, ocurren inesperadamente y no son fáciles de detectar previamente, dado que los peces que portan la toxina no presentan aspecto y/o síntomas de enfermos. En este trabajo proponemos un modelo matemático para el transporte y acumulación de una toxina a través de una cadena alimentaria. El modelo se plantea mediante un sistema rígido de ecuaciones diferenciales que describen la dinámica. Se analiza la estabilidad local de la solución de equilibrio. Se discuten diferentes escenarios de aparición de brotes de una toxina a partir de simulaciones numéricas obtenidas mediante un esquema de discretización que combina un método de Runge-Kutta de tercer orden y la regla del trapecio, evitando la rigidez del sistema. Los resultados muestran que el tiempo que tarda en desaparecer la toxina en la red trófica depende del estado en que se encuentra la dinámica poblacional al momento del brote. Esta información puede emplearse para establecer un tiempo de veda en la pesca de tal manera que la toxina se reduzca a niveles inocuos para la salud humana.

  10. Processi e temi per una smartculturalcity

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    Marco Gaiani

    2013-12-01

    Full Text Available ItIn questo contributo si assume il concetto di ‘Smart City’ come paradigma per sottolineare l’importanza che riveste l’Information Technology (IT di prima e seconda generazione ai fini del miglioramento del profilo competitivo di una città, soprattutto per ciò che riguarda il patrimonio culturale in essa contenuto. Si estende così il costrutto di William Mitchell dalla città al patrimonio culturale precisando, anche attraverso alcune esemplificazioni, come le Smart IT modifichino profondamente le modalità di trasmissione, acquisizione e produzione della conoscenza trasformando quest’ultima in un fattore di sviluppo economico, sociale e culturale. Non secondariamente esse contribuiscono alla soluzione di problemi tipici dei processi connessi al lifecycle dei beni culturali: la loro conservazione, fruizione, comunicazione e gestione, nonché quelli connessi alla grande quantità di dati e alla loro eterogeneità. Infine, i nuovi sistemi come l’Internet of Things o il fenomeno dello User Generated Content permettono di concepire i beni culturali come ‘smart cultural objects’ e la generazione di conoscenza da parte degli utenti. Tutto ciò, se da una parte amplifica le possibilità di interazione tra soggetti e oggetti della conoscenza, dall’altra ne modifica radicalmente le modalità. Questo deve sollecitare le Università, le Istituzioni culturali e le Imprese a collaborare, nel prossimo futuro, sugli usi possibili delle soluzioni tecnologiche prospettate, in vista dell’affermazione di una più consapevole e partecipata cultura della sostenibilità del nostro patrimonio culturale.EnThis contribution takes the concept of ' Smart City ' as a paradigm in order to underline the importance of first and second generation of Information Technology (IT for the purpose of improving the competitiveness of a city, especially for what concerns its Cultural Heritage (CH. We extends so the construct of William Mitchell from the city to

  11. Desahuciando inmigrantes: una etnografía en una comunidad dañada

    Directory of Open Access Journals (Sweden)

    Ignasi Bernat Molina

    2014-09-01

    Full Text Available El derrumbe financiero y económico que se inició en 2007 en Estados Unidos después de la conocida como crisis de las hipotecas subprime se tornó global un año después. En España, uno de los países más afectados por la larga crisis, la prosperidad anterior enseguida pareció ser un espejismo. Pero la crisis no ha afectado a todo el mundo en la misma medida. De hecho, hay gente que se ha enriquecido durante el período 2008-2012, en cambio, la crisis está teniendo un impacto mayor sobre los que ya se encontraba en una situación más precaria. En este artículo discutiré una de las múltiples caras de la crisis española que está afectando a los más desaventajados: los desahucios y su resistencia por parte de la población migrante. Para hacer esto, primero examinaré un municipio que ha sido paradigmático de enclave migrante en España: Salt. Salt es un municipio conocido en Girona, Catalunya, por haber sido descrito en los medios de comunicación como un gueto como resultado de los problemas que surgen con el exceso de inmigración (el 42% de su población es de origen extranjero. Salt se hizo famoso cuando en marzo de 2010 un grupo de vecinos entró en el ayuntamiento exigiendo más seguridad y denunciando la pasividad de la policía ante una ola de robos en el pueblo. Desde entonces, distinto conflictos aparecen en los medios de comunicación. De todos modos, una etnografía desde una perspectiva criminológica muestra que el problema que aparece en los medios de comunicación (el delito callejero es solo uno entre los varios que afectan a la población. Peor aún, toda la atención puesta sobre el municipio por medios, políticos y policías no ha servido para la detección de un problema que está generando mucho más daño social: los desahucios. La crisis ha servido para observar el modus operandi de bancos y agencias inmobiliarias, los principales victimarios en el conflicto de los desahucios. Vendían pisos, nunca los

  12. Biografía de una sombra

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    Gonzalo Ríos Ocampo

    1981-06-01

    Full Text Available Agustín Rodríguez Garavito nos ha entregado, en cordial gesto literario, un ejemplar dedicado de su último libro "Gaitán, biografía de una sombra" que hemos leído a la luz de nuestra ya antigua amistad y de predilecciones cuya impronta nos marca desde los tiempos ya casi desvanecidos de nuestra adolescencia manizaleña, cuando nos embriagábamos de D' Annunzio, Gautier, Barrés, Rodenbach, Larreta, Huidobro, Lotí, Balzac, los poetas malditos, Flaubert y otros que mezclábamos, en coctel espumoso y sápido, con Spencer, Leibnitz, Nietzsche, Chateaubriand, Schopenhauer el misógino, Lorrain el de los adjetivos esclavos, hiperbóreos, intuitivos y toda aquella baraja de líricos y pensadores que alumbraron los caminos de Europa y América con su linterna mental nutrida de pilas cósmicas.

  13. Si a tit e mantearon una vez

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    Mitja Skubic

    1999-12-01

    Full Text Available Esta oración compuesta, palabras pronunciadas por don Quijote* en el segundo capítulo de la segunda parte de la novela cervantina, "Si a ti te mantearon una vez, a mí me han molido ciento", solo en aparencia un periodo hipotético, representa en realidad un conjunto paratáctico de dos unidades contrapuestas en su significado. Suscitan nuestro interés por hallarse en el mismo período los dos paradigmas del pretérito español que llamaremos pretérito simple y préterito compuesto. Es sabido cuán variada es la denominación de estos dos paradigmas verbales en las gramáticas y en los tratádos españoles. Seguiremos la nomenclatura del francés: se prefiere, en cuanto sea posible, dejar a parte el contenido limitándose a la forma.

  14. Comentarios a una tesis de grado

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    Camilo Gutiérrez

    1938-06-01

    Full Text Available Por una casualidad llegó a mis manos la tesis que para optar el título de doctor en Medicina y Cirugía presentó al correspondiente Jurado Calificador el señor Aquilino Gaitán Mariño, con el nombre de "Crítica a la campaña antileprosa en Colombia", pero que más propiamente debiera llevar el de "Crítica a la organización de los lazaretos colombianos, en particular el de Agua de Dios", pues el panfleto se reduce a censurar varios aspectos de nuestras leproserías, que constituyen apenas un cortísimo capítulo de la gran obra de la lucha antileprosa en Colombia; y como el doctor Gaitán ejerció seis meses en Agua. de Dios, enfila sus baterías contra este leprosorioquizá el único conocido por él.

  15. Una riflessione interdisciplinare sul termine cambiamento

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    Giuseppe Licari

    2013-05-01

    Full Text Available Riassunto Il focus che presento propone una riflessione interdisciplinare sul campo semantico del termine cambiamento. Lo scopo è quello di cogliere, attraverso uno sguardo sulla complessità del reale, alcune delle situazioni e alcuni processi dove la parola cambiamento si va a collocare. Come sappiamo il cambiamento lo possiamo ritrovare sia nei processi evolutivi, come in quelli formativi, o in quelli epistemologici, si pensi ad esempio al cambio di paradigma più famoso nella conoscenza umana: il passaggio dal sistema di pensiero geocentrico al sistema eliocentrico. Così, al cambiamento troviamo associati lo spaesamento, le resistenze, la crisi, la rabbia, la tristezza, ma non ultimo, l’ampliamento dei propri orizzonti di crescita personale e collettiva. Parole chiave: paradigma, organizzazione, relazione, esperienze di vita.An interdisciplinary reflection on the term changeAbstract My presentation proposes an interdisciplinary reflection on the semantic field of the word change. While looking at the complexity of reality, it aims at grasping some situations and processes where the term change is involved. As we know, we can find changes in evolutionary, educational, epistemological processes, let us think for example of the most famous paradigm change of human knowledge: the passage from geocentric to heliocentric mindset. Bewilderment, resistances, crisis, anger, sadness are thus associated to change, as well as the enlargement of one’s own personal and collective growth.Key word : paradigm, organization, relationship, life experiences.

  16. LA INSTITUCION: UNA CATEGORIA A RECONSTRUIR

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    Gloria Alvarado Forero

    1995-01-01

    Full Text Available El desarrollo de las teorías del Sujeto modificó, de manera sensible, las estrategias de construcción del concepto de Institución y por tanto impuso la necesidad de reconsiderar a uno de los pilares en los cuales se fundamenta el saber de las Ciencias Sociales. Tales teorías, articuladas de manera indisoluble con los problemas del orden simbólico y por tanto con el problema del sentido, no han conducido sinembargo, a viabilizar satisfactoriamente un concepto dinámico de la institución como acción en y por la creación, manteniendo por el contrario afianzada su condición de entidad y estado de cosas. Una aproximación a la lógica del sentido, muestra por el contrario interesantes posibilidades, a la luz de las cuales ciertos debates sobre lo instituído y lo instituyente como momentos de la institución se revelan irrelevantes.

  17. Una lección que aprender

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    Roberto Lira Olmo

    2010-05-01

    Full Text Available Una tremenda tragedia se abatió sobre Chile entre estos dos últimos números de la revista. Como en todos los momentos impresionantes de la vida, cada uno de nosotros recordará para siempre qué hacía esa madrugada el 27 de febrero pasado, en el momento del terremoto. En lo particular, aparte de las memorias del sacudón interminable, el correr a casa de los hijos y pasar la noche en la calle, apenas, alumbrar el sol, recuerdo comenzar a ver los resultados de la tragedia: la gente desorientada en las plazas y en los cerros, las casas y los edificios resquebrajados y muchos en el suelo, las calles partidas. El asombro no terminó esa mañana: todavía perdura. Ver los desmanes y la pérdida de las normas cívicas con tanta facilidad, fue de lo más duro. Luego, con los días y las semanas y hasta los meses, hemos seguido descubriendo destrucción en los lugares más apartados.

  18. El Número Uno, una Retrospectiva Conceptual.

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    Alejandro Garciadiego Dantan

    2012-02-01

    Full Text Available The objective of this essay is to show how the concept of number ‘one’ has changed, from its initial formal definition in Euclid’s The Elements until very recently. Some of these changes are mathematical, others are philosophical, and others are historical in character. This retrospective of the concept of number ‘one’ implies that the history of mathematics is much more complex and rich than that which is suggested by our intuition when we limit ourselves to a unique, lineal and continuous mathematics. El objetivo de este ensayo es mostrar cómo es que el concepto de número ‘uno’ ha cambiado, desde que se definió de manera formal en Los Elementos de Euclides hasta hace relativamente unos cuantos años. Algunos de estos cambios son de naturaleza matemática, otros filosófica y otros histórica. Esta retrospectiva del concepto de número ‘uno’ implica que la historia de las matemáticas es mucho más compleja y rica que la que nuestra intuición nos sugiere, cuando nos limitamos a una matemática única, lineal y continua.

  19. una experiencia de intervención

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    Cecilia Villarreal Montoya

    2007-01-01

    Full Text Available El artículo resume la experiencia de intervención con una familia de la escuela de Villa Esperanza de Pavas. Se trata de un matrimonio con dificultades para disciplinar a sus tres hijos varones de ocho, seis, y cuatro años. En primer lugar, se exponen los principios teóricos y metodológicos, para luego mostrar la aplicación de ellos en el proceso vivido por la familia. Se aplica el modelo de intervención estructural, que busca que la misma familia logre realizar, paso a paso, los cambios requeridos en la dinámica y estructura familiar. En la situación específica de esta familia, se observa el fortalecimiento de la pareja como tal y como madre y padre en la medida que van logrando asumir la autoridad en forma compartida para disciplinar a los hijos. Al compartir esta experiencia, la autora pretende estimular a profesionales en Orientación a asumir el reto de considerar a las familias de la comunidad estudiantil, de las instituciones educativas donde laboran, como parte importante en el quehacer orientador.

  20. Entre Marx y una mujer desnuda

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    Omar Ospina García

    2015-01-01

    Full Text Available Comunicación y Género, acopia trabajos que vinculan a la mujer y la comunicación y sus esfuerzos por no ser consideradas inferiores. Del libro a la pantalla, acerca a algunas reflexiones sobre el proceso que lleva del libro a la pantalla por la polémica que despierta la adaptación de las novelas, puesto que muchos señalan que la trama se ve desfigurada. Se agregan varios temas sobre el cine. En "Días de Radio", se plantea el que a pesar de la censura y los problemas económicos que deben enfrentar, las radios populares de América Latina, siguen ganando espacios, de su desarrollo depende una mayor profundización de la democracia. Tema de debate es Estrategias comunicativas en Chiapas y Haití. Se añaden dos entrevistas a un caricaturista brasileño y a un corresponsal de guerra muy prestigiado.

  1. El ECTS y una Universidad que aprende

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    Mª Dolores BAENA CUADRADO

    2005-01-01

    Full Text Available El proceso de Convergencia Europea que está viviendo la Universidad Española, trae consigo una adaptación del sistema de créditos que se centra en el trabajo del alumnado, para definir los programas de estudio. Esto supone, entre otros aspectos, un replanteamiento de las metodologías utilizadas por el profesorado y, por tanto, un cambio en la concepción del proceso de enseñanza y aprendizaje en la Educación Superior. Ante este reto, es necesario conocer cuál es la situación actual de la práctica educativa universitaria. Presentamos los primeros resultados de un estudio exploratorio realizado en la Universidad de La Laguna, con la intención de contrastar la realidad actual con las demandas planteadas desde el modelo de Bolonia para la creación del Espacio Europeo de Educación Superior.

  2. Una perspectiva internacional de la contabilidad

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    Martha Lucia Suarez Suarez

    2005-01-01

    Full Text Available En la medida en que la internacionalización empresarial ha ido intensificándose y va surgiendo un nuevo usuario de la información internacional, la problemática ha ido pasando tanto al ámbito académico como al profesional. Consciente de esta realidad, la Facultad de Contaduría Pública de la Universidad de La Salle ha ido reformando el plan de estudios, e incorporando a los profesores a una visión internacional de la profesión, para atender la demanda formativa en este campo de la Contaduría Pública, para cualificar a los profesionales de la empresa en el escenario que la nueva dimensión internacional de la información contable está creando y necesitando. Uno de los principales objetivos de la contabilidad es proporcionar información útil para la toma de decisiones por parte de los usuarios. Esto adquiere mayor relevancia en la utilización de la información contable, la cual no se ciñe al ámbito nacional, sino que va más allá de las fronteras; la evolución del entorno que rodea a la empresa ha propiciado en los últimos años un proceso de internacionalización de la actividad económica, como consecuencia de la información contable.

  3. Una poética del pliegue

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    Ana Porrúa

    2000-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  4. Una poética del pliegue

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    Ana Porrúa

    2001-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  5. Recomendaciones para una lactancia materna exitosa

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    María Elena Ortega-Ramírez

    2015-03-01

    Full Text Available La lactancia materna es la única manera de proporcionar los nutrientes ideales para el adecuado crecimiento y desarrollo de los niños y las niñas. Es el único alimento que tiene una influencia biológica y emocional sobre la salud de la madre y su hijo. La lactancia materna protege a los lactantes de enfermedades gracias a sus propiedades antiinfecciosas, además de que es de más fácil digestión por la menor cantidad de caseína. No contiene betalactoglobulina, que es la proteína que más frecuentemente se asocia con alergia a proteína de leche de vaca. Por estas razones los médicos y trabajadores de la salud deben favorecer la práctica de la lactancia materna.

  6. Neurociencia en Psiquiatria; hacia una medicina integral y personalizada en el DSM-V: una propuesta

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    Carlos Augusto Novo Olivas

    2009-01-01

    Full Text Available En el último siglo la concepción de salud, y con ello de la ciencia médica, ha sufrido un cambio profundo, ontogénico, metanoico. Sin embargo, esta revolución no ha alcanzado de la misma manera a lo que hoy en día llamamos salud mental. En las siguientes páginas se tratará de mostrar, tomando como modelo al Trastorno Depresivo Mayor (TDM, la posibilidad y necesidad que tiene la psicopatología (comportamiento y capacidades “mentales”: intelectivas, racionales, cognitivas, ejecutivas, lingüísticas, emocionales, lógico-conceptuales, etc., de regresar a sus orígenes médicos, que le permitirán responder al “cómo” del funcionamiento cerebral y a su relación con el resto del organismo y con el medio ambiente, con el fin de obtener patrones que nos ayuden a definir enfermedad desde una perspectiva etiofisiopatogénica. Ha llegado el momento de cuestionar si hemos inventado una ciencia (psiquiatría que poco tiene que ver con la realidad, por lo que se propone la creación de bases de datos donde se integren variables biológicas (genéticas, cerebrales, endocrinológicas, inmunológicas, etc., sociales, personales, clínicas, etc., de forma multicéntrica e internacional, para finalmente obtener relaciones que nos permitan una reclasificación de la patología cerebral útil para proporcionar tratamientos integrales y personalizados.

  7. “creación de una papeleria en una zona residencial”

    OpenAIRE

    Moreno Velásquez, Grace Elizabeth; Vera Loor, Angie Azucena

    2013-01-01

    Sabemos que el mercado papelero tiene competidores fuertes como Juan Marcet y Súper paco que se encuentran en los primeros puestos, pero también sabemos que existe un espacio de potenciales compradores para nuestro proyecto. Mediante un estudio se pudo observar que muchas personas que viven en las urbanizaciones vía a Samborondón no pueden acceder con frecuencia a una papelería, ya sea por tiempo, o distancia. Por estos motivos hemos decidido que un buen lugar para implantar nuestra pap...

  8. Una escuela inclusiva para una sociedad plural : nuestro referente, nuestro futuro

    OpenAIRE

    Fernández Tilve, María Dolores; Malvar Méndez, María Laura

    2009-01-01

    La escuela del siglo XXI se torna cada día más compleja. El alumnado cada vez es más diverso, por lo que las situaciones de exclusión e inadaptación escolar se multiplican. Se hace necesario, más que nunca, promover desde la escuela la tolerancia, la solidariedad, la igualdad, la justicia y el respeto por la diversidad cultural, religiosa y lingüística, así como la integración escolar y social de las personas independientemente de sus particularidades. En una sociedad abierta, plu...

  9. Dimensionamiento de una EDAR para una población de 60.000 habitantes equivalentes

    OpenAIRE

    Vila Gordillo, Daniel Esteban

    2018-01-01

    La creciente importancia del agua como recurso natural indispensable, irreemplazable y altamente vulnerable, unida al creciente interés por la protección del medio ambiente, en general, han motivado una concienciación de la necesidad de depurar aguas procedentes de usos, tanto urbanos como industriales, e incluso, más recientemente, de los efluentes de riego. Es por ello necesario ayudar a la naturaleza con el diseño y la construcción de depuradoras que limiten los parámetros de c...

  10. Biocontabilidad: Hacia una definición de una nueva disciplina contable.

    OpenAIRE

    Mejía Soto, Eutimio

    2014-01-01

    La biocontabilidad se plantea como una nueva disciplina que pertenece a la ciencia contable, constituyendo así, un modelo que en conjunto con la sociocontabilidad y la contabilidad económica, configuran la Teoría tridimensional de la contabilidad T3C. La definición de biocontabilidad sugerida, principal objetivo de la investigación, se infiere de la definición general de contabilidad propuesta por la T3C y, metodológicamente, se soporta en los ítems básicos que debe tener toda acepción de un ...

  11. Sobre una redundancia: el Darwinismo social

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    Sandín, Máximo

    2000-12-01

    Full Text Available

    A review of the original sources and historical circunstances that encompassed the birth of darwinism make patent their poor entity as strictly biological theory. Otherwise their only original contribution to previous evolutive theories and hypothesis where limited to interpret the Nature by mean of the Malthus and Spencer economical and social concepts. The so called «social darwinism» is, therefore, not a distortion of «scientific darwinism» because is esentially social.



    Una revisión de las fuentes originales y de las circunstancias históricas que rodearon el nacimiento del darwinismo, pone de manifiesto su escasa entidad como teoría estrictamente biológica, ya que las únicas aportaciones originales a las teorías e hipótesis evolutivas previas, se limitan a la aplicacióPOR UNA ECONOMÍA ORIENTADA HACIA LA VIDA

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    Franz Hinkelammert

    2003-12-01

    Full Text Available El propósito de este trabajo es servir de plataforma teórica para las distintas temáticas que se abordarán con mayor profundidad en una obra conjunta en preparación. No es por tanto una simple introducción a la problemática, sino una toma de posición inicial sobre el ámbito y los contenidos de una “Economía de la Vida”.No siendo ésta una propuesta o un modelo para una nueva sociedad, ni un recetario de política económica, sino una interpelación crítica de las instituciones e ideologías económicas a partir del criterio central de la reproducción y desarrollo de la vida humana; creemos conveniente establecer claramente el punto de partida y los principales fundamentos de la investigación. Esto es lo que intentamos ofrecer al lector en el presente artículo, con la esperanza de que el mismo incite a la discusión, pues toda crítica es bienvenida.

  12. Una visión tridimensional emergiendo de la ciudad

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    Mª Pilar Pinchart Saavedra

    2016-10-01

    Full Text Available Las primeras décadas del siglo XX comienzan a mostrarnos la postal que detona el gran paradigma metropolitano del siglo: Nueva York y la altura de sus edificaciones, una ruptura total con el concepto de ciudad conocido por los europeos, al tiempo que la distopía nace como crítica literaria a la revolución rusa y derivará en imágenes de ciencia ficción producidas por el rascacielos que llevarán al urbanismo a nuevos niveles de planificación. Una visión tridimensional de la ciudad más allá del plano, al tiempo que el cine comienza a convertir el rascacielos en un personaje central de la narración visual. Progresivamente, las visiones de una sociedad futurista, mecanizada y alienante solo son posibles en una ciudad densamente verticalizada. Una imagen precisa, diseñada por Moses King, una ficción visual de 1911 que visionaba cómo sería la metrópolis de Nueva York en un futuro próximo, permite hacer una revisión sobre el paradigma de ciudad de rascacielos, y la evolución real de la metrópolis producto del fenómeno de verticalización producido por el rascacielos y la conquista de la altura.

  13. ¿ Como se hace una Telenovela ?

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    Iván Gavaldón

    2015-01-01

    Full Text Available La autora relata la historia de las Relaciones Públicas y dice que surgieron y se desarrollaron para legitimar ante el público los intereses económicos y políticos de quienes detentan el poder. Se cuestiona sobre el por qué no aplicar las relaciones públicas, en organizaciones populares, para que mejoren su publicación y orienten sus propósitos de desarrollo. El tema que aborda las Políticas culturales en América Latina acopia un extracto de lo más trascendente de los ensayos del libro editado por Néstor García Canclini. Sobre la telenovela se afirma que esta ha llegado a ser uno de los instrumentos más importantes de la comunicación popular: por ella desfilan las identidades de las más variadas culturas brasileñas. Y en cuanto a la caricatura se relata lo que ocurrió en el Seminario taller " Caricatura y Periodismo", realizado el(9-11 de Nov.- 1987 en el CIESPAL. El estudio sobre el mercado del vídeo se ve dificultado por la imprecisión de los datos obtenidos. Los datos oficiales no siempre se aproximan a la realidad, pues el mercado de vídeo se instauró en América Latina partiendo de una lógica totalmente diversa de los equipos de sonido e imagen.

  14. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum.

    Science.gov (United States)

    Busche, Tobias; Silar, Radoslav; Pičmanová, Martina; Pátek, Miroslav; Kalinowski, Jörn

    2012-09-03

    The expression of genes in Corynebacterium glutamicum, a Gram-positive non-pathogenic bacterium used mainly for the industrial production of amino acids, is regulated by seven different sigma factors of RNA polymerase, including the stress-responsive ECF-sigma factor SigH. The sigH gene is located in a gene cluster together with the rshA gene, putatively encoding an anti-sigma factor. The aim of this study was to analyze the transcriptional regulation of the sigH and rshA gene cluster and the effects of RshA on the SigH regulon, in order to refine the model describing the role of SigH and RshA during stress response. Transcription analyses revealed that the sigH gene and rshA gene are cotranscribed from four sigH housekeeping promoters in C. glutamicum. In addition, a SigH-controlled rshA promoter was found to only drive the transcription of the rshA gene. To test the role of the putative anti-sigma factor gene rshA under normal growth conditions, a C. glutamicum rshA deletion strain was constructed and used for genome-wide transcription profiling with DNA microarrays. In total, 83 genes organized in 61 putative transcriptional units, including those previously detected using sigH mutant strains, exhibited increased transcript levels in the rshA deletion mutant compared to its parental strain. The genes encoding proteins related to disulphide stress response, heat stress proteins, components of the SOS-response to DNA damage and proteasome components were the most markedly upregulated gene groups. Altogether six SigH-dependent promoters upstream of the identified genes were determined by primer extension and a refined consensus promoter consisting of 45 original promoter sequences was constructed. The rshA gene codes for an anti-sigma factor controlling the function of the stress-responsive sigma factor SigH in C. glutamicum. Transcription of rshA from a SigH-dependent promoter may serve to quickly shutdown the SigH-dependent stress response after the cells have

  15. Transcriptional regulation of the operon encoding stress-responsive ECF sigma factor SigH and its anti-sigma factor RshA, and control of its regulatory network in Corynebacterium glutamicum

    Directory of Open Access Journals (Sweden)

    Busche Tobias

    2012-09-01

    Full Text Available Abstract Background The expression of genes in Corynebacterium glutamicum, a Gram-positive non-pathogenic bacterium used mainly for the industrial production of amino acids, is regulated by seven different sigma factors of RNA polymerase, including the stress-responsive ECF-sigma factor SigH. The sigH gene is located in a gene cluster together with the rshA gene, putatively encoding an anti-sigma factor. The aim of this study was to analyze the transcriptional regulation of the sigH and rshA gene cluster and the effects of RshA on the SigH regulon, in order to refine the model describing the role of SigH and RshA during stress response. Results Transcription analyses revealed that the sigH gene and rshA gene are cotranscribed from four sigH housekeeping promoters in C. glutamicum. In addition, a SigH-controlled rshA promoter was found to only drive the transcription of the rshA gene. To test the role of the putative anti-sigma factor gene rshA under normal growth conditions, a C. glutamicum rshA deletion strain was constructed and used for genome-wide transcription profiling with DNA microarrays. In total, 83 genes organized in 61 putative transcriptional units, including those previously detected using sigH mutant strains, exhibited increased transcript levels in the rshA deletion mutant compared to its parental strain. The genes encoding proteins related to disulphide stress response, heat stress proteins, components of the SOS-response to DNA damage and proteasome components were the most markedly upregulated gene groups. Altogether six SigH-dependent promoters upstream of the identified genes were determined by primer extension and a refined consensus promoter consisting of 45 original promoter sequences was constructed. Conclusions The rshA gene codes for an anti-sigma factor controlling the function of the stress-responsive sigma factor SigH in C. glutamicum. Transcription of rshA from a SigH-dependent promoter may serve to quickly

  16. El desarrollo moral: una introduccion a la teoria de kohlberg

    OpenAIRE

    Enrique Barra Almagiá

    1987-01-01

    Se presenta una introducción a la teoría de los estadios morales de Lawrence Kohlberg, teoría que mantiene una estrecha relación con la teoría del desarrollo cognitivo de Jean Piaget. Las investigaciones de Kohlberg sobre el razonamiento moral, utilizando una entrevista individual basada en dilemas morales hipotéticos, lo han llevado a delinear 3 niveles y 6 estadios del juicio moral. Los estadios morales evolutivos, los cuales comparten las propiedades de los estadios co...

  17. Plan de negocio de una escuela infantil (primer ciclo)

    OpenAIRE

    San Román Gómez, Ana de

    2014-01-01

    El presente documento establece los pasos a seguir para poner en marcha una escuela infantil en el barrio de Butarque, en Madrid. En un primer lugar se han realizado diversos estudios, tanto sobre el sector como sobre el área geográfica, ya que se partía de una situación de absoluto desconocimiento. En el análisis del sector se ha puesto de manifiesto que las competencias en educación en España están reguladas por el Ministerio en primera instancia, pero las Autonomías tienen también una g...

  18. La planificación: una competencia fundamental del profesor

    OpenAIRE

    Gómez, Pedro

    2006-01-01

    La planificación es una de las actividades más importantes en el trabajo del profesor y una de sus competencias. Como profesores, realizamos al menos dos tipos de planificación: una de carácter global, cuando reflexionamos sobre el diseño curricular de un curso y otra local, cuando preparamos las experiencias que nuestros estudiantes vivirán a propósito de un tema concreto. A continuación presento algunas reflexiones sobre este último tipo de planificación. Tomo las matemáticas como ejemplo, ...

  19. Plan de Mercadeo para una “FinTech”.

    OpenAIRE

    Escalante Lee, Maria Alejandra

    2016-01-01

    Las empresas deben contar con una misión clara, estableciendo los objetivos de apoyo, diseñando una cartera de negocio sólida y coordinar sus estrategias a futuro, con el fin de cumplir las metas propuestas para entregar e intercambiar ofertas que tienen valor para los consumidores, clientes, socios y la sociedad en general. El presente trabajo de grado tiene como objetivo proponer un plan de mercadeo para la empresa Comyno una FinTech ubicada en Frankfurt am Main, en Alemania. Este tiene ...

  1. Desarrollo de una plataforma de crowdfunding distribuida sobre Ethereum

    OpenAIRE

    Calvo María, Adrián; Jacynycz García, Viktor

    2015-01-01

    Betfunding es una plataforma de crowdfunding distribuida que usa apuestas en lugar de donaciones para promover la producción artística y el trabajo creativo. A diferencia de otras plataformas de crowdfunding, en Betfunding son los inversores quienes proponen un proyecto y buscan creadores mediante la creación de una recompensa por su trabajo. Cualquier persona puede convertirse en creador de un proyecto si se compromete con los usuarios mediante una fianza. La evaluación de éxito o fracaso...

  2. Una escuela de todas (las personas) para todas (las personas)

    OpenAIRE

    Montolio Pastor, Rosa; Cervellera Martínez, Luiso

    2008-01-01

    Escuela 2 representa una particular manera de entender la educación. Un proyecto educativo nacido de la cooperación entre las personas, concebido para albergar todo un universo de realidades y gestionado de manera colaborativa bajo los principios de la economía social y el movimiento cooperativo. Una escuela de todas, las personas, para todas, las personas. Una escuela decidida a hacer realidad los principios de la inclusión educativa desde el día a día, esforzada por resituar a cada paso su ...

  3. Ecuador: hacia una seguridad con enfoque integral de buen vivir

    OpenAIRE

    Ecuador. Ministerio Coordinador de Seguridad Interna y Externa

    2013-01-01

    El derecho a la seguridad es una combinación de facultades y potestades que tiene la sociedad para requerir del Estado la adopción de condiciones propicias para una convivencia pacífica exenta de todo riesgo o peligro. En su significado semántico, la seguridad supone la exclusión de daño, peligro; en tal virtud, es una situación, estado social o mental con ausencia de todo riesgo o amenaza real. Dentro de este contexto, existen diferentes tipos de seguridad: integral, humana...

  4. Cuerpos singulares: Una lectura desde el pensamiento de Judith Butler

    OpenAIRE

    Galé Moyano, María José; Burgos Díaz, Elvira

    2013-01-01

    La aproximación que constituye este trabajo se inicia en la vacilación al respecto de la inserción del propio cuerpo, mi cuerpo, en distintos contextos vitales, de un cuestionamiento de la identidad a lo largo de la vida. Ello supondría un alejamiento de la pretendida objetividad en función de la cual el cuerpo vivo que investiga se comprende como algo ajeno a lo estudiado, una abstracción capaz de aproximarse sin una biografía previa, sin una configuración corporal concreta, a aquello que co...

  5. HISTORIAS DE APRENDIZAJE: UNA HERRAMIENTA PARA EL DESARROLLO ORGANIZACIONAL

    OpenAIRE

    Ana Cristina Marín Fernández; María Isabel Velasco de Lloreda

    2001-01-01

    El presente artículo parte de una reflexión acerca de la importancia del aprendizaje al interior de las organizaciones en función de su desarrollo organizacional. Presenta una reseña de la metodología de historias de aprendizaje desarrollada por los profesores Art Kleiner y George Roth, en el Center for Organizational Learning y el Reflection Learning Associates de MIT, como una herramienta de tipo administrativo, utilizada para promover el aprendizaje y el...

  6. Una narrativa del desborde: los cuentos de Juan Introini

    Directory of Open Access Journals (Sweden)

    Jorge Olivera

    2010-07-01

    Full Text Available Los cuentos “raros” de un escritor uruguayo ¿Es posible categorizar la presencia de los “raros” en la literatura uruguaya ? ¿Qué circunstancias de lectura son necesarias para enfrentarse a este tipo de escritores ? ¿Se trata de una forma de escribir o de una forma de leer ? Estas tres preguntas delimitan lo que se podría denominar un “campo de lecturas de lo raro”, y también una modalidad de escritura arraigada en la literatura uruguaya del siglo XX. Esta vertiente se extendió de manera prog...

  7. Cólera, ¿se aproxima una nueva pandemia?

    OpenAIRE

    Hernández-Flórez, Cristhian Eduardo; Cáceres-Manrique, Flor de María

    2014-01-01

    Introducción: el cólera es una enfermedad de origen bacteriano que ha causado epidemias, muerte y desolación desde los albores de la humanidad. Aún hoy, con todos los adelantos de las ciencias, sigue siendo una amenaza mortal para los seres humanos, en particular para quienes viven bajo condiciones de pobreza, con poco acceso al agua potable y a un adecuado manejo de excretas; de ahí su interés para la salud pública internacional. Metodología: se realizó una búsqueda virtual de boletines epid...

  8. HISTORIAS DE APRENDIZAJE: UNA HERRAMIENTA PARA EL DESARROLLO ORGANIZACIONAL

    Directory of Open Access Journals (Sweden)

    Ana Cristina Marín Fernández

    2001-01-01

    Full Text Available El presente artículo parte de una reflexión acerca de la importancia del aprendizaje al interior de las organizaciones en función de su desarrollo organizacional. Presenta una reseña de la metodología de historias de aprendizaje desarrollada por los profesores Art Kleiner y George Roth, en el Center for Organizational Learning y el Reflection Learning Associates de MIT, como una herramienta de tipo administrativo, utilizada para promover el aprendizaje y el desarrollo organizacional.

  9. Una fórmula exacta para el valor de una opción europea sobre una obligación en modelo multifactorial Orntein-Ulhenbeck

    Directory of Open Access Journals (Sweden)

    Gómez del Valle, L.

    1998-01-01

    Full Text Available En este trabajo se obtiene explícitamente el valor de una opción europea sobre una obligación que reparte cupones. Se supone que la estructura temporal de los tantos de interés viene determinada por el valor del tanto de interés instantáneo, el cual es una combinación lineal de n variables de estado. Estos factores son procesos estocásticos de tipo Ornstein-Uhlenbeck independientes y los precios del riesgo de mercado también son estocásticos. En primer lugar, aplicando un resultado de Friedman (1975 se resuelve de forma cerrada una ecuación general de valoración de activos derivados del tanto de interés. Posteriormente, se aplica al caso particular de la valoración de opciones sobre obligaciones que no reparten cupones y finalmente se obtiene el valor de las opciones sobre obligaciones que sí reparten cupones. Langetieg (1980 realizó un estudio con este modelo, pero con precios de riesgo de mercado constantes, utilizando otros procedimientos. Este trabajo supone una generalización de Jamshidian (1989, el cual obtuvo el valor de las opciones sobre obligaciones que reparten cupones para un modelo unifactorial.

  10. De una práctica profesional reflexiva a una “escritura reflexiva”

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    María José Acevedo

    2013-10-01

    Full Text Available Me referiré aquí a aquellos profesionales cuya práctica de pre-grado y de posgrado hemos tenido oportunidad de investigar, a partir de sus testimonios, a lo largo de más de veinte años de ejercicio de la docencia universitaria y de mi trabajo como analista institucional. Se trata entonces de profesionales de la salud, de trabajadores sociales y de docentes de todos los niveles de la enseñanza. Estos profesionales, practicantes de terreno, miembros de virtuales equipos disciplinarios, insertos en instituciones que rara vez prevén espacios formales para una reflexión grupal y sistemática de sus actos profesionales, son trabajadores solitarios que regulan sus prácticas en función de sus experiencias pasadas individuales y de las contingencias a las que los enfrenta una realidad, por lo general, altamente conflictiva e inestable. El género profesional (Clot, 1999 como sistema normativo flexible al que deberán ajustarse las acciones y las formas de relación en un medio profesional específico, sólo en muy pequeña medida constituye la brújula que guía las decisiones de dichos profesionales.

  11. La gestion bajo una cultura de calidad en Mexico: una verificacion empirica.

    Directory of Open Access Journals (Sweden)

    Rositas, J.

    2004-07-01

    Full Text Available El artículo presenta de entrada, enfoques administrativos que pueden ser englobados en el término “Gestión bajo una cultura de calidad” (GBCC, conocida internacionalmente como Total Quality Management [TQM], o simplemente Gestión de Calidad, citándose en seguida dos puntos de vista contrapunteados a nivel internacional en relación a este enfoque. Se presentan esfuerzos previos de consultores e implantadores mexicanos que, en base al método de casos y de generalizaciones empíricas de sus experiencias profesionales, consideran a la GBCC como una de las grandes tendencias y fuerzas de cambio en el siglo XXI. Se hace referencia a la escasez de investigaciones en las que se ponga a prueba estadísticamente los conceptos de teóricos, practicantes y consultores del área de la calidad. El autor propone y pone a prueba un modelo agregado de ecuaciones estructurales basado en datos de campo de su investigación de doctorado aportados por 45 empresas manufactureras mexicanas. El análisis de datos, realizado con los paquetes de software SPPS y AMOS, arroja coeficientes de regresión y de determinación, así como niveles de bondad del ajuste, altamente significativos. Al concluir, el autor sugiere estrategias adicionales para refinar futuros análisis de datos.

  12. Una defensa de la preferencia revelada

    Directory of Open Access Journals (Sweden)

    Dowding, Keith

    2008-04-01

    Full Text Available The paper defends revealed preference analysis against the attack of Dan Hausman that RPA is unclear and has not empirical advantages. RPA is consistent with externalist accounts of the theory of mind where preference is interpreted and gets its meaning through our understanding of the actions of those studied. The paper argues that Hausman assumes the conclusion he is maintaining by assuming preference means “desire”. RPA is unavoidable in empirical research where we interpret outcomes through the intentional actions of human beings and is especially important in aggregate-data analysis. One of the confusions of philosophical critiques of RPA is to treat aggregate “type” explanations as though they refer to each token individual within the type. It concludes with some thoughts on the ethical considerations of using RPA.

    En este artículo se defiende el análisis mediante preferencias reveladas (APR de los ataques de Dan Hausman, para quien dicho análisis no es claro ni proporciona ventaja empírica alguna. El APR es compatible con las versiones externistas de la filosofía de la mente, para las que la preferencia se interpreta, y obtiene su significado, mediante la comprensión de las acciones de los sujetos estudiados. En el artículo se sostiene que Hausman defiende su conclusión porque supone que preferencia significa “deseo”. En el análisis empírico el APR es inevitable, dado que los resultados se interpretan a través de la acción intencional de los seres humanos. Asimismo, es especialmente importante en el análisis de datos agregados. Una de las confusiones de la crítica filosófica del APR consiste en tratar las explicaciones de “tipos” como si se refirieran a cada caso individual dentro de un tipo. El artículo finaliza con algunas reflexiones sobre cuestiones éticas del uso del APR.

  13. El cas estrany d'una nena amb tuberculosi renal

    OpenAIRE

    Martínez Roig, Antonio

    2009-01-01

    La tuberculosi és una afecció més pròpia de localitzar-se als pulmons, a través del contagi per via aèria, que no pas fora d'ells. La que es produeix als ronyons seria només un 3% i la infecció estaria vinculada a la disseminació per via sanguínia i limfàtica de la tuberculosi pulmonar. Si considerem que la tuberculosi es diagnostica principalment a l'adolescència, trobarem força peculiar el cas d'una nena que va desenvolupar una tuberculosi renal amb tretze mesos de vida. La nena patia una d...

  14. Las revoluciones de Thomas Kuhn, una mirada discontinuista

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    Pablo Melogno

    Full Text Available Resumen Se discuten algunas divergencias entre La revolución copernicana (1957 y La estructura de las revoluciones científicas (1962, de Thomas Kuhn. Se muestra que presentan una consideración diferente de los factores extracientíficos, que tienen en la primera un peso explicativo mayor. Se propone que en 1957 Kuhn maneja una historiografía casuística, centrada en la revolución copernicana, y en 1962 una historiografía estructural, centrada en los rasgos invariantes de las revoluciones científicas. Se concluye que las diferencias entre las dos obras son lo suficientemente profundas como para no considerarlas expresión de una misma visión de la ciencia.

  15. Consentimiento informado: una praxis dialogica para la investigacion

    Science.gov (United States)

    Mondragon-Barrios, Liliana

    2009-01-01

    El consentimiento informado es un proceso, en el que una persona acepta participar en una investigation, conociendo los riesgos, beneficios, consecuencias o problemas que se puedan presenter durante el desarrollo de la misma. El objetivo de este trabajo es reunir las caracteristicas del proceso de consentimiento informado (PCI) pare que su discernimiento y cumplimiento posibilite el ejercicio etc° dialogico, reflexivo y responsable del investigador. Se presentan los resultados de una extensa revision de les elementos del PCI, desde sus cornponentes hasta su fundamento etico y legal, incluyendo los mites y realidades que existen sobre el formato de consentimiento informado come recurso legal de protection. El consentimiento informado no es un formato establecido que los investigadores repliquen, se trata de que la praxis del PCI sea una tarea cotidiana dentro de la investigation con seres humanos, como comunicaciOn deliberative y critica, responsable y comprometida entre dos agentes morales, investigador-investigado. PMID:19507477

  16. Tuberculosis, una Enfermedad de Ayer, de Hoy y del Futuro

    Directory of Open Access Journals (Sweden)

    Rafael Vargas

    2013-09-01

    Full Text Available La tuberculosis es una enfermedad tan antigua como la humanidad. A pesar de los avances en el conocimiento de su fisiopatología y en el desarrollo de medicamentos antituberculosos, todavía es una enfermedad común que afecta a una gran proporción de la población mundial. En los últimos años han aumentado los problemas relacionados con la morbi-mortalidad, lo cual se refleja en el incremento de la coinfección con VIH, el aumento de casos de neurotuberculosis y la mayor mortalidad en pacientes con tuberculosis. En el presente artículo se presenta una revisión de aspectos microbiológicos, epidemiológicos y clínico-terapéuticos de la enfermedad.

  17. UNA VERSIÓN AUTÉNTICA DE NUESTROS CONFLICTOS

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    Celia Matilde Giraldo P.

    2001-01-01

    Full Text Available Una forma de aprendizaje en la resolución de conflictos escolares deviene en buena parte de la intención pedagógica con que ellos se resuelvan, es decir, desarmándonos de aquellas prácticas autoritarias que impiden otras posibilidades de acercamiento. Consideramos que estamos despejando obstáculos y reinventando caminos concretos hacia una óptima resolución, atendiendo además a una realidad contextual que nos mueve a establecer mejores relaciones con el otro/a; es desde esta perspectiva que en el colegio Distrital Rodrigo Lara Bonilla le hemos venido apostando a la construcción de una convivencia más digna, con el tratamiento positivo de los conflictos.

  18. Resiliencia: una mirada positiva frente a la adversidad

    OpenAIRE

    Falagán Gómez, Leticia

    2012-01-01

    A través de una mirada histórica sobre el desarrollo del fenómeno de la resiliencia, se propone el conocimiento del constructo de la resiliencia, clarificando aspectos tales como sus antecedentes, definición, modelos explicativos y escuelas, factores de riesgo y protección, pilares y tutores de resiliencia. Además se realiza una mirada hacia la resiliencia en la infancia

  19. Enfermedades poco comunes: una prioridad de los sistemas de salud

    OpenAIRE

    RAP

    2017-01-01

    Las enfermedades poco comunes, incluidas las de origen genético, son aquellas enfermedades que tienen una prevalencia baja, menor de 5 casos por cada 10.000 habitantes en la comunidad, según la definición de la Unión Europea. Estas enfermedades tienen ciertas características comunes. Son, en su mayor parte, degenerativas y constituyen una prioridad de los sistemas de salud.

  20. Diseño de una Fuente de Alto Voltaje

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    José Enrique Eirez Izquierdo

    2013-10-01

    Full Text Available Este documento presenta las experiencias en el diseño de una fuente de alto voltaje, basada en multiplicadores de media onda. La fuente garantizará un voltaje de salida en el orden de 102 V y una corriente en el orden de 10-3 A. Se muestran y analizan resultados experimentales encaminados a su aplicación en la alimentación de un generador de pulsos de alto voltaje.

  1. Gestión de una empresa constructora

    OpenAIRE

    Zamora Cánovas, Jorge José

    2016-01-01

    Elaborar un presupuesto de costes de una empresa constructora. Analizar las fases en el proceso de ejecución de una obra pública. El control de los materiales a consumir en el proceso. Obtener el precio de venta de la obra pública. Estudio de la viabilidad del proyecto. Facultad de Ciencias de la Empresa Universidad Politécnica de Cartagena

  2. CLIMBING.CREACIÓN DE UNA MRCA DEPORTIVA

    OpenAIRE

    MESEGUER SANCHEZ, RAQUEL

    2017-01-01

    El presente TFG plantea el desarrollo de la imagen de marca de una empresa de ropa deportiva y la adaptación a sus productos, esta imagen plantea las connotaciones de fuerza y juventud y adaptable a cualquier tipo de deporte. Se estudian todos los valores implícitos en el branding y el proceso de elaboración. Meseguer Sanchez, R. (2017). CLIMBING.CREACIÓN DE UNA MRCA DEPORTIVA. http://hdl.handle.net/10251/92805 TFGM

  3. Proyecto de desarrollo de una base de datos

    OpenAIRE

    Boshoff de Jong, Etienne

    2013-01-01

    Desarrollo de las fases de planificación, análisis, diseño e implementación de un proyecto de desarrollo de una base de datos para un cliente ficticio. Desenvolupament de les fases de planificació, anàlisi, disseny i implementació d'un projecte de desenvolupament d'una base de dades per a un client fictici. Bachelor thesis for the Computer Science program on Databases.

  4. Omosessualità maschile: una chiave di lettura

    Directory of Open Access Journals (Sweden)

    Salvatore Polito

    2005-12-01

    Full Text Available Questo contributo, dunque, tenta di offrire una prima chiave di lettura del rapporto scambievole tra omosessualità maschile e società, analizzato in riferimento a una domanda pubblica di conoscenza non più trascurabile dalle scienze sociali. Soprattutto se si prende atto del fatto che l’omosessualità maschile rappresenta a tutti gli effetti un’alternativa stabile alla maschilità egemone eterosessuale per le sue specificità storiche, politiche e culturali.

  5. UNA POLÍTICA ALIMENTARIA PARA TIEMPOS DE CRISIS

    Directory of Open Access Journals (Sweden)

    Gustavo Gordillo

    2012-01-01

    Full Text Available Este artículo revisa el concepto de seguridad alimentaria. A partir de éste sugiere que es necesario considerar tanto la producción como el acceso a los alimentos como parte de una misma estrategia. Esto requiere implicar y al mismo tiempo fortalecer las capacidades nacionales, regionales y de las comunidades locales, prio-rizar el potencial de las comunidades, los agricultores y los ciudadanos de construir y apropiarse de las políticas alimentarias y de manera señalada la promoción a redes locales y regionales de productores de alimentos y consumidores. Argumenta que el propósito de entrecruzar en vez de confrontar el discurso de la seguridad alimen-taria y de la soberanía es una de las vías para avanzar en la discusión. Asimismo, argumenta que el significado de una política alimentaria en tiempos de crisis parte de la necesidad de enfrentar la desarticulación productiva y la desintegración social prevalecientes en el medio rural con una estrategia de reconstrucción institucional basada en la autonomía de los habitantes rurales y en una dinámica de intervencio-nes estatales a partir de una elaboración institucional inteligente capaz de aprender y adaptarse a las situaciones heterogéneas y cambiantes en el ámbito rural.

  6. Transformant una classe del grau en Psicologia a una flipped classroom

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    Marta Miragall

    2016-12-01

    Full Text Available La flipped classroom és una metodologia docent que tracta de modificar la dinàmica de la classe tradicional, en la que l'alumnat estudia la matèria abans d'assistir a classe (fonamentalment per mitjà de les Tecnologies de la Informació i Comunicació, i el temps en l'aula s'empra per a aclarir continguts i realitzar activitats significatives, amb el suport continuat del professorat. Estudis recents mostren que s'han obtingut resultats positius respecte a la utilització d'aquesta metodologia. No obstant això, la implantació d'aquesta metodologia en el grau en Psicologia és escassa. Per això, l'objectiu d'aquest treball va ser aplicar la metodologia flipped classroom a un tema de l'assignatura Psicopatologia, i comparar la seua efectivitat amb una classe tradicional. La mostra va estar composta per 87 alumnes (M = 23.02; DT = 7.88 anys, 73.1% dones del grau de Psicologia de la Universitat de València. En la condició flipped classroom (n = 47 l'exposició de la matèria es realitzava a través d'un vídeo que l'alumnat visualitzava a casa, i en l'aula s'avaluaven i aclarien continguts (per mitjà de la plataforma Kahoot! i es realitzaven activitats significatives en xicotets grups. En la condició tradicional (n = 40, es va impartir una classe magistral, es van avaluar i aclarir els continguts a través de la plataforma Kahoot!, i es va proposar la realització de les activitats significatives per a casa. L'alumnat de cada condició va avaluar l’interès, utilitat i dificultat de cada un dels components de les metodologies en una enquesta tipus Likert, que a més contenia dos preguntes obertes. Així mateix, es va avaluar el nivell de coneixements adquirits tant a través de la plataforma Kahoot! com a l'examen final de l'assignatura. No es van observar diferències significatives entre ambdós condicions respecte als continguts adquirits a través de l'examen de l'assignatura. No obstant això, la realització de les activitats a l

  7. UNA COLCHA: elementos de una etnografía que la arropan

    Directory of Open Access Journals (Sweden)

    LUIS ALBERTO SUÁREZ-GUAVA

    2002-01-01

    Full Text Available ESTE ENSAYO ABORDA, DE FORMA EXPLÍCITA, TRES TEMAS QUE SE CRUZARON EN UNA investigación etnográfica: la identidad cultural, las maneras -concepto que permite hablar de ese tipo de identidad- y la elaboración cultural del tiempo. En él están implícitas, mas no ocultas, algunas reflexiones que giran sobre la escritura en antropología -porque en nuestro ámbito lo real se presenta con palabras-, sobre la condición del investigador en tanto sujeto social y sobre el límite de la autoridad etnográfica, que, supongo, no es sólo autoridad para describir, sino que es, también, autoridad para conceptualizar.

  8. Hacia una conceptualización del plan de empresa: una mirada desde la estrategia.

    Directory of Open Access Journals (Sweden)

    Fabián Fernando Osorio Tinoco

    2011-03-01

    Full Text Available Es indudable la importancia actual del plan de empresa y su uso generalizado para abordar la búsqueda de recursos a la hora de crear una nueva empresa. El propósito de este artículo es presentar un análisis conceptual del plan de empresa, más allá del confinado a su uso y su elaboración, a partir de la mirada de la Estrategia. Se exponen elementos conceptuales de la Estrategia, la Planeación como proceso. Finalmente, la importancia del ambiente, y se concluye con planteamientos para considerar a futuro, un análisis exhaustivo sobre los planes de empresa, dada la  importancia que tal instrumento viene adquiriendo.

  9. Construyendo una cultura de innovación. Una propuesta de transformación cultural

    Directory of Open Access Journals (Sweden)

    Julia C. Naranjo-Valencia

    2015-04-01

    Full Text Available Este trabajo presenta el modelo de transformación cultural para la innovación que se viene implementando en la empresa Sumicol, perteneciente a la Organización Corona. El modelo diferencia 3 fases: diagnóstico de la cultura actual, definición de la cultura meta e identificación de las brechas que deben cerrarse para alcanzar esa cultura. La investigación se llevó a cabo como un estudio de caso con énfasis en la perspectiva cualitativa realizada a partir de análisis documental, entrevistas en profundidad y grupos focales, y se complementó con una descripción cuantitativa de la cultura. Como resultado se estructura un modelo para el desarrollo de transformaciones culturales, se identifican los formadores de cultura y se establecen los rasgos culturales necesarios para la innovación empresarial.

  10. Turbogas control unit using a hydraulic interface; Control de una unidad turbogas usando una interfase hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez Palacios, Ignacio Ramon; Castelo Cuevas, Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: irrp@iie.org.mx; lcastelo@iie.org.mx; Escarcega Navarrete, Luis [Servi-Control Monterrey S.A. de C.V., Monterrey, Nuevo Leon (Mexico)]. E-mail: lescarcega@servicontrol.com

    2010-11-15

    This paper presents the design and implementation of the control system of the Turbo Generator Unit (TGU) GE 5001, placed in Laguna Chavez power generation facility in Gomez Palacio, Dgo., Mexico. This TGU had been operating with an old control system, back to the 70's. The positioning of the control valves was carried out using a complex electro-hydraulic system. For the modernization of the control system, we use latest PLC technology and a current to pressure converter to communicate the PLC with the hydraulic control valves. The new control system helped us to obtain a best response at the start and generation phases, as well as an increase in the availability of the unit. We show the old and the new control architectures besides plot results obtained at the different operation points. [Spanish] En este articulo se presenta la implementacion y diseno del sistema de control de una Unidad Turbogas (UTG) GE-5001 de la Central Turbogas Laguna Chavez de CFE ubicada en Gomez Palacio, Durango, la cual originalmente era controlada mediante un sistema de control con tecnologia de los anos 70's. El posicionamiento de las valvulas de control se realizaba mediante un sistema electro-hidraulico complejo. Para la modernizacion del sistema de control a uno con tecnologia de punta fue necesario utilizar una interfase hidraulica por medio de un convertidor de corriente/presion (I/P) para el posicionamiento de las valvulas originales. Con la modernizacion se mejoro la respuesta del control asi como el incremento de la disponibilidad de la unidad. Se presentan la arquitectura anterior y actual de sistema de control asi como graficas de los resultados obtenidos en diferentes puntos de operacion de la UTG.

  11. Ingreso Temprano al Control Prenatal en una Unidad Materno Infantil

    Directory of Open Access Journals (Sweden)

    Delia Moya-Plata

    2010-12-01

    Full Text Available Introducción: El control prenatal se define como todas las acciones y procedimientos, sistemáticos y periódicos, destinados a la prevención, diagnostico y tratamiento de los factores que pueden coordinar la morbilidad y mortalidad materna y perinatal. La muerte de una madre es una tragedia evitable que afecta una vida joven llena de grandes esperanzas; es una de las experiencias más traumáticas que puede sufrir una familia y afecta seriamente el bienestar, la supervivencia y el desarrollo de los hijos, especialmente de los más pequeños. Todo lo anterior trae como consecuencia el debilitamiento de la estructura social en general. Materiales y Métodos: Es un estudio descriptivo de corte transversal, en el cual, se identificaron aspectos importantes como las variables sociodemográficas, clínicas, barreras de acceso y adherencia para el ingreso temprano al control prenatal de las gestantes que consultan a una unidad materno infantil. Resultados: El control prenatal representa una estrategia básica que permite identificar factores de riesgo y alteraciones fisiológicas en toda paciente gestante. Los resultados expresados en Le presente trabajo muestran el impacto favorable cuando no inciden las variables de riesgo. Discusión y Conclusiones: Queda demostrado que con un número suficiente de controles prenatales y efectuados en forma precoz, estas pacientes pueden ser contenidas en su situación y se llega a disminuir en forma muy importante la mortalidad perinatal. (Rev Cuid 2010;1(1:44-52.Palabras clave: Atención Prenatal, Factores Epidemiológicos, Accesibilidad a los Servicios de Salud. (Fuente: DeCS BIREME.

  12. Ampliación y actualización de una empresa de formación, sobre software libre

    OpenAIRE

    Palmer Padilla, Fco. Javier

    2010-01-01

    Este proyecto trata de una investigacion, sobre una migracion de una empresa a software libre. Este proyecto trata de una investigacion, sobre una migracion de una empresa a software libre. This project is a research in a company process of software migration to free software.

  13. Una taxonomía de modelos de desarrollo sustentable

    Directory of Open Access Journals (Sweden)

    Darcy Tetreault

    2004-01-01

    Full Text Available Este ensayo pretende ayudar a desenmarañar una parte del discurso sobre desarrollo sustentable mediante la construcción de una taxonomía de modelos de desarrollo sustentable. La misma taxonomía se basa en una revisión literaria extensiva que en cierta medida privilegia la experiencia mexicana. De este modo, el ensayo presenta y compara tanto modelos normativos como positivos. Los modelos incluidos son el modelo dominante, el cual corresponde con la estrategia esbozada en el Informe Bruntland y Agenda 21; la ecología política, un modelo desarrollado por el economista francés Alain Lipietz; el modelo comunitario de desarrollo sustentable, cuyas raíces se encuentran en una escuela de pensamiento de la década de los setenta conocida como el “otro desarrollo”; el comercio justo, una experiencia cuyas raíces se encuentran en las comunidades indígenas de Oaxaca; la producción forestal industrial comunitaria, que ha sido puesta en práctica por varias comunidades forestales en el sur y el centro del país; el activismo ambiental, sobre todo respecto a los con- fl ictos locales que giran en torno al control de los recursos naturales; y la conservación basada en la comunidad, cuya manifestación principal es la reserva de la biosfera

  14. Fragmentos para una historia del cuerpo en Chile.

    Directory of Open Access Journals (Sweden)

    Juan Aravena Hernández

    2011-09-01

    Full Text Available Sin duda la historia del cuerpo es la historia de un gran olvido; un olvido silencioso, casi cotidiano por convención, pero, sobre todo, uno que se ha ido forjando en Occidente por medio de la implicancia tanto desde la tensión situada en el credo cristiano entre el pecado y la redención como por la noción epistemológica tradicional asumida de la pertenencia estricta del cuerpo al mundo de la naturaleza y no al de la cultura. Ante lo anterior, Fragmentos para una historia del cuerpo en Chile se presenta como un conjunto de trabajos y visiones historiográficas que tienen al cuerpo como su eje conector, así mismo, como su objeto central de estudio en sus diversas perspectivas analíticas. Significados, representaciones, percepciones, continuidades y transformaciones referidas al cuerpo se presentan en esta obra dando cuenta, no sólo de una suerte de intento historiográfico nacional de saldar cuentas con la ausencia histórica de la corporalidad, sino más bien como una forma que, desde el acercamiento historiográfico a través del cuerpo, abre nuevas entradas y condiciones de posibilidad para la (una historia; una historia atravesada esta vez, no sólo de ideas y aconteceres, sino también, de tactos y roces, de carnes y huesos.

  15. Liderazgo preventivo para la universidad. Una experiencia plausible

    Directory of Open Access Journals (Sweden)

    Alejandro Rodríguez Rodríguez

    2015-06-01

    Full Text Available El desarrollo del liderazgo, en el ámbito educativo superior, busca soluciones de aplicación inmediata a contextos en que todo líder se desenvuelve, pero se diluye el sustento teórico-práctico en la formación del líder que posibilite entender los procesos intelectivos durante la toma de decisiones. El paradigma de convergencia entre el método antropológico lonerganiano, la comunidad de aprendizaje vygotskiana y una relectura del sistema preventivo salesiano se presentan como propuesta plausible de formación al liderazgo preventivo entre los diversos actores de una comunidad universitaria. Un estudio de caso de la Universidad Salesiana en México empleando un método mixto de investigación, facilita una relectura del liderazgo desde una óptica preventiva como posibilidad de convergencia en un diálogo interdisciplinar. Los resultados teórico-práctico propuestos y examinados se muestran como herramienta útil para evaluar, enriquecer y renovar la teoría sobre el líder y el desarrollo de liderazgo en las universidades frente a una sociedad globalizada.

  16. La Pareja: Dos mundos, una unidad.

    Directory of Open Access Journals (Sweden)

    Guillermo Sánchez Medina

    2000-12-01

    Full Text Available

    Comentario al trabajo del doctor Alvaro Villar Gavíria.

    Alvaro Villar Gaviria de 75 años, médico psiquiatra psicoanalista, hizo su tesis de grado sobre el “Tratamiento de la Esquizofrenia por medio de la Histamina”, graduándose en noviembre de 1950, es decir hace 46 años. Trabajó e hizo su especialización en el Asilo de Locas, de Bogotá, y realizó el entrenamiento psicoanalítico en el Instituto de Psicoanálisis; es fundador de la Sociedad Colombiana de siquiatría, de la Asociación Psicoanalítica Colombiana, de la Red de Alternativa a la Psiquiatría y de la Fundación del Psicoanáisis y Psicoterapia; además es Miembro de la Sociedad Colombiana de Epistemología; y pertenece a la Sociedad de Rorschach de New York, y a la Interamericana de Psicología.

    Es Profesor Emérito y Honorario de la Universidad Nacional; le fue otorgado el premio “Héctor Ortega Arbeláez” por su trabajo “Acerca de Michel Foucault”; pertenece a la Sociedad Colombiana de Educación Preescolar y a la Sociedad de Psiquiatría Democrática de Trieste, Italia.

    Ha sido Profesor de técnicas cuantitativas, de teoría psicoanalítica, de técnicas de psicoterapia, de psicología aplicada a la clínica, de técnica psicoanalítica, de psicoterapia de pareja y de familia, y de sexología.

    El Doctor Villar publicó una docena de libros desde: “El niño, otro oprimido”; “El servicio doméstico, un gremio en extinción”; ÒPsicología y clases sociales en Colombia”, Vols. 1, 2 Y 3;”Lexicon de León De Greiff”; “La autoridad en Colombia. Manicomio y prisiones”; “ÀLa salud pœblica para quién?”; “Freud, la mujer y los homosexuales”; “Glosario mínimo para los amantes de “El amor en los tiempos del cólera'”; “Los ángeles de Sopó”. Por los títulos, se dejan ver las motivaciones científicas que tiene por los oprimidos, y por un factor psicológico y social, hasta llegar al

  17. Corynebacterium glutamicum promoters: a practical approach

    Czech Academy of Sciences Publication Activity Database

    Pátek, Miroslav; Holátko, Jiří; Busche, T.; Kalinowski, J.; Nešvera, Jan

    2013-01-01

    Roč. 6, č. 2 (2013), s. 103-117 ISSN 1751-7907 R&D Projects: GA ČR GPP302/12/P633 Institutional support: RVO:61388971 Key words : VITRO TRANSCRIPTION SYSTEM * L-LYSINE PRODUCTION * SIGMA -FACTOR SIGB Subject RIV: EE - Microbiology, Virology Impact factor: 3.023, year: 2013

  18. Algunos conceptos para una perspectiva optimista de vivir la ciudad

    Directory of Open Access Journals (Sweden)

    Pablo Pu00E1ramo

    2004-01-01

    Full Text Available La tesis principal defendida en este artículo es que en lugar de estudiar la ciudad como una fuente de enfermedades, de estrés psicológico o de problemas sociales debería ser estudiada como una experiencia positiva que ofrece oportunidades para el crecimiento individual y el aprendizaje. Este artículo desarrolla una serie de conceptos que recogen las transacciones que tienen los individuos con el ambiente de la ciudad. Los conceptos propuestos se formulan con el fin de explicar la manera como la gente se comporta en el espacio público y contribuyen a crear su identidad urbana. Se propone que conceptos tales como lugar, control ambiental, y ciudad educadora puedan ser tenidos en cuenta con educativos y de planeación urbana de las mega/ciudades que se avecinan en el presente siglo.

  19. Una menorá grabada hallada en Gredos

    Directory of Open Access Journals (Sweden)

    Castaño, Javier

    2007-06-01

    Full Text Available A description and analysis of two late Medieval funerary brick fragments containing Hebrew text and decorated with a stylized Menorah, found in Navacepeda de Tormes (Ávila. According to the available evidence, they were brought from a Jewish cemetery located in another town.

    Noticia del hallazgo de dos fragmentos de ladrillos funerarios judíos bajomedievales con restos de inscripción hebrea en Navacepeda de Tormes, en la vertiente septentrional de la Sierra de Gredos. Una de las piezas aparece decorada con una menorá estilizada. Todos los indicios disponibles apuntan a su hallazgo fuera de su contexto original, que habría sido una sepultura de un cementerio judío de otra localidad.

  20. Per una poetica del plagio: il caso di Kathy Acker

    Directory of Open Access Journals (Sweden)

    Claudia Cao

    2012-10-01

    Full Text Available Dopo una breve introduzione intorno alla produzione letteraria di Kathy Acker e dopo una panoramica su alcuni saggi in cui l’autrice si sofferma sulla stretta relazione esistente tra scrittura e potere, e tra scrittura e desiderio, l’articolo esamina il significato assunto dal plagio in una delle sue opere più sperimentali: Great Expectations. Prendendo le mosse da un concetto centrale nella riflessione elaborata da Deleuze e Guattari all’interno del loro L’Anti-Œdipe. Capitalisme et Schizophrénie, come quello di “macchina desiderante”, questo contributo intende illustrare la relazione esistente tra l’atto del plagio e il pensiero schizofrenico elaborato dai due pensatori francesi.

  1. Posibilidades de conocer la edad de una obra

    Directory of Open Access Journals (Sweden)

    Calleja, J.

    1958-10-01

    Full Text Available Not availableEl problema de conocer la edad de una obra se presenta con cierta frecuencia, unas veces surgido de querellas entre arrendadores y arrendatarios (desahucios por realización de modificaciones por porte de los segundos en fincas de los primeros, sin la autorización de éstos, y otras planteado por investigaciones de índole arqueológica. En el primer caso la ley fija un plazo de prescripción de los derechos del arrendador sobre el arrendatario, y de ahí que el problema gire alrededor de la fecha de ejecución de la obra causa del desahucio. En el segundo, la naturaleza del tema es muy diferente y, en general, éste se plantea de forma que hay que determinar si los restos hallados en unas ciertas excavaciones son o no de la misma época que los encontrados en otras.

  2. Una búsqueda de la identidad regional em Astrometria

    Science.gov (United States)

    Abad, C.

    2003-11-01

    La idea sobre una reunión latino-americana que congregara a las personas que desarrollan su trabajo en el área de la astrometría, se gestó a partir de una de las reuniones que el proyecto QUEST realizaba anualmente en Mérida (Venezuela). El proyecto QUEST (Quasars Equatorial Survey Team) celebraba su IV Reunión Anual, en la cual se hacía una revisón de la marcha del proyecto durante el último año. Además, se exponían los logros científicos y técnicos alcanzados hasta el momento y se planificaba el futuro del mismo para el período anual siguiente.

  3. Flexión de una viga en voladizo

    OpenAIRE

    Beléndez, Augusto; Alvarez, Mariela L.; Beléndez Vázquez, Tarsicio; Bernabeu, Guillermo; Bleda, Sergio; Calzado Estepa, Eva María; Campo Bagatin, Adriano; Dale Valdivia, Roberto; Durá Domenech, Antonio; Fernandez-Varo, Helena; Gallego, Sergi; Hernández Prados, Antonio; Marco Tobarra, Amparo; Márquez, Andrés; Martín García, Agapito

    2010-01-01

    Los proyectos han sido dirigidos por Augusto Beléndez Vázquez. Material complementario de los vídeos de Física publicados en http://www.dfists.ua.es/experiencias_de_fisica y en https://www.youtube.com/playlist?list=PLoGFizEtm_6hVhzdWBZVW4O7TcPemL0c1 En esta experiencia se va analizar el problema clásico de la flexión de una viga en voladizo de material elástico lineal, bajo la acción de una fuerza concentrada vertical aplicada en su extremo libre. Se trata de una viga con un extremo empotr...

  4. Lengua y etnicidad: una relación con matices

    Directory of Open Access Journals (Sweden)

    Masatsugu Matsuo

    2009-06-01

    Full Text Available La lengua es uno de los principales factores que permiten diferenciar a un grupo étnico de otro. Sin embargo, la relación que los grupos étnicos tienen con respecto a su lengua no es invariable y el examen de casos particulares refleja una amplia gama de matices. Dada esta ambivalencia propia del tema, este artículo busca examinar qué propiedades puede asumirse que son necesarias para establecer un vínculo entre una lengua y un grupo étnico, para posteriormente explicar, por medio de algunos ejemplos, cómo dicho vínculo puede llegar a encontrarse más en una percepción compartida por el grupo que en un uso efectivo de la lengua.

  5. Multilocalización: Una Estrategia Para Competir Globalmente

    Directory of Open Access Journals (Sweden)

    Mónica María Sinisterra Rodríguez

    2009-01-01

    Full Text Available Este artículo busca mostrar, a través de una revisión bibliográfica analítica, la pertinencia de la hipótesis que plantea la multilocalización como una de las mejores estrategias empresariales para competir globalmente, específicamente, cuando las empresas tienen ventajas competitivas y son capaces de identificar y aprovechar las ventajas comparativas de las regiones. La principal implicación de esta hipótesis es que reclama una mayor atención sobre las nuevas necesidades de habilidades empresariales para ligar la ruptura de la cadena de valor que la integración comercial produce.

  6. MULTILOCALIZACIÓN: UNA ESTRATEGIA PARA COMPETIR GLOBALMENTE

    Directory of Open Access Journals (Sweden)

    MÓNICA MARÍA SINISTERRA RODRÍGUEZ

    2009-01-01

    Full Text Available Este artículo busca mostrar, a través de una revisión bibliográfica analítica, la pertinencia de la hipótesis que plantea la multilocalización como una de las mejores estrategias empresariales para competir globalmente, específicamente, cuando las empresas tienen ventajas competitivas y son capaces de identificar y aprovechar las ventajas comparativas de las regiones. La principal implicación de esta hipótesis es que reclama una mayor atención sobre las nuevas necesidades de habilidades empresariales para ligar la ruptura de la cadena de valor que la integración comercial produce.

  7. Una vez más sobre la eutanasia

    OpenAIRE

    Casado, María

    2008-01-01

    La discusión sobre la eutanasia continúa siendo una de las más candentes en el ámbito de la bioética. En este artículo, analizaremos el debate entre quienes rechazan la eutanasia amparándose en la santidad de la vida humana y quienes la defienden propugnando como ideas fundamentales la calidad de vida y la autonomía individual. Tras estas visiones enfrentadas, subyace una discusión más profunda entre una concepción antigua de los derechos humanos, basada en el respeto a un orden «natural» y u...

  8. una aplicación con datos regionales

    Directory of Open Access Journals (Sweden)

    Teresa Leal

    2005-01-01

    Full Text Available En este artículo evaluamos el grado de ajuste a los objetivos presupuestarios establecidos de un conjunto de datos de recaudación tributaria de la Comunidad Autónoma de Andalucía. Usamos la metodología de Kanda (2002, que permite evaluar la probabilidad de alcanzar el objetivo anual prefijado cuando se dispone de información mensual de una parte del año. Los perfiles mensuales estudiados se ajustaron a una senda compatible con el objetivo anual en casi todos los casos estudiados. Además se aprecia una tendencia en los Impuestos directos y Tasas, precios públicos y otros ingresos a mostrar un sesgo a la baja respecto al objetivo anual, mientras que el capítulo de Impuestos indirectos tiende a presentar errores positivos respecto al objetivo anual.

  9. Estudio de liderazgo en una carrera de educación superior, en una universidad regional

    Directory of Open Access Journals (Sweden)

    Alberto Martínez Quezada

    2016-06-01

    Full Text Available El objetivo del presente trabajo es determinar estilo de liderazgo presente en la dirección de carrera de Ingeniería Civil Industrial, de la Universidad Arturo Prat de Iquique. Para el levantamiento de información, se aplicó el Cuestionario Multifactorial de Liderazgo MLQ 5X, adaptado a la realidad organizacional chilena, a los académicos y al director de carrera. El estudio permitió determinar que, de los estilos de liderazgos evaluados (Liderazgo transformacional, Liderazgo transaccional y Laissez faire, el líder estudiado presenta características del Liderazgo transformacional y transaccional, con una diferencia cercana al 9%, siendo mayor el primero, logrando aplicar ambos estilos de liderazgo de acuerdo al contexto, en conjunto con otras variables como la efectividad y la satisfacción evaluada por los clasificadores.  Este resultado es respaldado por el estudio y análisis, del “Modelo de las nueve dimensiones de rango total”.

  10. Siempre que leemos una novela estamos viendo una película

    Directory of Open Access Journals (Sweden)

    Aníbal Alexandre

    2015-01-01

    Full Text Available Comunicación y Género, acopia trabajos que vinculan a la mujer y la comunicación y sus esfuerzos por no ser consideradas inferiores. Del libro a la pantalla, acerca a algunas reflexiones sobre el proceso que lleva del libro a la pantalla por la polémica que despierta la adaptación de las novelas, puesto que muchos señalan que la trama se ve desfigurada. Se agregan varios temas sobre el cine. En "Días de Radio", se plantea el que a pesar de la censura y los problemas económicos que deben enfrentar, las radios populares de América Latina, siguen ganando espacios, de su desarrollo depende una mayor profundización de la democracia. Tema de debate es Estrategias comunicativas en Chiapas y Haití. Se añaden dos entrevistas a un caricaturista brasileño y a un corresponsal de guerra muy prestigiado.

  11. El neoconstitucionalismo. Una definición y una taxonomía latinoamericana

    Directory of Open Access Journals (Sweden)

    Vicente Solano Paucay

    2016-12-01

    Full Text Available Con el objetivo de poder definir algunos elementos principales de las tesis neoconstitucionalistas debemos hacernos algunas preguntas fundamentales que pueden ayudarnos a distinguir la relación que existe de esta “corriente” frente a las teorías del derecho tradicionales. Estas preguntas serán las que nos permitirán ubicar a las diferentes nociones denominadas neoconstitucionalistas o no, en el objetivo de su identificación y clasificación. La primera tendría que ver con la tesis de la conexión existente entre Derecho y moral; la segunda, revisar la tesis de la necesidad de la moral para la identificación y validez del derecho; la tercera, explorar la tesis de que los principios o valores constitucionales remiten a la moral y como implicación la tesis de cómo se deben aplicar los principios y reglas. De esta forma, podremos encontrar que existen en las tesis neoconstitucionalistas convergencias o divergencias que puedan llevarnos a esclarecer de mejor forma criterios plausibles para la identificación de los elementos trascendentales. Estos elementos denotarían si el “neoconstitucionalismo” es una nueva “teoría” del derecho superadora de la dicotomía entre el no-positivismo y positivismo jurídico.

  12. La inclusión educativa: Una tarea que le compete a toda una sociedad

    Directory of Open Access Journals (Sweden)

    Ronald Soto Calderón

    2003-01-01

    Full Text Available Este artículo se escribe con referencia a las ideas acerca del proceso de integración e inclusión de personas con necesidades educativas especiales al aula. Se señala cómo la sociedad debe involucrarse para hacer de la integración una realidad, y cómo estas experiencias deben posibilitar el que haya estudiantes con NEE incluidos en clases regulares. También, con el fin de construir un proceso de inclusión en ambientes institucionales, este artículo recoge aspectos que deben ser imperativos de acción para las instituciones educativas, sean de primaria o secundaria, y de este modo, ofrecerles a todos los estudiantes, con o sin discapacidad (necesidades educativas especiales, la posibilidad de involucrarse en programas educacionales, y ayudarles a ser parte de la sociedad en diferentes formas: como estudiante, trabajador o miembro de la familia en la cual viven. En otras palabras, este artículo se escribe con la idea de hacer conciencia social sobre el papel que la institución educativa tiene, sobre todo, en cuanto a proporcionar oportunidades equitativas de progreso a todos los miembros de la sociedad; en un marco de respeto hacia las diferencias.

  13. La inclusión educativa: una tarea que le compete a toda una sociedad

    Directory of Open Access Journals (Sweden)

    Soto Calderón, Ronald

    2003-06-01

    Full Text Available Este artículo se escribe con referencia a las ideas acerca del proceso de integración e inclusión de personas con necesidades educativas especiales al aula. Se señala cómo la sociedad debe involucrarse para hacer de la integración una realidad, y cómo estas experiencias deben posibilitar el que haya estudiantes con NEE incluidos en clases regulares. También, con el fin de construir un proceso de inclusión en ambientes institucionales, este artículo recoge aspectos que deben ser imperativos de acción para las instituciones educativas, sean de primaria o secundaria, y de este modo, ofrecerles a todos los estudiantes, con o sin discapacidad (necesidades educativas especiales, la posibilidad de involucrarse en programas educacionales, y ayudarles a ser parte de la sociedad en diferentes formas: como estudiante, trabajador o miembro de la familia en la cual viven. En otras palabras, este artículo se escribe con la idea de hacer conciencia social sobre el papel que la institución educativa tiene, sobre todo, en cuanto a proporcionar oportunidades equitativas de progreso a todos los miembros de la sociedad; en un marco de respeto hacia las diferencias.

  14. Una simulación multi-agente del mecanismo de generalización de una norma social

    Directory of Open Access Journals (Sweden)

    Francisco Linares

    2012-01-01

    Full Text Available El presente artículo trata de abordar dos cuestiones interrelacionadas: ¿qué es una norma social? y ¿cómo se generaliza? Se argumenta que una norma social no es ni mero comportamiento sancionador ni tampoco comportamiento que tan solo se ajusta a las expectativas de los demás; sino que ambos requisitos deben cumplirse para que esta exista. A través de un modelo de simulación multi-agente se muestra cómo una dinámica de refuerzo mutuo entre la ejecución de sanciones y la generalización de expectativas explica la generalización de una norma social, dada la existencia de una masa crítica de sancionadores incondicionales. Además se muestra que a mayor densidad social, menor el tamaño de la masa crítica requerida en la población.

  15. Una experiencia didáctica con el collage.

    Directory of Open Access Journals (Sweden)

    Joaquim Cantalozella Planas

    2008-07-01

    Full Text Available El punto de partida que Joan Miró estableció para realizar las dieciocho Pintures segons collage de 1933 nos sirven hoy para hacer una propuesta que permita pensar en algunas de las claves de la pintura contemporánea. Términos como la apropiación, la autoría o la subjetividad del artista se ponen en juego cuando se activa el dispositivo del collage como modelo. Aquí se plantea una actividad de aprendizaje que confronta el trabajo individual con el colectivo y que tiene como objetivo principal la reflexión sobre el lenguaje pictórico.

  16. Propiedades de transporte de una superred de grafeno tipo sinusoidal

    OpenAIRE

    J. A. Briones-Torres; I. Rodríguez-Vargas

    2015-01-01

    En este trabajo usamos el método de la matriz de transferencia para estudiar el tunelamiento de los electrones de Dirac a través de superredes en grafeno. Consideramos una superred con potencial sinusoidal o polaridad invertida, para ello consideramos dos maneras de crearla, una por medio de sustratos mixtos junto con la aplicación de un campo perpendicular sobre el sustrato de Óxido de Silicio (SiO2), la otra por medio de potenciales alternados aplicados perpendicularmente sobre la sábana de...

  17. Plan de negocio de una residencia geriátrica

    OpenAIRE

    García Sanz, Federico

    2015-01-01

    El proyecto fin de carrera que a continuación se desarrolla denominado “Plan de Negocio de una Residencia Geriátrica” tiene como objetivo la realización de un Plan de Negocio como aplicación práctica de los conocimientos adquiridos durante los cinco cursos que componen la carrera de Ingeniería Industrial en su especialidad de Organización Industrial. En primer lugar se presenta una visión teórica de todos aquellos aspectos relacionados con el concepto “idea”. La intención es dejar const...

  18. Desarrollo de una red social para el aprendizaje

    OpenAIRE

    Cumbreras Tirado, Edgar

    2015-01-01

    En este trabajo de fin de grado se ha desarrollado una plataforma online que promociona y promueve el aprendizaje de nuevas tecnologías. La plataforma ha sido enteramente creada haciendo uso de JavaScript, con tecnologías como Node.js y Angular.js. En aquest treball de fi de grau s'ha desenvolupat una plataforma online que promociona i promou l'aprenentatge de noves tecnologies. La plataforma ha estat enterament creada fent ús de JavaScript, amb tecnologies com Node.js i Angular.js. Bac...

  19. Una guerra digital a la española

    Directory of Open Access Journals (Sweden)

    Tito Drago

    2015-01-01

    Full Text Available Incubada durante un lustro, en lo que va de 1997 se viene desarrollando en España una contienda por el control de la televisión digital, en la que se mezclan maniobras financieras, cruce de acusaciones penales, corte de transmisiones, venta y reventa de contratos, intervención de instancias internacionales y dinero, mucho dinero. Una relación actualizada de esta "guerra digital" en la que intereses económicos y políticos se entrecruzan y son decisivos es lo que presenta el autor del artículo.

  20. El deporte en la ciudad: una nueva manera de verlo

    Directory of Open Access Journals (Sweden)

    Marta Carranza

    2008-03-01

    Full Text Available Barcelona y el deporte forman ya un binomio indisoluble e indiscutible. Por una parte, la larga tradición deportiva de la ciudad fundamentada por un tejido asociativo centenario, potente y vanguardista; por otra, la experiencia y el reconocimiento internacional de Barcelona como organizadora y sede de acontecimientos deportivos, y finalmente, la amplia red docente y de investigación relacionada con la actividad deportiva, nos dan las condiciones idóneas y los ingredientes básicos para poder elaborar, de forma compartida, una nueva receta deportiva barcelonesa con secretos del pasado y productos del siglo xxi: un deporte que construye socialmente la ciudad.

  1. Sociedad civil: una concepción radical

    OpenAIRE

    García Marzá, Vicente Domingo

    2008-01-01

    El presente trabajo1 tiene como objetivos presentar un concepto de sociedad civil desde una perspectiva crítica, una perspectiva que pueda dar razón del potencial de cambio y transformación social que encierra este ámbito de la interacción social. Con este fin, se adentra en primer lugar en la difícil relación entre democracia y sociedad civil, analizándola desde el paso de las democracias participativas a las democracias deliberativas. El caràcter global de la sociedad civil y los problemas ...

  2. México hacia una sociedad del conocimiento

    OpenAIRE

    Héctor Carreón Mendoza; Ricardo Melgoza Ramos

    2012-01-01

    Es importante para México convertirse en una sociedad del conocimiento, con una clara estrategia en su plan de desarrollo con respecto a la inversión en: transferencia tecnológica, incremento del capital intelectual, mayor vinculación de los sectores nacionales que generan ciencia y la generación de políticas públicas que incentiven la innovación en ciencia y tecnología y la protección de la propiedad intelectual.

  3. PERFIL PARA REPRESENTAR UNA ARQUITECTURA DE COMPONENTES EN UML

    Directory of Open Access Journals (Sweden)

    Fernando Orejas Valdés

    2006-04-01

    Full Text Available

    El lenguaje unificado de modelado (Unified Modeling Language, UML es un lenguaje de modelado estándar para problemas generales, sin embargo, es necesario extenderlo para dominios específicos como puede ser el caso de determinadas arquitecturas. Aquí se presenta una extensión mediante un perfil para una arquitectura de componentes y conectores genéricos.

  4. Estigma hacia la demencia: una revisión

    OpenAIRE

    Mascayano, F.

    2015-01-01

    La demencia, hoy denominada trastorno neurocognitivo mayor en el DSM-V, es una prioridad para la salud pública debido a su creciente prevalencia y alto impacto individual social. El estigma, es decir, la devaluación y exclusión social que vive un individuo producto de una característica, atributo o comportamiento; es un fenómeno colectivo vinculado a esta condición, el cual impacta en la calidad de vida de las personas con demencia y sus entornos familiares que usualmente brindan apoyo, y ha ...

  5. Vulnerabilidad social y orfandad: trayectoria vital de una adolescente

    OpenAIRE

    Bertha Elvia Taracena-Ruiz; María Isabel Moratilla-Olvera

    2012-01-01

    El enfoque socio-clínico es una aproximación de producción de conocimiento, que busca generar una reflexión multirreferencial de las problemáticas psicosociales; su estrategia metodológica es la experiencia individual, ya que a partir de esta, es posible observar las influencias socio-culturales y de las instituciones en el sujeto. En este trabajo, nuestro interés fue el de reflexionar sobre la vulnerabilidad social y la orfandad de las adolescentes, que al vivir en medios socio-cultrales ...

  6. ¿Qué es una onda ecuatorial de Kelvin?

    OpenAIRE

    Ripa, P.

    1980-01-01

    La importancia del estudio de las ondas de Kelvin (ecuatoriales o costeras) radica, en parte, en el hecho de que éstas proveen un mecanismo eficaz para el transporte de energía (en la forma de perturbaciones de densidad y corriente) en una dirección particular. Estas señales se trasladan sin dispersión, es decir, sin cambiar de forma. Por otra parte, una onda de Kelvin provee un ejemplo muy sencillo de dos fenómenos fundamentales de la Oceanografía Física de frecuencias: el balance geostrófic...

  7. Mirar l'aula com es mira una imatge

    Directory of Open Access Journals (Sweden)

    Francisca Beneyto Ruiz

    2014-12-01

    Full Text Available En aquest article es proposa una metodologia d'aproximació a l'aula entenent-la a través del concepte d'imatge tal com ho contemplen els Estudis Visuals. Al llarg de tot el desenvolupament vaig apropant el concepte d'imatge i el concepte d'aula creant vincles entre un i altre. Si la imatge no és una estructura sinó un estructurant, l'aula és, igualment, un espai de construcció contínua on cada element i cada relació compten.

  8. Las relaciones empresariales: una tipología de redes

    OpenAIRE

    José Luis Galán; Cristóbal Casanueva; Ignacio Castro-Abancéns

    2010-01-01

    El conjunto de redes en las que participan las empresas son consideradas como un recurso para las mismas. Cada empresa participa en redes diferentes y su posición en cada red la hace diferente a las demás. Las relaciones de una empresa se comportan como un recurso que está en la base de la heterogeneidad que le permite ser soporte de una ventaja competitiva sostenible. Sin embargo, el análisis de las redes empresariales es complejo. Este trabajo pretende disminuir esa complejidad analiz...

  9. Disseny d'una microxarxa amb generació renovable

    OpenAIRE

    Durich Serra, Ruben

    2016-01-01

    El present projecte pretén abordar l’estudi dels costs de generació d’energia elèctrica renovable de la tecnologia solar-fotovoltaica per tal de formar part del disseny d’una microxarxa de generació d’energia elèctrica. Durant la realització del projecte s’ha realitzat una breu introducció a les microxarxes de distribució d’energia elèctrica i als seus reptes. Per estudiar el cost de generació d’energia fotovoltaica s’ha utilitzat la metodologia del Levelized Cost of Energy ...

  10. El control difuso de temperatura de una incubadora

    OpenAIRE

    Avilés Cortez, Juan Carlos

    2009-01-01

    El objetivo del proyecto es el diseño de un circuito para el monitoreo y control difuso de temperatura de una incubadora, utilizando un microcontrolador, un sensor de temperatura digital y se realiza la administración a través de una PC. Como características principales son la utilización del microcontrolador, el sensor de temperatura digital STH-11 y lo más importante el Control Difuso Mandani de la Temperatura, se utilizó el protocolo de comunicación I2C entre el sensor y el microc...

  11. Condiciones de trabajo y salud de una universidad venezolana

    OpenAIRE

    Rojas-Martini Maritza; Squillante Guido; Espinoza Carlos

    2002-01-01

    Objetivo. Identificar los procesos peligrosos a los que están expuestos los trabajadores de una universidad venezolana como consecuencia de sus actividades laborales. Material y métodos. Se realizó un diagnóstico de las condiciones de exposición laboral de los trabajadores de una universidad venezolana (UN), de sus potenciales procesos peligrosos (PP) y de sus causas, mediante un estudio de corte transversal, efectuado en 1999. Se estudiaron 90 trabajadores de uno u otro sexo, pertenecientes ...

  12. Por una mejora de la convivencia en el centro educativo

    OpenAIRE

    Gómez Modrego, María Blanca

    2014-01-01

    Para una educación de calidad, los maestros/as debemos comprometernos para ofrecer una educación en valores y emocional con el reto de potenciar actitudes y un ambiente favorable hacia la convivencia pacífica, introducir habilidades sociales, fomentando la igualdad, la solidaridad, la participación, responsabilidad, la tolerancia, respeto a la pluralidad comprendiendo y respetando las emociones y sentimientos de los demás entendimiento y aceptación del otro, el aprendizaje coop...

  13. Nuevas familias: análisis de una serie

    OpenAIRE

    Corte, Tatiana; Batiz, Federico; Piccoli Sáez, Bárbara

    2016-01-01

    El presente trabajo se enmarca dentro de un proyecto de investigación denominado “Presentaciones actuales de parentalidad y parejas del mismo sexo” dirigido por la Lic. Iara Vidal. Dicho proyecto tiene como objetivo la investigación sobre la parentalidad en parejas del mismo sexo, desde una perspectiva de género, pospatriarcal y posheteronormativa. Este trabajo surge a partir de la intención de establecer y construir una relación entre nuestra perspectiva y la implementación en los medios ...

  14. Stevia rebaudiana (Bert.) Bertoni. Una revisión

    OpenAIRE

    Martínez Cruz, Michel

    2015-01-01

    La stevia (Stevia rebaudiana (Bert.) Bertoni) es una especie del género Stevia de la familia de las Asteráceas nativa de la región tropical de Sudamérica. Es una planta considerada medicinal, pues varios estudios demuestran que puede tener efectos beneficiosos sobre la diabetes tipo II, ya que posee glicósidos con propiedades edulcorantes sin calorías. Muchas de las actividades de investigación sobre sus propiedades químicas y biológicas se han hecho en el pasado reciente. El objetivo de este...

  15. Reparto de holguras y costes en una red Pert

    OpenAIRE

    Castro Cantalejo, Javier

    2007-01-01

    En esta tesis se han planteado tres problemas relacionados con redes PERT. El primer problema es el reparto de la holgura existente en una red PERT entre las actividades de la misma (problema SPERT). Este reparto permite la elaboración de calendarios. Se ha definido un método con buenas propiedades y computable en tiempo polinomial en media. El segundo problema es el reparto del beneficio (coste), generado después de una ejecución, entre todas las actividades de la red (problema APERT). Se ha...

  16. El autismo desde una perspectiva neuropsicológica

    OpenAIRE

    Justo Rodríguez, Marta

    2013-01-01

    En la presente revisión bibliográfica se pretende dar una aproximación al autismo. Se revisarán diversos abordajes que atraviesa este trastorno desde sus inicios hasta la actualidad. Se tienen en cuenta los rasgos fundamentales del autismo revisando el conocimiento de la etiología de dicha enfermedad en la que la tríada la conformarían la ausencia de relaciones sociales, las dificultades para la comunicación, el comportamiento rutinario y obsesivo. Desde una perspectiva neuropsicológica se an...

  17. El sentido del chisme en una comunidad de pobres urbanos

    OpenAIRE

    Patricia Fasano; Aurora Ruiu; Juan M. Giménez; Alejandro Ramírez; Ana Aymá; Natalia Savulsky

    2009-01-01

    El artículo interpreta el sentido del chisme como práctica comunicacional en una comunidad barrial pobre urbana de la ciudad de Paraná (Argentina). A través de un estudio etnográfico realizado en el barrio La Pasarela (también denominado Belgrano) en los años 2002 y 2003, los autores muestran cómo la práctica del chisme pone en forma -da forma, performa- algunas características específicas de la socialidad de la pobreza urbana, constituyendo especialmente una manifestación paradigmática del l...

  18. EL PROBLEMA DEL CUMPLEAÑOS, UNA GENERALIZACIÓN

    OpenAIRE

    Aranda, Moisés; Departamento de Matemáticas, Pontificia Universidad Javeriana y Universidad Sergio Arboleda; Molina, Fabio; Departamento de Matemáticas, Pontificia Universidad Javeriana y Universidad Sergio Arboleda; Moreno, Vladimir; Departamento de Matemáticas, Facultad de Ciencias, Pontificia Universidad Javeriana Cra. 7 No 43-82. Bogotá,

    2008-01-01

    El problema del cumpleaños, en el contexto clásico, se resuelve asumiendo una distribución de probabilidades uniforme discreta de los nacimientos. El propósito de este artículo es resolver el mismo problema bajo una distribución de probabilidades discreta arbitraria, y demostrar que bajo la distribución uniforme discreta, la probabilidad de que dos o más personas cumplan años en el mismo día es subestimada. Palabras clave: combinatoria, probabilidad, distribuciones discretas, muestra aleator...

  19. La fuerza normal: ¿una fuerza conservativa?

    OpenAIRE

    Díaz-Solórzano, S.; González-Díaz, L.

    2011-01-01

    La fuerza normal es una fuerza de ligadura que surge del contacto entre un objeto y una superficie. Esta fuerza puede conservar la energía mecánica de un sistema o no. Se muestra que dicha fuerza es conservativa cuando la superficie no evoluciona en el tiempo, así como la tasa a la cual varía la energía mecánica cuando la fuerza normal es no conservativa. Para esta última situación, se propone la función energía pseudo-potencial asociada a la fuerza normal con la finalidad de obtener la ecuac...

  20. Dinámicas relaciones de una familia conformada por una pareja homosexual masculina en Santiago de Cali

    OpenAIRE

    Niño Valencia, Marlon Antonio

    2015-01-01

    Objetivo. Este estudio caracterizo las dinámicas relacionales de una familia homosexual de la ciudad de Cali, a través de la cohesión, la adaptabilidad, la comunicación y permeabilidad. Metodología. Investigación cualitativa basada en un estudio de caso a partir de una entrevista semiestructurada. El análisis de la información se realizó a través del programa Atlas Ti V6.0., utilizando la técnica de análisis temático. Resultados. Familia homosexual con una percepción de apoyo s...