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| Registros recuperados: 96 | |
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| Acevedo,Francisca; Pizzul,Leticia; Castillo,María del Pilar; Rubilar,Olga; Lienqueo,María Elena; Tortella,Gonzalo; Diez,María Cristina. |
| In this study, different growth conditions of Anthracophyllum discolor Sp4 including the effect of agitation, additions of lignocellulosic support, inducer and surfactant were evaluated on the MnP production in Kirk medium using a culture system made up of the tubes containing the glass bead . The highest MnP production (1,354 U/L on day 13) was obtained when the medium was supplemented with wheat grain and 0.25 mM MnSO4 as inducer, under static conditions at 30°C. Two isoenzymes were purified (35 and 38 kDa respectively). MnP presented a maximal activity in the pH range between 4.5 and 5.5, a relatively high temperature tolerance (50ºC) and a high catalytic activity for 2,6-dimethoxyphenol and hydrogen peroxide. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: White-rot fungi; Ligninolytic enzymes; Purification; Lignocellulosic material. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000600013 |
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| Chen,Sique; Zheng,Xiujuan; Cao,Hongrui; Jiang,Linghui; Liu,Fangqian; Sun,Xinli. |
| Background Thermostable DNA polymerase (Taq Pol ?) from Thermus aquaticus has been widely used in PCR, which was usually extracted with Pluthero's method. The method used ammonium sulfate to precipitate the enzyme, and it saved effort and money but not time. Moreover, we found that 30-40% activity of Taq Pol I was lost at the ammonium sulfate precipitation step, and the product contained a small amount of DNA. Results We provided a novel, simplified and low-cost method to purify the Taq Pol ? after overproduction of the enzyme in Escherichia coli, which used ethanol instead of ammonium sulfate to precipitate the enzyme. The precipitate can be directly dissolved in the storage buffer without dialysis. In addition, DNA and RNA contamination was removed with... |
| Tipo: Journal article |
Palavras-chave: Ethanol precipitation; PCR; Purification; Taq DNA polymerase. |
| Ano: 2015 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582015000500005 |
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| Borghetti,Fabian; Lima,Elisa Coutinho de; Silva,Lucas de Carvalho Ramos. |
| Most studies conducted to test the allelopathic activity of plant parts have made use of water as solvent. However, the presence of polar, water-soluble substances, such as proteins and carbohydrates, tends to hamper the purification of active compounds. In this study, we present a simple purification procedure that separates the active fraction of the extract from the undesirable substances, thus facilitating the search for active molecules through standard chromatographic methods. Aqueous leaf extracts of three Cerrado species (Caryocar brasiliense, Qualea parviflora and Eugenia dysenterica) were prepared at 5% concentration (w/v) and stored at 4ºC (crude extracts). After 24 h, these solutions were filtered and freeze-dried. The powder obtained was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allelopathy; Cerrado; Freeze-drying; Leaf extract; Purification. |
| Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-33062013000100007 |
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| Yehia,Ramy Sayed. |
| Manganese peroxidase (MnP) was produced from white rot edible mushroom Pleurotus ostreatus on the culture filtrate. The enzyme was purified to homogeneity using (NH4)2SO4 precipitation, DEAE-Sepharose and Sephadex G-100 column chromatography. The final enzyme activity achieved 81UmL-1, specific activity 78 U mg-1 with purification fold of 130 and recovery 1.2% of the crude enzyme. SDS-PAGE indicated that the pure enzyme have a molecular mass of approximately 42 kDa. The optimum pH was between 4-5 and the optimum temperature was 25 ºC. The pure MnP activity was enhanced by Mn2+,Cu2+,Ca2+ and K+ and inhibited by Hg+2 and Cd+2.H2O2 at 5 mM enhanced MnP activity while at 10 mM inhibited it significantly. The MnP-cDNA encoding gene was sequenced and determined... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Manganese peroxidase; Aflatoxin B1; Pleurotus ostreatus; Purification. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000100018 |
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| Thomas,Roshmi; Janardhanan,Anju; Varghese,Rintu T.; Soniya,E.V.; Mathew,Jyothis; Radhakrishnan,E.K.. |
| Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biosynthesis; Silver nanoparticles; Ochrobactrum anhtropi; Purification; Antibacterial activity. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400012 |
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| Silva,Anna Carolina da; Queiroz,Alana Emilia Soares de França; Oliveira,João Tiago Correia; Medeiros,Erika Valente; Souza-Motta,Cristina Maria de; Moreira,Keila Aparecida. |
| Abstract Protein hydrolysates originating from egg white have already been reported to be bioactive and, among their biological activities, possess the antioxidant property that protects the body from early ageing and diseases linked to oxidation. Therefore, the objective of this work was to evaluate the antioxidant activity of hydrolysates obtained by the hydrolysis of egg white from hen poultry. The protease produced by Aspergillus avenaceus URM 6706 was purified and subsequently applied to hydrolysate the egg white, and the degree of hydrolysis was verified during the protease exposure time (4-24 h). The hydrolysis was intensified over time of exposure to the protease. It was possible to detect the antioxidant activities of eliminating the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aspergillus; Purification; ABTS; +; DPPH; Chelators. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132019000100508 |
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| Fouche, Dominique. |
| De nombreuses bactéries, peuplant habituellement les zones estuariennes, se révèlent être de plus en plus fréquemment des agents de maladies dont les vecteurs principaux sont les coquillages et leur consommation par l'homme. Le présent travail synthétise l'état des connaissances sur les vibrios, en particulier Vibrio cholerae, Vibrio parahaemolyticus et Vibrio vulnificus, bactéries pour lesquelles il existe une abondante littérature. L'écologie, le pouvoir pathogène et les milieux de culture les plus couramment utilisés en vue de leur détection sont présentés. Enfin, leur interaction avec les mollusques bivalves, leur survie dans ceux-ci et le problème de l'épuration conséquente de ces derniers sont abordés. |
| Tipo: Text |
Palavras-chave: Vibrio cholerae; Vibrio parahaemolyticus; Vibrio vulnificus; Bactéries indigènes; Estuaires; Bivalves; Purification. |
| Ano: 1993 |
URL: http://archimer.ifremer.fr/doc/00408/51929/52554.pdf |
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| Parada,José Luis; Caron,Carolina Ricoy; Medeiros,Adriane Bianchi P.; Soccol,Carlos Ricardo. |
| Biopreservation systems in foods are of increasing interest for industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoiling microorganisms in foods and feed. The spreading of bacterial antibiotic resistance and the demand for products with fewer chemicals create the necessity of exploring new alternatives, in order to reduce the abusive use of therapeutic antibiotics. In this context, bacteriocins are indicated to prevent the growth of undesirable bacteria in a food-grade and more natural way, which is convenient for health and accepted by the community. According to their properties, structure, molecular weight... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Lactic acid bacteria; Bacteriocins; Purification; Food preservation. |
| Ano: 2007 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000300018 |
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| Slivinski,Christiane Trevisan; Machado,Alex Vinicius Lopes; Iulek,Jorge; Ayub,Ricardo Antônio; Almeida,Mareci Mendes de. |
| In this work, glucoamylase was produced by Aspergillus niger in solid-state fermentation. The enzyme was partially purified by ammonium sulphate precipitation and ion exchange and gel filtration chromatographies. Its molecular mass was estimated as 118.17 kDa by electrophoresis. The partially purified enzyme had an optimum pH range of 4.5-5.0 and an optimum temperature of 60 °C, with average activity 152.85 U mL-1. Thermal and pH stability assays with the crude extract showed that more than 60 % of the activity remained at pH 4.6 and 60 °C, even after an exposition to these conditions longer than 24 h. Yet, after purification, the enzyme was stable at these for at least 4 h, which indicated that its purification for use in starch saccharification was... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Glucoamylase; Aspergillus niger; Solid-state fermentation; Biochemical characterization; Purification. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000300018 |
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| Dobrev,Georgi Todorov; Zhekova,Boriana Yordanova. |
| An extracellular endoglucanase was isolated from the culture liquid of xylanase producing strain Aspergillus niger B03. The enzyme was purified to a homogenous form, using consecutive ultrafiltration, anion exchange chromatography, and gel filtration. Endoglucanase was a monomer protein with a molecular weight of 26,900 Da determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 28,800 Da determined by gel filtration. The optimal pH and temperature values for the enzyme action were 3.5 and 65ºC respectively. Endoglucanase was stable at 40ºC, pH 3.0 for 210 min. The substrate specificity of the enzyme was determined with carboxymethyl cellulose, filter paper, and different glycosides. Endoglucanase displayed maximum activity in the case... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Endoglucanase; Purification; Characterization; Aspergillus niger; Endoxylanase. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822012000100008 |
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| Sharma,Nivedita; Gupta,Anupama; Gautam,Neha. |
| In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Bacteriocin; Purification; SDS -PAGE; Marcha; Preservation. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300033 |
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| Dahiya,Neetu; Tewari,Rupinder; Tiwari,Ram P; Singh Hoondal,Gurinder. |
| Enterobacter sp. NRG4 was shown to excrete chitinase into the culture supernatant when cultivated in medium containing chitin. A 60 kDa extracellular chitinase was purified to homogeneity and characterized. The enzyme hydrolyzed swollen chitin, colloidal chitin, regenerated chitin and glycol chitin but did not hydrolyze chitosan. The chitinase exhibited Km and Vmax values of 1.43 mg ml-1 and 83.33 µM µg-1 h-1 for swollen chitin, 1.41 mg ml-1 and 74.07 µM µg-1 h-1 for colloidal chitin, 1.8 mg ml-1 and 40 µM µg-1 h-1 for regenerated chitin and 2.0 mg ml-1 and 33.33 µM µg-1 h-1 for glycol chitin, respectively. The optimal temperature and pH for activity were 45ºC and pH 5.5, respectively. Mg2+, K+ and Ca2+ stimulated chitinase activity by 13, 16 and 18%,... |
| Tipo: Journal article |
Palavras-chave: Chemical modification; Chitinase; Enterobacter sp. NRG4; Purification; Substrate binding. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000200003 |
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| Kitajima,Elliot Watanabe; Kubo,Karen Sumire; Ferreira,Paulo de Tarso Oliveira; Alcântara,Berenice Kussumoto de; Boari,Alessandra Jesus; Gomes,Renata Takassugi; Freitas-Astua,Juliana; Rezende,Jorge Alberto Marques; Morais,Gilberto José de; Salaroli,Renato Barbosa. |
| Chlorotic spots have been observed in plants of Clerodendrum x speciosum growing in residential gardens and parks in Piracicaba, SP, Brazil. Thin sections of diseased tissues revealed characteristic cytopathic effects of the nuclear type of the Brevipalpus (Acari: Tenuipalpidae) mite-transmitted viruses (BTrV). Brevipalpus mites, identified as B. phoenicis, infesting symptomatic C. x speciosum plants transmitted the pathogen to healthy C. x speciosum and to C. thomsonae, Gomphrena globosa, Hibiscus cannabinus, H. coccineus, H. schizopetalus, Salvia leucantha, Spathiphyllum wallasi and Tetragonia expansa causing chlorotic spots on their leaves. Mechanical inoculation using leaf extracts from infected C. x speciosum resulted in chlorotic spots on inoculated... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brevipalpus phoenicis; Clerodendrum x speciosum; Host range; Transmission; Purification. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162008000100006 |
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| Feng,Bao Zhen; Li,Peiqian. |
| Laccases are blue copper oxidases (E.C. 1.10.3.2) that catalyze the one-electron oxidation of phenolics, aromatic amines, and other electron-rich substrates with the concomitant reduction of O2 to H2O. A novel laccase gene pclac2 and its corresponding full-length cDNA were cloned and characterized from Phytophthora capsici for the first time. The 1683 bp full-length cDNA of pclac2 encoded a mature laccase protein containing 560 amino acids preceded by a signal peptide of 23 amino acids. The deduced protein sequence of PCLAC2 showed high similarity with other known fungal laccases and contained four copper-binding conserved domains of typical laccase protein. In order to achieve a high level secretion and full activity expression of PCLAC2, expression... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Phytophthora capsici; Laccase; Expression; Purification; Activity. |
| Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000100050 |
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| Wanderley,Maria Carolina de Albuquerque; Duarte Neto,José Manoel Wanderley; Lima Filho,José Luiz de; Lima,Carolina de Albuquerque; Teixeira,José António Couto; Porto,Ana Lúcia Figueiredo. |
| Abstract Specific proteases capable of degrading native triple helical or denatured collagen have been required for many years and have a large spectrum of applications. There are few complete reports that fully uncover production, characterization and purification of fungi collagenases. In this review, authors searched through four scientific on line data bases using the following keywords (collagenolytic OR collagenase) AND (fungi OR fungus OR fungal) AND (production OR synthesis OR synthesize) AND (characterization). Scientific criteria were adopted in this review to classify found articles by score (from 0 to 10). After exclusion criteria, 21 articles were selected. None obtained the maximum of 10 points defined by the methodology, which indicates a... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Collagenase; Fungus; Characterization; Purification; Production. |
| Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822017000100013 |
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| Fawzi,Eman Mohamed. |
| Thirty fungal species grown on Cichorium intybus L. root extract as a sole carbon source, were screened for the production of exo-inulinase activities. The thermophile Thielavia terrestris NRRL 8126 and mesophile Aspergillus foetidus NRRL 337 gave the highest production levels of inulinases I & II at 50 and 24 ºC respectively. Yeast extract and peptone were the best nitrogen sources for highest production of inulinases I & II at five and seven days of incubation respectively. The two inulinases I & II were purified to homogeneity by gel-filtration and ion-exchange chromatography with 66.0 and 42.0 fold of purification respectively. The optimum temperatures of purified inulinases I & II were 75 and 50 ºC respectively.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Inulinases; Production; Purification; Thermophile; Thermostability. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000200028 |
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| García-Nogales,Paula; Serrano,Alicia; Secchi,Sonia; Gutiérrez,Serafín; Arís,Anna. |
| Nucleic-acid based methods for bacterial identification are extremely useful in diagnostic applications due to their specificity and sensitivity. However, they require an optimal purification of the target molecules. As part of the development of a new diagnostic method for the detection of bacterial RNA in cow milk, we have compared four commercially available RNA extraction kits for the isolation of bacterial RNA from spiked UHT milk samples. The kits were compared in terms of extraction efficiency and RNA purity using two bacterial species, the Gram negative Escherichia coli and the Gram positive Staphylococcus aureus. Two kits are based in silica-matrix extraction, and the other two in the guanidinium thiocyanate-phenol-chloroform extraction. In our... |
| Tipo: Journal article |
Palavras-chave: Bacteria; Milk; Purification; RNA. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500019 |
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| Registros recuperados: 96 | |
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