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| Registros recuperados: 7.826 | |
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| Cong,Lina; Liang,Wenjing; Wu,Yao; Li,Cheng; Chang,Yihai; Dong,Liang; Song,Wanlin; Ma,Jun. |
| Background The sea cucumber lysozyme belongs to the family of invertebrate lysozymes and is thought to be a key defense factor in protecting aquaculture animals against bacterial infection. Recently, evidence was found that the sea cucumber lysozyme exerts broad spectrum antimicrobial action in vitro against Gram-negative and Gram-positive bacteria, and it also has more potent antimicrobial activity independent of its enzymatic activity. To explore the antimicrobial role of this non-enzymatic lysozyme and model its structure to novel antimicrobial peptides, the peptide from the C-terminal amino acid residues 70-146 of the sea cucumber lysozyme in Stichopus japonicus (SjLys-C) was heterologously expressed in Escherichia coli Rosetta(DE3)pLysS. Results The... |
| Tipo: Journal article |
Palavras-chave: Affinity purification; Lysozyme peptide; Molecular modeling; Recombinant protein. |
| Ano: 2014 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582014000600005 |
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| Zaccaro,María Cristina; Kato,Adriana; Zulpa,Gloria; Storni,Mónica Magdalena; Steyerthal,Noemí; Lobasso,Karina; Stella,Ana María. |
| Cyanobacteria produces bioactive compounds including plant growth regulators. Naphthalene acetic acid (NAA), a toxic substance, is a synthetic plant regulator used in micropropagation. The aim of this work was to evaluate morphogenetic and antioxidant effects produced by intra and extracellular substances from Scytonema hofmanni (Cyanobacteria) during the multiplication in vitro of Lilium alexandrae and to compare them to those produced by NAA. Intra and extracellular cyanobacterial products increased a) bulblets production reaching 83% and 78% of NAA effect, respectively; b) the bulblet diameter compared to NAA; and c) the bulblet survival due to the promotion of antioxidant activity measured as catalase, ascorbate peroxidase, and glutathione reductase... |
| Tipo: Journal article |
Palavras-chave: Ascorbate peroxidase; Bioactive substances; Bulb regeneration; Catalase; Cyanobacteria; Glutathione reductase; Lilium alexandrae; Scytonema hofmanni. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000300007 |
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| Cavanagh,Heather; Hood,Jennie; Wilkinson,Jenny. |
| A survey investigating the knowledge and perception of biotechnology by high school students living in the rural Riverina region of New South Wales, Australia, was undertaken. Data relating to the student preferred and trusted information sources was also gathered. This study has demonstrated that at least two-thirds of students had a good knowledge of medical biotechnology issues, however, a significant proportion of the students did have concerns about the use and/or safety of biotechnology. Nearly 90% of the respondents would like further information on biotechnology. In agreement with other surveys, the students reported an apparent lack of trust in articles from the lay press (newspapers, television, radio) and yet still report that these media as... |
| Tipo: Journal article |
Palavras-chave: Biotechnology; Education; Science; Secondary school. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000200001 |
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| Rajoka,Muhammad Ibrahim; Khan,Sana. |
| Production of β-xylosidaseby a cycloheximide and 2-deoxy-D-glucose-resistant mutant of Kluyveromyces marxianus PPY125 was studied when cultured on growth media containing galactose, glucose, xylose, cellobiose, sucrose and lactose as carbon sources. Xylose, cellobiose, lactose and sucrose were the key substrates. Both K. marxianus PPY125 and its mutant (M 125) supported maximum β-xylosidase specific product yield (Y P/X) following growth on xylose. Basal level of activity was observed in non-induced cultures grown on glucose. The mutant produced 1.5 to 2-fold more β-xylosidase than that produced by the wild cells. Synthesis of β-xylosidase was regulated by an induction mechanism in both wild and mutant cells. Addition of... |
| Tipo: Journal article |
Palavras-chave: Enthalpy; Entropy; Enzyme kinetics; Fermentation; Induction; Thermodynamics. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000200007 |
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| Santana,Paula; Palacios,Claudia; Narváez,Edgar; Guzmán,Fanny; Gallardo,José A; Mercado,Luis. |
| Background: Interleukin 8 is a chemokine that is produced by several types of cells, like macrophages and has chemotactic activity in particular on neutrophils, playing a key role during the inflammatory process. It has been demonstrated at the molecular level that this molecule is present and conserved in several vertebrate groups, pointing its importance. Analysis of the amino acid sequence of IL-8, projected from cDNA of Salmo salar, presents homology with the sequences of mammals, poultry and lamprey, indicating the presence of a homologous molecule in higher fish. However, there is no information at protein level, which allows characterizing the regulatory role of this molecule during the immune response in fish. Results: In this work, we designed and... |
| Tipo: Journal article |
Palavras-chave: Anti-IL-8; Fish antibodies; Fish chemokine; Rainbow trout; Synthetic peptide epitope. |
| Ano: 2012 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582012000500020 |
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| Telles Benatti,Cláudia; Granhen Tavares,Célia Regina; Dias Filho,Benedito Prado; Ribeiro Moitinho,Maria da Luz. |
| This study was designed to evaluate the performance of a slow rate anaerobic digester in treating secondary sewage sludge received from one local municipal wastewater treatment plant. The digester was fed by secondary sewage sludge without any previous thickening. A series of three independent batch experiments was investigated at an operation time of 60 days. The total solids (TS) in the influent sludge contained a percentage of organic matter of 59, 63 and 54%, a concentration of volatile suspended solids (VSS) of 23.7, 29.2 and 27.8 g L-1 and a chemical oxygen demand (COD) of 51.8, 32.9 and 65.7 g L-1 for the three experiments, respectively. The operation of anaerobic digestion was stable, with no noticeable scum or foaming problems. The COD reduction... |
| Tipo: Journal article |
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| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582002000300005 |
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| Betancur,Gabriel J. Vargas; Pereira Jr,Nei. |
| Sugar cane bagasse is produced in Brazil as waste of the sugar and ethanol industries. This lignocellulosic material is a potential source for second-generation ethanol production; however a pretreatment stage is essential, which aims at removing the hemicellulose component by disorganizing the lignocellulosic complex. In this work sugar cane bagasse was pretreated by diluted acid hydrolysis resulting in xylose-rich hydrolysates, which could be fermented to ethanol by a strain of the yeast Pichia stipitis. Statistical approach was used to investigate the effects of factors associated with the diluted acid hydrolysis process (acid concentration, solid:liquid ratio and time of exposure) on the fermentability of different hydrolysates. The statistical... |
| Tipo: Journal article |
Palavras-chave: Bioethanol; Pichia stipitis; Xylose fermentation. |
| Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582010000500014 |
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| Biocatalysts are inherently labile; therefore their operational stability is of paramount importance for any bioprocess. The problem of biocatalyst stability has been tackled from different perspectives, which are reviewed in the present paper. Inherently stable biocatalysts are well appreciated and a systematic effort is being done in the search of new organisms that harbor them. The potential of extremophiles has recently been recognized. Moreover, cloning such termophilic genes into more suitable mesophilic hosts is now at hand to produce stable biocatalysts. Another approach is to use site-directed mutagenesis to code for more stable proteins. A relevant number of actual industrial biocatalysts are being produced using such genetic and protein... |
| Tipo: Journal article |
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| Ano: 1999 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34581999000100001 |
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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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| Zaldívar,Mercedes; Velásquez,Juan Carlos; Contreras,Inés; Pérez,Luz María. |
| A mutant of the native fungus Trichoderma aureoviride, 7-121, selected for its overproduction of extracellular cellulase and ß-glucosidase (cellobiase) was obtained. In shake flask cultures, production of endoglucanase, filter paper activity and cellobiase increased two to four- fold as compared with the wild type strain. The mutant strain is stable and grows rapidly in liquid as well as in solid culture media. Enzyme yields were best when pH was controlled so that it did not fall bellow pH 3.5. Cellobiase production by this mutant is particularly high (approximately 5 U/ml) as compared to other Trichoderma, strains, which makes it a suitable candidate for waste cellulose degradation. In addition, the mutant strain showed enhanced production of fungal cell... |
| Tipo: Journal article |
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| Ano: 2001 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582001000300011 |
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| Zhong-Tao,Sun; Lin-Mao,Tian; Cheng,Liu; Jin-Hua,Du. |
| Apple pomace is a wasted resource produced in large quantities and its deposit has caused serious environmental problems, so it is significance to make the full utilization of the residues. The objectives of this work were to produce multienzyme bio-feed, biodegrade the anti-nutritional factors such as pectin and tannins in apple pomace, and obtain the nutritional enrichment of the fermented substrate. The mixture of apple pomace and cottonseed powder (1:1, w/w), supplemented with 1% (w/w) (NH4)2SO4 and 0.1% (w/w) KH2PO4, was proved to be the optimum medium for the mixed strains of Aspergillus niger M2 and M3 (2:1, w/w). The activities of pectinase, proteinase and cellulase achieved 21168 u/g, 3585 u/g and 1208u/g, and the biodegradation rates of pectin... |
| Tipo: Journal article |
Palavras-chave: Apple pomace; Aspergillus niger; Multienzyme bio-feed; Pectin; Solid state fermentation; Tannins. |
| Ano: 2009 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582009000100002 |
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| Biagioli,Carolina; Rios,Raúl; Basso,Alicia; Franzone,Pascual; Prina,Alberto. |
| Although it is generally accepted that plant in vitro culture response is influenced by the donor genotype, the genetic and molecular bases of this phenomenon are barely known. As a consequence, the optimization of tissue culture protocols is mainly empirically done. Researchers of the IGEAF studied the genetic basis of the in vitro regeneration of various plant species, including the tissue culture response of artificially induced barley mutants. One barley mutant, MC 169, carries a nuclear gene, recently described controlling the root growth in hydroponic cultivation. Under this condition, the roots of MC 169 mutant plants were longer than those of the original wild type line MC 182, a fact that was associated with a reduced ethylene biosynthesis. On the... |
| Tipo: Journal article |
Palavras-chave: Callus induction; Ethylene; Habituated calli; Hydroponic culture; Regeneration. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000300019 |
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| Registros recuperados: 7.826 | |
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