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| Registros recuperados: 13.863 | |
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| Abdullah,Ruslan; Zainal,Alizah; Yew Heng,Wee; Chui Li,Leaw; Chee Beng,Yeap; Mei Phing,Lee; Abdullah Sirajuddin,Salwa; Soo Ping,Winnie Yap; Lourdes Joseph,Juanita; Azma Jusoh,Siti. |
| Oil palm (Elaeis guineensis Jacq.) is the highest yielding oil-bearing crop. However, being a perennial crop, genetic improvement of oil palm is extremely slow. Indeed, compared to other annual oil crops such as soybean and rapeseed, genetic manipulations remained less important. Therefore, to remain competitive, oil palm growers and breeders need new and novel approaches. In this report, the potential of immature embryos (IE) as a useful tool for oil palm genetic transformation studies was evaluated. It was evident that IEs were amenable to both direct and Agrobacterium-mediated gene transfer. Due to the abundant supply of IE, optimization of biolistic and Agrobacterium-mediated gene transfer into IEs were easily carried out. Transient transformation... |
| Tipo: Journal article |
Palavras-chave: Genetic transformation studies; Immature embryos; In vitro culture; Oil palm; Plant regeneration. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100006 |
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| Yongzhong,Lu; Zhang,Xuecheng. |
| In cyanobacteria, few details are known of the mechanisms through which the expression of the light-harvesting pigment c-phycocyanin is regulated. In the present study, a 419 bp upstream sequence of the phycocyanin b subunit (cpcB) gene from Arthrospira platensis FACHB341 was fused with green fluorescent protein (gfp) gene, and a heterologous reporting system was built up to investigate the influence of light intensity on the expression of gfp gene, and the regulation function of different region of the upstream sequence of cpcB gene. Results showed that the upstream sequence of cpcB gene could drive the expression of gfp gene in Synechococcus sp. strain PCC7942, and the expression was influenced by light intensity, the lower the light intensity, the... |
| Tipo: Journal article |
Palavras-chave: CpcB gene; Deletion analysis; Light intensity; Synechococcus; Transformation. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100010 |
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| Tu,Zhiming; He,Guangyuan; Li,Kexiu X.; Chen,Mingjie J.; Chang,Junli; Chen,Ling; Yao,Qing; Liu,Dongping P.; Ye,Huan; Shi,Jiantao; Wu,Xuqian . |
| This paper describes an efficient bacterial transformation system that was established for the preparation of competent cells, plasmid preparation, and for the storage in bacterial stocks in our laboratory. Using this method, a number of different plasmids have been amplified for further experiments. Competent cells for bacterial transformation were prepared by the calcium chloride method with an optimum concentration of 75 mM. Three different strains of Escherichia coli that were tested are DH5α, TG1 and XL1 blue, and the most efficient strain being XL1 blue. The optimal optical density (OD600) range for competent cell preparation varied for each of the strains investigated, and for XL1 blue it was 0.15-0.45; for TG1 it was 0.2-0.5; and for... |
| Tipo: Journal article |
Palavras-chave: Competent cells; E. coli; Plasmid; Storage; Transformation. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100014 |
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| Peñaloza,Patricia; Ramirez-Rosales,Gerardo; McDonald,Miller B; Bennett,Mark A.. |
| High seed quality is essential for optimum stand establishment in lettuce. As a result, it is necessary to have seed vigour tests that permit rapid, objective and accurate evaluation of seed quality. This study evaluated physical and physiological seed quality components of four seed lots of six lettuce varieties obtained from a commercial company. Seeds were evaluated for seedling emergence under greenhouse conditions, standard germination, seed physical aspects, the Saturated Salt Accelerated Aging (SSAA) test and the Seed Vigour Imaging System (SVIS). Results indicated that large-seeded lettuce varieties had higher percentage germination, higher SSAA values, higher SVIS index and more rapid and uniform greenhouse emergence. Black-seeded lettuce... |
| Tipo: Journal article |
Palavras-chave: Vegetables; Deterioration; Seedling; Performance. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000300010 |
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| Alarcón,Evelyn; Decap,Jacqueline; Vidal,Gladys. |
| Kraft mills are responsible for the massive discharge of highly polluted effluents, and new bleaching processes (i.e. Total Chlorine Free (TCF)) is presented as a feasible option to reduce this environmental impact. However, increased TCF pulp production is accompanied by an increase in chelate use. The most commonly used chelates, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DPTA), are considered to be relatively persistent substances in water treatment plants, and consequently environmentally critical compounds. The purpose of this work is to investigate DPTA behaviour in an anaerobic system. An Anaerobic Filter (AF) was operated with three different DPTA load rates (LR DPTA = 0.07 - 0.28 gDPTA/L×d), and the... |
| Tipo: Journal article |
Palavras-chave: Anaerobic biodegradation; DTPA; Kraft mill effluent. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000300011 |
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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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| Mat Radzi,Salina; Basri,Mahiran; Bakar Salleh,Abu; Ariff,Arbakariya; Mohammad,Rosfarizan; Abdul Rahman,Mohd. Basyaruddin; Abdul Rahman,Raja Noor Zaliha Raja. |
| High performance enzymatic synthesis of oleyl oleate, a liquid wax ester was carried out by lipase-catalysed esterification of oleic acid and oleyl alcohol. Various reaction parameters were optimised to obtain high yield of oleyl oleate. The optimum condition to produce oleyl oleate was reaction time; 5 min, organic solvents of log P ≥ 3.5, temperature; 40-50ºC, amount of enzyme; 0.2-0.4 g and molar ratio of oleyl alcohol to oleic acid; 2:1. The operational stability of enzyme was maintained at >90% yield up to 9 cycles. Analysis of the yield of the product showed that at optimum conditions, >95% liquid wax esters were produced |
| Tipo: Journal article |
Palavras-chave: Oleyl oleate; Immobilised lipase; Esterification; Liquid wax ester. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000300009 |
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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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| B,Jayashree; Ferguson,Morag; Ilut,Dan; Doyle,Jeff; Crouch,Jonathan H. |
| Peanut is an important legume crop across the world. However, in contrast to most legume crops, groundnut lacks taxonomic proximity to any major model genome. A relatively large number of genomic sequences were generated from groundnut as part of a microsatellite marker development project. In the current study, a total of 1312 sequences were analyzed of which 448 contained microsatellite motifs. All sequences (GenBank Accessions: BZ999351-CC000573) were analyzed after clustering for possible similarity with publicly available sequences from Arabidopsis, Lotus, soybean and Medicago. At least 39% of the sequences analyzed had significant BLAST similarities with sequences from the four databases searched, of which nearly half (47%) found significant... |
| Tipo: Journal article |
Palavras-chave: Arachis hypogaea; Codon usage; Gene-based markers; Peanut; SSR markers. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000300002 |
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| Firdaus-Raih,Mohd; Senafi,Sahidan; Munir Murad,Abdul; Marzuki Sidik,Nik; Kiew Lian,Wan; Daud,Fauzi; Zainal Ariffin,Shahrul Hisham; Zamrod,Zulkeflie; Chon Seng,Tan; Sofiman Othman,Ahmad; Azni Harmin,Sharr; Radzuan Saad,Mohd Yusof; Mohamed,Rahmah. |
| Biotechnology education in developing nations remains one of the rate limiting factors in achieving optimal human resource capacity to drive and tap the bio-resources of these nations. Many developing countries are situated within rich bio-diversity enclaves. Biotechnology offers the promise of tapping these bio resources towards due process of developing these nations. While there may be a steady stream of biology and biotechnology based graduates, from Malaysian as well as foreign universities contributing to the human resource base for these countries, the numbers and knowledge diversity produced, still lack the capacity to optimally power research and development as well as supply the industrial biotechnology sectors of these countries. Realizing the... |
| Tipo: Journal article |
Palavras-chave: Biotechnology awareness; Biotechnology education; Capacity building. |
| Ano: 2005 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582005000100004 |
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| Registros recuperados: 13.863 | |
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