Scielo RSS <![CDATA[Electronic Journal of Biotechnology]]> http://www.scielo.cl/rss.php?pid=0717-345820040002&lang=es vol. 7 num. 2 lang. es <![CDATA[SciELO Logo]]> http://www.scielo.cl/img/en/fbpelogp.gif http://www.scielo.cl <![CDATA[<STRONG>Taking a lead in applied mining biotechnology</STRONG>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200001&lng=es&nrm=iso&tlng=es <![CDATA[Assessment of Grenada’s capacity to implement the Biosafety Protocol]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200002&lng=es&nrm=iso&tlng=es <![CDATA[<b>International experience in human resource development in biotechnology</b>: <b>achievements and lessons learnt</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200003&lng=es&nrm=iso&tlng=es <![CDATA[<B>Biotechnology in Mauritius</B>: <B>current status and constraints</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200004&lng=es&nrm=iso&tlng=es Agriculture today faces the challenge of sustainable productivity and improved food security on a shrinking area of land under cultivation. Until recently, biotechnology has been viewed as an expensive technology affordable only by rich industrial countries. However, it is now increasingly considered as an essential tool for developing countries to tackle the numerous problems of underdevelopment. Unfortunately, to date, Mauritius, like many other countries in Africa, lags far behind in development, use and commercialisation of biotechnology. This paper outlines the current status of biotechnology in Mauritius, some important constraints faced, as well as how policy makers are planning to make Mauritius &ldquo;assume the role of a service provider and know-how disseminator in the field of biotechnology by acting as a regional hub and a regional nursery&rdquo;. <![CDATA[<B>Catalytical properties of N-glycosylated <I>Gluconacetobacter diazotrophicus</I> levansucrase produced in yeast</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200005&lng=es&nrm=iso&tlng=es The influence of N-glycosylation on the kinetic and catalytical properties of a bacterial fructosyltransferase (LsdA) produced in Pichia pastoris was studied. The glycosylated enzyme behaved similarly to non-glycosylated LsdA when substrate specificity, fructo-oligosaccharide (FOS) production, sucrose hydrolysis or levan formation reactions were carried out under different experimental conditions. The kinetic parameters for native or yeast-expressed LsdA determined at 60ºC, condition for the highest hydrolytic activity, followed a conventional Michaelis-Menten kinetics. Synthase activity of this levansucrase increased in water-restricted environments by addition of salt or organic solvent to the reaction mixtures <![CDATA[Immortalized human keratinocytes: A model system to study the efficacy of therapeutic drugs in response to the chemical warfare agent sulfur mustard (HD)]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200006&lng=es&nrm=iso&tlng=es Cytokines have been established as biomarkers to detect exposure of cells to chemical warfare agents such as sulfur mustard (2,2'-dichlorodiethyl sulfide, HD). In this study cultured normal and SV40 immortalized human epidermal keratinocyte (NHEK/IHEK) cells were compared as potential model systems to measure the efficacy of therapeutic drugs against HD. Immortalized human epidermal keratinocytes resemble their primary cell counterparts but have the advantage of being carried through long-term culture. Immortalized cells also provide consistency and durability and are less costly than primary keratinocytes. Immunoassay studies were performed to examine the response of these two cell lines to HD. We found that both normal and immortalized NHEKs secreted the pro-inflammatory mediator interleukin-8 (IL-8) when exposed to HD. However, a major difference was observed between the NHEK cell line 6207 and IHEK cell line 425. IHEK cell line 425 produced higher levels of Interleuken-8 then those of its normal counterpart cell line 6207. This observation is significant since therapeutic drugs such as ibuprofen, which depress cytokine production, may not allow these biomarkers to be detected efficiently in experimental analysis of certain NHEK cell lines. The fact that Il-8 production higher in cell line 425 cell makes this in vitro model a potential screening tool to study the efficacy of drugs that suppress production of cytokine markers. <![CDATA[<b>Art, biotechnology and the culture of peace</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200007&lng=es&nrm=iso&tlng=es Biotechnology, in its voyage from ancient times into the expanding frontier areas of today's world of scientific research, has revealed itself as the gene of diplomacy and international cooperation in the relationships between nations (<a href="#16">DaSilva, 2002</a>). Economic and biotechnological considerations, strong elements in themselves, drive policy implementation that draws upon the support and sustenance of the public's logic and understanding of science obtained through the avenues of art and culture. More and more scientists are teaming up with artists to harness the world of microbes and biotechnology in the pursuit of one's natural well-being, of the conservation of environmental heritage, and of human comradeship and welfare. Art and culture in revealing the human face of biotechnology help engender solidarity amongst different cultures. Furthermore, they nurture individual solidarity and collective commitment in especially young children ---tomorrow's architects in the quest of the culture of a sustainable peace. <![CDATA[<B>L (+) lactic acid fermentation and its product polymerization</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200008&lng=es&nrm=iso&tlng=es Lactic acid has been first introduced to us as early as 1780 as a sour component of milk. Ever since we have found its applications in food, pharmaceutical, cosmetic industries etc. Now there are emerging uses as a potential feedstock for the biodegradable polymer industry. The microorganisms being used for lactic acid fermentation, the raw materials reported, the various novel fermentation processes and its processing methods have been reviewed. The properties and applications of lactic acid, its derivatives and polymer have been discussed. The various routes to polymerization and the companies presently involved in lactic acid production have been covered <![CDATA[<STRONG>Protein engineering of <FONT FACE=Symbol>d</FONT>-endotoxins of <I>Bacillus thuringiensis</I></STRONG>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200009&lng=es&nrm=iso&tlng=es Bacillus thuringiensis (Bt) is a valuable environment-friendly biopesticide, which occupies 90% of the world biopesticide market. Its insecticidal properties are attributed to the presence of <FONT FACE=Symbol>d-</FONT>endotoxins which are synthesized during the sporulation phase of the bacterium. <FONT FACE=Symbol>d-</FONT>endotoxin or crystal toxin is a multi-domain protein molecule comprising of three distinct domains. Domain I is made of seven alpha-helices, domain II comprises three antiparallel beta sheets, which are folded into loops and domain III is made of a beta sandwich of two antiparallel beta strands. Molecular studies on the structure and functional properties of different <FONT FACE=Symbol>d-</FONT>endotoxins revealed that the domain I by virtue of its membrane spanning hydrophobic and amphipathic alpha-helices is capable of forming pores in the cell membranes of the larval midgut. Domain II being hyper variable in nature determines the insecticidal specificity of a toxin and domain III is involved in varied functions like structural stability, ion channel gating, binding to Brush Border Membrane Vesicles and insecticidal specificity. Recent studies on toxin aggregation and interaction revealed that the three domains interact closely to bring about the insecticidal activity of Bt. In this review we describe the protein engineering studies conducted on different <FONT FACE=Symbol>d-</FONT>endotoxins which led to an understanding of their molecular mode of action and construction of novel toxins with enhanced insecticidal activity and specificity. <![CDATA[<b>Strategies to capture biotechnology opportunities in Chile</b>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200010&lng=es&nrm=iso&tlng=es Two complementary strategies are proposed to help develop the biotechnology industry in Chile. The objectives of such propositions are based on identifying business opportunities, which can be transformed into biotechnology projects that complement the competitive advantages of the most active areas of the Chilean economy. As a result, the establishment of these initiatives may create the proper business environment where good information, investors&rsquo; safeguards and economic incentives would be provided to encourage investors to support new biotechnology ventures focused on mining, aquaculture, forestry, as well as wine and fruit production. In addition, a complete description of the Chilean biotechnology industry is provided. Amongst other characteristics, this report shows that the industry lacks financial support from venture capital and foreign investors, has a relatively modest proportion of highly qualified employees that work in Research and Development, presents insufficient patent productivity and is mostly regulated in terms of the use of GMOs. <![CDATA[Comment on 'An evaluation of copper biosorption by a brown seaweed under optimized conditions' by Antunes, W.M., Luna, A.S., Henriques, C.A. and da Costa, A.C.A.]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200011&lng=es&nrm=iso&tlng=es Two complementary strategies are proposed to help develop the biotechnology industry in Chile. The objectives of such propositions are based on identifying business opportunities, which can be transformed into biotechnology projects that complement the competitive advantages of the most active areas of the Chilean economy. As a result, the establishment of these initiatives may create the proper business environment where good information, investors&rsquo; safeguards and economic incentives would be provided to encourage investors to support new biotechnology ventures focused on mining, aquaculture, forestry, as well as wine and fruit production. In addition, a complete description of the Chilean biotechnology industry is provided. Amongst other characteristics, this report shows that the industry lacks financial support from venture capital and foreign investors, has a relatively modest proportion of highly qualified employees that work in Research and Development, presents insufficient patent productivity and is mostly regulated in terms of the use of GMOs. <![CDATA[<B>Bacteriophage prophylaxis against <I>Salmonella enteritidis</I> and <I>Salmonella pullorum</I> using <I>Caenorhabditis elegans</I> as an assay system</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200012&lng=es&nrm=iso&tlng=es Two complementary strategies are proposed to help develop the biotechnology industry in Chile. The objectives of such propositions are based on identifying business opportunities, which can be transformed into biotechnology projects that complement the competitive advantages of the most active areas of the Chilean economy. As a result, the establishment of these initiatives may create the proper business environment where good information, investors&rsquo; safeguards and economic incentives would be provided to encourage investors to support new biotechnology ventures focused on mining, aquaculture, forestry, as well as wine and fruit production. In addition, a complete description of the Chilean biotechnology industry is provided. Amongst other characteristics, this report shows that the industry lacks financial support from venture capital and foreign investors, has a relatively modest proportion of highly qualified employees that work in Research and Development, presents insufficient patent productivity and is mostly regulated in terms of the use of GMOs. <![CDATA[<B>Efficient identification of tetR-expressing cell lines for tetracycline-regulated gene expression</B>]]> http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582004000200013&lng=es&nrm=iso&tlng=es The technology of tetracycline-inducible gene expression has been successfully used in experimental biology to identify the function and downstream signaling pathways of an interested gene. It has been significantly improved to meet the criteria with specificity to exogenous non-toxic inducers, independent regulation from cellular pathways, and dose-dependent inducibility and reversibility. However, to establish tetracycline-inducible gene expression in mammalian cells is still a time-and effort-consuming process. With a tetracycline-inducible gene expression system T-REx, we have developed a practical protocol to use the oncogenic H-ras gene as a dominant reporter gene to increase efficiency in attaining desired cell lines in which ectopic expression of a particular gene in cells can be introduced and reversibly induced by the presence or absence of tetracycline in cultures.