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Texto completo SciELO Chile
Texto completo
Id: lil-640514
Autor: Sacher, Johannes; Saa, Pedro; Cárcamo, Martín; López, Javiera; Gelmi, Claudio A; Pérez-Correa, Ricardo.
Título: Improved calibration of a solid substrate fermentation model
Fonte: Electron. j. biotechnol;14(5):7-7, Sept. 2011. ilus, tab.
Idioma: en.
Resumo: Background: Calibration of dynamic models in biotechnology is challenging. Kinetic models are usually complex and differential equations are highly coupled involving a large number of parameters. In addition, available measurements are scarce and infrequent, and some key variables are often non-measurable. Therefore, effective optimization and statistical analysis methods are crucial to achieve meaningful results. In this research, we apply a metaheuristic scatter search algorithm to calibrate a solid substrate cultivation model. Results: Even though scatter search has shown to be effective for calibrating difficult nonlinear models, we show here that a posteriori analysis can significantly improve the accuracy and reliability of the estimation. Conclusions: Sensibility and correlation analysis helped us detect reliability problems and provided suggestions to improve the design of future experiments.
Descritores: Biotecnologia/métodos
Meios de Cultura
Modelos Biológicos
Dinâmica não Linear
Responsável: CL1.1 - Biblioteca Central

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Texto completo SciELO Chile
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Id: lil-591937
Autor: Carvajal, Marcela; Espinoza, Luis; Caggia, Silvia; Cardile, Venera; Garbarino, Juan A; Peña-Cortés, Hugo; Russo, Alessandra.
Título: New stereoisomeric derivatives of jasmonic acid generated by biotransformation with the fungus Gibberella fujikuroi affect the viability of human cancer cells
Fonte: Electron. j. biotechnol;14(2):7-7, Mar. 2011. ilus, tab.
Idioma: en.
Projeto: MECESUP.
Resumo: Background: Several studies have shown that (-)-Jasmonic acid, (+)-7-iso-Jasmonic acid and its methyl ester, methyl jasmonate, have anti-cancer activity in vitro and in vivo, exhibiting selective cytotoxicity towards cancer cells. The degree of activity of these molecules is strongly related to their stereochemistry. The biotransformation of known compounds, natural or synthesized, related to interesting biological activities, generates new molecules displaying new improved properties compared with the original ones, increasing its value and providing new more effective products. Therefore, based on the above rationales and observations, in this work a biotransformation protocol to modify the chemical structure of the plant hormone jasmonic acid by using the fungus Gibberella fujikuroi was established. Results: The three jasmonic acid derivatives obtained, 3(S)-Hydroxy-2(R)-(2Z-pentenyl)-cyclopentane-1(R)-acetic acid (1), 3(R)-Hydroxy-2(R)-(2Z-pentenyl)-cyclopentane-1(R)-acetic acid (2), 3-Hydroxy-2(S)-(2Z-pentenyl)-cyclopentane-1(S)-acetic acid (3), were tested for cell-growth inhibition activity towards the human cancer epithelial cell line, the oral squamous carcinoma cells (KB). The results obtained show that jasmonic acid derivatives (1-3) are active on human cancer cells examined in different concentration ranges, with IC50 value less than of 25 uM. The compound 3, with the same molecular structure of compounds 1 and 2, but with different stereochemistry, was more active confirming that the activity of jasmonate compounds is related to their stereochemistry and to substituents in the cyclopentane ring. In this study, we also tested the potential proapoptotic activity of compound 3, and our data suggest that it, as other jasmonate compounds, is able to trigger apoptotic death in cancer cells. This event may be correlated at an elevation of reactive oxygen species (ROS). Administration of N-acetylcysteine (NAC) prevented compound 3 cytotoxicity...
Descritores: Apoptose
Sobrevivência Celular
Ensaio Cometa
Espécies Reativas de Oxigênio
L-Lactato Desidrogenase
Limites: Seres Humanos
Responsável: CL1.1 - Biblioteca Central

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Texto completo SciELO Brasil
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Id: lil-480692
Autor: Pinto, V. E. Fernandez; Terminiello, L. A; Basilico, J. C; Ritieni, A.
Título: Natural occurrence of nivalenol and mycotoxigenic potential of Fusarium graminearum strains in wheat affected by head blight in Argentina
Fonte: Braz. j. microbiol;39(1):157-162, Jan.-Mar. 2008. tab.
Idioma: en.
Resumo: The principal agents of Fusarium head blight in the main cropping area of Argentina were investigated in heavily infected samples. The ability of the isolates to produce trichothecenes was determined by GC and HPLC. Fusarium graminearum was the predominant species and of 33 isolates, 10 produced deoxinivalenol (DON) (0.1- 29 mg kg-1), 13 produced both deoxinivalenol (1.0- 708 mg kg-1) and nivalenol (0.1- 6.2mg kg-1), 12 produced 3-acetyldeoxinivalenol (0.1- 14 mg kg-1), 13 produced 15-acetyldeoxinivalenol (0.1- 1.9 mg kg-1), 10 produced Fusarenone X (0.1- 2.4 mg kg-1) and 7 produced zearalenone (0.1- 0.6 mg kg-1). These results suggest that F. graminearum strains isolated from the wheat growing regions in Argentina belong to DON chemotype. Although some strains produced both deoxinivalenol and nivalenol, nivalenol was produced in lower levels. The natural occurrence of nivalenol in wheat affected by head-blight collected in the main production area during two years (2001-2002) was also determined. From 19 samples 13 were contaminated with deoxinivalenol in a range of 0.3 to 70 mg kg-1and 2 samples with both deoxinivalenol (7.5 and 6.7 mg kg-1) and nivalenol (0.05 and 0.1 mg kg-1), respectively. This is the first report of natural occurrence of nivalenol in wheat cultivate in Argentina.

O principal causador de giberela no trigo na Argentina e sua capacidade de produzir tricotecenos foram estudados por GC e HPLC em amostras altamente infectadas. A espécie predominante foi Fusarium graminearum, sendo que de um total de 33 isolados, 10 produziram deoxinivalenol (0,1-29 mg kg -1), 13 produziram deoxinivalenol (1,0-708 mg kg-1) e nivalenol (0,1-6,2 mg kg-1), 12 produziram 3-acetildeoxinivalenol (0,1-14 mg kg-1), 13 produziram 15-acetildeoxinivalenol (0,1-1,9 mg kg-1), 10 produziram fusarenona X (0,1- 2,4 mg kg-1) e 7 produziram zearalenona (0,1- 0,6 mg kg-1). Esses resultados sugerem que as cepas de F. graminearum isoladas de trigo cultivado na Argentina pertencem ao quimiotipo DON. Embora algumas cepas tenham produzido tanto DON quanto NIV, NIV foi produzido em quantidade inferior ao DON. A ocorrência natural de nivalenol em trigo afetado pela giberela coletado na principal área de produção durante dois anos (2001-2002) foi também determinada. De 19 amostras, 13 estavam contaminadas com deoxinivalenol na faixa de 0,3 a 70 mg kg-1 e 2amostras continham tanto deoxinivalenol (7,5 e 6,7 mg kg-1) quanto nivalenol (0,05 e 0,1 mg kg-1), respectivamente. Esse é o primeiro relato da ocorrência de nivalenol em trigo cultivado na Argentina.
Descritores: Fusarium/isolamento & purificação
Gibberella/isolamento & purificação
Técnicas In Vitro
-Cromatografia Líquida de Alta Pressão
Amostras de Alimentos
Tipo de Publ: Estudo Comparativo
Relatório Técnico
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica

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