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Chavez-Cabrera C.,CINVESTAV | Flores-Bustamante Z.R.,CINVESTAV | Marsch R.,CINVESTAV | Montes M.D.C.,CINVESTAV | And 3 more authors.
Applied Microbiology and Biotechnology | Year: 2010

ATP-citrate lyase (ACL) is the key cytoplasmic enzyme which supplies acetyl-CoA for fatty acids in oleaginous yeast. Although it has been suggested that fatty acid and carotenoid biosynthesis may have a common source of acetyl-CoA in Phaffia rhodozyma, the source for carotenoids is currently unknown. The purpose of this work was to analyze the development of ACL activity during batch cultures of P. rhodozyma under ammonium-limited and nonammonium-limited conditions and study its possible relationship with carotenoid synthesis. Every experiment showed carotenoid accumulation linked to an increasing ACL activity. Moreover, the ACL activity increased with dissolved oxygen (DO), i.e., ACL responded to DO in a similar way as carotenoid synthesis. Additionally, in the ammonium-limited culture, ACL activity increased upon ammonium depletion. However, the contribution to carotenoid accumulation in that case was negligible. This suggests that P. rhodozyma has developed two components of ACL, each one responsive to a different environmental stimulus, i.e., DO and ammonium depletion. The role of each component is still unknown; however, considering that the former responds to DO and the known role of carotenoids as antioxidants, it may be a provider of acetyl-CoA for carotenoid synthesis. © 2009 Springer-Verlag. Source


Rodriguez-Morales O.,Instituto Nacional Of Cardiologia Ignacio Chavez | Carrillo-Sanchez S.C.,Instituto Nacional Of Cardiologia Ignacio Chavez | Garcia-Mendoza H.,Instituto Nacional Of Cardiologia Ignacio Chavez | Aranda-Fraustro A.,Instituto Nacional Of Cardiologia Ignacio Chavez | And 5 more authors.
BioMed Research International | Year: 2013

The dog is considered the main domestic reservoir for Trypanosoma cruzi infection and a suitable experimental animal model to study the pathological changes during the course of Chagas disease (CD). Vaccine development is one of CD prevention methods to protect people at risk. Two plasmids containing genes encoding a trans-sialidase protein (TcSP) and an amastigote-specific glycoprotein (TcSSP4) were used as DNA vaccines in a canine model. Splenomegaly was not found in either of the recombinant plasmid-immunized groups; however, cardiomegaly was absent in animals immunized only with the plasmid containing the TcSSP4 gene. The inflammation of subendocardial and myocardial tissues was prevented only with the immunization with TcSSP4 gene. In conclusion, the vaccination with these genes has a partial protective effect on the enlargement of splenic and cardiac tissues during the chronic CD and on microscopic hearth damage, since both plasmids prevented splenomegaly but only one avoided cardiomegaly, and the lesions in heart tissue of dog immunized with plasmid containing the TcSSP4 gene covered only subepicardial tissue. © 2013 Olivia Rodríguez-Morales et al. Source


Arias-Penaranda M.T.,CINVESTAV | Cristiani-Urbina E.,Escuela Nacional de Ciencias Biologicas del IPN | Montes-Horcasitas C.,CINVESTAV | Esparza-Garciia F.,CINVESTAV | And 2 more authors.
Bioresource Technology | Year: 2013

The potential of microalgal oil from Scenedesmus incrassatulus as a feedstock for biodiesel production was studied. Cell concentration of S. incrassatulus and lipid content obtained during mixotrophic growth were 1.8g/L and 19.5±1.5% dry cell weight, respectively. The major components of biodiesel obtained from S. incrassatulus oil were methyl palmitate (26%) and methyl linoleate (49%), which provided a strong indication of high quality biodiesel. Fuel properties were determined by empirical equations and found to be within the limits of biodiesel standard ASTM D6751 and EN 14214. The quality properties of the biodiesel were high cetane number (62), low density (803kg/m3), low viscosity (3.78mm2/s), oxidation stability (9h) and cold filter plugging point (-4°C). Hence, S. incrassatulus has potential as a feedstock for the production of excellent quality biodiesel. © 2013 Elsevier Ltd. Source


Vigueras-Cortes J.M.,Centro Interdisciplinario Of Investigacion Para El Desarrollo Integral Regional | Villanueva-Fierro I.,Centro Interdisciplinario Of Investigacion Para El Desarrollo Integral Regional | Garzon-Zuniga M.A.,Mexican Institute of Water Technology | De Jesus Navar-Chaidez J.,Centro Interdisciplinario Of Investigacion Para El Desarrollo Integral Regional | And 2 more authors.
Water Science and Technology | Year: 2013

Agave plants grow in semi-arid regions and are used for mescal production. However, agave fiber by-products are considered waste materials. Thus, we tested agave fiber as a filter media and biofilm material carrier for removing pollutants from municipal wastewater. Three laboratory-scale biofiltration reactors were used in two trials with five hydraulic loading rates (HLRs = 0.27, 0.54, 0.80, 1.07 and 1.34 m3 m-2 d-1). One series was conducted using mechanical aeration (0.62 m3 m -2 h-1). To prevent compaction, decreasing pressure and clogging of the filter media, 4, 8 and 12 internal divisions were evaluated in the biofilter column. After 17 months of continuous operation at an HLR of 0.80 m3 m-2 d-1, the removal efficiencies of the aerated biofilters were 92.0% biochemical oxygen demand, 79.7% chemical oxygen demand, 98.0% helminth eggs, 99.9% fecal coliforms and 91.9% total suspended solids. Statistical analysis showed that the chosen operational parameters significantly influenced the removal efficiencies of the biofilters. The effluent quality obtained under these conditions complied with the Mexican and US EPA standards for agricultural irrigation and green spaces, except for coliforms, which is why the effluents must be disinfected. Thus, agave fiber is a favorable choice for use as a packing material in biofiltration processes. © IWA Publishing 2013. Source


Lopez-Villegas O.,Escuela Nacional de Ciencias Biologicas del IPN | Heredia-Mira F.J.,University of Seville | Melendez-Martinez A.J.,University of Seville | Paredes-Lopez O.,CINVESTAV
In Vitro Cellular and Developmental Biology - Plant | Year: 2011

Marigold (Tagetes erecta) flowers are primarily used in industry for their high pigment content. Flower color development implies that chloroplast-chromoplast transition is associated with carotenoid biosynthesis. We report the recovery of undifferentiated pigmented marigold cells, various callus tissues, and their analysis by transmission electron microscopy in order to observe accumulating pigment and development of subcellular structures. Callus was generated from leaf explants and after several rounds of recurrent selection. Green-, yellow-, and brown-colored callus were obtained that showed distinct carotenoid profiles. For green material, violaxanthin, lutein, zeaxanthin, and β-carotene were produced, while yellow callus generated mainly lutein, as did the brown callus. Chloroplast-chromoplast transition was followed by measuring plastid size and shape in undifferentiated marigold cells by digital image analysis. Cellular alterations were evident in brown callus. Chloroplasts were the main structure in green callus, while yellow callus clearly showed the formation of plastoglobules, structures that are correlated with chloroplast-chromoplast transition. The high number of plastoglobules observed in yellow callus is possibly directly related to pigment synthesis and accumulation. © 2011 The Society for In Vitro Biology. Source

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