Mostrando ítems 41-60 de 131

Bubble coalescence model effect on oxygen mass transfer using non-newtonian fluids

Niño, Lilibeth; Peñuela Vásquez, Mariana; Gelves, German (Journal of Engineering Science and TechnologyMalasia, 2021-08)

A modified bubble coalescence model including rheological conditions and shear forces in non-Newtonian fluids is evaluated using CFD (Computational Fluid Dynamics). Euler's model, along with population balance equations, ...
Enhancement of Metabolite Production in High-Altitude Microalgal Strains by Optimized C/N/P Ratio

Suárez Quintana, William H.; García Rico, Ramón O.; García Martínez, Janet B.; Urbina Suarez, Néstor A.; López-Barrera, Germán L.; Barajas Solano, Andrés F.; Zuorro, Antonio (Applied SciencesSuiza, 2022-07-04)

: This study evaluated the role of C/N/P in the increase in the synthesis of carbohydrates, proteins, and lipids in two high-mountain strains of algae (Chlorella sp. UFPS019 and Desmodesmus sp. UFPS021). Three carbon ...
Kinetic modeling of biosurfactant production from crude oil using Bacillus subtilis cells

Alvarado, Kelly; Niño, Lilibeth; German, Gelves (South African Journal of Chemical EngineeringPaíses Bajos, 2022-06-23)

Crude oil and its derivatives have high application in different industries, and unforeseen spills or overexploitation generate a significant threat in ecosystems, causing negative impacts on soil, water, and air. There ...
Inherent Safety Analysis and Sustainability Evaluation of a Vaccine Production Topology in North-East Colombia

González Delgado, Ángel Darío; García Martínez, Janet B.; Barajas Solano, Andrés F. (SustainabilitySuiza, 2022-08-12)

: Influenza is a respiratory disease that may cause severe consequences to human health. Influenza caused between 99,000 and 200,000 deaths worldwide in 2019. Studies have reported the presence of this virus in Santander, ...
Evaluación de residuos de papa, yuca y naranja para la producción de etanol en cultivo discontinuo utilizando Saccharomyces cerevisiae

Urbina-Suarez, Nestor Andres; Muñoz Peñaloza, Yaneth Amparo; VELASCO, JOSMAN (Revista IONBucaramanga,Colombia, 2015-01-25)

El presente trabajo de investigación tuvo como objetivo producir etanol utilizando un jarabe glucosado elaborado a partir de residuos de papa, naranja y yuca, por cultivo discontinuo como una alternativa para el manejo de ...
Inoculation of Cilantro (Coriandrum sativum L.) with Rhizobacterias in Villa del Rosario, Norte de Santander

Carrillo Becerra, Katherine; Colmenares, Andreína; Ramírez Caicedo, Lilian; Moreno Rozo, Laura; Cárdenas Caro, Diana (Revista Facultad Nacional de AgronomiaMedellín, Colombia, 2015-01-01)

Plant growth promoting rhizobacteria (PGPR) represent an alternative biofertilization form. In this study, was evaluated PGPR inoculation in cilantro plants. Likewise, was evaluated the practice of burning rice husk in ...
Caracterización Viscoelástica de Biopelículas Obtenidas a Base de Mezclas Binarias

Urbina-Suarez, Nestor Andres; GONZALEZ CUELLO, RAFAEL EMILIO; Morón Alcázar, Lena (Informacion TecnologicaChile, 2015-01-18)

El objetivo de este trabajo fue caracterizar la viscoelasticidad dinámica lineal de biopelículas obtenidas con glicerol al 12 % (v/v), goma gelana (GG), concentrado de proteína de suero lácteo (CPS) y sus mezclas. Las ...
Alarmin’ immunologists: IL-33 as a putative target for modulating T cell-dependent responses

YANEZ MENESES, LUZ FRANCY; Gajardo Carrasco, Tania Fernanda; Pérez Béssolo, Francisco Andrés; Terraza-Aguirre, Claudia; Campos-Mora, Mauricio; Pino Lagos, Karina (Frontiers in ImmunologyChile, 2015-06-02)

IL-33 is a known member of the IL-1 cytokine superfamily classically named “atypical” due to its diverse functions. The receptor for this cytokine is the ST2 chain (or IL-1RL1), part of the IL-1R family, and the accessory ...
Sustratos inoculados con microorganismos para el desarrollo de plantas de cacao (Theobroma cacao L.) en etapa de vivero

SIGARROA RIECHE, ALINA KATIL; Moreno Rozo, laura Yolima; Cárdenas Caro, Diana Maria; VESGA AYALA, NELCY PAOLA (BioagroBarquisimeto,Venezuela, 2015-09-27)

La renovación de plantaciones del cultivo de cacao debe hacerse con material vegetal que asegure la supervivencia en el trasplante a campo, por lo cual, es indispensable la producción de plantas en vivero utilizando sustratos ...
Determining the Viability of Orchid seeds using the Tetrazolio and Carmín Índigo Tests

SALAZAR MERCADO, SEIR ANTONIO; Gélvez Manrique, Javier Darío (Revista De CienciasValle, Colombia, 2015-12-01)

Orchid species are endangered worldwide due to human intervention. Therefore, it is necessary to analyze the germination capacity (viability) of orchids' seeds as essencial step for its conservation. This research determined ...
Efecto del uso y manejo sobre las propiedades físicas de un suelo bajo dos sistemas de cultivo en el distrito de riego del rio zulia, norte de Santander

Valenzuela Balcázar, Ibonne Geaneth; Camarón R, Franyer; Visconti M, Efraín (Suelos EcuatorialesCauca,Colombia, 2015-12-10)

El estudio de las propiedades físicas de un Entisol bajo dos sistemas de producción, un cultivo de arroz con el mismo uso desde hace más de 40 años y un sistema agroforestal (Bosque con cacao) con el mismo tiempo de uso, ...
Design of a microalgae bio-reactive facade reactor for cultivation of Chlorella vulgaris

Barajas Ferreira, Crisóstomo; Castro Padilla, Lucero; Sánchez, Ginna Vanegas; González-Delgado, Angel Darío; Barajas Solano, andres F (Contemporary Engineering SciencesBulgaria, 2017-11-14)

The increasing global demand for energy that has existed during many decades has affected the environment due to the greenhouse gas emissions, which are the result of the inadequate use of fossil fuels. This situation ...
Evaluation of In-Situ Transient Simultaneous Cell Disruption and Transesterification of Microalgae

González-Delgado, Angel Darío; Barajas Solano, andres F; Peralta-Ruiz, Yeimmy (Contemporary Engineering SciencesBulgaria, 2017-12-07)

Microalgae has recently been highlighted as source of valuable products including biofuel. The production process of biofuels from microalgae involves mass cultivation, harvesting, deep dewatering, lipid extraction and ...
Bioremediation of Aquaculture Wastewater Using Microalgae Chlorella vulgaris

Blanco, Estefany; González-Delgado, Angel Darío; García-Martinez, Janet; Sanchez-Galvis, Edwar; Barajas Solano, andres F (Contemporary Engineering SciencesBulgaria, 2017-12-24)

Microalgae have received increasing attentions as an alternative treatment approach to remediate wastewater for both nutrient removal and biomass production. Wastewater from aquaculture industry contains high levels of ...
Removal of Organic Pollutants from San Pablo Farm Wastewater Using a Pilot-Scale Biological Treatment

Ortiz Alvarez, Maria Daniela; SUAREZ GELVEZ, JOHN HERMOGENES; Pérez, Michael Edgardo; González-Delgado, Angel Darío; Barajas Solano, andres F; Urbina-Suarez, Nestor Andres (Contemporary Engineering Sciences, 2017-12-24)

Biological treatment is the most common process used to treat organics-containing wastewaters from industrial, domestic and agricultural activities. This work aims to remove organic pollutants using pilot-scale biological ...
Astaxanthin production from Haematococcus pluvialis: effects of light wavelength and salinity

González-Delgado, Angel Darío; Barajas Solano, andres F; Torres, Luz Karime; SUAREZ GELVEZ, JOHN HERMOGENES; Urbina-Suarez, Nestor Andres (Contemporary Engineering SciencesBulgaria, 2017-12-28)

Haematococcus pluvialis has attracted much global attention due to its ability to produce huge amounts of astaxanthin, a carotenoid pigment widely applied in pharmaceutical, cosmetic and food industries. In this work, ...
The Effects of Wavelength and Salinity on Biomass Production from Haematococcus pluvialis

Torres, Luz Karime; González-Delgado, Angel Darío; Barajas Solano, andres F; Urbina-Suarez, Nestor Andres (Contemporary Engineering SciencesBulgaria, 2017-12-24)

Currently, microalgae have emerged as promising source of high-value products due to its biomass productivity, high photosynthetic efficiency and non-competitive environment for growth. In this work, biomass production ...
Evaluación de la capacidad antifúngica de los extractos etanólicos depropóleoante la antracnosis en tomate de árbol (Solanum betaceum Cav.)

CAMPO VERA, YESENIA; Muñoz, Yaneth; López, Ana; Contreras, Julio; Martínez-Soto, Moisés Enrique; Bermúdez, Valmore (Revista De La Facultad De AgronomiaVenezuela, 2018-12-19)

La antracnosis es una enfermedad fúngica que tienen una importante incidencia en los cultivos de tomate de árbol. La misma es ocasionada por los fitopatógenos Colletotrichum gloeosporioides (Penz.) o su teleomorfo ...
Improvement of Biorefinery Efficiency for Microalgae Nannochloropsis sp. via Harvesting Technology Evaluation

Sanguino, Paola Andrea; González-Delgado, Angel Darío; Barajas Solano, andres F (Contemporary Engineering SciencesBulgaria, 2018-04-04)

Recently, microalgal biomass has attached much attention due to the wide diversity of compounds synthesized from different metabolic pathways. This work attempts to study metabolites recovery from Nannochloropsis sp. ...
Effect of Flocculation Technology on Lipids, Carbohydrates and Proteins and Extraction from Chlorella vulgaris

Sanguino, Paola Andrea; González-Delgado, Angel Darío; Barajas Solano, andres F (Contemporary Engineering SciencesBulgaria, 2018-03-03)

Nowadays, Chlorella vulgaris has emerged as an attractive source of metabolites such as lipids, proteins and carbohydrates, which are widely applied to obtain high value products. This work is focused on evaluating the ...

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Bubble coalescence model effect on oxygen mass transfer using non-newtonian fluids
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Niño, Lilibeth | 2021-08

A modified bubble coalescence model including rheological conditions and shear forces in non-Newtonian fluids is evaluated using CFD (Computational Fluid Dynamics). Euler's model, along with population balance equations, was used to simulate bubble size distribution. Simultaneously, different bubble breakage and coalescence models were evaluated to investigate mass transfer and bubble diameter. A conventional aeration stirring system (Rushton turbine, ring sparger) was used and the results were validated by determining the experimental mass transfer coefficient. A 10-liter bioreactor operated under different operating conditions commonly used for non-Newtonian rheology was used. Xanthan Gum 0.25% was used to resemble the rheological conditions developed during fungal culture. CFD results were contrasted with tested data obtained from 𝑘�𝑘�𝐿�𝐿�𝑎�𝑎� measurements at different stirring speeds using the concordance d-index. A reasonable prediction was obtained comparing the modified model Luo-New to the most used conventional models Luo-Luo and Laakkonen-Luo. Therefore, model Luo-New shows the highest d values at 400-700 rpm with values of 0.83, 0.95, 0.98 and 0.69. By contrast, the model Luo-Luo showed less inaccurate values with levels lower than 0.62 in almost all comparisons. The latter concludes numerically that the inclusion of viscosity effects and shear on a bubble coalescence model improves the degree of prediction related to oxygen transfer. The latter being a critical factor in the design and testing of stirring and aeration devices.

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Enhancement of Metabolite Production in High-Altitude Microalgal Strains by Optimized C/N/P Ratio
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Suárez Quintana, William H. | 2022-07-04

: This study evaluated the role of C/N/P in the increase in the synthesis of carbohydrates, proteins, and lipids in two high-mountain strains of algae (Chlorella sp. UFPS019 and Desmodesmus sp. UFPS021). Three carbon sources (sodium acetate, sodium carbonate, and sodium bicarbonate), and the sources of nitrogen (NaNO3 ) and phosphate (KH2PO4 and K2HPO4 ) were analyzed using a surface response (3 factors, 2 levels). In Chlorella sp. UFPS019, the optimal conditions to enhance the synthesis of carbohydrates were high sodium carbonate content (3.53 g/L), high KH2PO4 and K2HPO4 content (0.06 and 0.14 g/L, respectively), and medium-high NaNO3 (0.1875 g/L). In the case of lipids, a high concentration of sodium acetate (1.19 g/L) coupled with high KH2PO4 and K2HPO4 content (0.056 and 0.131 g/L, respectively) and a low concentration of NaNO3 (0.075 g/L) drastically induced the synthesis of lipids. In the case of Desmodesmus sp. UFPS021, the protein content was increased using high sodium acetate (2 g/L), high KH2PO4 and K2HPO4 content (0.056 and 0.131 g/L, respectively), and high NaNO3 concentration (0.25 g/L). These results demonstrate that the correct adjustment of the C/N/P ratio can enhance the capacity of high-mountain strains of algae to produce high concentrations of carbohydrates, proteins, and lipids.

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Kinetic modeling of biosurfactant production from crude oil using Bacillus subtilis cells
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Alvarado, Kelly | 2022-06-23

Crude oil and its derivatives have high application in different industries, and unforeseen spills or overexploitation generate a significant threat in ecosystems, causing negative impacts on soil, water, and air. There are microorganisms capable of metabolizing hydrocarbons through the bioremediation process with biosurfactant production, but large-scale culturing and technification are still a significant challenge due to their high costs and optimization stage requirement. An unstructured kinetic model provides crucial information regarding improvements and process optimization at the first stages. Thereof prediction of bioprocess kinetic behavior is expected from mathematical expressions. Considering the above, biosurfactants’ bioprocess modeling tends to be an essential tool to increasingly focus on the efficiency and profitability of oil industries. That is why biosurfactant kinetics production from Bacillus subtilis is investigated in this research, implementing a mathematical model. Previous studies refereed experimental data to integrate into Monod, Contois, Haldane, Moser, Powell, Tessier, Aiba-Edward, Luong, Yano-Koga, and Chen-Hashimoto equations. Therefore, a nonlinear regression parameterization procedure is applied using the Matlab Fmincon Function. The best accuracy found between experimental and simulated data was achieved using the Chen-Hashimoto kinetic model with μmax, kd and ks values of 2.3239 d− 1 , 0.3748 d− 1 and 1.1619 g/L, respectively. This research suggests that biosurfactant production occurs under anaerobic conditions where hydrolysis controls microbial growth. These research results are a promising aim related to industrial biotechnology since computational modeling is essential for process efficiency from a technical and economic perspective.

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Inherent Safety Analysis and Sustainability Evaluation of a Vaccine Production Topology in North-East Colombia
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González Delgado, Ángel Darío | 2022-08-12

: Influenza is a respiratory disease that may cause severe consequences to human health. Influenza caused between 99,000 and 200,000 deaths worldwide in 2019. Studies have reported the presence of this virus in Santander, Colombia, a region with a high humanitarian flow. An influenza vaccine production plant topology has been proposed previously. Nevertheless, the inherent safety and sustainably behavior of this topology is unknown. Process safety plays a crucial role in the evaluation of emerging technologies since it allows the identification of potential risks. Moreover, the current sustainability policies enforce the assessment of processes considering economic, social, and environmental aspects. For this reason, a safety and sustainability evaluation of a vaccine production topology is performed in this work. The inherent safety index (ISI) methodology was implemented to analyze the process. The sustainability evaluation was performed using the sustainability weighted return on investment metric (SWROIM), in which return on investment (ROI), output potential environmental impact (PEI output), total safety inherent index (ITI), and exergy efficiency were considered. The results showed that influenza vaccine production is inherently safe since the total inherent safety index was 11. The destroyed exergy was 378.69 MJ/h, the return on investment was 86%, and the SWROIM was estimated at 81%, which means slightly negative impacts on sustainability

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Evaluación de residuos de papa, yuca y naranja para la producción de etanol en cultivo discontinuo utilizando Saccharomyces cerevisiae
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Urbina-Suarez, Nestor Andres | 2015-01-25

El presente trabajo de investigación tuvo como objetivo producir etanol utilizando un jarabe glucosado elaborado a partir de residuos de papa, naranja y yuca, por cultivo discontinuo como una alternativa para el manejo de los residuos generados. Para cumplir con el objetivo planteado se utilizaron cepas Saccharomyces cerevisiae, una cepa nativa (LYP) y una cepa control (CTL) obtenida del Cepario de la Universidad. Posteriormente, para la elaboración de los medios de fermentación los residuos se sometieron a un tratamiento de hidrólisis química con ácido clorhídrico al 2%v, temperatura de 75°C y 8 horas, estos parámetros fueron seleccionados como resultado del análisis estadístico del diseño factorial 33 el cual encontró diferencias estadísticamente significativas (p≥0,05) en las variables evaluadas sobre la generación de azucares reductores. Finalmente, se realizaron fermentaciones de 500ml a 30°C 150rpm con base en un diseño factorial 42 para la evaluación de los sustratos fermentativos y el microorganismo fermentador, en donde se encontró que no existen diferencias significativas (p≥0,05) tanto para los sustratos como para las cepas: control (CTL) y nativa (LYP), en la producción de etanol. Sin embargo, en las interacciones entre variables si se encontraron diferencias altamente significativas (p≤0,05), la mayor producción de etanol obtenido fue de 3,15 y 2,6%v para la cepa LYP y CLT, respectivamente, cuando se emplearon los jarabes de naranja y yuca como fuente de carbono.

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Inoculation of Cilantro (Coriandrum sativum L.) with Rhizobacterias in Villa del Rosario, Norte de Santander
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Carrillo Becerra, Katherine | 2015-01-01

Plant growth promoting rhizobacteria (PGPR) represent an alternative biofertilization form. In this study, was evaluated PGPR inoculation in cilantro plants. Likewise, was evaluated the practice of burning rice husk in soil preparation for crop establishment. An experimental design was used in a split plot where the main plots were soil preparation with burning rice husk and without burning rice husk with prior inoculation of Trichoderma sp. The subplots correspond to treatments with simple inoculation and co-inoculation of Azotobacter RzH120 and Azospirillum RzH132 and chemical and absolute control. Once the assumptions were tested in model residuals, normality, homogeneity of variance and randomness, an analysis of variance and multiple comparison tests by Tukey's test and principal component analysis technique was performed as size reduction. According to principal component analysis, the results showed a positive effect on the growth of plants inoculated with PGPR in the two plots with burning and without burning rice husk, however, the variable yield (P≤0.05). Also, it was found that the population of bacteria in the rhizosphere culture media NFb semisolid, Ashby and King B, was not favored by the burning of rice husks on the soil. Importantly, the results were obtained with the 30% decrease in the chemical fertilizer, which can reduce the use of these chemicals.

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Caracterización Viscoelástica de Biopelículas Obtenidas a Base de Mezclas Binarias
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Urbina-Suarez, Nestor Andres | 2015-01-18

El objetivo de este trabajo fue caracterizar la viscoelasticidad dinámica lineal de biopelículas obtenidas con glicerol al 12 % (v/v), goma gelana (GG), concentrado de proteína de suero lácteo (CPS) y sus mezclas. Las biopelículas basadas en biopolímeros funcionales y concentrado de proteína de suero lácteo (CPS) son una alternativa en la industria alimentaria al empaque tradicional de alimentos con materiales sintéticos, por lo cual se hace necesario realizar estudios iniciales de tipo técnico. Para la caracterización de las biopelículas se utilizó análisis reológico dinámico y curvas de Creep ajustadas al modelo de Burgers. Todas las biopelículas estudiadas se comportaron como sistemas reológicos con características predominantemente elásticas. El comportamiento de los módulos dinámicos puede ser un indicativo de la formación de redes interdependientes de la GG y el CPS. Por tanto, es posible utilizar estos materiales individualmente o en mezclas, para la obtención de biopelículas activas y recubrir diversos sistemas alimentarios sólidos.

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Alarmin’ immunologists: IL-33 as a putative target for modulating T cell-dependent responses
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YANEZ MENESES, LUZ FRANCY | 2015-06-02

IL-33 is a known member of the IL-1 cytokine superfamily classically named “atypical” due to its diverse functions. The receptor for this cytokine is the ST2 chain (or IL-1RL1), part of the IL-1R family, and the accessory chain IL-1R. ST2 can be found as both soluble and membrane-bound forms, property that explains, at least in part, its wide range of functions. IL-33 has increasingly gained our attention as a potential target to modulate immune responses. At the beginning, it was known as one of the participants during the development of allergic states and other Th2-mediated responses and it is now accepted that IL-33 contributes to Th1-driven pathologies as demonstrated in animal models of experimental autoimmune encephalomyelitis (EAE), collagen-induced arthritis, and trinitrobenzene sulfonic acid-induced experimental colitis, among others. Interestingly, current data are placing IL-33 as a novel regulator of immune tolerance by affecting regulatory T cells (Tregs); although the mechanism is not fully understood, it seems that dendritic cells and myeloid suppressor-derived cells may be cooperating in the generation and/or establishment of IL-33-mediated tolerance. Here, we review the most updated literature on IL-33, its role on T cell biology, and its impact in immune tolerance.

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Sustratos inoculados con microorganismos para el desarrollo de plantas de cacao (Theobroma cacao L.) en etapa de vivero
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SIGARROA RIECHE, ALINA KATIL | 2015-09-27

La renovación de plantaciones del cultivo de cacao debe hacerse con material vegetal que asegure la supervivencia en el trasplante a campo, por lo cual, es indispensable la producción de plantas en vivero utilizando sustratos que les proporcionen condiciones apropiadas de crecimiento. Por lo anterior, se determinó el efecto de la inoculación microbiana en sustratos utilizados para la producción de plantas de cacao en etapa de vivero para lo cual se utilizaron semillas del clon IMC 67. Se evaluaron los siguientes tratamientos: (T1) testigo absoluto, 1:1 suelo:arena; (T2) bioabono, 2:1:1 suelo:bioabono:arena; (T3) Inoculante comercial mixto, 2:1:1 suelo:lombricompuesto:arena; (T4) rizobacterias cacao, 2:1:1 suelo:lombricompuesto:arena y (T5) testigo químico, 2:1:1 suelo:lombricompuesto:arena + fertilización química. Cada uno de estos cinco tratamientos fue sembrado en 60 bolsas (repeticiones) bajo un diseño experimental completamente al azar. Se determinó la altura de la planta, número de hojas, diámetro del tallo, longitud radical y peso seco foliar y radical, así como las poblaciones de bacterias en agar SRS. El análisis de varianza registró diferencias significativas (P≤0,05) en las plantas de los tratamientos T3 y T4, con respecto a los testigos absoluto y químico en la mayoría de las variables, por lo cual se recomienda la inoculación de estos microorganismos para mejorar el desarrollo vegetal de las plantas de cacao en etapa de vivero y por tanto, su supervivencia en el trasplante a campo. La inoculación microbiana en los sustratos también promovió el incremento de las poblaciones de rizobacterias.

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Determining the Viability of Orchid seeds using the Tetrazolio and Carmín Índigo Tests
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SALAZAR MERCADO, SEIR ANTONIO | 2015-12-01

Orchid species are endangered worldwide due to human intervention. Therefore, it is necessary to analyze the germination capacity (viability) of orchids' seeds as essencial step for its conservation. This research determined the viability of the seeds species of orchids Elleanthus arauntiacum, Epidendrum sp, Maxillaria sp, Odontoglossum lindenii, Prosthechea sp, Telipogon dubios, Stelis sp, Elleanthus sp, Epidendrum elongatum y Cyrtochilum sp, using the Tetrazolium and Indigo carmin tests. Several f eld trips to the province of El Escorial in Norte de Santander, Colombia were done for collection of mature capsules of the different species of orchids. Then, was the seeds' viability by using the tetrazolium and Indigo Carmine tests. Subsequently, the data obtained from the two tests was evaluated. The correlation coeff cient between the Tetrazolium and Indigo Carmine tests was 0.419, indicating a weak relationship between the two trials with statistically signif cant differences P:0.05. It was found that the tetrazolium test was the most eff cient to determine the viability of orchid seeds being studied.

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Efecto del uso y manejo sobre las propiedades físicas de un suelo bajo dos sistemas de cultivo en el distrito de riego del rio zulia, norte de Santander
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Valenzuela Balcázar, Ibonne Geaneth | 2015-12-10

El estudio de las propiedades físicas de un Entisol bajo dos sistemas de producción, un cultivo de arroz con el mismo uso desde hace más de 40 años y un sistema agroforestal (Bosque con cacao) con el mismo tiempo de uso, en el Distrito de riego del Rio Zulia, Norte de Santander, tuvo como fin conocer el efecto de las prácticas de manejo del suelo sobre la densidad aparente, porosidad, textura, estabilidad de agregados y estabilidad estructural. El trabajo consistió en una investigación de campo con diseño experimental factorial aleatorio de tres factores (Uso del suelo, Profundidad del suelo y Etapa del Cultivo) y tres repeticiones. En los tres lotes de suelo estudiados la distribución de partículas minerales estuvo dominada por las arcillas, siendo las texturas dominantes las arcillosas. La estructura es fina, fuerte, muy dura y plástica en los lotes de arroz (AR y ASR), mientras que en el lote del bosque con cacao (BC) es fina, moderada, moderadamente dura y ligeramente plástica. Con respecto a la estabilidad de los agregados para todos los usos, todas las profundidades y todas las etapas, se encontraron agregados inestables a ligeramente estables. Sobre la densidad aparente (Da) del suelo se expresó un efecto significativo de los tres factores evaluados, siendo el manejo de BC, la capa superficial y la etapa 5, los de menor Da. El suelo en todos los casos mostró limitaciones de porosidad, siendo el suelo en BC el que tiene las menores dificultades.

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Design of a microalgae bio-reactive facade reactor for cultivation of Chlorella vulgaris
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Barajas Ferreira, Crisóstomo | 2017-11-14

The increasing global demand for energy that has existed during many decades has affected the environment due to the greenhouse gas emissions, which are the result of the inadequate use of fossil fuels. This situation has contributed to the development of researchers regarding the microalgae production to capture the CO2 present in the atmosphere. Therefore, this paper presents the influence of the design variables (width and depth) of a flat-plate photobioreactor on the biomass productivity of Chlorella vulgaris UTEX 1803 and the evaporated volume for a period of 74 days, under the environmental conditions of Bucaramanga, Colombia. In addition, the effect of evaporated volume and temperature on biomass productivity was analyzed. It was verified that the average temperature of 29.72 °C is not an influential variable on biomass productivity. According to the results, the design of a photobioreactor with width dimensions greater than 15 cm and depth 3 cm is required to obtain a productivity of 0.35 g/L d.

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Evaluation of In-Situ Transient Simultaneous Cell Disruption and Transesterification of Microalgae
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González-Delgado, Angel Darío | 2017-12-07

Microalgae has recently been highlighted as source of valuable products including biofuel. The production process of biofuels from microalgae involves mass cultivation, harvesting, deep dewatering, lipid extraction and biofuel conversion. In this work, lipids from microalgae Navicula sp. were obtained using multifunctional process that consists of acid hydrolysis or cellular disruption, oil extraction and in situ transesterification. The effect of alcohol added to produce ethyl and methyl esters on lipid extraction efficiency was evaluated using methanol and ethanol in order to determine the most suitable route for obtaining the high values of lipids and total reducing sugar. The highest lipid extraction efficiency and total reducing sugar (7.72 % and 2.63 mg/ml, respectively) was obtained for methanol. The low lipid extraction efficiency of multifuctional process is due to transesterification of lipids that gradually released into the system. The formation of alkyl esters was confirmed by FTIR with an increase in carbonyl peak as the reaction progressed, thus muntifuctional process reduce cost of alkyl esters production by eliminating the step of lipid extraction by solvent.

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Bioremediation of Aquaculture Wastewater Using Microalgae Chlorella vulgaris
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Blanco, Estefany | 2017-12-24

Microalgae have received increasing attentions as an alternative treatment approach to remediate wastewater for both nutrient removal and biomass production. Wastewater from aquaculture industry contains high levels of nitrogen and phosphorus, which affect plant growth. Conventional methods for treating aquaculture wastewater generally are inefficient and unprofitable. In this work, microalgae Chlorella vulgaris growth was studied in aquaculture effluent medium in order to reduce its contents of NO3 and PO4. Furthermore, the effect of NaHCO3 and Na2CO3 concentrations and addition time on biomass productivity was evaluate to determine the most suitable conditions for biomass growth. It was found that highest biomass content (0.3 g/L) was achieved at 3.4 g/L of sodium bicarbonate concentration and 19 h of addition time.

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Removal of Organic Pollutants from San Pablo Farm Wastewater Using a Pilot-Scale Biological Treatment
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Ortiz Alvarez, Maria Daniela | 2017-12-24

Biological treatment is the most common process used to treat organics-containing wastewaters from industrial, domestic and agricultural activities. This work aims to remove organic pollutants using pilot-scale biological treatment system based on activated sludge. In addition, physical, chemical and microbiological characteristics of San Pablo Farm wastewaters were determined through analyses such as COD, DO, VSS, TSS and BOD and kinetic parameters were calculated by monod model. It was observed a significant decrease of this contaminant load in wastewater, achieving removal yields of 98% of BOD, 93% of COD and 99% of total coliforms. Kinetic coefficients obtained at pilot-scale registered similar values to those described by other researches and reveal a good performance of activated sludge in wastewater treatment.

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Astaxanthin production from Haematococcus pluvialis: effects of light wavelength and salinity
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González-Delgado, Angel Darío | 2017-12-28

Haematococcus pluvialis has attracted much global attention due to its ability to produce huge amounts of astaxanthin, a carotenoid pigment widely applied in pharmaceutical, cosmetic and food industries. In this work, production of astaxanthin from Haematococcus pluvialis was performed under three different salt concentrations (0, 0.45 and 0.9% v/v) and wavelengths (blue, white and red) in order to evaluate the effects of salinity and light wavelengths on microalgae growth. A multifactorial 32 experimental design was used and its results were studied by Manova analyzer with 95% of reliability. According to the results, the highest amount of astaxanthin (9.72 μg/mL) was obtained at 0.45 %v/v of salt concentration and blue wavelength.

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The Effects of Wavelength and Salinity on Biomass Production from Haematococcus pluvialis
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Torres, Luz Karime | 2017-12-24

Currently, microalgae have emerged as promising source of high-value products due to its biomass productivity, high photosynthetic efficiency and non-competitive environment for growth. In this work, biomass production from Haematococcus pluvialis was studied at three salt concentrations (0, 0.45 and 0.9% v/v) and blue, white and red wavelengths in order to evaluate the effects of these factors on microalgae growth. A 32 experimental design was performed and its results were analyzed by Manova test with 95% of reliability. The results obtained suggest that the best combination for biomass production consists of red wavelength and salt concentration of 0% v/v with a maximum productivity of 8172.2 mg/mL.

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Evaluación de la capacidad antifúngica de los extractos etanólicos depropóleoante la antracnosis en tomate de árbol (Solanum betaceum Cav.)
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CAMPO VERA, YESENIA | 2018-12-19

La antracnosis es una enfermedad fúngica que tienen una importante incidencia en los cultivos de tomate de árbol. La misma es ocasionada por los fitopatógenos Colletotrichum gloeosporioides (Penz.) o su teleomorfo Glomerella cingulata (Stoneman). La presente investigación evaluó la capacidad antifúngica del propóleo, un derivado de los productos apícolas, obtenido en tres localidades diferentes de Norte Santander (Oripaya, San Cayetano, Los Patios). Inicialmente, se realizó una caracterización de la resina mediante la identificación de sus propiedades fisicoquímicas, tales como: cenizas 3,56±0,64%; humedad 5,11±0,11%;material insoluble 5,11±0,11%; índice de oxidación 49± 1%; puntos de fusión 80,90±3,21; espectro de absorción UV en el rango de 270 a 350 nm tales como: cenizas, humedad, material insoluble, índice de oxidación, puntos de fusión, espectro de absorción UV y posteriormente, se verificó el porcentaje de inhibición de los microorganismos empleando la técnica de antibiograma con sensidiscos impregnados con tres concentraciones de extracto etanólico de propóleo EEP (10%, 20%, 30%). Se encontró que los propóleos cumplen con los estándares internacionales para los parámetros de cenizas, humedad, puntos de fusión y espectros de absorción de la radiación ultra violeta (UV), evidenciándose la calidad del propóleo y la presencia de flavonoides, además del mismo se halló que el propóleo de la localidad de Oripaya al 10% tiene mayor capacidad de inhibición frente a C. gloeosporioides (Penz.).

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Improvement of Biorefinery Efficiency for Microalgae Nannochloropsis sp. via Harvesting Technology Evaluation
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Sanguino, Paola Andrea | 2018-04-04

Recently, microalgal biomass has attached much attention due to the wide diversity of compounds synthesized from different metabolic pathways. This work attempts to study metabolites recovery from Nannochloropsis sp. biomass concentrated by centrifugation and flocculation. Carbohydrates were obtained using acid and alkaline hydrolysis required for cell disruption. Protein extraction was performed after alkaline pretreatment and lipids were recovery by acid hydrolysis- Soxhlet and alkaline hydrolysis- Soxhlet extraction routes. It was found that carbohydrates were recovered by acid hydrolysis in 41 % and 35.39 % for centrifuged and flocculated biomass, respectively, values higher than thus reported using alkaline hydrolysis. For protein extraction, centrifuged biomass exhibited higher recovery yield (55.48%) than flocculated biomass (38.40%). The lipid extraction route that achieved highest yield (43.45%) was acid hydrolysis with HCl followed by Soxhlet extraction with hexane. In addition, statistical analysis by T test suggested that flocculants affect negatively biomass culture, hence, efficiency of metabolites extraction.

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Effect of Flocculation Technology on Lipids, Carbohydrates and Proteins and Extraction from Chlorella vulgaris
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Sanguino, Paola Andrea | 2018-03-03

Nowadays, Chlorella vulgaris has emerged as an attractive source of metabolites such as lipids, proteins and carbohydrates, which are widely applied to obtain high value products. This work is focused on evaluating the effect of flocculation on metabolites recovery from Chlorella vulgaris microalgae biomass. Carbohydrates were extracted through acid and alkaline hydrolysis in order to identify the efficiency of these treatments for cell wall disruption. Protein quantification was carried out under alkaline conditions and lipids were recovered by solvent extraction with hexane. It was found that carbohydrate recovery was higher using centrifuged biomass (40.55%) than flocculated biomass (24.31%) by acid treatment, while alkaline treatment exhibited yield of 20.37% and 13.19%, respectively. In addition, efficiency of 53.75% and 32.27% in protein recovery was obtained from both centrifuged and flocculated biomass. The highest lipid extraction yield (54.2%) was achieved using acid hydrolysis and hexane solvent route when centrifuged biomass was used as metabolite source. These results suggested that flocculation affect significantly the efficiency of metabolites extraction.

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