Estudio de las condiciones de mezclado en fermentador para la producción de blastosporas de beauveria bassiana

Título en ingles: Study of the mixing conditions in bioreactor for blastospores production of Beauveria bassiana.Resumen: Se caracterizaron tres fermentadores: New Brunswick M-19 de 14 litros, Applikon Biocontroller 1035 de 7 litros y New Brunswick Bioflo III de 7 litros, determinando el coeficiente volumétrico de transferencia de oxígeno (KLa), la retención de gas (RG) y el tiempo de mezclado (tM). El fermentador New Brunswick Bioflo III tuvo los mejores valores con una relación de diámetro del impulsor/diámetro del tanque (DI/DT) de 0.43, KLa = 9.5-208 h-1 y tM = 1.0-3.0 s, por lo que fue seleccionado para realizar la producción de blastosporas de Beauveria bassiana, utilizando melaza como fuente de carbono. Se estudiaron las condiciones de mezclado, utilizando diferentes combinaciones de impulsores tipo Rushton, Maxflo y Lightnin, bajo un diseño experimental factorial 32. El tiempo de propagación fue de 4 días, el volumen de trabajo 4 litros, 10% de inóculo (1x106 blastosporas/ml), temperatura 30°C, agitación de 400-500 rpm, aireación de 0.5-1.0 vvm, y pH de 5.4.El hongo se desarrolló mejor utilizando la combinación de impulsores Rushton-Maxflo a 400 rpm y 1.0 vvm (F = 10.324, p £ 0.0123) (DMS=0.585), obteniendo una concentración de 1.2x109 blastosporas/ml, 2.2 g/l de biomasa y 2.48 g/l de consumo de sustrato (Y x/s=0.89). Las condiciones de mezclado y los parámetros obtenidos pueden ser aplicados en otros fermentadores para optimizar la producción de blastosporas de B. bassiana en la elaboración experimental de bioinsecticidas.Palabras clave: fermentación líquida, aireación, agitación, hongo entomopatógeno.Abstract: In this work three fermenters were characterized: New Brunswick M-19 of 14 liters, Biocontroller Applikon 1035 of 7 liters and New Brunswick Bioflo III of 7 liters, determining the volumetric coefficient of oxygen transfer (KLa), gas retention (GH) and the mixing time (tM). The fermenter New Brunswick Bioflo III had the best values with a ratio of diameter of the impeller/vessel (DI/DT) of 0.43, KLa = 9.5-208 h-1 and tM = 1.0-3.0 s, as a result, it was selected for the production of blastospores of Beauveria bassiana, using molasses as carbon source. We studied the mixing conditions, using different combinations of impellers, of type Rushton, Lightnin and Maxflo under a factorial experimental design 32. The propagation time was of 4 days, working volume was 4l, 10% inoculum (1x106 blastospores/ml), temperature of 30°C, agitation of 400-500 rpm, aeration 0.5-1.0 vvm, and pH of 5.4. The fungus growth was better using a combination of impellers Rushton-Maxflo at 400 rpm and 1.0 vvm (F = 10.324, p £ 0.0123) (LSD = 0.585) obtaining a concentration of 1.2x109blastospores/ml, 2.2 g/l biomass and 2.48 g/l of substrate consumption (Y x/s = 0.89). The mixing conditions and the parameters obtained can be applied to optimize the blastospore  productions of B. bassiana to fermenter level in the experimental production of bioinsecticides.Key words: liquid fermentation, aeration, agitation, entomopathogenic fungus

Development and Evaluation of an Extruded Balanced Food for Sheep Based on Cottonseed Meal <em>(Gossypium hirsutum)</em>

The objective of this research was to evaluate the effect of the content of cottonseed meal (Gossypium hirsutum) and the processing variables on the functional properties and the content of gossypol of an extruded feed for sheep (Ovis aries). The diet was balanced according to the requirements of fattening Dorper sheep breed under 1 year. The extrusion process was optimized using a surface response methodology, with four independent variables: temperature in the last heating zone (120–160°C), moisture content (14–18%), screw speed (120 rpm–180 rpm), and cottonseed meal content (9 g–27 g 100 g−1), in a single screw extruder. The optimal food had 27.25% crude protein, 4.24% crude fat, 12.21% crude fiber, 46.95% nitrogen-free extract, and 9.35% ash. The composition of essential amino acids in the optimal diet was 1.00 g kg−1 of lysine, 1.25 g kg−1 of phenylalanine, 2.04 g kg−1 of leucine, 0.87 g kg−1 of isoleucine, 0.98 g kg−1 of threonine, 1.15 g kg−1 of valine, and 0.65 g kg−1 of histidine. The fatty acids present in the highest concentration in the optimal diet were 2.14% linoleic acid, 1.11% oleic acid, and 0.81% palmitic acid. The gossypol content of the optimal diet was less than 0.1%, which ensures the safety of cottonseed meal as a protein source. The optimum conditions of the extrusion process were 120°C temperature, 120 rpm screw speed, 14.00% humidity, and 27 g 100 g−1 cottonseed meal

Prediction of Solubility and Miscibility Parameters of Bismuth-Arsenic Complex and Amorphous Mineral Compounds Using Molecular Dynamics Simulation

Bismuth is one of the most difficult impurities to remove in mining concentrates and low concentrations generate problems in silver and copper refineries. Therefore, financial penalties are established when concentrations exceed 0.05%. Some researchers had used arsenic to remove bismuth with results of up to 52% of extraction. Unfortunately, this mechanism is not yet fully understood. The objective of this research was to obtain the solubility parameters of amorphous mineral compounds, including bismuth-based compounds, through computational simulation using molecular dynamics. The composition of the mineral sample was determined by X-ray diffraction and the crystalline species were obtained and modeled using Materials Studio software. The nanostructures were optimized by an energy minimization methodology using the Broyden-Fletcher-Goldfarb-Shanno algorithm and were validated using the figure of merit equation and density. Simulations were performed using the Universal Force Field at constant pressure and temperature. The results of the minerals identified in the sample were compared with arsenic trioxide, indicating miscibility between As2O3 and Bi2O3, possible miscibility with 10 other minerals, and immiscibility with the rest. The results indicate that As2O3 can be successfully used for the removal of Bi2O3 without a negative effect on the recovery of other minerals of higher commercial value

Rendimiento de grano y calidad del forraje de amaranto (Amaranthus spp.) cultivado a diferentes densidades en el noreste de México

Se evaluaron cuatro genotipos de Amaranthus hypochondriacus (655, 653, 153-5-3, y Criollo Tlaxcala) y uno de Amaranthus cruentus (genotipo 33) bajo cuatro densidades de población (DP): 31250; 41666; 62500 y 125000 plantas/ha, durante los ciclos agrícolas primavera-verano (PV) 2000, otoño-invierno (OI) 2001 y OI 2002, en la estación experimental de la Facultad de Agronomía de la Universidad Autónoma de Nuevo León, México. En cada ciclo agrícola se utilizó un diseño en parcelas divididas sobre bloques completos al azar con dos repeticiones. Se evaluaron las características agronómicas de rendimiento de grano (RG), rendimiento de materia seca (MS), altura de planta (AP), diámetro del tallo (DT) y longitud de panícula (LP). Únicamente en OI 2001 se evaluó contenido de proteína bruta (PC), cenizas (C), fibra detergente ácida (FDA) y fibra detergente neutra (FDN) en tallo y hoja. Tanto la interacción triple A x B x C (genotipos x densidades x años), como la doble A x C (genotipos x años) resultaron estadísticamente significativas (p<0,05) para todas las variables de rendimiento. El mayor RG en PV 2000 se registró en el genotipo 655 con 2221 kg/ha, mientras que en OI 2001 y 2002 el genotipo con mayor RG fue 33 con 1274 y 1926 kg/ha, respectivamente. El mayor rendimiento de grano se obtuvo con la densidad de población de 125 mil plantas/ha para todos los genotipos, en todos los ambientes de prueba. En cuanto a PC el genotipo 33 fue el que presentó los mayores valores para tallo y hoja con 95 y 248 g/kg, respectivamente. Para FDA los mayores valores fueron de 594 g/kg en el genotipo 655, y de 252 g/kg para el genotipo 653. Con respecto a FDN el genotipo 655 fue el de mayor contenido tanto en tallo como en hoja con 731 g/kg y 474 g/kg, respectivamente. Sobre la base de una mayor concentración de PC en la hoja y su mayor RG, el genotipo 33 es el que se recomienda para siembra extensiva en el ciclo OI, y el genotipo 655 para el ciclo de PV

Estudio sobre los parámetros de fermentación de importancia industrial durante la propagación de Bacillus thuringiensis var. kumamotoensis C-4 para producción de bioinsecticidas / por Hiram Medrano Roldán.

Tesis (Doctor en Ciencias con Especialidad en Microbiología) U.A.N.L.UANLhttp://www.uanl.mx

Estudio de las condiciones de mezclado en fermentador para la producción de blastosporas de Beauveria bassiana

In this work three fermenters were characterized: New Brunswick M-19 of 14 liters, Biocontroller Applikon 1035 of 7 liters and New Brunswick Bioflo III of 7 liters, determining the volumetric coefficient oxygen transfer (KLa), gas hold up (GH) and the mixing time (tM). The fermenter New Brunswick Bioflo III had the best values with a ratio of diameter of the impeller/vessel (DI/DT) of 0.43, KLa = 9.5-208 h-1 and tM = 1.0-3.0 s, so it was selected for the production of blastospores of Beauveria bassiana, using molasses as carbon source. We studied the mixing conditions, using different combinations of impellers, type Rushton, Lightnin and Maxflo under a factorial experimental design 32. The propagation time was of 4 days, working volume 4l, 10% inoculum (1x106 blastospores/ml), temperature 30°C, agitation of 400-500 rpm, aeration 0.5-1.0 vvm, and pH of 5.4. The fungus growth better using a combination of impellers Rushton-Maxflo at 400 rpm and 1.0 vvm (F = 10.324, p . 0.0123) (LSD = 0.585) obtaining a concentration of 1.2x109blastospores/ml, 2.2 g/l biomass and 2.48 g/l of substrate consumption (Y x/s = 0.89). The mixing conditions and the parameters obtained can be applied to optimize the blastospore productions of B. bassiana to fermenter level in the experimental production of bioinsecticides.Se caracterizaron tres fermentadores: New Brunswick M-19 de 14 litros, Applikon Biocontroller 1035 de 7 litros y New Brunswick Bioflo III de 7 litros, determinando el coeficiente volumétrico de transferencia de oxígeno (KLa), la retención de gas (RG) y el tiempo de mezclado (tM). El fermentador New Brunswick Bioflo III tuvo los mejores valores con una relación de diámetro del impulsor/diametro del tanque (DI/DT) de 0.43, KLa = 9.5-208 h-1 y tM = 1.0-3.0 s, por lo que fue seleccionado para realizar la producción de blastosporas de Beauveria bassiana, utilizando melaza como fuente de carbono. Se estudiaron las condiciones de mezclado, utilizando diferentes combinaciones de impulsores tipo Rushton, Maxflo y Lightnin, bajo un diseño experimental factorial 32. El tiempo de propagación fue de 4 días, el volumen de trabajo 4 litros, 10% de inoculo (1x106 blastosporas/ml), temperatura 30°C, agitación de 400-500 rpm, aireación de 0.5-1.0 vvm, y pH de 5.4.El hongo se desarrolló mejor utilizando la combinación de impulsores Rushton-Maxflo a 400 rpm y 1.0 vvm (F = 10.324, p . 0.0123) (DMS=0.585), obteniendo una concentración de 1.2x109 blastosporas/ml, 2.2 g/l de biomasa y 2.48 g/l de consumo de sustrato (Y x/s=0.89). Las condiciones de mezclado y los parámetros obtenidos pueden ser aplicados en otros fermentadores para optimizar la producción de blastosporas de B. bassiana en la elaboración experimental de bioinsecticidas

Effect of extrusion temperature, moisture and sunflower oil content on the functional properties and digestibility of bovine cattle feeds

Preparation of extruded products with high oil content, presents a technological challenge, due oil decreases specific mechanic force but also acts as a lubricant, and forms starch-lipid complexes; thus, decreasing starch gelatinization. This research aimed to evaluate the effect of temperature, moisture, and sunflower oil content, on the extrusion process of bovine cattle feed. Two main ingredients were used for each diet: alfalfa (Medicago sativa L.), and bean (Phaseolus vulgaris L.). The obtained results showed that high temperature, moisture, and oil content, decreased bulk density, and hardness (P < 0.05). Oil content-temperature interaction increased both bulk density and hardness, while moisture-oil content interaction increased (P < 0.05) hardness. Optimization was performed based on the physicochemical characteristics of commercial feeds, showing that the best bean diets were obtained at 121ºC, 14% moisture content with 0% sunflower oil; 120ºC and 16% moisture content with 3.5% sunflower oil; and, 142ºC and 15% moisture content with 7% sunflower oil. Effective degradability ranged from 87.4 - 90.4% for all extruded diets; and none of them showed significant differences between bean and alfalfa (P < 0.05), which opens a high potential opportunity of producing high concentrations of CLA from sunflower oil at a ruminal leve

Response Surface Methodology Analysis of the Effect of the Addition of Silicone Oil on the Transfer of Carbon Dioxide during Bioleaching of Mining Tailings by Native Microorganisms

The bioleaching of manganese present in mining waste after metal extraction can be catalyzed by Leptospirillum (L.) ferriphilum by allowing atmospheric carbon dioxide to be used in this autotrophic process and generating the subsequent recovery of silver. Bioleaching of metals is widely performed in agitated tanks; therefore, it is important to assess the mass transfer capacity of gaseous substrates, such as carbon dioxide, during the microbial processes. The main objective of this research was to evaluate the effects of the presence and concentration of a transfer vector (silicone oil) added into a stirred-tank bioreactor during bioleaching of mining tailings catalyzed by L. ferriphilum, determined by the combined gas/oil mass transfer coefficient of carbon dioxide (kLaCO2) into the aqueous phase. The experiments were carried out following a Box&ndash;Behnken experimental design, evaluating the concentrations of mining waste (30%, 40%, and 50%), Fe2+, serving as electron donor (2, 8, and 14 g/L), and silicon oil (0%, 5%, and 10%). A significant increase in kLaCO2 was observed after the addition of the transfer vector by comparing the lowest kLaCO2 value of 1.68 h&minus;1 (obtained at 50% pulp, 8 g/L Fe2+, and 0% silicone oil) and the highest kLaCO2 of 21.81 h&minus;1 (obtained at 30% pulp, 2 g/L Fe2+, 5% silicone oil). The results showed statistically significant differences in the transfer of carbon dioxide during the bioleaching process with a transfer vector