FRD - Investigación - Ciencia y Tecnología
Permanent URI for this communityhttp://48.217.138.120/handle/20.500.12272/1225
Browse
9 results
Search Results
Item Optimization of a site-specific biostimulation strategy using response-surface methodology to remediate a chronically hydrocarbon-contaminated industrial soil.(Argentine Society for Biochemistry and Molecular Biology, 2021-11) Conde Molina, Débora; Liporace, Franco; Quevedo, CarlaIn present times, contamination with petroleum compounds is one of the most important environmental problems, mainly in industrial areas. The Zárate-Campana petrochemical pole, Buenos Aires, Argentina, has a history of hydrocarbon contamination of more than 100 years, so it is relevant to recover these contaminated areas through the development of site-specific bioremediation technologies that are compatible with the environment. In this work, biostimulation strategy to remediate chronically hydrocarbon-contaminated soil was approached by the addition of nutrients such as nitrogen (N) and phosphorus (P) in order to evaluate the influence of these on the growth of the autochthonous microflora. Therefore, the response-surface methodology as a statistical tool was used to predict the optimum values of N and P concentration with the aim of obtaining the maximum total hydrocarbon removal in the soil. Microcosm systems were carried out into flasks containing contaminated samples belonging to RHASA refinery areas. Different N (NaNO3) and P (Na2HPO4) concentrations were added to each system according to central composite design, and incubated at 20-25°C for 90 days. Hydrocarbon concentration content was measured by gas chromatography as the response of the model. Results showed that the addition of 0.589 g N/kg and 0.304 g P/kg leads to the highest hydrocarbon removal efficiency, decreasing from 6881 ppm to 728 ppm. In addition biostimulation strategy was compared with natural attenuation and 89.71% of total hydrocarbons were removed when the biostimulation was applied, while in natural attenuation was 72.06%. In both treatments, total aerobic heterotrophic bacteria increased during 90 days, whereas the count of hydrocarbon degrading bacteria remained stable. The biostimulation strategy approached in this work showed to be a promising alternative to remediate the soils of the study site.Item Aplicación de cepas autóctonas en estrategia de bioaumento para remediar suelos crónicamente contaminados con hidrocarburos.(Congreso Argentino de Microbiología Agrícola y Ambiental, 2021-09) Conde Molina, Débora; Liporace, Franco; Quevedo, CarlaUno de los problemas ambientales más importantes es la contaminación con hidrocarburos del petróleo, principalmente en las zonas industriales. El polo petroquímico Zárate -Campana, Buenos Aires, Argentina presenta un historial de contaminación con hidrocarburos de más de 100 años, es por eso que resulta importante la recuperación de estas áreas contaminadas a partir del desarrollo de tecnologías de biorremediación sitio específicas, compatibles con el medio ambiente. En este trabajo se estudiaron 6 cepas de bacterias degradadoras de hidrocarburos TK1A2, MT1A3, LG1A, AG1A, CO1A1 y CO1A2, aisladas de sitios crónicamente contaminados con hidrocarburos e identificadas en los géneros Pseudomonas, Cellulosimicrobium y Ochrobactrum. A fin de evaluar la producción de biomasa y biosurfactantes, las cepas aisladas fueron cultivadas en medio mínimo salino con diferentes fuentes de carbono (mezcla de hidrocarburos, glucosa, glicerol, suero de leche bovino, suero de leche ovino, aceite de girasol refinado, aceite de girasol alto oleico, aceite de maní crudo, aceite de maní frito o aceite de camelina) y de nitrógeno (NaNO3, NH4Cl urea). Si bien todas las cepas fueron capaces de crecer en todas las fuentes de carbono y nitrógeno ensayadas, en presencia de aceite de maní crudo, exhibieron mayor producción de biomasa. Con respecto a las fuentes de nitrógeno estudiadas, las cepas MT1A3, LG1A, AG1A y CO1A2 tuvieron mayor crecimiento en NaNO3, mientras que las cepas TK1A2 y CO1A1 crecieron manera similar en las fuentes de nitrógeno. MT1A3, TK1A2, CO1A1 y CO1A2 no mostraron ser productoras de biosurfactantes en las todas las condiciones ensayadas, mientras que en los medios de cultivos con LG1A y AG1A se registró disminución de la tensión superficial con respecto a los controles en varios de los medios formulados. Resultando ser AG1A en glicerol la mejor condición para producir biosurfactantes. Partiendo de estos resultados, todas las cepas fueron cultivadas en un mismo medio de cultivo con el objetivo de emplear esta mezcla en estrategias de bioaumento en un sistemas de microcosmos para la remoción de hidrocarburos de un suelo crónicamente contaminado. El tratamiento mostró que las bacterias aeróbicas heterótrofas totales aumentaron durante los 90 días que duró el ensayo, mientras que el crecimiento de bacterias degradadoras de hidrocarburos se mantuvo estable. Paralelamente, se observó una degradación de 84,17% de hidrocarburos totales, cuando se aplicó el bioaumento, mientras que en el control (atenuación natural) fue del 72,06%. En base a estos resultados, las cepas estudiadas muestran un gran potencial para ser usadas como bioaumento en sistemas de microcosmos, siendo una alternativa prometedora combinada con una estrategia de bioestimulación para remediar los suelos del sitio de estudio.Item Evaluation of xylanse, alpha-amylase and cellulase production from Cellulosimicrobium sp. using a sweet potatoe root residues medium.(NUFT, 2021-09) Conde Molina, Débora; Tubio, Gisela; Corbino, GracielaEnzymes such as xylanase, alpha-amylase and cellulase are widely used in the food industry, mainly in baking. Most enzyme production processes have focused on fungi as producer of enzymes, however, bacterial producers (have) been less studied. On the other hand, search for low-cost and easily available raw materials that can be used as fermentable substrates is one of the most interesting challenges in biotechnology. In this work, we evaluated a biotechnological process for the valorization of sweet potato root residues as carbon source in order to obtain xylanase, alpha-amylase and cellulose from Cellulosimicrobium sp. The three enzymes evaluated were detected from Cellulosimicrobium sp. CO1A1 when bacteria were harvested at 5 days of incubation. Enzyme activities were not detected in the supernatant culture, however, they were registered in the cell pellet, being 2.1 ± 0.1 U/mL for xylanase, 1.6 ± 0.1 U/mL for alpha-amylase and 0.8 ± 0.1 U/mL for cellulose. We conclude that Cellulosimicrobium sp. CO1A1 is able to produce xylanase, alpha-amylase and cellulose using an alternative low-cost carbon source. Further testing will be needed to study xylanase production from Cellulosimicrobium sp. in order to generate a value-added product from the transformation of a residue product of agricultural activity.Item Use of sweet potato root residues as carbon source for the growth of xylanase-producing Cellulosimicrobium sp.(NUFT, 2021-09) Conde Molina, Débora; Corbino, GracielaApplication of sweet potato root (SRP) residues as an alternative carbon source to formulate a culture medium for the growth of xylanase-producing microorganisms, is presented in this article. Six commercial varieties of SPR were tested for evaluating the growth of Cellulosimicrobium sp. CO1A strain in shaken flask cultures. Results showed that Cellulosimicrobium sp. CO1A1 was able to grow in a medium formulated with SPR. Biomass estimated by optical density was the most appropriate method for the medium evaluated. Additionally, biomass did not show significant differences (p>0.05) between commercial varieties of SPR, being between 8.12 and 9.26 of OD. All the varieties of RPS tested in this work are equally promising source to be applied in a bioprocess to obtain xylanase by Cellulosimicrobium sp. CO1A1.Item Valorización de un cultivo andino (yacón) mediante la producción de una fitasa de levadura asociada a la célula mediante un proceso estadísticamente optimizado.(6to Simposio Argentino de Procesos Biotecnológico, 2021-08) Conde Molina, Débora; Novelli Poisson, Guido; Iannone, Leopoldo; Galvagno, Miguel AngelEl Yacón, Smallanthus sonchifolius (Asteraceae) es un cultivo tradicional andino pre-incaico extendido desde Colombia hasta el norte de Argentina. En sus raíces reservantes acumula hasta un 70% del peso en fructooligosacáridos (FOS, oligómeros de fructosa unidos por enlaces (2→1)-β-glicosídicos), sacarosa y fructosa. En 1981 la FAO declaró al yacón en estado de emergencia promoviendo su conservación y uso sostenible. En los alimentos para animales, elaborados en base a cereales el 80% del fósforo se encuentra en forma de ácido fítico (hexakis[dihidrogeno(fosfato)] de (1r,2R,3S,4s,5R,6S)-ciclohexano-1,2,3,4,5,6-hexailo). El ácido fítico actúa como antinutriente al ser quelante de micronutrientes, Zn y Fe. Debido a su degradación incompleta en animales monogástricos deficientes en actividad de fitasa el fósforo no puede ser asimilado por lo que pasa al medio ambiente con el correspondiente aumento de la DBO produciendo también eutrofización Por lo tanto las dietas deben ser suplementadas con el agregado de fitasa. En este trabajo se propone valorizar al yacón mediante la utilización de sus azúcares y estudiar la capacidad de la levadura Debaryomyces occidentalis para producir actividad fitasa en un medio basado en extracto de S. sonchifolius (yacón) (YM). Utilizando un diseño de optimización Box-Behnken, y analizado por metodología de superficie de respuesta se evaluaron las condiciones óptimas para la producción de fitasa en YM optimizando la concentración de YM, temperatura, pH, inóculo, concentración de (NH4)2SO4 y tiempo de fermentación en matraces agitados. Los máximos títulos de actividad fitasa se obtuvieron mediante cultivo a 28 ° C y pH 5,5, con un inóculo de 107 células/mL en medio con 0,11% p/v azúcares reductores de yacón, 0,65% p/v de (NH4)2SO4 y 16 horas de fermentación. La localización de la fitasa se determinó mediante fraccionamiento subcelular y formación de protoplastos. La actividad máxima de fitasa alcanzada en estas condiciones fue más de 6 veces mayor que en medio no optimizado. El escalado en un biorreactor de tipo STR, O2 disuelto 30% saturación, aumentó aún más la productividad de la fitasa en 1,5 veces. La fitasa producida se asoció a la fracción de la pared celular y su actividad óptima se obtuvo entre valores de rango de temperatura y pH de 75-80 ° C y 4.0-5.0, respectivamente, reteniendo el 80% de su actividad a 80 ° C durante 40 min. Los valores de Km y Vmax para fitato de la fitasa calculados a partir de gráficos de Lineawever Burk fueron 2,5 mM y 357 mU/mg de proteína, respectivamente. Los cationes Fe 2+, Cu2+ y Zn 2+ inhibieron la actividad enzimática en un 87, 48 y 35%, respectivamente. Progresivamente el aumento de la concentración de fósforo en el medio inhibió la producción de enzimas, hasta 60% con 0,1% p/v H2KPO4. En conclusión, la biomasa de levadura, la producción de fitasa y la cinética de producción en YM fueron similares a los producidos en un medio a base de melaza de caña. El yacón resultó ser un sustrato nutritivo alternativo y prometedor para producir una fitasa unida a levadura como aditivo nutricional potencialmente aplicable en la industria de piensos.Item Valorization of an Andean crop (Yacon) through the production of a yeast cell-bound phytase.(2021-08) Conde Molina, Débora; Novelli Poisson, Guido; Kronberg, Florencia; Galvagno, Miguel Angel;The suitability of the yeast Schwanniomyces (f. Debaryomyces) occidentalis to produce phytase activity on a Smallanthus sonchifolius (yacon) extract-based medium (YSM) was studied. Optimal conditions for phytase production were evaluated in YSM at 28 ◦C and pH 5.5, with an inoculum of 107 cells/mL, in shaken flasks, using a Box-Benkhen optimization design, and analyzed by response surface methodology. Phytase location was determined by subcellular fractioning and protoplast formation. Maximum phytase titres were obtained with 0.11% w/v yacon reducing sugar, 0.65% w/v (NH4)2SO4 and 16 h of fermentation. The maximum phytase activity attained under these conditions was over 6-fold higher than in non-optimized medium. Scaling-up in a STR-type bioreactor further increased phytase productivity by 1.5-fold. Phytase produced was associated to the cell wall fraction, and presented optimal temperature and pH range values of 75–80 ◦C and 4.0–5.0, respectively, retaining 80% of its activity at 80 ◦C for 40 min. Progressively increasing phosphorus concentration in the medium inhibited enzyme production, up to 60% with 0.1% w/v KH2PO4. Yeast biomass, phytase production and production kinetics in YSM were similar to those produced in a cane molasses-based medium. Yacon resulted in a promising alternative feed stock to produce a yeast-bound phytase potentially applicable in the feed industry as a nutritional additive.Item Strategies to develop healthier industrial white slice diary bread through fat, sugar and flour substitution(2021-04) Conde Molina, Débora; Quevedo, Carla; Arqueros, ValeriaIntroduction. Industrial white slice dairy bread (WSDB) is an interesting target for developing a reduced calorie bread as it contains fat and sugar in its formulation. Three commercial substitutes were evaluated in this study in order to improve nutritional profile of bread. Materials and methods. Toler Fat Less Saladas (TFLS) as fat substitute, Granofiber Sweet (GS) as sugar substitute and Granofiber Sym 200 (GS200) as flour substitute, were assessed by analyzing the dough fermentative properties using Rheofermentometer, and the dough behaviour properties on mixing–heating–cooling using Mixolab. Additionally, loaf specific volume and texture profile were measured as baking quality parameters. Results and discussion. In case of fat substitution, TFLS caused a similar effect to fat, showing high starch gelatinization. In agreement, fat and TFLS provided WSDB with similar changes in crumb texture, which led to improve the quality of bread preservation at short shelf life of end-product (5 and 10 days). Otherwise, sugar substitution influenced mainly gas production during fermentation stage. However, dough development was similar when sugar or GS was added in WSDB, thereby increasing loaf specific volume. These results may indicate that GS applied in a complex formulation bread as WSDB, provides a suitable effect like sugar. Concerning flour replacement, several rheology changes and a significant decrease of gas production occurred on GS200 added-dough. However, GS200 showed an important contribution in gas retention capacity, influencing in good dough development. Therefore, bread loaf specific volume of WSDB+GS200(3%) and WSDB+GS200(6%) showed satisfactory results, indicating the potential capacity to use GS200 on WSDB recipe to formulate high fiber bread. Conclusions. We conclude that substitutes evaluated in this work can be used for breadmaking to improve nutritious quality of bread for health benefits.Item Evaluating effect of fat, sugar and flour substitutes on properties of white slice dairy bread(2020-12-31) Conde Molina, Débora; Quevedo, Carla; Arqueros, ValeriaImproving nutritional profile food is a growing area of interest in the food industry, due to there being a raising awareness toward healthy foods. Furthermore, knowledge about the relationship between food, its physiological function and diseases is increasing, particularly in obesity, diabetes, cardiovascular diseases and some types of cancer [1, 2, 3, 4]. Therefore, food industry works with healthcare professionals, scientific community, government, and media in order to ensure that the public has accurate information on healthy food [5]. Accordingly, the improvement of the nutritional quality of bread represents an interesting alternative to accompany the planning of food policies for healthy lifestyles, due bread is one of the most consumed food products in the world, in Argentina 70 it being kg / inhab / year [6]. Particularly white slice dairy bread (WSDB) is the most important industrial bread consumed in Argentina, and it contains fat and sugar in its formulation, resulting in an interesting target to reduce calory content. Knowing the functions and responses of substitutes in dough, it is very important to establish when reducing or removing it from the baking products. Substitutes result in the induction of different bread properties; hence, these effects study should be considered in order to preserve the original quality parameters required for bread production. Bread may be successfully prepared with a reduction of fat, sugar and flour, this modification may fit into many calorie-restricted diets and the product will be similar than the unmodified original counterpart. Thus, this research aims to evaluate the effect of fat, sugar and flour substitution on fermentative and rheological properties on flour and then on WSDB. Toler Fat Less Saladas (TFLS) as fat substitute, Granofiber Sweet (GS) as sugar substitute, Granofiber Sym 200 (GS200) as flour substitute, were respectively tested in order to validate their replacement capabilities to formulate bread with better nutritional quality than originally formulated. Manuscript is organized as follows. Section I contains the introduction of the background of this investigation. Section II focuses in the process involved in the bread production and the properties of each stage. Section III provides an explanation on the determination of the fermentative and rheological properties of flour and bread formulations, including preparation of bread and bread baking quality. Section IV discusses the effects of substitutes on flour and bread properties. Section V provides the concluding remarks.Item Sodium chloride substitution in industrial white slide diary bread(2021-03) Conde Molina, Débora; Quevedo, Carla; Arqueros, ValeriaIntroduction. The effect of sodium chloride replacement was studied in industrial white slice diary bread, promoting a technological approach to decrease the sodium content from bakery products in order to respond to the World Health Organization´s recommendation to reduce dietary salt intake. Materials and methods. Granolife CV Sustisal 100 (GCVS100) was evaluated as sodium chloride substitute analyzing the dough fermentative properties by Rheofermentometer, and the dough behaviour properties on mixing–heating–cooling by Mixolab. Additionally, loaf specific volume and texture profile were considered as baking quality parameters. Results and discussion. The addition of GCVS100 or NaCl to wheat flour dough led to decrease gas production during fermentation stage. However, they significantly increased the coefficient of gas retention, promoting the improvement of the gluten network and allowing to get a dough development curve similar to dough flour. Additionally, both ingredients changed several flour dough parameters in Mixolab. Water absorption was decreased, dough stability was prolonged, gelatinization process (C3-C2) was reduced, stability of the starch gel when heated (C4- C3) was improved and retrogradation of the starch was increased. GCVS100 assessed in WSDB formula showed similar effects than NaCl. The addition of GCVS100 or NaCl to WSDB caused reduction of gas production during fermentation. Meanwhile, the coefficient of gas retention did not show significant differences between the treatments, due to WSDB formulation include compounds promoter of strengthening of the gluten structure of the dough that masked NaCl and GCVS100 effect. In this way, NaCl and GCVS100 led to decrease dough development according to less gas production. WSDB baking parameters revealed that bread loaf specific volume was significantly higher for WSDB without NaCl or GCVS100, in agreement with fermentation results. Texture profile analysis of WSDB did not showed changes in crumb firmness and springiness when NaCl or GCVS100 is added. Conclusions. The addition of GCVS100 in WSDB caused a similar effect to NaCl. The results of the present study suggest that GCVS100 exhibits a potential use to obtain sodium-free WSDB.