Producción continua de etanol en biorreactores de lecho empacado con células de levadura inmovilizadas en residuos lignocelulósicos

RESUMEN: Los procesos continuos con células inmovilizadas son una alternativa para mejorar la eficiencia y el rendimiento de las fermentaciones alcohólicas. Recientemente, se han comenzado a evaluar materias primas derivadas de residuos agroindustriales y su aplicación como soportes promisorios para la inmovilización celular. En este trabajo se evaluó la producción continua de etanol en reactores de lecho empacado con células de levadura inmovilizadas en residuos lignocelulósicos de viruta, bagazo de caña, capacho y tusa de maíz. Se empleó glucosa como fuente de carbono para establecer las condiciones de referencia y se realizaron las fermentaciones con sacarosa comercial. Además, se evaluó como sustrato alternativo el jarabe glucosado obtenido de la harina de yuca. Las experimentaciones fueron realizadas a nivel de laboratorio en reactores de columna de 250 mL. El bagazo de caña fue el material en el que se inmovilizó mayor cantidad de células. Se obtuvo un valor de 0,047 g de Biomasa/g de soporte (gX/gC). Para la fermentación realizada con glucosa, la productividad alcanzada fue de 13,33 ± 1,5 g/L h. Un valor similar, 13,00 ± 0,02 g/L h fue alcanzado para la productividad de la fermentación con sacarosa. En las fermentaciones realizadas con jarabe glucosado, se obtuvo mayor cantidad de etanol en el proceso que empleó tusa como soporte. Se produjeron 31,99 ± 1,93 g/L de etanol y se alcanzó una productividad de 10,66 ± 0,64 g/L h. Los resultados obtenidos han permitido establecer el potencial que tienen estos residuos lignocelulósicos como soportes en la inmovilización celular para la producción en continuo de etanol, y la posibilidad de emplear el jarabe glucosado como sustrato alternativo.ABSTARCT: Continuous processes with immobilized cells are a good alternative for improving the efficiency and the performance of alcoholic fermentations. The potential use of raw materials obtained from agro-industrial waste as supports for cell immobilization was recently evaluated. In this work, we evaluated the continuous production of ethanol in packed-bed reactors with yeast cells immobilized on wood shaving, cane bagasse, corn leave, and corn cob lignocellulosic waste. We used glucose as a carbon source to establish the reference conditions and we made the fermentations with commercial sucrose. We also evaluated the glucose syrup obtained from cassava flour as alternative substrate. The experiments were performed on a laboratory level in column reactors of 250 mL. The cane bagasse was the material on which the highest amount of cells was immobilized. A value of 0.047 g Biomass/g Carrier (gX/gC) was obtained. For the fermentation performed with glucose, the productivity reached was 13.33 ± 1.5 g/L h. A similar value, 13.00 ± 0.02 g/L h was reached for the productivity of fermentation with sucrose. In the fermentations performed with glucose syrup, a higher amount of ethanol was obtained in the process that used corn cob as the carrier. 31.99 ± 1.93 g/L of ethanol was produced and the productivity of 10.66 ± 0.64 g/L h was reached. The results obtained have allowed us to establish the potential this lignocellulosic waste has as carriers for cell immobilization for the continuous production of ethanol, and the possibility of using glucose syrup as an alternative substrate

Inmovilización de levaduras en residuos lignocelulósicos para la producción de etanol en biorreactor de lecho empacado

ABSTRACT: This study is focused on the development of an immobilization process of yeast cells in waste lignocellulosic materials and their evaluation in the ethanol production by using packed bed bioreactors. We evaluated four different waste lignocellulosic materials: wood shavings, cane bagasse, corn cobs and corn leaves. The characterization made it possible to establish the microscopic structural differences between the four materials, as well as the differences in composition of lignin, cellulose, hemicelluloses and ash. A protocol for packaging materials and a quantification methodology of immobilized biomass was developed. An experimental design was conducted to determine the effects of the size of lignocellulosic materials on cell immobilization and to establish the effects of the flow rate in the immobilized cells when the fermentation is performed in packed bed bioreactors. Under the established experimental conditions we determined the size and flow rate that provided the better operational stability for the fermentation in packed bed bioreactor. The result of the study showed that the material in which the biggest amount of cells was immobilized was the sugar cane bagasse, and we obtained a value of 0.04657 dry immobilized biomass gX/gS (grams of dry biomass per grams of lignocellulosic material). This amount of immobilized biomass is significant compared to the values reported by other authors. As a result of the experimental design of the influence of flow and size of the carrier on the immobilization, it was established that there is no significant statistical difference in the range of the values used in the experiment (size of 3.4; 6.7 and 10 mm and flow rate of 0.36; 1.6 and 3.33 ml/s), so the best conditions for cell immobilization could be established taking into account the operational conditions and system stability. The size of the carrier selected was 3.4 mm and the flow rate of 0.36 ml/s. In the fermentations carried out in packed bed bioreactors with the biocatalyst (carrier + yeast), it was possible to obtain an increase of the amount of immobilized cells up to a value of 0.1444 ± 0.0061 grams of biomass after 12 hours of fermentation. Ethanol production using these biocatalysts reached a value of 20 g/L in 12 hours fermentation batch, equivalent to a volumetric productivity of 1.67 g/Lh. The results have established the implementation potential of ethanol production by continuous fermentation with immobilized cells in waste lignocellulosic materials.RESUMEN: El presente estudio se ha orientado hacia el desarrollo de un proceso de inmovilización de células de levaduras en residuos de materiales lignocelulosicos y a su evaluación en la producción de etanol mediante el uso de biorreactores de lecho empacado. Se evaluaron cuatro diferentes residuos de materiales lignocelulosicos: viruta de madera, bagazo de caña, tusa y capacho de maíz. La caracterización realizada permitió establecer las diferencias estructurales microscópicas que presentan los cuatro materiales, al igual que las diferencias en composición de lignina, celulosa, hemicelulosa y cenizas. Se desarrolló un protocolo para el acondicionamiento de los materiales y una metodología de cuantificación de biomasa inmovilizada. Se realizó un diseño experimental para determinar el efecto del tamaño de los materiales lignocelulósicos en la inmovilización celular y para establecer el efecto del caudal empleado en el proceso de inmovilización en los biorreactores de lecho empacado. Bajo las condiciones experimentales establecidas se determinó el tamaño y caudal que mejor estabilidad operacional proporcionaron a la fermentación en el biorreactor de lecho empacado. Como resultado del estudio se obtuvo que el material en el que se inmovilizó mayor cantidad de células de levadura fue el bagazo de caña, se obtuvo un valor de biomasa seca inmovilizada de 0,04657 gX/gS (gramos de biomasa por gramos de material lignocelulósico empleado). Esta cantidad de biomasa inmovilizada es significativa comparada con los valores reportados por otros autores. Como resultado del diseño experimental de la influencia del caudal y el tamaño del soporte en la inmovilización se pudo establecer que no existe diferencia estadística significativa en el rango de valores empleados en la experimentación (tamaño de 3,4, 6,7 y 10 mm y caudal de 0,36, 1,6 y 3,33 ml/s), así que las mejores condiciones para la inmovilización celular pudieron ser establecidas teniendo en cuenta las condiciones operacionales y estabilidad del sistema, el tamaño de soporte empleado fue de 3,4 mm y el caudal de 0,36 ml/s. En las fermentaciones realizadas en los biorreactores de lecho empacado con el biocatalizador (soporte + levaduras), se logró obtener un aumento en la cantidad de células inmovilizadas hasta un valor de 0,1444 ± 0,0061 gramos de biomasa inmovilizada después de 12 horas de fermentación. La producción de etanol empleando estos biocatalizadores alcanzó un valor de 20 g/L en 12 horas de fermentación por lote, es decir, una productividad volumétrica de 1,67 g/Lh. Los resultados obtenidos han permitido establecer el potencial de la implementación de la producción de etanol mediante fermentaciones en continuo con células inmovilizadas en residuos de materiales lignocelulosicos.

Physicochemical characterization of the yeast cells and lignocellulosic waste used in cell immobilization for ethanol production

Ethanol is one of the leading alternative fuels. Efforts have increased the development of technologies for producing ethanol efficiently and economically. The continuous fermentation using yeast cells immobilized in lowcost materials is presented as an excellent alternative. We used four lignocellulosic wastes for the inmobilization process. The materials were characterized physicochemically. The composition was determined by the Van Soest method. Zeta potential was measured to establish the hydrophobic or hydrophilic character of the material surfaces. The contact angles measurements were used to confirm the hydrophobic or hydrophilic character and the free energies interaction was established. Images were obtained by scanning electron microscope, and determination of surface areas and volumes was performed by adsorption and desorption isotherms. It was established that cell surface properties are modified by the immobilization process to which they are subjected. It was evident that cell immobilization depended on the properties of the carrier, as well as cell surface properties. Thus, in order to improve the process of cell immobilization, it is essential to understand the type of carriercell interactions that occur during the immobilization process, making necessary the knowledge of the main surface characteristics of both the media and of cells that can affect the process.This research was in collaboration with the IBB Institute for Biotechnology and Bioengineering Centre of biological Engineering University of Minho, Campus de Gualtar, Braga, Portugal.info:eu-repo/semantics/publishedVersio

Continuous production of ethanol in bed packed bioreactors with immobilized yeast cells on lignocellulosic waste

The continuous processes with immobilized cells are a good alternative for improving the efficiency and the performance of alcoholic fermentations. Raw materials derived from agroindustrial waste and their usage for promising carries have recently been tested for the cell immobilization. In this work, we evaluated the continuous production of ethanol in bed packed reactors with yeast cells immobilized on lignocellulosic waste of wood shaving, cane bagasse, corn leave and corn cob. We used glucose as carbon source to establish the reference conditions and we made the fermentations with commercial sucrose. We also evaluated the glucose syrup obtained from cassava flour as alternative substrate. The experiments were performed on a laboratory level in column reactors of 250 mL. The cane bagasse was the material on which the highest amount of cells was immobilized. A value of 0.047 g Biomass/g Carrier (gX/gC) was obtained. For the fermentation performed with glucose, the productivity reached was 13.33 ± 1.5 g/L h. A similar value, 13.00 ± 0.02 g/L h was reached for the productivity of fermentation with sucrose. In the fermentations performed with glucose syrup, a higher amount of ethanol was obtained in the process that used corn cob as carrier. 31.99 ± 1.93 g/L of ethanol was produced and the productivity of 10.66 ± 0.64 g/L h was reached. The results obtained have allowed us establish the potential these lignocellulosic waste has as carriers for cell immobilization for the continuous production of ethanol, and the possibility of using the glucose syrup as alternative substrate

Effects of aeration, agitation and pH on the production of mycelial biomass and exopolysaccharide from the filamentous fungus Ganoderma lucidum1

Due to the increasing demand for functional foods and dietary supplements, mushroom production has increased significantly in recent years, which is why the study of operational conditions affecting the biotechnology cultivation of these mushrooms has become the aim of numerous studies. This study attempted to know the effect of pH, agitation and aeration on the biomass and polysaccharides production of filamentous fungus Ganoderma lucidum in fermentations made in a 5L bioreactor. The results allowed to establish that a bistage pH strategy (one stage with a fixed pH control, and a second stage without control), combined with hydrodynamic stress, which involves high agitation and high aeration, favors biomass and polysaccharides production, achieving increases of up to 100% compared to that obtained with the reference conditions.Debido a la creciente demanda de alimentos funcionales y suplementos dietarios, la producción de hongos ha aumentado significativamente en los últimos años, razón por la cual el estudio de las condiciones operacionales que afectan el cultivo biotecnológico de estos hongos se ha convertido en el objeto de estudio de muchos investigadores. Con esta investigación se busca evaluar el efecto que tiene el pH, la agitación y la aireación sobre la producción de biomasa y polisacáridos de un hongo filamentoso en fermentaciones realizadas en biorreactor de 5L. Los resultados permitieron establecer que una estrategia de pH escalonado que incluye dos etapas una con control a un pH fijo y una segunda etapa sin control, combinada con estrés hidrodinámico, que implica alta agitación y alta aireación, favorece la producción de biomasa y polisacáridos, alcanzando incrementos de hasta 100% comparados con los obtenido con las condiciones de referencia

Guía de práctica clínica para la prevención, diagnóstico, tratamiento y rehabilitación de la falla cardiaca en población mayor de 18 años, clasificación B, C y D

La falla cardíaca es un síndrome clínico caracterizado por síntomas y signos típicos de insuficiencia cardíaca, adicional a la evidencia objetiva de una anomalía estructural o funcional del corazón. Guía completa 2016. Guía No. 53Población mayor de 18 añosN/

Memorias de investigación: Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.

Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.Esta publicación busca divulgar investigaciones y producción académica en diferentes disciplinas, realizadas por estudiantes y docentes de UNIMINUTO Seccional Antioquia – Chocó, así como dar a conocer los semilleros de investigación que participaron en la V Feria de Semilleros, con el fin de visibilizar el trabajo que realiza el Centro de Investigación para el Desarrollo de UNIMINUTO Bello —CIDUB—, con respecto a debates académicos y espacios de interlocución. Igualmente, permite que la comunidad educativa conozca los temas de investigación y las discusiones que se están dando entre los semilleros y grupos de investigación, para así buscar puntos de encuentro y sinergias entre los investigadores. Adicionalmente, el texto se convierte en una invitación para que se vinculen otros investigadores, docentes, estudiantes e incluso otras instituciones a los procesos investigativos coordinados desde el CIDUB

Memorias de investigación: Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.

Feria de Semilleros y Jornadas de Investigación de uniminuto, Seccional Antioquia - Chocó.Esta publicación busca divulgar investigaciones y producción académica en diferentes disciplinas, realizadas por estudiantes y docentes de UNIMINUTO Seccional Antioquia – Chocó, así como dar a conocer los semilleros de investigación que participaron en la V Feria de Semilleros, con el fin de visibilizar el trabajo que realiza el Centro de Investigación para el Desarrollo de UNIMINUTO Bello —CIDUB—, con respecto a debates académicos y espacios de interlocución. Igualmente, permite que la comunidad educativa conozca los temas de investigación y las discusiones que se están dando entre los semilleros y grupos de investigación, para así buscar puntos de encuentro y sinergias entre los investigadores. Adicionalmente, el texto se convierte en una invitación para que se vinculen otros investigadores, docentes, estudiantes e incluso otras instituciones a los procesos investigativos coordinados desde el CIDUB

Determination of Electrogenic Potential and Removal of Organic Matter from Industrial Coffee Wastewater Using a Native Community in a Non-Conventional Microbial Fuel Cell

Microbial fuel cells (MFCs) are an alternative to conventional wastewater treatments that allow for the removal of organic matter and cogeneration of electrical energy, taking advantage of the oxidation–reduction metabolism of organic compounds conducted by microorganisms. In this study, the electrogenic potential and the capacity for the reduction of the organic matter of native microbial communities in wastewater from the wet processing of coffee were evaluated using open-cathode MFCs. To determine the electrogenic potential, a factorial experimental design was proposed in which the origin of the residual water and the source of the inoculum were evaluated as factors. The MFCs operated for 21 days in both open-circuit and closed-circuit operation modes. Voltage records, current determinations, and chemical oxygen demand (COD) analyses were used to establish the power reached in the electrochemical system and the degree of the decontamination of the wastewater. During the MFC operation, voltages from 200–400 mV and power and current densities from 300–900 mW·m−2 and 10–22 mA·m−2, respectively, were reached. The inoculum used, with a statistical significance of α −1·day−1, indicating the metabolic capacity of the microbial community in the MFCs to achieve the decontamination of wastewater from the coffee agroindustry. It was shown the implementation of bioelectrochemical systems constituted a viable option for the treatment of agricultural waste in Colombia. In addition, it was observed the capacity to cogenerate electrical energy from the biotransformation of the polluting organic matter in the effluents of the coffee industry

Microorganisms and Microbial Communities in Bioelectrochemical Systems for Wastewater Bioremediation and Energy Generation

Water resource sustainability is a critical global concern, leading to extensive scientific research. Proposed alternatives for wastewater effluent use include the promising Bioelectrochemical Systems (BES) that not only treat wastewater effectively but also generate electricity, produce biofuels, and synthesize valuable compounds through integrated microbial and electrochemical processes. BES research aims to enhance device design and develop superior electrochemical materials for optimal performance. The efficiency of treatment and energy co-generation depends on the metabolic characteristics of microbial communities responsible for oxidation-reduction processes in wastewater. The diversity of these communities, along with electron transport mechanisms and metabolic pathways, significantly impacts BES functionality and effectiveness. This study focuses on microorganisms in various BES setups, presenting their electrochemical performance. It compiles data on microbial ecology, emphasizing controlled communities and model microorganisms from wastewater treatment systems. The study highlights the scarce research on native microbial communities for agroindustrial wastewater. Its main goal is to consolidate information on microorganisms with electrogenic capacity, demonstrating their potential in different bioelectrochemical systems. These applications can transform wastewater bioremediation and enable the production of green energy, biofuels, and high-value compounds