Caracterización morfológica, fisicoquímica, mecánica y térmica de celulosa bacteriana producida por Komagataeibacter xylinus empleando semilla de palta como sustrato
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Date
2024
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Universidad Nacional de Trujillo
Abstract
El presente trabajo de investigación se realizó con el objetivo de obtener celulosa bacteriana (CB) por Komagataeibacter xylinus a partir del hidrolizado de semilla de palta en polvo (SPP). El residuo agroindustrial fue previamente seleccionado, pelado, cortado en trozos y secado a 38 °C por 2 días. Después de ello se trituraron en un molino y tamizaron con el fin de unificar el tamaño de partículas. Se realizó una extracción con etanol (96%) al residuo triturado, para eliminar todos los compuestos no estructurales o extractivos. El residuo agroindustrial libre de extractivos fue sometido a una hidrólisis ácida con ácido sulfúrico al 4,23% y fue posteriormente centrifugado; la fracción líquida o sobrenadante resultante de la centrifugación, se usó para cuantificar los azúcares reductores por espectrofotometría UV-Vis (51,16 g/L), e identificar los azúcares estructurales mediante HPLC (glucosa, maltosa, xilosa y manosa). Se produjeron membranas de CB en medio Hestrin–Schramm (HS), en el cual se empleó sacarosa como fuente de carbono. Así mismo, se utilizó medio de cultivo Hestrin–Schramm modificado (HSM) sustituyendo la sacarosa por el hidrolizado de semilla de palta en polvo (SPP) para producir dichas membranas. Las condiciones de cultivo fueron durante 10 días a 30 °C en condiciones estáticas, después, las muestras se secaron a 45 °C en estufa por 24 h hasta peso constante. Se determinó el rendimiento volumétrico y tasa de producción de las membranas de CB en los medios HS y HSM, también se calculó el porcentaje de azúcares reductores (AR) consumidos en ambos medios. Las membranas de CB-HS Y CB-HSM obtenidas se caracterizaron por contenido de humedad, densidad, microscopía electrónica de barrido (SEM), difractometría de rayos X (XRD), espectroscopía infrarroja por transformada de fourier (FTIR), análisis mecánico, análisis termogravimétrico (TGA) y calorimetría diferencial de barrido (DSC). Los resultados obtenidos confirmaron que la sustitución de hidrolizado de semilla de palta en polvo (SPP) por sacarosa en el medio HS para la producción de CB por Komagataeibacter xylinus, no afectaría ni alteraría significativamente sus propiedades.
ABSTRACT The present research work was carried out with the objective of obtaining bacterial cellulose (CB) by Komagataeibacter xylinus from the hydrolyzate of avocado seed powder (SPP). The agroindustrial waste was previously selected, peeled, cut into pieces and dried at 38 °C for 2 days. After that, they were crushed in a mill and sieved in order to unify the particle size. An extraction with ethanol (96%) was carried out on the crushed residue, to eliminate all non-structural or extractive compounds. The agroindustrial residue free of extractives was subjected to acid hydrolysis with 4.23% sulfuric acid and was subsequently centrifuged; The liquid fraction or supernatant resulting from centrifugation was used to quantify reducing sugars by UV-Vis Spectrophotometry (51.16 g/L), and identify structural sugars by HPLC (glucose, maltose, xylose and mannose). CB membranes were produced in Hestrin–Schramm (HS) medium, in which sucrose was used as a carbon source. Likewise, modified Hestrin–Schramm culture medium (HSM) was used, replacing sucrose with powdered avocado seed hydrolyzate (SPP) to produce said membranes. The culture conditions were for 10 days at 30 °C in static conditions, then the samples were dried at 45 °C in an oven for 24 h until constant weight. The volumetric yield and production rate of the CB membranes in the HS and HSM media were determined, and the percentage of reducing sugars (AR) consumed in both media was calculated. The obtained CB-HS and CB-HSM membranes were characterized by moisture content, density, Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Mechanical Analysis, Analysis Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC). The results obtained confirmed that the replacement of powdered avocado seed hydrolyzate (SPP) with sucrose in the HS medium for the production of CB by Komagataeibacter xylinus would not significantly affect or alter its properties.
ABSTRACT The present research work was carried out with the objective of obtaining bacterial cellulose (CB) by Komagataeibacter xylinus from the hydrolyzate of avocado seed powder (SPP). The agroindustrial waste was previously selected, peeled, cut into pieces and dried at 38 °C for 2 days. After that, they were crushed in a mill and sieved in order to unify the particle size. An extraction with ethanol (96%) was carried out on the crushed residue, to eliminate all non-structural or extractive compounds. The agroindustrial residue free of extractives was subjected to acid hydrolysis with 4.23% sulfuric acid and was subsequently centrifuged; The liquid fraction or supernatant resulting from centrifugation was used to quantify reducing sugars by UV-Vis Spectrophotometry (51.16 g/L), and identify structural sugars by HPLC (glucose, maltose, xylose and mannose). CB membranes were produced in Hestrin–Schramm (HS) medium, in which sucrose was used as a carbon source. Likewise, modified Hestrin–Schramm culture medium (HSM) was used, replacing sucrose with powdered avocado seed hydrolyzate (SPP) to produce said membranes. The culture conditions were for 10 days at 30 °C in static conditions, then the samples were dried at 45 °C in an oven for 24 h until constant weight. The volumetric yield and production rate of the CB membranes in the HS and HSM media were determined, and the percentage of reducing sugars (AR) consumed in both media was calculated. The obtained CB-HS and CB-HSM membranes were characterized by moisture content, density, Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Mechanical Analysis, Analysis Thermogravimetric (TGA) and Differential Scanning Calorimetry (DSC). The results obtained confirmed that the replacement of powdered avocado seed hydrolyzate (SPP) with sucrose in the HS medium for the production of CB by Komagataeibacter xylinus would not significantly affect or alter its properties.
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Keywords
Celulosa bacteriana, Komagataeibacter xylinus, Residuo, Semilla de palta, Hidrolizado