Optimización de la hidrólisis para el tratamiento de residuos lignocelulósicos con enzimas de Aspergillus niger.

Abstract

The purpose of this study was to optimize the enzymatic hydrolysis process for the degradation of the cellulose present in corn stubble, by using enzymes from Aspergillus niger. During the first phase of the experimentation, 500 g of stubble were selected and characterized, determining the amount of dry matter, organic matter, ashes, crude protein, ethereal extract and lignin content. Subsequently, the pre-drying and milling of the corn stubble was carried out, prior to the alkali and acid-alkali pre-treatment processes carried out, which were dried at different temperatures. Once the previous phase was completed, enzymatic hydrolysis was carried out in the presence of a solution of cellulase enzymes of Aspergillus niger containing 39,125 U at different pH (4,0, 4,8 and 5,6), for a period of 24 hours. , 48 and 72 hours at 37 ° C. During the incubation period, the quantification of the concentrations of reducing sugars released during the reaction in each of the treatments was carried out using the DNS method. Finally, it was determined that corn stubble without pre-treatment, dried at a temperature of 60 ° C and subjected to an enzymatic hydrolysis for 72 hours at pH 4.8 (P1T4), presented a higher concentration of sugars released, being able to use lignocellulosic residues as a possible source of carbohydrates for the production of biofuels through biotechnological processes and as a substrate in cattle feed. It is important to perform new experimental tests where they are considered pre-treated waste under different alkaline conditions, in order to preserve the available cellulose without generating significant losses, which would favor the release of reducing sugars during enzymatic hydrolysis