Production of xylanase by Aspergillus sp. ART500.1 on agroindustrial residues and its biochemical properties

The aim of this work was to evaluate the use of different agro-industrial residues for the production of xylanase by Aspergillus sp. ART 100.1, as well as analyzing the biochemical properties of the enzyme. Agroindustrial residues malt bagasse, pineapple crown, açaí bagasse and soybean husk present in large quantities in the Tocantins region were used to evaluate the production of xylanase. Cultivation conditions for xylanase production were evaluated in submerged and solid-state cultivation. The highest production of xylanase in submerged cultivation was obtained using soybean husk residue (23.60 U/mL), while, for solid-state cultivation conditions, the highest production of xylanase was obtained with malt bagasse (110.00 U/g). The effect of additives to the culture medium was also evaluated, with the best result for the use of the xylose additive in the pineapple crown in solid-state cultivation. The enzyme produced in solid-state cultivation was characterized in terms of pH and temperature. The optimum activity pH was observed at 5.0 and for temperature at 55 °C. The xylanase was stable in a pH range between 4 and 5 and retained 50% of its activity at 45 °C after 110 minutes. The Aspergillus sp. ART 500.1 presents potential for the production of xylanase using agro-industrial residues, enabling the development of bioprocesses for the scaling of production.

Recovery and evaluation of cellulose from agroindustrial residues of corn, grape, pomegranate, strawberry-tree fruit and fava

Considering the expected increasing demand for cellulose fibers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fibers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological differences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have thermal properties (TOnset of 307.17 °C, TD of 330.31 °C, and ΔH of 306.04 kJ/kg) suitable for biomedical applications.