An integrated approach to the sustainable production of xylanolytic enzymes from Aspergillus niger using agroindustrial by-products

TADDIA ANTONELA; BRANDALEZE GERÓNIMO NICOLÁS; BOGGIONE MARÍA JULIA; BORTOLATO SANTIAGO ANDRÉS; TUBIO GISELA

PREPARATIVE BIOCHEMISTRY AND BIOTECHNOLOGY

TAYLOR & FRANCIS INC

Lugar: Londres; Año: 2020

1082-6068

Xylanolytic enzymes were produced by Aspergillus niger NRRL3 grown on agro-industrial 3 by-products obtained from the processing of wheat flour without pre-treatment. Significant 4 parameters for xylanase production were screened and optimized. The xylanolytic activity 5 obtained in the optimized extract was 138.3 ± 2.6 U/mL, higher than the activity obtained in 6 an unoptimized medium (14.5 ± 0.3 U/mL) in previous work. The optimized fermentation 7 process was performed in a successful 40-fold scale-up. The optimized enzymatic extract 8 obtained was characterized by LC-MS. Nine enzymes were identified as constituents of the 9 xylanolytic complex. Moreover, the xylanolytic enzymes were stable until 60°C and over a 10 broad range of pH. Sodium, calcium, cobalt and manganese had no inhibitory effect, 11 meanwhile 1% w/v polyvinylpyrrolidone and 1% w/v dextran increased the xylanolytic 12 activity. The saccharification efficiency was evaluated and the surface morphology of the 13 lignocellulosic substrate was monitored by using scanning electron microscopy (SEM). The 14 synergistic combination of the extracted (o purified) xylanolytic enzymes permitted a higher 15 xylan conversion beneficial for diverse applications, such as bioethanol production. Thus, 16 these agroindustrial by-products can be used within the framework of a circular economy, 17 rendering an added value bioproduct, which is reused in the industry