ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Characterization of a novel Aspergillus niger beta-glucosidase tolerant to saccharification of lignocellulosic biomass products and fermentation inhibitors

Alesandra Oriente, Robson Tramontina, Diandra de Andrades, Caroline Henn, Jose L. C. Silva, Rita C. G. Simão, Alexandre Maller, Maria de Lourdes T. M. Polizeli, and Marina K. Kadowaki

Centro de Cięncias Médicas e Farmacęuticas – Universidade Estadual do Oeste do Paraná R: Universitária, 2069-Cascavel, CEP 85814-110 Paraná, Brazil

E-mail: marinakk@gmail.com

Abstract: Properties of beta-glucosidase produced by Aspergillus niger URM 6642 recently isolated from the Atlantic rainforest biome and its potential tolerance to saccharification of lignocellulosic biomass products and fermentation inhibitors was evaluated. The fungus was cultivated under solid state culture conditions at 37°C with different agro-industrial wastes. High levels of beta-glucosidase (3778.9 U g⁻¹) from A. niger were obtained with rice meal as substrate under solid state culture conditions after ten days. Optimum pH for this particular beta-glucosidase activity was 4.0 although it was stable in the range of 4.0 to 7.0. The half-life (T_1/2) of beta-glucosidase at 55°C is 3 h. However, at the optimum temperature of the enzyme, 65°C, T_1/2 is 20 min. The enzyme showed tolerance to various compounds such as glucose, xylose, 5-hydroxymethyl furfural, furfural, coumarin, ethanol and acetic acid. Therefore, beta-glucosidase from the novel A. niger species may be of potential use in the saccharification of lignocellulosic biomass, as well as an additional enzyme supplement in cellulase cocktails used to increase the yield of fermentable sugars.

Keywords: Aspergillus niger – Atlantic rainforest biome – cellulase – rice meal – fermentation inhibitors

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0111

Chemical Papers 69 (8) 1050–1057 (2015)