A Thermostable Aspergillus fumigatus GH7 Endoglucanase Over-Expressed in Pichia pastoris Stimulates Lignocellulosic Biomass Hydrolysis

Autor(es)

Bernardi, Aline Vianna ; Yonamine, Deborah Kimie ; Uyemura, Sergio Akira ; Dinamarco, Taisa Magnani

• Tipo de documento: Artigo Científico
• Fonte: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES; v. 20, n. 9, p. 15-pg., 2019-05-01.

Resumo

In the context of avoiding the use of non-renewable energy sources, employing lignocellulosic biomass for ethanol production remains a challenge. Cellulases play an important role in this scenario: they are some of the most important industrial enzymes that can hydrolyze lignocellulose. This study aims to improve on the characterization of a thermostable Aspergillus fumigatus endo-1,4--glucanase GH7 (Af-EGL7). To this end, Af-EGL7 was successfully expressed in Pichia pastoris X-33. The kinetic parameters K-m and V-max were estimated and suggested a robust enzyme. The recombinant protein was highly stable within an extreme pH range (3.0-8.0) and was highly thermostable at 55 degrees C for 72 h. Low Cu2+ concentrations (0.1-1.0 mM) stimulated Af-EGL7 activity up to 117%. Af-EGL7 was tolerant to inhibition by products, such as glucose and cellobiose. Glucose at 50 mM did not inhibit Af-EGL7 activity, whereas 50 mM cellobiose inhibited Af-EGL7 activity by just 35%. Additionally, the Celluclast((R)) 1.5L cocktail supplemented with Af-EGL7 provided improved hydrolysis of sugarcane bagasse in natura, sugarcane exploded bagasse (SEB), corncob, rice straw, and bean straw. In conclusion, the novel characterization of Af-EGL7 conducted in this study highlights the extraordinary properties that make Af-EGL7 a promising candidate for industrial applications. (AU)

• Processo FAPESP: 18/11231-7 - Caracterização funcional da endoglucanase GH7 de Aspergillus fumigatus
• Beneficiário: Deborah Kimie Yonamine
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 14/10466-0 - Análise transcricional do fungo Aspergillus fumigatus quando crescido em bagaço de cana-de-açúcar
• Beneficiário: Taisa Magnani Dinamarco
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOEN - Regular