The functional properties of a xyloglucanase (GH12) of Aspergillus terreus expressed in Aspergillus nidulans may increase performance of biomass degradation

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Vitcosque, Gabriela Leal ; Ribeiro, Liliane Fraga Costa ; de Lucas, Rosymar Coutinho ; da Silva, Tony Marcio ; Ribeiro, Lucas Ferreira ; de Lima Damasio, Andre Ricardo ; Farinas, Cristiane Sanchez ; Lopes Goncalves, Aline Zorzetto ; Segato, Fernando ; Buckeridge, Marcos Silveira ; Jorge, Joao Atilio ; Polizeli, Maria de Lourdes T. M.

• Document type: Journal article
• Source: Applied Microbiology and Biotechnology; v. 100, n. 21, p. 9133-9144, NOV 2016.
• Web of Science Citations: 3

Abstract

Filamentous fungi are attractive hosts for heterologous protein expression due to their capacity to secrete large amounts of enzymes into the extracellular medium. Xyloglucanases, which specifically hydrolyze xyloglucan, have been recently applied in lignocellulosic biomass degradation and conversion in many other industrial processes. In this context, this work aimed to clone, express, and determine the functional properties of a recombinant xyloglucanase (AtXEG12) from Aspergillus terreus, and also its solid-state (SSF) and submerged (SmF) fermentation in bioreactors. The purified AtXEG12 showed optimum pH and temperature of 5.5 and 65 A degrees C, respectively, demonstrating to be 90 % stable after 24 h of incubation at 50 A degrees C. AtXEG12 activity increased in the presence of 2-mercaptoethanol (65 %) and Zn+2 (45 %), while Cu+2 and Ag+ ions drastically decreased its activity. A substrate assay showed, for the first time for this enzyme's family, xylanase activity. The enzyme exhibited high specificity for tamarind xyloglucan (K (M) 1.2 mg mL(-1)) and V (max) of 17.4 mu mol min(-1) mg(-1) of protein. The capillary zone electrophoresis analysis revealed that AtXEG12 is an endo-xyloglucanase. The heterologous xyloglucanase secretion was greater than the production by wild-type A. terreus cultivated in SmF. On the other hand, AtXEG12 activity reached by SSF was sevenfold higher than values achieved by SmF, showing that the expression of recombinant enzymes can be significantly improved by cultivation under SSF. (AU)

• FAPESP's process: 12/20549-4 - Secretion of heterologous glycoproteins in Aspergillus: effect of glycosylation pattern in functional parameters of glycosyl hydrolases
• Grantee: André Ricardo de Lima Damasio
• Support type: Program for Research on Bioenergy (BIOEN) - Young Investigators Grants
• FAPESP's process: 14/18714-2 - Enzymatic oxidation of sugarcane bagasse: discovery, characterization and new application of oxidative enzymes active in carbohydrates, applied to the enhancement of a fungal cell factory
• Grantee: Fernando Segato
• Support type: Program for Research on Bioenergy (BIOEN) - Young Investigators Grants
• FAPESP's process: 10/10184-3 - Development of an enzymatic cocktail for application in biorefinery
• Grantee: Liliane Fraga Costa Ribeiro
• Support type: Scholarships in Brazil - Doctorate