Engineered GH11 xylanases from Orpinomyces sp. PC‐2 improve techno‐functional properties of bread dough
2019
Passarinho, Amanda Tafuri Paniago | Ventorim, Rafaela Zandonade | Maitan‐Alfenas, Gabriela Piccolo | de Oliveira, Eduardo Basílio | Guimarães, Valéria Monteze
BACKGROUND: Endo‐1,4‐β‐xylanases have marked hydrolytic activity towards arabinoxylans. Xylanases (xynA) produced by the anaerobic fungus Orpinomyces sp. strain PC‐2 have been shown to be superior in specific activity, which strongly suggests their applicability in the bakery industry for the processing of whole‐wheat flour containing xylans. In the present study, two xylanases from this source, the small wild‐type xylanase SWT and the small mutant xylanase SM2 (V108A, A199T), were expressed in Escherichia coli, purified, characterized, tested for their ability to hydrolyze whole‐wheat flour and applied in dough processing. RESULTS: Both purified SM2 and SWT showed high specific activity against oat spelt xylan and wheat arabinoxylan, exhibiting maximum activity at pH 3–7 and 60 °C. SM2 was more thermostable than SWT, which suggests that the mutations enhanced its stability. Both SWT and SM2 were able to hydrolyze whole‐wheat flour, and evaluation of their applicability in dough processing by the sponge method indicated that use of these enzymes increased dough volume by 60% and reduced texture hardness by more than 50%, while gumminess and chewiness were reduced by 40%. CONCLUSION: The recombinant xylanases showed potential for application in bakery processing and can improve techno‐functional properties in sponges. © 2018 Society of Chemical Industry
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