GH11 xylanase from Emericella nidulans with low sensitivity to inhibition by ethanol and lignocellulose-derived phenolic compounds.

Autor:	Silva Cde O; Laboratory of Enzymology, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil caio.gorgulho@gmail.com., Aquino EN; Laboratory of Enzymology, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil Laboratory of Biochemistry and Protein Chemistry, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil., Ricart CA; Laboratory of Biochemistry and Protein Chemistry, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil., Midorikawa GE; Laboratory of Microbiology, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil., Miller RN; Laboratory of Microbiology, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil., Filho EX; Laboratory of Enzymology, Department of Cellular Biology, University of Brasília, Brasília, DF, Zip Code 70910-900, Brazil.
Jazyk:	angličtina
Zdroj:	FEMS microbiology letters [FEMS Microbiol Lett] 2015 Jul; Vol. 362 (13), pp. fnv094. Date of Electronic Publication: 2015 Jun 03.
DOI:	10.1093/femsle/fnv094
Abstrakt:	An endo-β-1,4-xylanase (X22) was purified from crude extract of Emericella nidulans when cultivated on submerged fermentation using sugarcane bagasse as the carbon source. The purified protein was identified by mass spectrometry and was most active at pH and temperature intervals of 5.0-6.5 and 50-60°C, respectively. The enzyme showed half-lives of 40, 10 and 7 min at 28, 50 and 55°C, respectively, and pH 5.0. Apparent Km and Vmax values on soluble oat spelt xylan were 3.39 mg/mL and 230.8 IU/mg, respectively, while Kcat and Kcat/Km were 84.6 s(-1) and 25.0 s(-1) mg(-1) mL. Incubation with phenolic compounds showed that tannic acid and cinnamic acid had an inhibitory effect on X22 but no time-dependent deactivation. On the other hand, ferulic acid, 4-hydroxybenzoic acid, vanillin and p-coumaric acid did not show any inhibitory effect on X22 activity, although they changed X22 apparent kinetic parameters. Ethanol remarkably increased enzyme thermostability and apparent Vmax and Kcat values, even though the affinity and catalytic efficiency for xylan were lowered. (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
Databáze:	MEDLINE
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