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Archaea
Volume 2015, Article ID 978632, 6 pages
http://dx.doi.org/10.1155/2015/978632
Research Article

A Novel Highly Thermostable Multifunctional Beta-Glycosidase from Crenarchaeon Acidilobus saccharovorans

Centre “Bioengineering”, Russian Academy of Sciences, Moscow 117312, Russia

Received 10 March 2015; Revised 25 June 2015; Accepted 5 July 2015

Academic Editor: Frédéric Pecorari

Copyright © 2015 Vadim M. Gumerov et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We expressed a putative β-galactosidase Asac_1390 from hyperthermophilic crenarchaeon Acidilobus saccharovorans in Escherichia coli and purified the recombinant enzyme. Asac_1390 is composed of 490 amino acid residues and showed high sequence similarity to family 1 glycoside hydrolases from various thermophilic Crenarchaeota. The maximum activity was observed at pH 6.0 and 93°C. The half-life of the enzyme at 90°C was about 7 hours. Asac_1390 displayed high tolerance to glucose and exhibits hydrolytic activity towards cellobiose and various aryl glucosides. The hydrolytic activity with p-nitrophenyl (pNP) substrates followed the order pNP-β-D-galactopyranoside (328 U mg−1), pNP-β-D-glucopyranoside (246 U mg−1), pNP-β-D-xylopyranoside (72 U mg−1), and pNP-β-D-mannopyranoside (28 U mg−1). Thus the enzyme was actually a multifunctional β-glycosidase. Therefore, the utilization of Asac_1390 may contribute to facilitating the efficient degradation of lignocellulosic biomass and help enhance bioconversion processes.