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

Abstract EN

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.