title: A Novel Highly Thermostable Multifunctional Beta-Glycosidase from Crenarchaeon Acidilobus saccharovorans.
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.
authors.affiliation: Centre "Bioengineering", Russian Academy of Sciences, Moscow 117312, Russia.
authors.forename: Vadim M
authors.initials: VM
authors.lastname: Gumerov
authors.affiliation: Centre "Bioengineering", Russian Academy of Sciences, Moscow 117312, Russia.
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Rakitin
authors.affiliation: Centre "Bioengineering", Russian Academy of Sciences, Moscow 117312, Russia.
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Mardanov
authors.affiliation: Centre "Bioengineering", Russian Academy of Sciences, Moscow 117312, Russia.
authors.forename: Nikolai V
authors.initials: NV
authors.lastname: Ravin
mesh_terms: D019615:Crenarchaeota / Q000201:enzymology* / Q000235:genetics; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005960:Glucosides / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013696:Temperature; D013997:Time Factors; D001617:beta-Glucosidase / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005960:Glucosides; D011994:Recombinant Proteins; D001617:beta-Glucosidase