title: Cloning, expression, and characterization of a thermostable GH7 endoglucanase from Myceliophthora thermophila capable of high-consistency enzymatic liquefaction.
abstract: An endoglucanase gene from the thermophilic fungus Myceliophthora thermophila, belonging to the glycoside hydrolase family 7, was functionally expressed in methylotrophic yeast Pichia pastoris. The putative endoglucanase from the genomic DNA was successfully cloned in P. pastoris X-33 and the recombinant enzyme was purified to its homogeneity (65 kDa) and subsequently characterized. Substrate specificity analysis revealed that the enzyme exhibits high activity on substrates containing β-1,4-glycosidic bonds such as carboxymethyl cellulose, barley β-glucan, and cello-oligosaccharides, as well as activity on xylan-containing substrates, including arabinoxylan and oat spelt xylan. MtEG7a was proved to liquefy rapidly and efficiently pretreated wheat straw, indicating its key role to the initial step of hydrolysis of high-solids lignocellulose substrates. High thermostability of the endoglucanase reflects potential commercial significance of the enzyme.
authors.affiliation: Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 5 Iroon Polytechniou Str, Zografou Campus, 15700, Athens, Greece.
authors.forename: Anthi C
authors.initials: AC
authors.lastname: Karnaouri
authors.forename: Evangelos
authors.initials: E
authors.lastname: Topakas
authors.forename: Paul
authors.initials: P
authors.lastname: Christakopoulos
mesh_terms: D002480:Cellulase / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004795:Enzyme Stability; D008970:Molecular Weight; D010843:Pichia / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D020037:Sordariales / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D002480:Cellulase