초록
<P><B>Abstract</B></P> <P>Hydrolysis of lignocellulosic biomass depends on the concerted actions of cellulases and accessory proteins. In this work we examined the combined action of two auxiliary proteins from the brown rot fungus <I>Gloeophyllum trabeum</I>: a family AA9 lytic polysaccharide monooxygenase (GtLPMO) and a GH10 xylanase (GtXyn10A). The <I>e</I>nzymes were produced in the heterologous host <I>Pichia pastoris.</I> In the presence of an electron source, GtLPMO increased the activity of a commercial cellulase on filter paper, and the xylanase activity of GtXyn10A on beechwood xylan. Mixtures of GtLPMO, GtXyn10A and Celluclast 1.5L were used for hydrolysis of pretreated wheat straw. Results showed that a mixture of 60% Celluclast 1.5L, 20% GtXyn10A and 20% GtLPMO increased total reducing sugar production by 54%, while the conversions of glucan to glucose and xylan to xylose were increased by 40 and 57%, respectively. This suggests that GtLPMO can contribute to lignocellulose hydrolysis, not only by oxidative activity on glycosidic bonds, but also to hemicellulose through the oxidation of xylosyl bonds in xylan. The concerted action of these auxiliary enzymes may significantly improve large-scale recovery of sugars from lignocellulose.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Gloeophyllum trabeum</I> lytic polysaccharide monooxygenase enhances lignocellulose hydrolysis by Celluclast 1.5L, a commercial cellulase. </LI> <LI> <I>G. trabeum</I> lytic polysaccharide monooxygenase enhances xylan hydrolysis by <I>G. trabeum</I> xylanase 10A. </LI> <LI> A mixture of 60% Celluclast 1.5L, 20% <I>G. trabeum</I> lytic polysaccharide monooxygenase and 20% G. trabeum xylanase 10A improves the hydrolysis of wheat straw by 54%. </LI> <LI> Functional cooperation between <I>G. trabeum</I> lytic polysaccharide monooxygenase and xylanase 10A is proposed. </LI> </UL> </P>