Discovery of the combined oxidative cleavage of plant xylan and cellulose by a new fungal polysaccharide monooxygenase

Table 1 MtLPMO9A oxidation on various polysaccharide substrates

Substrate	Occurrence of oxidation
	Without ascorbic acid		With 1 mM ascorbic acid
	GlcOS ^#_n *^a	XOS ^#_n *^b	GlcOS ^#_n *	XOS ^#_n *
Cellulose
Avicel^c	−	−	+	+
RAC^c	−	−	+	+
Hemicellulose
Glucan
Xyloglucan^d	−	−	+	−
β-Glucan barley	−	−	+	−
β-Glucan oat spelt	−	−	+	−
Xylan
OSX^e	−	−	−	−
BiWX^e	−	−	−	−
WAX^e	−	−	−	−
Oligosaccharides
Gluco-oligosaccharides^f	−	−	−	−
Xylo-oligosaccharides^f	−	−	−	−
Galactomannan^g	−	−	−	−
RAC/hemicellulose combination
RAC + BiWX	−	−	+	+
RAC + OSX	−	−	+	+
RAC + WAX	−	−	−	−

^aGluco-oligosaccharides oxidized at the C1 (GlcOS ^#_n ) or C4 position (GlcOS_n *).
^bXylo-oligosaccharides oxidized at the C1 (XOS ^#_n ) or C4 position (XOS_n *).
^cRegenerated amorphous cellulose (RAC), crystalline cellulose (Avicel).
^dXyloglucan from tamarind seed.
^eOat spelt xylan (OSX), birchwood xylan (BiWX), wheat arabinoxylan (WAX).
^fβ-(1 → 4)-linked gluco- and xylo-oligosaccharides, degree of polymerization 2–5.
^gβ-(1 → 4)-linked-d-mannosyl backbone from guar (medium viscosity), purchased from Megazyme (Bray, Ireland).

ISSN: 2731-3654