The role of acetyl xylan esterase in the solubilization of xylan and enzymatic hydrolysis of wheat straw and giant reed

Table 2 Carbohydrates released from pretreated wheat straw and giant reed after 48 h hydrolysis by cellulases and xylan-acting enzymes in 50 mM sodium citrate buffer at pH 5.0 and 45°C

Substrate	Enzyme preparation	Glucose	Xylose	Xylobiose	Xylotriose	Cellobiose
Wheat straw	CEL	28.2	bdl^a	2.9	0.4	0.5
	CEL+XYL	50.4	7.7	34.6	5.7	1.2
	CEL+XYL+ARA	46.6	9.8	29.8	4.6	0.9
	CEL+XYL+AXE	55.6	17.7	46.6	bdl	1.0
Giant reed	CEL	10.8	2.1	2.1	1.1	0.1
	CEL+XYL	26.6	5.5	16.4	5.2	0.1
	CEL+XYL+ARA	26.8	5.9	16.6	5.2	0.1
	CEL+XYL+AXE	28.9	8.7	21.1	bdl	0.1

Glucose and cellobiose are expressed as % of cellulose (as glucose), and xylose, xylobiose and xylotriose are expressed as % of xylan (as xylose) in wheat straw or giant reed. The values of xylobiose, xylotriose and xylotetraose contained both acetylated and non-acetylated xylo-oligosaccharides. ARA: α-L-arabinofuranosidase; AXE: acetyl xylan esterase; bdl: below detection limit; CEL: mixture of cellulose-acting enzymes; XYL: xylanase.

ISSN: 2731-3654