The sample per flask was extracted with 100 ml HAc-NaAc (pH4.8) while stirring (150 r/min) at room temperature for 4 h, then filtered through fine filter paper, and the filtrate was used for enzyme activities measurement.The filter paper activity (FPA), the cellulase activities of endoglucanase (EG), cellobiohydrolase (CBH) and -glucosidase (BG), were measured according to the procedures of Cai [26]. Xylanase was determined at 50 ◦C [27]. Laccase was assayed by monitoring the oxidation of 5mM2,2-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) in a 50mMsodium acetate buffer (pH 5.0) [28]. Cellulase and hemicellulase activities were expressed as international units (IU) and were defined as 1mol of product formed per minute under the assay conditions. One unit (U) of laccase activity was defined as a 0.001 absorbance value increase per minute. Enzymatic activities were expressed as IU (U) per gram of dry corn stover in each culture
(IU (U)/g).