Fig. 3

Impact of microbial expansins on hydrolytic and oxidative enzymes used to treat hardwood kraft pulp. The reactions were performed at 40 °C, pH 5.5 up to 72 h. Soluble sugars released were measured in the presence of a Endoglucanase (EG) + microbial expansin (EXLX); b Xylanase (Xyl) + EXLX; c TrAA9A + EXLX. The first, most left column in each panel shows product release by a Endoglucanase (EG), b Xylanase, and c TrAA9A alone. Addition of BSA instead of expansin was used in each case as a reference. Total reducing sugars released in the hydrolysis of pulp by endoglucanase and xylanase after 5/6, 24, 48, and 72 h reaction time were measured using the PAHBAH assay (a and b). In the case of the oxidative TrAA9A enzyme (c), the soluble products were analyzed using UHPLC-IMS-MS at the 72 h time point. Error bars indicate standard deviations for triplicate samples. Asterisks (*) indicate statistically significant (p ≤ 0.05; two-tailed t-test) difference between EXLX and BSA-treated samples