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Most cellulases contain carbohydrate-binding modules (CBMs) that largely contribute to their activity for insoluble substrates. Clostridium thermocellum Cel5E is an endoglucanase having xylanolytic activity. The Cel5E originally has a family 11 CBM preferentially binding to β-1,4- and β-1,3-1,4-mixed linkage glucans. In this study, we replaced the CBM with a different type of CBM, either a family 3 microcrystalline cellulose-directed CBM from Clostridium josui scaffoldin, or a family 6 xylan-directed CBM from Clostridium stercorarium xylanase 11A. Chimeric endoglucanases showed enhanced activity that was affected by CBM binding specificity. These chimeric enzymes could efficiently degrade milled lignocellulosic materials, such as corn hulls, because of heterologous components in the plant cell wall, indicating that diverse CBMs play roles in degradation of lignocellulosic materials.

The article discusses a study which examines the significance of family 17 and 8 carbohydrate-binding modules (CBMs) on the identification of different cell-wall sites in sweet potato roots. Findings of the study reveal that CBMs determined several components on sweet potato root's cell wall. It also indicates that family 17 and family 28 of CBMs recognized that the polysaccharides configuration in the cell wall differ between tissues.

The article presents a study on the differences of the binding properties of three Clostridium josui carbohydrate-binding modules (CjCBMs) families such as 17, 28, and 17/28. It notes that an isothermal titration calorimetry was used to determine the thermodynamic parameter for the binding of the CBMs with cellooligosaccharides. Results show that the individual CBMs had different mechanisms for binding to cellooligosaccharides but with similar binding constants (Ka) for cellopentaose.

In vitro rumen dry matter degradability, volatile fatty acid (VFA) and methane production were examined in a total mixed ration pretreated with different levels of either commercial cellulolytic enzyme (CCE), the surfactant poly oxyethylene sorbitan monoolate (Tween 80) or both: (i) no pretreatment (Control); (ii) with 1% CCE alone; (iii) with 2% CCE alone; (iv) with 1% Tween 80 alone; (v) with 1% Tween 80 + 1% CCE;(vi) with 1% Tween 80 + 2% CCE; (vii) with 2% Tween 80 alone; (viii) with 2% Tween 80 + 1% CCE; and (ix) with 2% Tween 80 +2% CCE. In all culture supernatants of rumen microorganisms, activities of xylanase and cellulase were significantly ( P < 0.001) increased with pretreatment of CCE alone, Tween 80 alone and both combined. Within the same treatment of no CCE and 1% CCE levels, the total VFA concentration was significantly ( P < 0.001) higher with 2% Tween 80 than with no or 1% Tween 80 treatments. The molar percentage of propionate significantly ( P < 0.001) increased only with Tween 80. Throughout the in vitro incubation, the average value of methane concentration decrease was greater ( P < 0.001) with 1% CCE treatment than with no CCE and 2% CCE treatments, accounting for 0.797 and 0.887 of no CCE and 2% CCE treatments, respectively. Accumulative methane production was significantly lower with 1% CCE treatment than with no CCE and 2% CCE treatments. A ratio of VFA : methane production was significantly ( P < 0.001) higher with 2% Tween 80 treatment than with no Tween 80 and 1% Tween 80 treatments, showing the average values of 7.28, 5.33 and 6.69, respectively. [ABSTRACT FROM AUTHOR]