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Most cellulases contain carbohydrate-binding modules (CBMs) that largely contribute to their activity for insoluble substrates.Clostridium thermocellumCel5E 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 fromClostridium josuiscaffoldin, or a family 6 xylan-directed CBM fromClostridium stercorariumxylanase 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. Substrate specificities of an endoglucanase, Cel5E fromClostridium thermocellumwere affected by fusion of different type CBMs. [ABSTRACT FROM PUBLISHER]

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.

The article investigates the local variability of bacterial species within the lumen of the cecum and proximal colon of guinea pigs by using PCR-denaturing gradient gel electrophoresis. The DGGE banding profiles revealed radial and axial variation of the bacteria. The article discusses the physiological importance of the variation of bacteria within the large intestinal lumen for the degradation of dietary fiber and interaction between bacteria and the mucosal immune system.

Characterizes a novel cellulolytic, anaerobic and thermophilic anaerobe, Moorella sp. strain F21, isolated from soil. Gene sequence analysis showing that the bacterium was closely related to Moorella thermoacetica; Data suggesting that the strain is a noncellulosomal cellulolytic bacterium; Major fermentation product from ball-milled cellulose.