Multifunctional cellulase and hemicellulase

1. A multifunctional polypeptide capable of hydrolyzing a cellulosic material, xylan, and mannan, comprising

the catalytic core (cc) of Clostridium thermocellum Cthe — 0797 (CelE),

a cellulose-specific carbohydrate-binding module (CBM), wherein the CBM is CBM3 of the cellulosome anchoring protein cohesion region (CipA) of Clostridium thermocellum (CBM3a), and

a linker region interposed between the catalytic domain and the cellulose-specific carbohydrate binding module.

2. The polypeptide of claim 1 , wherein the linker region is a 5-150 amino acid sequence.

3. The polypeptide of claim 1 , wherein the linker region is a 15-40 amino acid sequence.

4. The polypeptide of claim 1 , wherein the polypeptide comprises the amino acid sequence of SEQ ID NO:6.

5. A polypeptide composition for increasing the rate and the extent of fiber digestion for a mammal comprising the polypeptide of claim 1 .

6. A method of hydrolyzing a substrate comprising a cellulosic material, xylan, and mannan, comprising the step of contacting a substrate comprising a cellulosic material, xylan, and mannan with an effective amount of the multifunctional polypeptide of claim 1 , whereby the cellulosic material, xylan, and mannan in the substrate are at least partially hydrolyzed.

7. The method of claim 6 , wherein the cellulosic material is selected from the group consisting of filter paper, crystalline cellulose allomorph I, and amorphous cellulose.

8. The method of claim 6 , wherein the cellulosic material is cellulose III.

9. The method of claim 6 , further comprising the step of pretreating the cellulosic material is under acidic, basic, or oxidative conditions.

10. The method of claim 8 , wherein the cellulose III is a non-natural cellulose produced by extractive ammonia fiber expansion treatment of biomass.

11. The method of claim 6 , wherein the substrate further comprises SIGMACELL, beta-glucan, galactan, galactomannan, or lichenan.

12. The method of claim 6 , wherein the catalytic reactivity exhibited by the multifunctional polypeptide is at least 50% higher than the catalytic reactivity exhibited by native CelE.

13. The method of claim 6 , wherein the catalytic reactivity exhibited by the multifunctional polypeptide is at least 1.5 times higher than the catalytic reactivity exhibited by the catalytic core (cc) of native CelE.

14. The method of claim 6 , wherein the catalytic reactivity exhibited by the multifunctional polypeptide is at least 2 times higher than the catalytic reactivity exhibited by the catalytic core (cc) of native CelE.

15. The method of claim 6 , wherein the method is performed at a temperature of about 60° C.

16. The method of claim 6 , wherein the method is performed at a pH of about 6.0.

17. The method of claim 6 , wherein the effective amount of multifunctional polypeptide is in the range of 1-100 mg/g (enzyme/glucan).

18. The method of claim 6 , wherein the effective amount of multifunctional polypeptide is in the range of 1-10 mg/g (enzyme/glucan).

19. A method of increasing the rate and the extent of fiber digestion in a mammal comprising the step of administering to a mammal an effective amount of the multifunctional polypeptide of claim 1 , whereby the cellulosic materials, xylan, and mannan in the fiber consumed by the mammal are at least partially hydrolyzed.

20. A method of making a multifunctional polypeptide comprises the step of linking the catalytic core (cc) of Clostridium thermocellum Cthe — 0797 (CelE) with a cellulose-specific carbohydrate-binding module (CBM) by using a linker region, wherein the linker region is interposed between the catalytic domain and the cellulose-specific carbohydrate binding module, and wherein the CBM is CBM3 of the cellulosome anchoring protein cohesion region (CipA) of Clostridium thermocellum (CBM3a).