Abstract: Two family-I cellulose-binding domains(CBD) of acetyl xylan esterase from Volvariella volvacea were fused to form a recombinant protein. The recombinant bifunctional cellulose-binding protein was expressed in E.coli. Then the mechanical properties of Whatman filter paper treated with the recombinant protein were tested. The purified protein improved the treated paper's tensile strength, bursting strength and folding endurance by 10%, 8.7% and 30%, respectively. This research demonstrated that the cellulose-binding domains have an immense potential for the application in the field of fiber and paper industries.

Key words: acetyl xylan esterase, cellulose-binding domain, mechanical properties, paper-strengthening agent