Family 11 alkaline xylanases have great potential economic applications in the pulp and paper industry. In this study, we would improve the alkalophilicity of family 11 alkaline xylanase Xyn11A-LC from Bacillus sp. SN5, for the better application in this field. | Improvement of alkalophilicity of an alkaline xylanase Xyn11A-LC from Bacillus sp. SN5 by random mutation and Glu135 saturation mutagenesis