Secreted Overexpression of Alkali-tolerant Xylanase Gene in Bacillus pumilus

The xylanase encoding gene xynA was cloned from Bacillus pumilus BP51, a xylanase over producer. The xynA gene was inserted in Bacillus expression vector pWH1520, downstream of xylA promoter.The recombinant plasmid pWSX11 was transformed back into the original strain B.pumilus BP51 and the recombinant B.pumilus BPx11 was obtained.The xynA was over expressed and the xylanase was secreted into medium. The xylanase activity produced by recombinant BPX11 had increased about 87% as compared with the original strain BP51 The properties of the recombinant xylanase were characterized.