Expression of Thermophilic Endo-1,4-β-xylanase in Bacillus subtilis

Abstract:

The PCR primers were designed based on the endo-1,4-β-xylanase gene of the Thermopolyspora flexuosa was PCR amplified using designed primer. The amplified product was then digested and ligated into plasmid pHT43. After transformation of Escherichia coli DH5α,the positive clones were selected and the correct plasmids were largely extracted and transformed into Bacillus subtilis WB800N,the expression was induced by 1mM IPTG. SDS-PAGE electrophoresis of the extracellular supernatant showed that the targeted protein was successfully expressed. The apparent molecular weight of the endo-1,4-β-xylanase is 27 kD. The optimal reaction temperature is 80 ℃,whereas the optimal pH is 6. Hence,an engineered B. subtilis strain which could secrete endo-1,4-β-xylanase was successfully constructed.