Efficient secretory expression of β-1, 3-1, 4-glucanase in E.coli

In this study, the highly secretory expression of β- 1, 3- 1, 4- glucanase was achieved in E. coli. Signal peptide ff53 developed by our team was fused with mature peptide gene ( bgl) of β- 1, 3- 1, 4- glucanase, then cloned into the p ET- 28a ( +) plasmid. Efficient extracellular expression was obtained under following optimized conditions: 8g / L lactose at 28 ℃ for 10 h, resulting in the enzyme activity of E.coli BL21 / p ET- ff53- bgl in culture medium reached 1093 U / m L, which increased 0.87 folds compared with enzyme activity of E.coli BL21 / p ET- bgl ( 583 U/m L) induced with IPTG.The study laid the foundation of high density fermentation of β-1, 3-1, 4-glucanase production.