ABSTRACT
OBJECTIVE: We searched optimal signal peptide for heterologous and exogenous secretion of xylanase in Bacillus subtilis. METHODS: We constructed a screening vector for signal peptides from B. subtilis. The Alkali resistance xylanase gene (xynA) from Bacillus pumilus was chosen as reporter gene and cloned into E. coli and B. subtilis shuttle vector pGJ148 which has maltose-inducible promoter Pglv and spectinomycin resistant gene. 24 Sec-type signal peptides (SPs) was amplified from B. Subtilis 1A747 and cloned into the screening vector for the expression of xynA in B. Subtilis WB700. The xylanase activity of the culture supernatant were detected after 24h incubation. RESULTS: The screening of these signal peptides revealed differences in xylanase activity of the culture supernatants, The recombinant strain containing YnfF signal peptide showed the highest xylanase acitivity (37.2 IU/mL). CONCLUSION: Experiment proved screening of signal peptides is effective way for optimization of the export of heterologous protein in B. subtilis.
