Efficient Overexpression of Recombinant Nattokinase in Bacillus subtilis by Tandem Promoters
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
In Bacillus subtilis WB800, the efficient secretory expression of nattokinase by tandem promoters was investigated. Several previously reported strong promoters were compared and arranged in tandem repeat sequence, and the optimal promoter for nattokinase and its maximum yield were determined. In this study, five recombinant strains harboring five different strong promoters were successfully constructed in Bacillus subtilis WB800, including pSG101 (PHpaII), pSG102 (PBcaprE), pSG103 (PluxS), pSG104 (PgsiB), and pSG105 (PyxiE), the secretory expression of nattokinase was achieved and the fibrinolytic activity was measured. The results indicated that the fibrinolytic activity of nattokinase mediated by promoter PHpaII (110.80 FU/mL) was higher than that mediated by the other four promoters. Subsequently, three plasmids were built by arranging the promoter PHpaII in multi-tandem sequences, including pSG106 (PHpaII-PHpaII), pSG107 (PHpaII-PHpaII-PHpaII), and pSG108 (PHpaII-PHpaII-PHpaII-PHpaII). The data showed that the highest yield of nattokinase (213.30 FU/mL) was achieved under promotion mediated by PHpaII-PHpaII-PHpaII, which increased the production of nattokinase by 92.51% compared with that achieved by mediation by the single promoter PHpaII. Through comparing five strong promoters and arranging them in tandem repeat sequences, the efficient expression of nattokinase was successively achieved in B. subtilis WB800. The highest fibrinolytic activity reached 213.30 FU/mL, significantly higher than that reported in the literature.
