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High cell density cultivation of a recombinant Bacillus subtilis for nattokinase production
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  • Qing Cui,
  • Bingjun Qian,
  • Xiangjun Sun,
  • Jianhua Zhang
Qing Cui
Shanghai Jiao Tong University
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Bingjun Qian
Shanghai Jiao Tong University
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Xiangjun Sun
Shanghai Jiao Tong University
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Jianhua Zhang
Shanghai Jiao Tong University
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Abstract

Several hundred U mL-1 of Nattokinase (NK), a fibrinolytic enzyme, can be produced by culturing recombinant Bacillus subtilis in Luria-Bertani broth in a shaking flask. For use as a nutraceutical, large-scale preparation and a simple purification process is required. The present study utilized a fed-batch process with a pH-stat and low-glycerol-level-maintain feeding strategy to cultivate a B. subtilis strain carrying a pHT01 plasmid with an NK-encoding gene (B. subtilis/pHT01-aprN1). Finally, a NK activity of 7778 ±17.28 U mL-1 was obtained, which represented a 26-fold increase of NK activity by high cell density cultivation compared to the flask culture. Furthermore, fermentation supernatant was successively purified by ammonium sulfate precipitation and nickel column affinity chromatography with a total NK recovery rate of 65.2%.

Peer review status:POSTED

11 Sep 2020Submitted to Biotechnology and Bioengineering
12 Sep 2020Assigned to Editor
12 Sep 2020Submission Checks Completed