loading page

Novel auto-induction expression systems with high expression strength and wide induction initiation in Bacillus subtilis
  • +5
  • kuidong xu,
  • Yi Tong,
  • Yi Li,
  • Jin Tao,
  • sheng Rao,
  • Jianghua Li,
  • Jingwen Zhou,
  • Song Liu
kuidong xu
Jiangnan University

Corresponding Author:[email protected]

Author Profile
Yi Tong
Jilin COFCO Biochemical Co. Ltd.
Author Profile
Yi Li
Jilin COFCO Biochemical Co. Ltd.
Author Profile
Jin Tao
Jilin COFCO Biochemical Co. Ltd.
Author Profile
sheng Rao
Yangzhou University
Author Profile
Jianghua Li
Jiangnan university
Author Profile
Jingwen Zhou
Jiangnan Univ.
Author Profile
Song Liu
Jiangnan Univ.
Author Profile

Abstract

The low expression strength and fixed induction initiation have always been the main obstacle for applying the bacterial quorum sensing (QS) system to protein production. As a typical QS system in Bacillus subtilis, ComQXPA activates the promoter PsrfA using ComX and ComA as the auto-inducer and promoter activator, respectively. This study developed a series of novel auto-induction expression systems in B. subtilis WB600 based on ComQXPA using super-folder green fluorescent protein as the reporter. First, the -35 region of PsrfA was replaced by the corresponding conserved sequence of σA-dependent promoters, yielding P1 with an 85% enhanced expression strength. Second, by conducting a semi-rational design within the spacer between -35 and -15 regions of in P1, we generated the ComQXPA promoter PS1E, the expression strength of which is 8.22-fold higher than that of PsrfA. Based on PS1E, we finally obtained three types of auto-induction expression systems with the induction initiations ranging from 1.5 h to 9.5 h by optimizing the combination of the promoters for ComX and ComA. By using the auto-induction expression systems, the yield of Bacillus deramificans pullulanase in B. subtilis reached 80.2 U/mL, 0.36-fold higher than the strongest constitutive promoter P566. With the diversity in dynamic features, the novel auto-induction expression systems provide great potential for improving protein expression and metabolite production in B. subtilis.