Development of inducer-free expression plasmids using IPTG-inducible Pspac promoter for Bacillus subtilis

Authors

  • Phuong Thi Bich Chu Vietnam National University, Ho Chi Minh city, Vietnam
  • Hanh Thi Thu Phan Vietnam National University, Ho Chi Minh city, Vietnam
  • Hoang Duc Nguyen Vietnam National University, Ho Chi Minh city, Vietnam
  • Trang Thi Phuong Phan Vietnam National University, Ho Chi Minh city, Vietnam

Keywords:

Bacillus subtilis, inducer-free, pHT vector, Pspac, weak promoter

Abstract

An inducer-free expression vector for the low expression levels in Bacillus subtilis (B. subtilis) is necessary for fundamental research. In this study, we constructed inducer-free expression plasmids carrying Pspac, a well-known IPTG-inducible promoter, by removing a part of the lacI gene. Then, we analysed the expression of the target genes bgaB and gfp+ in B. subtilis. Western blot experiments demonstrated that the reporters from the inducer-free plasmids with Pspac could be produced at low levels in B. subtilis strains and were equivalent to their corresponding inducible constructs with 1 mM IPTG. The reporter activities showed that inducer-free expression from the Pspac promoter was dramatically less than that of the inducer-free plasmids with the strong promoters Pgrac01 and Pgrac100 reported previously, about 16.2 to 20.3 times for BgaB and 24.7 to 34.3 times for GFP+, respectively. In conclusion, the inducer-free expression vectors carrying Pspac promoters allow the constitutive expression of heterologous recombinant proteins at low levels in B. subtilis.

DOI:

https://doi.org/10.31276/VJSTE.63(1).64-70

Classification number

3.5

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Published

2022-03-03

Received 1 December 2019; accepted 3 March 2020

How to Cite

Chu, P. T. B., Phan, H. T. T., Nguyen, H. D., & Phan, T. T. P. (2022). Development of inducer-free expression plasmids using IPTG-inducible Pspac promoter for Bacillus subtilis. Vietnam Journal of Science, Technology and Engineering, 63(1), 64-70. https://doi.org/10.31276/VJSTE.63(1).64-70

Issue

Section

Life Sciences