[Auto-inducible expression system based on the SigB-dependent ohrB promoter in Bacillus subtilis]

Mol Biol (Mosk). 2014 Nov-Dec;48(6):970-6. doi: 10.7868/s0026898414060135.
[Article in Russian]

Abstract

The reliable production of heterologous proteins is important in the field of industrial biotechnology. This can be achieved by applying auto-inducible gene expression systems. The development of a Bacillus subtilis expression plasmid harboring SigB-dependent ohrB promoter was reported. The expression system was subjected to high cell density cultivation to produce xylanase as a stable model protein. The recombinant strain was cultured in a synthetic medium containing glucose as the carbon source. The exponential fed-batch feeding strategy was applied to prevent substrate inhibition. A sharp increase of xylanase activity (about 6-fold) at the end of the fermentation was observed as a result of sigma factor B (SigB) protein activation, supporting auto-inducibility of the expression system. For the control strain a specific induction of the xylanase activity was not observed. The recombinant strain was capable to offer a 5-fold increase in xylanase activity in comparison with the control strain. In addition, the constructed system displayed catabolite repression resistance ability. This SigB-dependent expression system can be considered as a biotechnology tool and an alternative to eliminate the cost of conventional inducers, e.g. isopropyl-β-galactopyranoside.

Publication types

  • English Abstract
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacillus subtilis / drug effects
  • Bacillus subtilis / genetics*
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Batch Cell Culture Techniques
  • Culture Media / chemistry
  • Endo-1,4-beta Xylanases / genetics*
  • Endo-1,4-beta Xylanases / metabolism
  • Feedback, Physiological
  • Fermentation
  • Gene Expression Regulation, Bacterial*
  • Isopropyl Thiogalactoside / analogs & derivatives
  • Isopropyl Thiogalactoside / pharmacology
  • Molecular Sequence Data
  • Plasmids / chemistry*
  • Plasmids / metabolism
  • Promoter Regions, Genetic*
  • Sigma Factor / genetics*
  • Sigma Factor / metabolism

Substances

  • Bacterial Proteins
  • Culture Media
  • SigB protein, Bacteria
  • Sigma Factor
  • Isopropyl Thiogalactoside
  • isopropyl-beta-galactopyranoside
  • Endo-1,4-beta Xylanases