Skip to main content
Log in

Systematic metabolic pathway modification to boost l-ornithine supply for bacitracin production in Bacillus licheniformis DW2

  • Biotechnological products and process engineering
  • Published:
Applied Microbiology and Biotechnology Aims and scope Submit manuscript

Abstract

Bacitracin is a cyclic dodecyl peptide antibiotic that is an effective bacteriocide against Gram-positive and some Gram-negative bacteria. Bacitracin has been widely used as an antibacterial feed additive for livestock since it is not absorbed easily by the intestine and is easily excreted. Precursor availability has been proven to be one of the core factors for bacitracin production by many previous studies. In this study, we focused on enhancing the supply of the precursor amino acid l-ornithine to enhance bacitracin production by Bacillus licheniformis DW2 through systematic metabolic pathway modification. Several genes encoding rate-limiting enzymes for l-ornithine biosynthesis were episomally overexpressed, including argB, rocF, ppnk1, and ppnk2. The results showed that the overexpression of ppnK1 was the most effective for both l-ornithine and bacitracin biosynthesis. Secondly, the competitive branch pathways for l-ornithine biosynthesis were blocked, and the repressor was also deleted to boost l-ornithine biosynthesis. The results suggested that the deletion of genes proB and proJ to prevent proline biosynthesis and the disruption of the gene encoding the arginine repressor ArgR could enhance the intracellular concentration of l-ornithine by 49% and 2.1 times respectively, and the bacitracin production also increased accordingly by 6.6% and 11.9% respectively. Finally, several most effective efforts were combined to construct the optimal strain DW2ΔproBΔproJΔargR::ppnk1. In the optimal strain, the NADPH availability was improved and the expression levels of several essential genes for l-ornithine biosynthesis were upregulated, resulting in the enhancement of both l-ornithine and bacitracin production by 71.4% and 16.5% respectively. The final bacitracin production titer was 950 U/mL, which reached the level for industrial production.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

Download references

Funding

This work was supported by the National Natural Science Foundation of China (Grand No: 31500074)

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Qin Wang.

Ethics declarations

Conflict of interest

The authors declare that they have no competing interests.

Ethical approval

This paper does not contain any studies with human participants or animals performed by any of the authors

Additional information

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

ESM 1

(PDF 155 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yu, W., Li, D., Jia, S. et al. Systematic metabolic pathway modification to boost l-ornithine supply for bacitracin production in Bacillus licheniformis DW2. Appl Microbiol Biotechnol 103, 8383–8392 (2019). https://doi.org/10.1007/s00253-019-10107-7

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00253-019-10107-7

Keywords

Navigation