loading page

Developing a Base Editing System to Expand the Carbon Source Utilization Spectra of Shewanella oneidensis MR-1 for Enhanced Pollutant Degradation
  • +3
  • Lei Cheng,
  • Di Min,
  • Ru-Li He,
  • Zhou-Hua Cheng,
  • Dong-Feng Liu,
  • Han-Qing Yu
Lei Cheng
University of Science and Technology of China
Author Profile
Di Min
University of Science and Technology of China
Author Profile
Ru-Li He
University of Science and Technology of China
Author Profile
Zhou-Hua Cheng
University of Science and Technology of China
Author Profile
Dong-Feng Liu
University of Science and Technology of China
Author Profile
Han-Qing Yu
University of Science & Technology of China
Author Profile

Peer review status:ACCEPTED

24 Feb 2020Submitted to Biotechnology and Bioengineering
24 Feb 2020Submission Checks Completed
24 Feb 2020Assigned to Editor
21 Mar 2020Reviewer(s) Assigned
23 Apr 2020Editorial Decision: Revise Major
23 Apr 2020Review(s) Completed, Editorial Evaluation Pending
26 Apr 20201st Revision Received
27 Apr 2020Submission Checks Completed
27 Apr 2020Assigned to Editor
29 Apr 2020Review(s) Completed, Editorial Evaluation Pending
29 Apr 2020Editorial Decision: Accept

Abstract

Shewanella oneidensis MR-1, a model strain of exoelectrogenic bacteria (EEB), plays a key role in environmental bioremediation and bioelectrochemical systems because of its unique respiration capacity. However, only a narrow range of substrates can be utilized by S. oneidensis MR-1 as carbon sources, resulting in its limited applications. In this work, a rapid, highly efficient and easily manipulated base editing system pCBEso was developed by fusing a Cas9 nickase (Cas9n (D10A)) with the cytidine deaminase rAPOBEC1 in S. oneidensis MR-1. The C-to-T conversion of suitable C within the base editing window could be readily and efficiently achieved by the pCBEso system without requiring double strand break or repair templates. Moreover, double-locus simultaneous editing was successfully accomplished with an efficiency of 87.5. With this tool, the roles of the key genes involving in N-acetyl-glucosamine (GlcNAc) or glucose metabolism in S. oneidensis MR-1 were identified. Furthermore, an engineered strain with expanded carbon source utilization spectra was constructed and exhibited a higher degradation rate for multiple organic pollutants (i.e., azo dyes and organoarsenic compounds) than the wild type when glucose or GlcNAc was used as the sole carbon source. Such a base editing system could be readily applied to other EEB. This work not only enhances the substrate utilization and pollutant degradation capacities of S. oneidensis MR-1, but also accelerates the robust construction of engineered strains for environmental bioremediation.