Developing a base‐editing system to expand the carbon source utilization spectra of Shewanella oneidensis MR‐1 for enhanced pollutant degradation

Citations Over TimeTop 11% of 2020 papers

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 study, 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 key genes involving in N-acetylglucosamine (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 study 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.

Related Papers

• → Biogenic Formation of As-S Nanotubes by Diverse Shewanella Strains(2009)55 cited
• → Comparative Microbial Fuel Cell Evaluations of Shewanella spp.(2010)46 cited
• → Comparisons of Shewanella strains based on genome annotations, modeling, and experiments(2014)39 cited
• Metabolic networks of electricigens Shewanella for anaerobic respiration(2015)
• → Genome-Based Studies of Shewanella Ecophysiology(2013)