Biomolecular Insights into Extracellular Pollutant Reduction Pathways of Geobacter sulfurreducens Using a Base Editor System

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

5 Scopus Citations
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Author(s)

  • Ru-Li He
  • Jie Wu
  • Zhou-Hua Cheng
  • Hui-Hui Li
  • Jia-Qi Liu
  • And 2 others
  • Dong-Feng Liu
  • Wen-Wei Li

Detail(s)

Original languageEnglish
Pages (from-to)12247–12256
Journal / PublicationEnvironmental Science & Technology
Volume56
Issue number17
Online published12 Aug 2022
Publication statusPublished - 6 Sept 2022
Externally publishedYes

Abstract

Geobacter species are critically involved in elemental bio-geochemical cycling and environmental bioremediation processes via extracellular electron transfer (EET), but the underlying biomolecular mechanisms remain elusive due to lack of effective analytical tools to explore into complicated EET networks. Here, a simple and highly efficient cytosine base editor was developed for engineering of the slow-growing Geobacter sulfurreducens (a doubling time of 5 h with acetate as the electron donor and fumarate as the electron acceptor). A single-plasmid cytosine base editor (pYYDT-BE) was constructed in G. sulfurreducens by fusing cytosine deaminase, Cas9 nickase, and a uracil glycosylase inhibitor. This system enabled single-locus editing at 100% efficiency and showed obvious preference at the cytosines in a TC, AC, or CC context than in a GC context. Gene inactivation tests confirmed that it could effectively edit 87.7-93.4% genes of the entire genome in nine model Geobacter species. With the aid of this base editor to construct a series of G. sulfurreducens mutants, we unveiled important roles of both pili and outer membrane c-type cytochromes in long-range EET, thereby providing important evidence to clarify the long-term controversy surrounding their specific roles. Furthermore, we find that pili were also involved in the extracellular reduction of uranium and clarified the key roles of the ExtHIJKL conduit complex and outer membrane c-type cytochromes in the selenite reduction process. This work developed an effective base editor tool for the genetic modification of Geobacter species and provided new insights into the EET network, which lay a basis for a better understanding and engineering of these microbes to favor environmental applications.

Research Area(s)

  • environmental remediation, Geobacter, pollutant transformation, c-type cytochromes, pili, ELECTRON-TRANSFER, GENETIC SYSTEM, MECHANISMS, DNA

Citation Format(s)

Biomolecular Insights into Extracellular Pollutant Reduction Pathways of Geobacter sulfurreducens Using a Base Editor System. / He, Ru-Li; Wu, Jie; Cheng, Zhou-Hua et al.
In: Environmental Science & Technology, Vol. 56, No. 17, 06.09.2022, p. 12247–12256.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review