Recently, a research team led by Prof. Li Wenwei from Suzhou Institute for Advanced Research (SIAR), the University of Science and Technology of China (USTC), in collaboration with Prof. Liu Dongfeng from USTC, made progress in the gene editing system of Geobacter species. The study was published in Environmental Science & Technology with a title of Biomolecular Insights into Extracellular Pollutant Reduction Pathways of Geobacter sulfurreducens using a Base Editor System. 

Geobacter species are electroactive environmental microorganisms with a unique extracellular electron transfer (EET) ability, playing an important role in elemental biogeochemical cycling, environmental bioremediation and green energy production. However, the complicated EET networks remain elusive and research in this field even faces controversy. Therefore, it is urgent to develop more effective analytical research methods.

He Ruli, PhD candidate and the first author, developed a simple and highly efficient cytosine base editor that can accurately edit genes related to EET. The system fused cytosine deaminase, Cas9 nickase, and a uracil glycosylase inhibitor, enabling single-locus editing at 100% efficiency and effective editing of 87.7-93.4% genes of the entire genome in several Geobacter species. The technology was used to analyze EET of Geobacter species and unveiled the important roles of both pili and outer membrane c-type cytochromes in long-range EET and revealed the key electron transfer proteins involved in the reduction of uranium and selenite respectively.

The work has deepened the understanding of Geobacter species’ EET and pollutant transformation processes. It is of great significance to the modification of electroactive bacteria and their application in environmental governance, resource recycling and green energy production.

Paper Link: https://pubs.acs.org/doi/10.1021/acs.est.2c02756