Electrochemical Activity Produced from Abundant Expression of C‐Type Cytochromes in a Filamentous Gram‐Positive Bacterium

Abstract

AbstractNatural microbes employing c‐type cytochromes (c‐Cyts) for extracellular electron transport (EET) were greatly valuable to develop redox‐based bioelectrochemical applications. However, low levels of c‐Cyt expression limited the phylogenetically diverse Gram‐positive species to be used in bioelectrochemical devices. This work reported the remarkable finding that a high level of c‐Cyts was expressed in the cells of the Gram‐positive strain Lysinibacillus varians GY32. c‐Cyts in Lysinibacillus varians GY32 cells were expressed at a level close to those in Shewanella oneidensis. These c‐Cyts were found to cluster in cytoplasmic membrane and periplasmic space, along the length of Lysinibacillus varians GY32 cell. With voltammetry and spectroelectrochemical titration, phenazine methosulfate‐mediated electron transfer between the c‐Cyts and an electrode was proved. These results expanded the accessible natural models of EET and suggested a new microbial platform for developing bioelectrochemical applications.