Mevalonate production by electro-fermentation in Escherichia coli via Mtr-based electron transfer system

Implementation of a flavin biosynthesis operon improves extracellular electron transfer in bioengineered Escherichia coli

“…Microbes offer a largely untapped potential for the development of sustainable electrochemical systems for energy [1] , sensing [2][3][4] , environmental [3][4][5] , and synthesis [6][7][8] applications. At the core of these technologies lies extracellular electron transfer (EET), which enables the exchange of energy and information between microbes and electrodes in bioelectrochemical systems (BES).…”

“…While these mechanisms equip Shewanella species with the efficient EET capabilities necessary for implementation in BES, S. oneidensis MR-1 and other native exoelectrogens are often lacking in their substrate spectrum and genetic amenability to realize specific BES applications. Therefore, E. coli has emerged as a promising alternative to native exoelectrogens for BES applications, and as a target for engineering to enable efficient EET [4,6,[15][16][17][18][19][20][21][22] . Over the past two decades, different [15] , overexpression of the full MtrCAB complex in the outer membrane [16] and co-expression of the inner membrane cytochrome CymA [18] , to the expression of both membrane-associated and periplasmic cytochromes [22] .…”

“…Over the past two decades, different [15] , overexpression of the full MtrCAB complex in the outer membrane [16] and co-expression of the inner membrane cytochrome CymA [18] , to the expression of both membrane-associated and periplasmic cytochromes [22] . These advances in implementing direct EET mechanisms in E. coli are promising and have led to applications in electrode-assisted biosynthesis of chemicals and biosensing [4,6,17,20,23] . Beyond direct electron transfer through cytochromes, EET in engineered E. coli can be further improved using exogenous mediators [6,[17][18]21,23] .…”

“…Beyond direct electron transfer through cytochromes, EET in engineered E. coli can be further improved using exogenous mediators [6,17–18,21,23] . Indeed, commonly available lab strains of E. coli are limited in their ability to form biofilms, making it challenging to rely on direct electron transfer in BES with no specific immobilization on the electrode [24] .…”

“…These advances in implementing direct EET mechanisms in E. coli are promising and have led to applications in electrode-assisted biosynthesis of chemicals and biosensing [4,6,17,20,23] . Beyond direct electron transfer through cytochromes, EET in engineered E. coli can be further improved using exogenous mediators [6,[17][18]21,23] . Indeed, commonly available lab strains of E. coli are limited in their ability to form biofilms, making it challenging to rely on direct electron transfer in BES with no specific immobilization on the electrode [24] .…”