Table 1.

Application of microbial electrosynthesis for bioproduction.

Microorganism	EET Mode	Key engineering strategy	Substrate	Product	Key Findings	Ref
Shewanella oneidensis	DET	Two-stage electro-fermentation; electro-regulated CRISPRi for pathway suppression	Lactate	Isobutanol	Two-stage electro-fermentation process, using different voltages for growth and biosynthesis, enhanced isobutanol production. Directing reducing equivalents using NADH biosensor and suppressing byproduct pathways via CRISPRi led to an isobutanol titre of 1321.5 mg/L (94.9 % of theoretical yield).	28
Shewanella oneidensis	DET	Engineered glycerol utilization and (R)-acetoin biosynthesis pathway	Glycerol	(R)-Acetoin	Expanded substrate range of S. oneidensis to glycerol. (R)-acetoin production reached 313.61 mg/L.	29
Escherichia coli	DET	Expressed heterologous S. oneidensis electron transfer proteins and biosynthesis pathways for isobutanol and 3-methylbutanol	Glycerol	Isobutanol, 3-methylbutanol	Enhanced anoxic glycerol utilization. Total isobutanol and 3-methylbutanol production reached 232 mg/L, 25 % higher than using glucose	30
Escherichia coli	IET (Neutral red- and 2-hydroxy-1,4-naphthoquinone mediated)	Engineered glycerol reductive pathways to produce 1,3-propanediol (1,3-PDO) and 3-hydroxypropionic acid (3-HP)	Glycerol	1,3-PDO, 3-HP	Increased 1,3-PDO titre by 2.5-fold–15.5 mM with negative potential. Enable 3-HP production at 10.9 mM with positive potential.	33
Rhodopseudomonas palustris	DET	Engineered n-butanol biosynthesis pathway; deleted nitrogenases	CO2	n-Butanol	Produced 0.91 mg/L of n-butanol using CO2, electricity, and light. Demonstrated first solar panel-powered microbial electrosynthesis platform for n-butanol production.	39
Rhodopseudomonas palustris	DET	Overexpressed RuBisCO form I and II to increase CO2 fixation	CO2	Polyhydroxyalkanoate	Overexpression of RuBisCO increased polyhydroxyalkanoate production up to five-fold; engineered RuBisCO strains increased electron uptake under non-nitrogen-fixing conditions	40
Yarrowia lipolytica	IET (Neutral red-mediated)	Expressed AckA and Pta to increase acetyl-CoA; expressed pathway genes to produce fatty alcohols, lupeol and betulinic acid	Acetate, glucose	Fatty alcohols, lupeol, betulinic acid	Enhanced NADPH regeneration by MES drove acetate utilization, resulting in 6.17-fold increase in fatty alcohol production; demonstrated first MES application in Y. lipolytica	32
Synechocystis sp. PCC 6803	DET	Inactivated photosystem II; expressed heterologous ethylene-forming enzyme	CO2, HCO3−	Acetate, ethylene	External electrons and light enabled CO2 fixation at 9.3 % energy conversion efficiency; achieved acetate and ethylene production from CO2.	25
Cupriavidus necator	IET (H2-mediated)	Expressed heterologous mevalonate pathway and α-humulene synthase	H2, CO2	α-Humulene	Produced 10.8 mg/L α-humulene by MES; first example of electroautotrophic terpene production from CO2	37
Cupriavidus necator	IET (H2-mediated)	Expressed lycopene pathway	H2, CO2	Lycopene	Produced 1.73 mg/L lycopene from CO2 from power plant exhaust gas	38
Cupriavidus necator	DET and IET (flavin-mediated)	Expressed heterologous S. oneidensis MtrCAB electron conduit proteins and Gloeobacter violaceus rhodopsin; overexpressed native carbonic anhydrase	CO2	Biomass	Created an artificial photoelectrochemical microbial system that directs CO2 into the central metabolism	41