Clostridium ljungdahlii is an anaerobic, rod-shaped, motile, endospore-forming, gram-positive bacterium.^[1] It is named after the biochemist Lars G. Ljungdahl.^[2] When originally harvested from the waste matter of animals, it tended to produce acetate with respect to ethanol, but a major undertaking to increase the ethanol-to-acetate ratio was initiated. A 1993 publication by researchers from the University of Arkansas, in cooperation with Oak Ridge National Laboratories, showed results from a series of continuous reactor studies caused a major change in the bacterium's preference for ethanol production, which increased from <0.1 g/L to 1.8 g/L in a continuous stirred tank reactor.^[3]

Clostridium ljungdahlii
Scientific classification
Domain:	Bacteria
Phylum:	Bacillota
Class:	Clostridia
Order:	Eubacteriales
Family:	Lachnospiraceae
Genus:	Clostridium
Species:	C. ljungdahlii
Binomial name
Clostridium ljungdahlii Tanner et al. 1993

This species can ferment certain components of syngas into ethanol.^[4] It also possesses properties of electrosynthesis, producing acetate on cathodes.^{[citation needed]}