''Clostridium ljungdahlii'' is an

anaerobic Anaerobic means "living, active, occurring, or existing in the absence of free oxygen", as opposed to aerobic which means "living, active, or occurring only in the presence of oxygen." Anaerobic may also refer to: *Adhesive#Anaerobic, Anaerobic ad ...

rod-shaped Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archae ...

motile Motility is the ability of an organism to move independently using metabolic energy. This biological concept encompasses movement at various levels, from whole organisms to cells and subcellular components. Motility is observed in animals, mi ...

endospore An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., not ...

-forming,

gram-positive bacterium In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. The Gram stain is ...

. It is named after the Swedish biochemist Lars G. Ljungdahl. When originally harvested from the waste matter of animals, it tended to produce acetate with respect to

ethanol Ethanol (also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound with the chemical formula . It is an Alcohol (chemistry), alcohol, with its formula also written as , or EtOH, where Et is the ps ...

, but a major undertaking to increase the ethanol-to-acetate ratio was initiated. A 1993 publication by researchers from the

University of Arkansas The University of Arkansas (U of A, UArk, or UA) is a Public university, public Land-grant university, land-grant research university in Fayetteville, Arkansas, United States. It is the Flagship campus, flagship campus of the University of Arkan ...

, 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 The continuous stirred-tank reactor (CSTR), also known as vat- or backmix reactor, mixed flow reactor (MFR), or a continuous-flow stirred-tank reactor (CFSTR), is a common model for a chemical reactor in chemical engineering and environmental eng ...

. This species can

ferment Fermentation is a type of anaerobic metabolism which harnesses the redox potential of the reactants to make adenosine triphosphate (ATP) and organic end products. Organic compound, Organic molecules, such as glucose or other sugars, are Catabo ...

certain components of

syngas Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide in various ratios. The gas often contains some carbon dioxide and methane. It is principally used for producing ammonia or methanol. Syngas is combustible and can be used as ...

into

.Younesi, H., G. Najafpour, and A.R. Mohamed (2005) Ethanol and acetate production from synthesis gas via fermentation processes using anaerobic bacterium, ''Clostridium ljungdahlii''. Biochem. Eng. J. 27:110-119 It also possesses properties of electrosynthesis, producing

acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...

cathode A cathode is the electrode from which a conventional current leaves a polarized electrical device such as a lead-acid battery. This definition can be recalled by using the mnemonic ''CCD'' for ''Cathode Current Departs''. Conventional curren ...

Notes

References

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External links

Type strain of ''Clostridium ljungdahlii'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
Gram-positive bacteria Bacteria described in 1993 ljungdahlii Ethanol fuel {{Clostridia-stub