Editing Anaerobic organism (section)

=== Fermentation ===
There are many anaerobic fermentative reactions.

Fermentative anaerobic organisms typically use the lactic acid fermentation pathway:

{{block indent|[[glucose|C<sub>6</sub>H<sub>12</sub>O<sub>6</sub>]] + 2 [[Adenosine diphosphate|ADP]] + 2 phosphate → 2 [[lactic acid]] + 2 [[Adenosine triphosphate|ATP]] + 2 H<sub>2</sub>O}}

The energy released in this reaction (without ADP and phosphate) is approximately 150 [[Kilojoule per mole|kJ per mol]], which is conserved in generating two ATP from ADP per [[glucose]]. This is only 5% of the energy per sugar molecule that the typical aerobic reaction generates.

Plants and fungi (e.g., yeasts) in general use alcohol (ethanol) fermentation when oxygen becomes limiting:

{{block indent|C<sub>6</sub>H<sub>12</sub>O<sub>6</sub> ([[glucose]]) + 2 ADP + 2 phosphate → 2 C<sub>2</sub>H<sub>5</sub>OH + 2 CO<sub>2</sub>↑ + 2 ATP + 2 H<sub>2</sub>O}}

The energy released is about 180 kJ per mol, which is conserved in generating two ATP from ADP per glucose.

Anaerobic bacteria and [[archaea]] use these and many other fermentative pathways, e.g., [[propionic acid]] fermentation,<ref>{{Cite journal |last1=Piwowarek |first1=Kamil |last2=Lipińska |first2=Edyta |last3=Hać-Szymańczuk |first3=Elżbieta |last4=Kieliszek |first4=Marek |last5=Ścibisz |first5=Iwona |date=January 2018 |title=Propionibacterium spp.—source of propionic acid, vitamin B12, and other metabolites important for the industry |journal=Applied Microbiology and Biotechnology |language=en |volume=102 |issue=2 |pages=515–538 |doi=10.1007/s00253-017-8616-7 |issn=0175-7598 |pmc=5756557 |pmid=29167919}}</ref> [[butyric acid]] fermentation,<ref>{{Cite journal |last1=Seedorf |first1=Henning |last2=Fricke |first2=W. Florian |last3=Veith |first3=Birgit |last4=Brüggemann |first4=Holger |last5=Liesegang |first5=Heiko |last6=Strittmatter |first6=Axel |last7=Miethke |first7=Marcus |last8=Buckel |first8=Wolfgang |last9=Hinderberger |first9=Julia |last10=Li |first10=Fuli |last11=Hagemeier |first11=Christoph |last12=Thauer |first12=Rudolf K. |last13=Gottschalk |first13=Gerhard |date=2008-02-12 |title=The genome of Clostridium kluyveri , a strict anaerobe with unique metabolic features |journal=Proceedings of the National Academy of Sciences |language=en |volume=105 |issue=6 |pages=2128–2133 |doi=10.1073/pnas.0711093105 |issn=0027-8424 |pmc=2542871 |pmid=18218779 |bibcode=2008PNAS..105.2128S |doi-access=free }}</ref> solvent fermentation, [[mixed acid fermentation]], [[butanediol fermentation]], [[Stickland fermentation]], [[acetogenesis]], or [[methanogenesis]].{{citation needed|date=February 2022}}