User:HarappanBoyz/Anaerobic organism

Energy metabolism
Bacterial photosynthesis is another process capable of occurring anoxically, but ultimately provides oxygen to its environment as an end product.

CrP hydrolysis
Creatine, an organic compound found in animals, provides a way for ATP to be utilized in the muscle. The phosphorylation of creatine allows for the storage of readily available phosphate that can be supplied to the muscles.

The reaction is reversible as well, allowing cellular ATP levels to be maintained during anoxic conditions. This process is coupled with metabolic suppression to allow certain fish, such as goldfish, to survive environmental anoxic conditions for a short period.

Multicellularity
Henneguya zschokkei also lack mitochondria, mitochondrial DNA, and oxidative pathways. The microscopic, parasitic cnidarian is observed to have mitochondria-related organelles contained within it. This mitochondria-related organelle within it is observed to have genes encoding for metabolic functions such as amino acid metabolism. However, these mitochondria-related organelles lack the key features of typical mitochondria found in closely related aerobic Myxobolus squamalus. Due to the difficulty of culturing H. zschokkei, there is little understanding of its anaerobic pathway.

Symbiosis
Anaerobic respiration and its end products can facilitate symbiosis between anaerobes and aerobes. This occurs across taxa, often in compensation for nutritional needs.

Anaerobiosis, and symbiosis, is found in interactions between ciliates and prokaryotes. Anaerobic ciliates participate in an endosymbiotic relationship with prokaryotes. These relationships are mediated in which the ciliate leaves end products that its prokaryotic symbiont utilizes. The ciliate achieves this through the use of fermentative metabolism. The rumen of various animals house this ciliate, alongside may other anaerobic bacteria, protozoans, and fungi. In specific, methanogenic archaea found in the rumen acts as a symbiont to anaerobic ciliates. These anaerobes are useful to those with a rumen due to their ability to break down cellulose, making it bioavailable when otherwise indigestible by animals.

Termites utilize anaerobic bacteria to fix and recapture nitrogen. In specific, the hindgut of the termite is full of nitrogen fixing bacteria, ranging in function depending on nitrogen concentration of the diet. Acetylene reduction in termites was observed to upregulate in termites with nitrogen-poor diets, meaning that nitrogenase activity rose as the nitrogen content of the termite was reduced. One of the functions of termite microbiota is to recapture nitrogen from the termite's own uric acid. This allows conservation of nitrogen from an otherwise nitrogen-poor diet. The hindgut microbiome of different termites has been analyzed, showing 16 different anaerobic species of bacteria, including Clostridia, Enterobacteriaceae, and Gram-positive cocci.