Anaerobic organism

The sea floor is possibly one of the largest accumulation of anaerobic organisms on Earth, where microbes are primarily concentrated around hydrothermal vents.

In his 14 June 1680 letter to The Royal Society, Antonie van Leeuwenhoek described an experiment he carried out by filling two identical glass tubes about halfway with crushed pepper powder, to which some clean rain water was added.

Not expecting to see any life in the sealed glass tube, Van Leeuwenhoek saw to his surprise 'a kind of living animalcules that were round and bigger than the biggest sort that I have said were in the other water.'

[4] In 1913, Martinus Beijerinck repeated Van Leeuwenhoek's experiment and identified Clostridium butyricum as a prominent anaerobic bacterium in the sealed pepper infusion tube liquid.

Beijerinck commented: We thus come to the remarkable conclusion that, beyond doubt, Van Leeuwenhoek in his experiment with the fully closed tube had cultivated and seen genuine anaerobic bacteria, which would happen again only after 200 years, namely about 1862 by Pasteur.

[4]For practical purposes, there are three categories of anaerobe: However, this classification has been questioned after recent research showed that human "obligate anaerobes" (such as Finegoldia magna or the methanogenic archaea Methanobrevibacter smithii) can be grown in aerobic atmosphere if the culture medium is supplemented with antioxidants such as ascorbic acid, glutathione and uric acid.

Plants and fungi (e.g., yeasts) in general use alcohol (ethanol) fermentation when oxygen becomes limiting: The energy released is about 180 kJ per mol, which is conserved in generating two ATP from ADP per glucose.

[17] This process in animals is seen to be coupled with metabolic suppression to allow certain fish, such as goldfish, to survive environmental anoxic conditions for a short period.

The thioglycollate supplies a medium mimicking that of a dicot plant, thus providing not only an anaerobic environment but all the nutrients needed for the bacteria to multiply.

[19] On May the 6 2018, a French team evidenced a link between redox and gut anaerobes[20] based on clinical studies of severe acute malnutrition.

However, these mitochondria-related organelles lack the key features of typical mitochondria found in closely related aerobic Myxobolus squamalus.

In specific, the hindgut of the termite is full of nitrogen-fixing bacteria, ranging in function depending on the nitrogen concentration of the diet.

[29][30] The hindgut microbiome of different termites has been analyzed, showing 16 different anaerobic species of bacteria, including Clostridia, Enterobacteriaceae, and Gram-positive cocci.