Mesosome

Mesosomen are invaginations of the plasma membrane of bacteria, which are probably produced by chemical fixation. They were first observed in 1953 in electron microscopic preparations. Various functions were then proposed in the 1960s, until it turned out since the late 1970s that it suspected to be artifacts.

Observed Mesosomen to Gram- positive bacteria. The name goes back to a paper from the year 1959. A function of the Mesosomen was suspected as the organelles in various cellular processes, such as for the construction of the cell wall during cell division, doubling the bacterial chromosome or as a site of oxidative phosphorylation.

In the late 1970s, data collected, which could suggest that it is Mesosomen are structures that are caused only by chemical fixation, since they did not occur in cells that were fixed with other methods .. With the advancement in electron microscopic fixation methods ( cryofixation and freeze substitution ') found several works that Mesosomen not occur in living cells. However, some researchers were of the opinion that the available data is inconclusive and that Mesosomen may not in all cases be artefacts.

In 2000 Mesosomen -like invaginations were observed in bacteria, the antibacterial peptides called defensins were exposed in 2007 to those that have been treated with certain antibiotics. The appearance of these Mesosomen - like structures may be a result of the damage to the plasma membrane or the cell wall of these chemicals.

The "discovery" of Mesosomen and their eventual unmasking as artifact served in the philosophy of science as a practical example of the process of falsification of a scientific idea or hypothesis. In this example, one could study how the scientific community (English: ' Scientific Community ') carried out this test method and has the original hypothesis eventually rejected.