Fountain thread

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Fountain thread
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Methylococcales
Family : Crenotrichaceae
Genre : Crenothrix
Type : Fountain thread
Scientific name of the  genus
Cohn 1870
Scientific name of the  species
Crenothrix polyspora
Cohn 1870

The well thread ( Crenothrix polyspora ) is a bacterium that occurs in limnic waters with low concentrations of dissolved substances and forms long threads.

Properties, reproduction, distribution

The bacterium mainly forms cylindrical cells with a diameter of 0.6-5 µm, which are located in thin, unbranched, up to 10 mm long tubes (sheaths) made of transparent organic material. Often the scabbards are attached with one end to solid bodies, occasionally they are coated with compounds of trivalent iron or tetravalent manganese . In the microscope , the thread shape of the well thread is easy to distinguish from almost all other bacteria and has a complex life cycle that includes the formation of so-called macro and micro gonidia. The vagina tend to clump together and sometimes form lumps so large that they can be seen with the naked eye. The bacterium is gram negative .

At the free ends of the sheaths, the cells occasionally divide perpendicular to the longitudinal axis of the thread without any significant increase in length. This creates short-cylindrical cells with a diameter like that of "normal" cells. These short cells, called macrogonidia , are released from the vagina and are used to multiply and spread. Another form of the formation of multiplication and spreading stages consists in the fact that at the vaginal ends the bacteria divide without significant growth in different, approximately perpendicular planes. This creates a lot of small cells called microgonidia , like the macrogonidia are released from the vagina and spread throughout the habitat .


Crenothrix occurs in standing and flowing waters which contain organic substances in low concentrations, preferably in those which also contain low concentrations of divalent iron ions and / or traces of methane . It often occurs in drinking water extraction systems and water pipes. Scientists from the Vienna Institute for Microbial Ecology were able to prove for the first time that the bacterium can utilize the greenhouse gas methane

In 2017, in a study with 13 C- labeled methane molecules in Switzerland, scientists found that the thread of wells in lakes is one of the most important methane oxidizers.

Systematic position

For a long time the systematic classification of this bacterium was not possible. No details were known about the physiology either. The reason for this is that to date it has not been possible to get Crenothrix polyspora to grow under laboratory conditions. The 16S rRNA base sequence of the well thread indicates that the bacterium belongs to the genus Methylobacter .

Discovery story

The fountain thread was discovered in 1870 by one of the founding fathers of modern bacteriology , Ferdinand Cohn .

Technical importance

If water supply systems are infested, pipes and sieves can become severely blocked. There are historically proven cases in Berlin and Rotterdam , for example , where the bacteria were even detected at the water supply points in households. In addition, the bacterium colors the water reddish to blood red, making it inedible. The bacterium is not considered a pathogen .


  • Friedrich Bumb, Reinhart Schweisfurth: Summary of the knowledge about Crenothrix polyspora COHN and own studies: University Collection Natural Science, Biology, Vol. 15. Hochschulverlag / Günter Mainz Verlag, Freiburg (Breisgau) 1981, ISBN 3-8107-2125-5 .


  1. a b Kilian Stoecker, Bernd Bendinger, Björn Schöning, Per H. Nielsen, Jeppe L. Nielsen: Cohn's Crenothrix is ​​a filamentous methane oxidizer with an unusual methane monooxygenase . In: Proceedings of the National Academy of Sciences . tape 103 , no. 7 , February 14, 2006, p. 2363-2367 , doi : 10.1073 / pnas.0506361103 , PMC 1413686 (free full text).
  2. fountain thread eats methane ChemLin, February 14, 2006
  3. Kirsten Oswald, Jon S. Graf, Sten Littmann, Daniela Tienken, Andreas Brand: Crenothrix are major methane consumers in stratified lakes . In: The ISME Journal . June 6, 2017, doi : 10.1038 / ismej.2017.77 ( PDF ).