The oxidation of Ammonia was for decades believed to be performed solely by certain autotrophic bacteria (i.e. Nitrosomona) Later it was discovered that this oxidation process was also performed by certain Heterotrophic bacteria under certain conditions that were completely void of any organic carbon source or oxygen.
With the advent of gene sequencing, it was discovered in 1977 that what was thought to be a type of bacteria was actually not a bacteria at all, but an entirely different and new domain. This group of microorganisms was given the name “Archaea”.
Originally thought to be exclusively extremeophiles that lived in environments such as hot springs and very acid and saline conditions, it was recently (2006) discovered and subsequently verified (2008) that Archaea are ubiquitous and exist in all environments and more importantly play a very large role in the oxidation of Ammonia. Unlike nitrifying bacteria, nitrifying Archaea are suspected to be adaptable to a wider range of temperatures. Evidence of their existence has been found in the very cold waters of Antarctica.
Unfortunately, at the present time, Archaea are very difficult, if not impossible, to reproduce under laboratory conditions, so current knowledge is limited.
No nitrite oxidizing Archaea have been detected to date, but, given the relative infancy and current limits of research, this does not mean that they don’t exist.
The results of future research could have a major impact on how we view the basic biological processes of our ponds. For example, it has already been shown that Archaea tend to colonize the rhizosphere (root zone) of aquatic plants. This fact alone increases the importance of aquatic plantings in maintaining water quality. Archaea’s wider tolerance of extreme temperatures could possibly shed light on why some Northern ponds endure winter stresses better than others.
Much still needs to be learned about this newly named, but very old, microorganism.
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