Editing Nitrification (section)

== History ==
The idea that oxidation of ammonia to nitrate is in fact a biological process was first given by [[Louis Pasteur]] in 1862.<ref>{{Cite journal| vauthors = Pasteur L |date=1862|title=Etudes sur les mycoderme|journal=C. R. Acad. Sci.|volume=54|pages=265–270}}</ref> Later in 1875, [[Alexander Müller (chemist)|Alexander Müller]], while conducting a quality assessment of water from wells in [[Berlin]], noted that ammonium was stable in sterilized solutions but nitrified in natural waters. [[Alexander Müller (chemist)|A. Müller]] put forward, that nitrification is thus performed by microorganisms.<ref>{{Cite journal| vauthors = Müller A |date=1875|title=Ammoniakgehalt des Spree- und Wasserleitungs wassers in Berlin|journal=Fortsetzung der Vorarbeiten zu einer zukünftigen Wasser-Versorgung der Stadt Berlin ausgeführt in den Jahren 1868 und 1869.|pages=121–123}}</ref> In 1877, [[Jean-Jacques Schloesing]] and [[Achille Müntz]], two French agricultural chemists working in [[Paris]], proved that nitrification is indeed microbially mediated process by the experiments with liquid sewage and artificial soil matrix (sterilized sand with powdered chalk).<ref>{{Cite journal| vauthors = Schloesing T, Muntz A |date=1877|title=Sur la nitrification pas les ferments organisés|journal=C. R. Acad. Sci.|volume=84|pages=301–303}}</ref> Their findings were confirmed soon (in 1878) by [[Robert Warington (agricultural chemist, born 1838)|Robert Warington]] who was investigating nitrification ability of garden soil at the [[Rothamsted Research|Rothamsted experimental station]] in [[Harpenden]] in England.<ref name=":1">{{Cite journal| vauthors = Warington R |date=1878|title=IV.—On nitrification|url=http://xlink.rsc.org/?DOI=CT8783300044|journal=J. Chem. Soc., Trans.|language=en|volume=33|pages=44–51|doi=10.1039/CT8783300044|issn=0368-1645}}</ref> [[Robert Warington (agricultural chemist, born 1838)|R. Warington]] made also the first observation that nitrification is a two-step process in 1879<ref name=":2">{{Cite journal|vauthors=Warington R|date=1879|title=XLIX.—On nitrification. (Part II.)|url=http://xlink.rsc.org/?DOI=CT8793500429|journal=J. Chem. Soc., Trans.|language=en|volume=35|pages=429–456|doi=10.1039/CT8793500429|issn=0368-1645|access-date=2021-03-12|archive-date=2021-06-12|archive-url=https://web.archive.org/web/20210612114744/https://pubs.rsc.org/en/content/articlelanding/1879/CT/CT8793500429|url-status=live}}</ref> which was confirmed by [[John Munro (chemist)|John Munro]] in 1886.<ref>{{Cite journal| vauthors = Munro JH |date=1886|title=LIX.—The formation and destruction of nitrates and nitrates in artificial solutions and in river and well waters|url=http://xlink.rsc.org/?DOI=CT8864900632|journal=J. Chem. Soc., Trans.|language=en|volume=49|pages=632–681|doi=10.1039/CT8864900632|issn=0368-1645}}</ref> Although at that time, it was believed that two-step nitrification is separated into distinct life phases or character traits of a single microorganism.

The first pure nitrifier (ammonia-oxidizing) was most probably isolated in 1890 by [[Percy F. Frankland|Percy Frankland]] and [[Grace Frankland]], two English scientists from Scotland.<ref>{{Cite journal|date=1890-12-31|title=V. The nitrifying process and its specific ferment.—Part I|journal=Philosophical Transactions of the Royal Society of London B|language=en|volume=181|pages=107–128|doi=10.1098/rstb.1890.0005|issn=0264-3839|doi-access=free}}</ref> Before that, [[Robert Warington (agricultural chemist, born 1838)|Warington]],<ref name=":1" /> [[Sergei Winogradsky]]<ref name=":3">{{Cite journal| vauthors = Winogradsky S |date=1890|title=Sur les organisms de la nitrification|journal=Ann. Inst. Pasteur|volume=4|pages=215–231}}</ref> and the Franklands were only able to enrich cultures of nitrifiers. Frankland and Frankland succeeded with a system of serial dilutions with very low inoculum and long cultivation times counting in years. [[Sergei Winogradsky]] claimed pure culture isolation in the same year (1890),<ref name=":3" /> but his culture was still co-culture of ammonia- and nitrite-oxidizing bacteria.<ref name=":4">{{cite journal | vauthors = Sedlacek CJ | title = It Takes a Village: Discovering and Isolating the Nitrifiers | journal = Frontiers in Microbiology | volume = 11 | pages = 1900 | date = 2020-08-11 | pmid = 32849473 | pmc = 7431685 | doi = 10.3389/fmicb.2020.01900 | doi-access = free }}</ref> [[Sergei Winogradsky|S. Winogradsky]] succeeded just one year later in 1891.<ref>{{Cite journal| vauthors = Winogradsky S |date=1891|title=Sur les organisms de la nitrification|url=|journal=Ann. Inst. Pasteur|volume=5|pages=92–100 }}</ref>

In fact, during the serial dilutions ammonia-oxidizers and nitrite-oxidizers were unknowingly separated resulting in pure culture with ammonia-oxidation ability only. Thus Frankland and Frankland observed that these pure cultures lose ability to perform both steps. Loss of nitrite oxidation ability was observed already by [[Robert Warington (agricultural chemist, born 1838)|R. Warington]].<ref name=":2" /> Cultivation of pure nitrite oxidizer happened later during 20th century, however it is not possible to be certain which cultures were without contaminants as all theoretically pure strains share same trait (nitrite consumption, nitrate production).<ref name=":4" />