Johannes Gijsbrecht Kuenen (born 9 December 1940,

Heemstede Heemstede () is a town and a municipality in the Netherlands, in the province of North Holland. It is the fourth richest municipality of the Netherlands. History Heemstede formed around the Castle ''Heemstede'' that was built overlooking the ...

) is a Dutch microbiologist who is

professor emeritus ''Emeritus'' (; female: ''emerita'') is an adjective used to designate a retired chair, professor, pastor, bishop, pope, director, president, prime minister, rabbi, emperor, or other person who has been "permitted to retain as an honorary title ...

at the

Delft University of Technology Delft University of Technology ( nl, Technische Universiteit Delft), also known as TU Delft, is the oldest and largest Dutch public technical university, located in Delft, Netherlands. As of 2022 it is ranked by QS World University Rankings among ...

and a visiting scientist at the

University of Southern California , mottoeng = "Let whoever earns the palm bear it" , religious_affiliation = Nonsectarian—historically Methodist , established = , accreditation = WSCUC , type = Private research university , academic_affiliations = , endowment = $8.1 ...

. His research is influenced by, and a contribution to, the scientific tradition of the Delft School of Microbiology. Kuenen studied at the

University of Groningen The University of Groningen (abbreviated as UG; nl, Rijksuniversiteit Groningen, abbreviated as RUG) is a public research university of more than 30,000 students in the city of Groningen in the Netherlands. Founded in 1614, the university is th ...

, where he received both his Doctorandus degree and in 1972 his Doctorate (PhD) under the supervision of Professor Dr. Hans Veldkamp. The title of his thesis was ‘‘Colourless sulphur bacteria from Dutch tidal mudflats’’. After a short post-doc at the

University of California in Los Angeles The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California St ...

(USA), he returned as a senior lecturer to Groningen. In 1980, he moved to Delft to become the 4th Professor of Microbiology (succeeding M.W. Beijerinck and A.J. Kluyver) at Delft University of Technology. Kuenen's initial research interests were (the application of) bacteria involved in the natural sulfur cycle and

yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...

physiology and metabolism. His later interest in the (eco)physiology of nitrifying and

denitrifying Denitrification is a microbially facilitated process where nitrate (NO3−) is reduced and ultimately produces molecular nitrogen (N2) through a series of intermediate gaseous nitrogen oxide products. Facultative anaerobic bacteria perform denitr ...

bacteria has led a.o. to the discovery of the bacteria within the phylum

Planctomycetota The Planctomycetota are a phylum of widely distributed bacteria, occurring in both aquatic and terrestrial habitats. They play a considerable role in global carbon and nitrogen cycles, with many species of this phylum capable of anaerobic ammoniu ...

that perform the

Anammox Anammox, an abbreviation for anaerobic ammonium oxidation, is a globally important microbial process of the nitrogen cycle that takes place in many natural environments. The bacteria mediating this process were identified in 1999, and were a gre ...

process. In addition, his research has been focussed on (halo) alkaliphilic sulfur-oxidizing bacteria from soda lakes. Gijs Kuenen retired in 2005 but remains active in science.

Awards

In 2004 Gijs Kuenen became a Knight in the

Order of the Netherlands Lion The Order of the Netherlands Lion, also known as the Order of the Lion of the Netherlands ( nl, De Orde van de Nederlandse Leeuw, french: L'Ordre du Lion Néerlandais) is a Dutch order of chivalry founded by King William I of the Netherlands on ...

, In 2005 he was elected Fellow of the

American Academy of Microbiology The American Society for Microbiology (ASM), originally the Society of American Bacteriologists, is a professional organization for scientists who study viruses, bacteria, fungi, algae, and protozoa as well as other aspects of microbiology. It wa ...

. In 2006 he received the Jim Tiedje Award for his outstanding contribution to microbial ecology at the 11th International Symposium on Microbial Ecology in Vienna and in 2007 he was awarded the Procter & Gamble Award in Applied and Environmental Microbiology. For his contribution to the founding of the education Life Science and Technology (

and Leiden University) in 2005 he received an honorary membership of Study Association LIFE.

Named after Kuenen

One of the five known anammox genera, with the single member Kuenenia stuttgartiensis, has been named after Kuenen. The Kuenen lab had named the first discovered species

Brocadia anammoxidans "''Candidatus'' Brocadia" is a ''candidatus'' genus of bacteria. Many of the species in this genus are capable of anammox. Phylogeny Phylogeny based on GTDB 07-RS207 by Genome Taxonomy Database The Genome Taxonomy Database (GTDB) is an onl ...

, after the company Gist-Brocades (now DSM Gist), for which Kuenen did consulting work and in which wastewater the bacteria was discovered.

References

*van Caulil G. (2006) ''Anammox, the cleaning creature that could not exist; Beijerinck, Kluyver, Kuenen - A goodbye to a remarkable microbiologist''
Delft Outlook 2006.1
* The anammox online resource
www.anammox.com
*la Rivière JWM. (2004) The Delft School of Microbiology in historical perspective
Antonie van Leeuwenhoek 71:3-13
*Kuenen JG. (2008) Anammox bacteria: from discovery to application
Nature Reviews Microbiology 6:320-326
*Sorokin DY. & Kuenen JG. (2005) "Chemolithotrophic haloalkaliphiles from soda lakes". ''FEMS Microbiology Ecology''. 52:287-295 *van de Graaf AA., Mulder A., de Bruijn P., Jetten MS., Robertson LA., Kuenen JG. (1995) Anaerobic oxidation of ammonium is a biologically mediated process
Applied and Environmental Microbiology. 61:1246-1251
{{DEFAULTSORT:Kuenen, Gijs 1940 births Living people Dutch microbiologists Nitrogen cycle Environmental microbiology People from Heemstede University of Groningen alumni Academic staff of the University of Groningen Academic staff of the Delft University of Technology