title: Anaerobic Metabolism in Haloferax Genus: Denitrification as Case of Study.
abstract: A number of species of Haloferax genus (halophilic archaea) are able to grow microaerobically or even anaerobically using different alternative electron acceptors such as fumarate, nitrate, chlorate, dimethyl sulphoxide, sulphide and/or trimethylamine. This metabolic capability is also shown by other species of the Halobacteriaceae and Haloferacaceae families (Archaea domain) and it has been mainly tested by physiological studies where cell growth is observed under anaerobic conditions in the presence of the mentioned compounds. This work summarises the main reported features on anaerobic metabolism in the Haloferax, one of the better described haloarchaeal genus with significant potential uses in biotechnology and bioremediation. Special attention has been paid to denitrification, also called nitrate respiration. This pathway has been studied so far from Haloferax mediterranei and Haloferax denitrificans mainly from biochemical point of view (purification and characterisation of the enzymes catalysing the two first reactions). However, gene expression and gene regulation is far from known at the time of writing this chapter.
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Torregrosa-Crespo
authors.affiliation: Universidad de Alicante, Alicante, Spain. Electronic address: rosa.martinez@ua.es.
authors.forename: R M
authors.initials: RM
authors.lastname: Martínez-Espinosa
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Esclapez
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Bautista
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Pire
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Camacho
authors.affiliation: University of East Anglia, Norwich, United Kingdom.
authors.forename: D J
authors.initials: DJ
authors.lastname: Richardson
authors.affiliation: Universidad de Alicante, Alicante, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Bonete
mesh_terms: D000693:Anaerobiosis / Q000502:physiology; D015374:Biosensing Techniques; D002704:Chlorates / Q000378:metabolism; D058440:Denitrification / Q000235:genetics / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D019621:Haloferax / Q000378:metabolism*; D050901:Nitrate Reductase / Q000378:metabolism; D009572:Nitrite Reductases / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D010100:Oxygen / Q000378:metabolism*; D010472:Perchlorates / Q000378:metabolism; D062065:Wastewater / Q000382:microbiology; D018508:Water Purification
chemical_list: D002704:Chlorates; D050901:Nitrate Reductase; D009572:Nitrite Reductases; D010088:Oxidoreductases; D010100:Oxygen; D010472:Perchlorates; D062065:Wastewater; C022763:nitrous oxide reductase; C034747:nitric-oxide reductase; C494474:perchlorate
keywords: Anaerobic metabolism; Bioremediation; Denitrification; Haloarchaea; NO(x) emissions