Location
University of Nevada, Las Vegas
Start Date
3-8-2010 9:00 AM
End Date
3-8-2010 12:00 PM
Description
Nitrification and denitrification are two important steps in the nitrogen cycle . Nitrification, a two step process, leads to the production of NO3-, (Fig. 1). In the first step, ammonia oxidation, NH3 is oxidized to NO2-, and in the second step, nitrite oxidation, NO2- is oxidized to NO3-. Until recently, very little was know about nitrification in high temperature environments. However, in 2008 a thermophilic archaeon, named “Candidatus Nitrosocaldus yellowstonii”, was shown to mediate ammonia oxidation up to 74°C. More recently , NO2- oxidizing bacteria were discovered that are active in temperatures up to 48°C(4). While NH3 oxidation is generally considered to be the rate limiting step, this may not be the case at high temperatures since accumulation of NO2- has been reported in some hot springs where NH3 is the dominant form of inorganic nitrogen (1).
Keywords
Hot springs; Nitrification; Nitrogen cycle; Thermophilic microorganisms; United States – Great Basin
Disciplines
Chemistry | Environmental Sciences | Physical Sciences and Mathematics
Language
English
Previous Versions
Nitrogen cycle in Great Basin hot springs
University of Nevada, Las Vegas
Nitrification and denitrification are two important steps in the nitrogen cycle . Nitrification, a two step process, leads to the production of NO3-, (Fig. 1). In the first step, ammonia oxidation, NH3 is oxidized to NO2-, and in the second step, nitrite oxidation, NO2- is oxidized to NO3-. Until recently, very little was know about nitrification in high temperature environments. However, in 2008 a thermophilic archaeon, named “Candidatus Nitrosocaldus yellowstonii”, was shown to mediate ammonia oxidation up to 74°C. More recently , NO2- oxidizing bacteria were discovered that are active in temperatures up to 48°C(4). While NH3 oxidation is generally considered to be the rate limiting step, this may not be the case at high temperatures since accumulation of NO2- has been reported in some hot springs where NH3 is the dominant form of inorganic nitrogen (1).
Comments
Poster research sponsored by Nevada NASA Space Grant Consortium