Transcript NITROGEN CYCLE - Western Connecticut State University

NITROGEN CYCLE
Wikipedia.org
Nitrogen Fixation
N2
NH4+
Let’s visit an AMMONIA FACTORY
Recent increases in anthropogenic N fixation in relation to “natural” N fixation.
Modified from Vitousek, P. M. and P. A. Matson (1993). Agriculture, the global
nitrogen cycle, and trace gas flux. The Biogeochemistry of Global Change: Radiative
Trace Gases. R. S. Oremland. New York, Chapman and Hall: 193-208.
Nitrogen Assimilation
NH4+
Organic N
Nitrogen Mineralization (decay)
Organic N
NH4+
Nitrification
NH4+
Nitrosomonas
NO2-
NO3Nitrobacter
Aerobic
Autotrophs
Energy obtained?
Denitrification
NO3N2+ N2O
Denitrification is an anaerobic process that
is carried out by denitrifying bacteria,
which convert nitrate to dinitrogen (gas) in
the following sequence:
NO3-
NO2-
NO
N2O
N2