NITROGEN FIXATION .
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Transcript of NITROGEN FIXATION .
NITROGEN FIXATION
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Introduction
Most Abundant Essential Organic Component Primary Nutrient Green Plants Fixed Nitrogen ?? Nitrogen Fixing organisms
Diazatrophs
Prokaryotes
Nitrogen Cycle :
What it is ?
Relationship b/w Organic & Inorganic N2 Metabolism.
IAtmospheric Nitrogen
Breaking of N2 bonds Energy Two Ways :
Abiotic Fixation
Biological Fixation
Abiotic Fixation
Result : Nitrates Source: Lightening & Cosmic Radiations
Nitrogen+ Oxygen Nitrogen Oxides
(NO , NO2) Nitrogen Oxides + Water Nitric
Acid
Biological Fixation
Soil Microrganisms Water
Cyanobacteria
Green Sulfur Bacteria
Azotobacteraceae Rhizobia
Cyanobacteria:
Imp. In Carbon and Nitrogen Cycle
Utilize variety of inorganic and organic sources of combined nitrogen such as nitrate, nitrite, ammonium
Rhizobia & Flankia
SEHRISH KHAN
Nitrogen cycle
Series of natural processes by which nitrogen passes through successive stations in air, soil, and organisms.
The atmospheric nitrogen occur in an inert form (N2)/can’t be used by most of the orangnims.
Atmospheric nitrogen is fixed by nitrogen cycle.Which principally invovles:-• Nitrogen fixation.• Nitrification.• Assimilation.• Ammonification.• Dentrification.
Nitrogen fixation:-
Deposits into soil & surface water precipitation.
Once settled; undergo changes
Conversion via Microorganisms:• Bacteria in symbiotic relation with
plants.• Free aerobic bacteria/alga. • Cyanobactetria
Nitrification:-
Two step process; converts NH3/NH4+ to NO3.
In first step:- Nitrosomanas/nitrococcus (soil bacteria)
convert NH3 to NO2-.
In second step:- Nitrobacter converts NO2- to NO3-. Bacteria gain energy known as
( nitrifying bacteria).
Assimilation:-
Process by which plants/animals take up nitrates and ammonia.
Plants take up NO3- and NH4+ through their roots and integrate them into various plant proteins /nucleic acids.
Animals take up this nitrogen by consuming plant tissues.
Ammonification:-
Many bacteria and fungi convert nitrogen into ammoniumNH4+ known as ammonification.
Converted ammmonia become available to take part in other biological processes.
Denitrification:-
‘Reduction of NO3+ N2 (anaerobic bacteria)’
Pseudomonas/Clostridium (anaerobic conditions)
Marine nitrogen fixation:-
Ecological Implications of Human Alterrations to Nitrogen Cycle:-
Burning fossils fuels. Primary productivity of many ecosystems. Alterations in both aquatic/terrestrial ecosystems. Argicultural systems (leach out of soil) Haber-bosch process. Anoxio/hypoxia. Harmful algal blooms. Change in boidiversty/overall ecosystem function. Parasitic/infectious diseases (humans/wildlife). Increased acidification in freshwater ecosystems.
CONCLUSION