Question: Which organism is most likely associated with non-symbiotic nitrogen fixation?
Options:
Rhizobium
Penicillium
Azotobacter
Pythium
–
📌Other Options Explanations:
-(a) Rhizobium: Rhizobium forms a symbiotic relationship with legumes, fixing nitrogen within root nodules for the plant's benefit.
-(b) Penicillium: Penicillium is a mold fungus known for producing antibiotics.
-(d) Pythium: Pythium is a fungal genus that can cause root rot diseases in plants.
🛑 Additional Information::
-Nitrogen Fixation – Conversion of atmospheric nitrogen into nitrates so that it can be utilized by plants is termed nitrogen fixation.
-The ability of nitrogen fixation is possessed only by certain prokaryotes containing an enzyme complex called dinitrogenase that catalyzes the reduction of dinitrogen to ammonia. eg: Rhizobium, Azotobacter, Clostridium, Beijerinckia, etc.
-The prokaryotes either fix nitrogen symbiotically (by living in association with the cells of higher plants) or non-symbiotically (by living freely in the soil).
Azotobacter
-It is a non-symbiotic nitrogen-fixing bacteria.
-These are gram-negative, aerobic, free-living that play an important role in the nitrogen cycle
-The first representative of the genus, Azotobacter chroococcum, was discovered and described in 1901 by Dutch microbiologist and botanist Martinus Beijerinck.