Select the match ones. I Nitrosomonas – Nitrite to nitrate II Thiobacillus - Denitrification III Nostoc - Free-living nitrogen-fixer IV Azotobacter - Anaerobic nitrogen-fixer |
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a) |
I and II |
b) |
III and IV |
c) |
II and III |
d) |
II and IV |
Select the match ones. I Nitrosomonas – Nitrite to nitrate II Thiobacillus - Denitrification III Nostoc - Free-living nitrogen-fixer IV Azotobacter - Anaerobic nitrogen-fixer |
|||||||
a) |
I and II |
b) |
III and IV |
c) |
II and III |
d) |
II and IV |
(c) Nitrate present in the soil is reduced to nitrogen by the process of denitrification. Denitrification is carried by bacteria Pseudomonas and Thiobacillus. A number of cyanobacteria such as Anabaena and Nostoc are free-living nitrogen-fixers. Azotobacter and Beijernickia are free-living nitrogen fixing aerobic microbes. Nitrosomonas and/or Nitrosococcus oxidise to nitrite. The nitrite is further oxidised to nitrate with the help of Nitrobacter and Nitrocystis. |