Q. Denitrification is carried out by :

Q. Denitrification is carried out by :

(a) Pseudomonas and Nitrosococcus

(b) Nitromonas and Nitrobacter

(c) Nitrosomonas and Nitrosococcus

(d) Pseudomonas and Thiobacillus

Solution :

Correct option : D 
Pseudomonas and Thiobacillus cause denitrification which is the conversion of nitrites into Nitrogen gas in the absence of oxygen. Nitrobacter, Nitrosomonas, and Nitrosococcus cause nitrification. So the correct answer is ‘Pseudomonas and Thiobacillus‘.