Q. Which of the following is a free living nitrogen fixing bacterium present in the soil?
A) $Nitrosomonas$
B) $Rhizobium$
C) $Azotobacter$
D) $Pseudomonas$
Explanation
The genus-$Azotobacter$ comprises large, free-living, Gram negative, obligately aerobic, rod-shaped bacteria which are capable of fixation of nitrogen non-symbiotically. $Rhizobium$is a symbiotic nitrogen fixing bacteria, $Nitrosomanas$ is a nitrifying bacteria, while $Pseudomonas$ sp. is denitrifying bacteria.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.