Question
Biology Question on Microbes in human welfare
Which one of the following is non-symbiotic bio fertilizer ?
A
Rhizobium
B
Azotobacter
C
VAM
D
Mycorrhiza
Answer
Azotobacter
Explanation
Solution
Biofertilizers are organisms which bring about nutrient enrichment of the soil. Azotobacter is a free living, aerobic, nitrogen fixing bacteria. Anabena is a nitrogen fixing cyanobacteria that occurs in both free living and symbiote associations with Azolla, Cycas roots etc. Rhizobium lives symbiotically in root nodules of legumes and non-legumes. Vesicular-arbuscular mycorrhiza (VAM) is an example of endomycorrhiza in which fungal hyphae penetrate the cortical cells of grasses to form vesicles.