CUET Preparation Today
Which of the following is not a nitrogen fixing microorganism? |
Azotobacter Oscillatoria Acetobacter Nostoc |
Acetobacter |
The correct answer is Option (3) - Acetobacter Biofertilizers are living organisms that enhance the nutrient content of the soil. They primarily derive from bacteria, fungi, and cyanobacteria. As you've learned, one notable example involves the formation of nodules on the roots of leguminous plants through a symbiotic partnership with Rhizobium bacteria. These bacteria play a crucial role in converting atmospheric nitrogen into organic forms, which can then be utilized by the plant as a nutrient source. Additionally, there are other types of bacteria, such as Azospirillum and Azotobacter, capable of fixing atmospheric nitrogen even when existing independently in the soil. This activity serves to augment the nitrogen levels within the soil, further enriching its nutrient content. Cyanobacteria, also known as blue-green algae, are autotrophic microorganisms found in various aquatic and terrestrial environments. Many cyanobacteria species, such as Anabaena, Nostoc, and Oscillatoria, possess the remarkable ability to fix atmospheric nitrogen. This capability makes them valuable contributors to soil fertility. In particular, in paddy fields, cyanobacteria play a significant role as biofertilizers by converting atmospheric nitrogen into organic forms that can be readily utilized by plants. Furthermore, cyanobacteria offer an additional benefit by contributing to soil health. They enrich the soil by adding organic matter, which enhances its fertility. This dual role of cyanobacteria in nitrogen fixation and soil enrichment makes them valuable components of sustainable agricultural practices. Commercial acetic acid is produced from fermented alcohol with the help of acetic acid bacteria -Acetobacter aceti .It is used in the preparation of ' vinegar'. |
