EVERYDAY SCIENCE

Detailed explanation-1: -Many heterotrophic bacteria live in the soil and fix significant levels of nitrogen without the direct interaction with other organisms. Examples of this type of nitrogen-fixing bacteria include species of Azotobacter, Bacillus, Clostridium, and Klebsiella.

Detailed explanation-2: -Nitrogen fixation is carried out naturally in soil by microorganisms termed diazotrophs that include bacteria, such as Azotobacter, and archaea. Some nitrogen-fixing bacteria have symbiotic relationships with plant groups, especially legumes.

Detailed explanation-3: -Nitrogen fixation is carried out primarily by bacteria. Typically these bacteria, such as the Rhizobium bacteria, are found among the roots of legumes, such as soybeans. The bacteria are able to take the atmospheric nitrogen and transform it into a usable form.

Detailed explanation-4: -Rhizobium bacteria thriving in the root nodules of leguminous plants are capable of nitrogen fixation. They are able to convert atmospheric nitrogen to the form usable by plants.