Question

Enumerate various free living and symbiotic nitrogen fixing systems with suitable examples.

Answer 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.

Answer 2

Dear Student,

● Nitrogen fixation -

• Nitrogen fixation is conversion of molecular nitrogen into ammonia or related compounds that can be metabolised by organisms.
• Nitrogen fixation most commonly occurs by two methods - either by lightening or by nitrogen-fixing bacteria.

# Free-living nitrogen fixing organisms -

1. Cyanobacteria
2. Clostridium
3. Azobacter
4. Rhodobacter
5. Azosporilium

# Symbiotic nitrogen fixing organisms -

1. Rhizobium on leguminous plants
2. Frankia on non-leguminous plants

Thanks dear. Hope this helps you...