How many among the the following bacteria are involved in nitrogen fixation? Bacillus ramosus,Pseudomonas, Lactobacillus, Beijerinckia, Frankia,Klebsiella, Clostridium, Bacillus subtilis, Salmonella, Rhizobium

Options

A. 4
B. 7
C. 6
D. 5

Answer

To determine how many of the listed bacteria are involved in nitrogen fixation, we will analyze each bacterium individually based on their known roles in nitrogen fixation.

1. **Bacillus ramosus**: This bacterium is primarily involved in ammonification, not nitrogen fixation.
- **Hint**: Check the role of Bacillus ramosus in the nitrogen cycle.

2. **Pseudomonas**: This genus is known for its role in denitrification, not nitrogen fixation.
- **Hint**: Identify the processes associated with Pseudomonas.

3. **Lactobacillus**: This bacterium is primarily a lactic acid bacterium involved in fermentation processes, not nitrogen fixation.
- **Hint**: Consider the primary functions of Lactobacillus in food production.

4. **Beijerinckia**: This is a free-living aerobic bacterium that is capable of nitrogen fixation.
- **Hint**: Look for free-living nitrogen-fixing bacteria.

5. **Frankia**: This bacterium is a symbiotic nitrogen-fixing organism associated with non-leguminous plants.
- **Hint**: Recall the symbiotic relationships of nitrogen-fixing bacteria.

6. **Klebsiella**: This is another free-living aerobic bacterium that can fix nitrogen.
- **Hint**: Determine the nitrogen-fixing capabilities of Klebsiella.

7. **Clostridium**: This genus includes anaerobic bacteria that are capable of nitrogen fixation.
- **Hint**: Explore the anaerobic nitrogen-fixing bacteria.

8. **Bacillus subtilis**: This bacterium is primarily found in the gastrointestinal tract of ruminants and is not known for nitrogen fixation.
- **Hint**: Investigate the ecological role of Bacillus subtilis.

9. **Salmonella**: Known for causing typhoid fever, Salmonella does not play a role in nitrogen fixation.
- **Hint**: Consider the pathogenic nature of Salmonella.

10. **Rhizobium**: This is a well-known symbiotic nitrogen-fixing bacterium that forms nodules on leguminous plants.
- **Hint**: Remember the relationship between Rhizobium and legumes.

Now, let's summarize the findings:

- **Nitrogen-fixing bacteria identified**:
- Beijerinckia
- Frankia
- Klebsiella
- Clostridium
- Rhizobium

Thus, the total number of bacteria involved in nitrogen fixation from the list is **5**.

**Final Answer**: 5