78. Roll tube technique is used for isolation of
1. Aerobic bacteria
2. Cyanobacteria
3. Stringent anaerobic bacteria
4. Pathogenic fungi

 

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What is the Roll Tube Technique?

The roll tube technique is a laboratory method used to isolate and cultivate microorganisms, particularly anaerobic bacteria. This technique involves the preparation of agar plates in test tubes that are then rolled to evenly spread the agar medium. The key advantage of this method is its ability to maintain an anaerobic environment, which is crucial for isolating microorganisms that require the absence of oxygen for growth.

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How Does the Roll Tube Technique Work?

1. Preparation of Agar Medium:

   • The medium is prepared with nutrients that support the growth of bacteria.

   • The medium often contains reducing agents to remove oxygen.

2. Inoculation:

   • A small sample containing microorganisms is introduced into the medium.

3. Rolling:

   • The test tube is gently rolled to spread the agar evenly, ensuring that bacteria settle in a controlled, solid medium.

4. Incubation:

   • The test tube is incubated in a way that maintains an anaerobic atmosphere, which is essential for the growth of anaerobic bacteria.

5. Observation:

   • The results are then observed after incubation, with the growth of colonies indicating the presence of the microorganism.

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Which Organisms are Best Isolated Using the Roll Tube Technique?

The roll tube technique is particularly useful for isolating stringent anaerobic bacteria, which are bacteria that cannot survive in the presence of oxygen. These bacteria require anaerobic conditions for proper growth, making this technique ideal.

• Aerobic bacteria can thrive in oxygen-rich environments and are generally not isolated using the roll tube technique.

• Cyanobacteria and pathogenic fungi do not specifically require anaerobic environments for isolation, so this method is not suited for them.

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Correct Answer: Option 3 – Stringent Anaerobic Bacteria

The roll tube technique is most commonly used for isolating stringent anaerobic bacteria because it helps maintain the anaerobic conditions that these bacteria need to grow.

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Conclusion

The roll tube technique is an effective method for isolating anaerobic bacteria, particularly stringent anaerobic bacteria, that cannot survive in the presence of oxygen. By providing an oxygen-free environment, this technique ensures that the growth of oxygen-sensitive bacteria can be carefully controlled and studied.