Preservation of industrially important microbes

Summary

This video explains the critical importance of preserving industrially significant microbial strains used in bioprocessing industries. It covers various preservation methods, categorizing them into metabolically active state and suspended metabolic state storage. The methods discussed range from periodic transfers to fresh media, overlaying with oil, and soil storage, to advanced techniques like lyophilization and liquid nitrogen storage. Each method's effectiveness is assessed based on three key parameters: viability, genetic stability, and contamination prevention. The video highlights the pros and cons of each method, ultimately recommending lyophilization and liquid nitrogen storage as the best options for long-term preservation of microorganisms.

Takeaways

• 😀 The type of microbial strains used in the bio-processing industry is critical to process viability.
• 😀 Primary and secondary screening methods are used to isolate industrially important microorganisms, a process that can take 5 to 20 years.
• 😀 Preserving industrial strains is vital to avoid losing valuable microorganisms after significant investment in isolation.
• 😀 When preserving industrial strains, three key objectives must be met: viability, genetic stability, and contamination-free conditions.
• 😀 Viability means that microorganisms should be able to grow and produce colonies after preservation, not just show metabolic activity.
• 😀 Genetic stability ensures that ideal characteristics of microorganisms are maintained during preservation, preventing unwanted changes.
• 😀 Contamination-free preservation means that no other microorganisms or viruses should contaminate the stored cultures.
• 😀 Microbial strains can be preserved in two main states: metabolically active state (for short-term storage) or suspended metabolic state (for long-term storage).
• 😀 Periodic transfer to fresh media is a common method for storing microorganisms in a metabolically active state, but it can lead to genetic instability and higher contamination risks.
• 😀 Long-term preservation methods like lyophilization (freeze-drying) and liquid nitrogen storage maintain viability and genetic stability while minimizing contamination risk, but require careful handling.

Q & A

What is the main focus of the video?

The video focuses on methods of preserving industrial microbial strains used in bio-processing, highlighting both short-term and long-term preservation techniques.

Why is preserving industrial microbial strains important in the bio-processing industry?

Preserving microbial strains is essential to maintain their viability, genetic stability, and contamination-free status, which are crucial for successful bio-processing operations.

What are the key objectives when preserving microbial strains?

The key objectives are ensuring the viability of the strain, maintaining its genetic stability, and preventing contamination by other microorganisms or viruses.

What are the two major categories of microbial strain preservation methods?

The two major categories are preservation in a metabolically active state (short-term) and suspended metabolic state (long-term).

What methods are used for preserving microbial strains in a metabolically active state?

Methods for metabolically active state storage include periodic transfer to fresh media, overlaying with mineral oil, sterile soil storage, and silane suspension culture.

What are the advantages and disadvantages of periodic transfer to fresh media?

Periodic transfer maintains viability but can affect genetic stability, and it carries a higher risk of contamination due to frequent subculturing.

How does overlaying microbial cultures with mineral oil help in preservation?

Overlaying with mineral oil slows down microbial growth, helping to maintain viability. However, it can also affect the genetic stability of the microorganisms.

What is lyophilization, and why is it an effective method for long-term microbial strain preservation?

Lyophilization, or freeze-drying, involves converting ice directly into gas, preserving a wide range of microorganisms. It ensures long-term viability, genetic stability, and a contamination-free environment, though revival requires careful handling.

How does liquid nitrogen storage work, and what are its pros and cons?

Liquid nitrogen storage involves freezing microorganisms at extremely low temperatures (-150°C to -196°C), which preserves them for decades. It ensures genetic stability and viability but requires constant temperature control and can be more expensive over time.

What is the key difference between lyophilization and liquid nitrogen storage?

The main difference is that lyophilization is more cost-effective and can be stored at room temperature, but it's less universally applicable than liquid nitrogen, which can preserve a wider range of microorganisms but requires continuous monitoring and can be more costly.