What is Batch Sterilization: Process, Its Advantages, and Disadvantages:
What is Sterilization?
- Sterilization is the process of removing or killing unwanted microorganisms like bacteria, fungi, etc. from the fermentation medium.
- It includes both pathogenic and non-pathogenic microorganisms, as well as bacterial spores and fungal spores.
- Sterilization is a measure that uses strong physical and chemical factors to make all microorganisms inside and outside any object lose their ability to grow and reproduce forever.
- Sterilization is a necessary condition to obtain pure culture, and it is also a necessary technology in the field of the food industry and medicine.
- The types of sterilization are Batch sterilization, Continuous sterilization, and Filter sterilization.
Batch Sterilization Definition:
Batch sterilization is a process where all the substrate and nutrients added to the vessel are allowed to reduce contaminant organisms present in the medium through the heating of a vessel.
What is Batch Sterilization?
- Batch sterilization is the reduction of contaminant organisms through the heating of a vessel.
- In batch sterilization entire fermentation medium is added to a vessel.
- Batch sterilization is generally used to sterilize liquid media.
- The highest temperature for batch sterilization is 121°C.
- The advantage of batch sterilization over continuous sterilization is that it has lower capital of equipment costs, high destruction rate, simple operation, etc.
Process of Batch Sterilization:
- Batch sterilization is the most commonly used and suitable method for liquid media sterilization.
- Generally, the Batch Sterilization process is completed in three steps: heating, holding, and cooling period.
- In the heating step, the steam is directly injected into the fermentation medium, or the vessel is heated electrically by heating jackets / Coils.
- Now the temperature is increased until it reaches the sterilization temperature where it is held for a set period. During this period, most of the unwanted microorganisms are destroyed by the media and Bioreactor.
- Finally, the system is cooled to bring the sterile culture media back to the desired temperature.
- The autoclave is an instrument that works on the principle of batch sterilization. It is used to kill germs that invade the fermentation media.
- The highest temperature, which appears to be feasible for batch sterilization is 121°C.
- The advantage of batch sterilization it has lower capital of equipment costs.
- The disadvantages of batch sterilization are it wastes energy and can overcook the medium and it requires more expensive heat requirements than continuous sterilization.
- The long exposure of batch sterilization may lead to the degradation of the medium.
- The medium may lose all its nutritional quality.
- The heat-labile components like proteins and vitamins get degraded due to overheating.
- It will leave some bacteria a chance to survive, and once the bacteria have formed spores (a kind of dormant body), it is difficult to kill them.
- Batch sterilization is the most common and widely used technique to sterilize the fermentation medium.
- Batch sterilization is more reliable to scale up the fermentation process.
- It has a simple operation.
- No additional materials are required to add to the fermentation media.
- Batch sterilization can reduce thermal damage to the fermentation medium significantly.
- Batch sterilization achieves high levels of cell destruction.
- The other advantages of batch sterilization are strong continuity, rapid sterilization and disinfection, and less damage to the nutrients in the fermentation medium.
- Batch sterilization utilizes more expensive heat.
- Best results only occur in well-mixed closed vessels.
- It is suitable for manual operation.