Fungal Culture Preservation
The main objectives of fungal culture are to grow the organisms, isolate the organisms, and if necessary preserve the organisms. A fungal culture is a genetic resource and thus fungal culture preservation is applicable for the following purposes;
- Germplasm conservation
- Developmental studies
- Industrial Application
- Research programs
Fungal Culture Preservation Techniques
Fungal culture preservation techniques are as follows-
- Periodic serial subcultures
- Sterile water
- Sterile mineral oil overlay
- Sterile soil or sand
- Silica gel
- Drying on organic substrates
- Mechanical freezers
Sterile Water Preservation Technique
Sterile Water Preservation Technique is recommended as easy, cheap and satisfactory for preservation of most species of fungi.
Requirements for Sterile Water Preservation Technique
- Screw cap tubes
- Distilled water
- Fungal isolates
- Inoculating loop/wire
- Bunsen burner
- Biosafety cabinet (BSC)
- Tube rack
Procedure of Sterile Water Preservation Technique
- Take strile screw cap tube with sterile distilled water.
- Submerge the fungal isolate into a screw cap tube.
- Store it at room temperature (25-28 ° C).
Sub culturing from the water
- Clean of the screw caps with 70% ethanol before unscrewing them.
- Transfer a fragment from the tube to culture media.
- Incubate the culture media at room temperature (24-28° C) between 5-30 days depending on the nature of organisms.
- Perform LPCB preparation from culture and you may also use slide cultures for better expression morphological features of fungi.
Note-Only perform these types of activities in biosafety cabinet.
- Preservation of fungal cultures in sterile distilled water is also called Castellani’s method that has been endorsed as a method ensuring high rates of fungal viability, purity and stability, low costs and great simplicity where facing economic difficulties.
- Numerous fungi will survive for a decade or more in sterile water.
- There is no ideal technique of preservation appropriate for all laboratories and applicable to all fungi.
- It is noteworthy that all of these approaches are more expensive as compare to sterile water which can significantly reduce culture storage expense.
- Liquid nitrogen (LN2) freezers- It is beneficial for following purposes-√Unexcelled for duration of storage
√Long-term viability is maximized
√All types of culturable fungi can be stored.