Question

Briefly describe the following methods of microbial culture preservation which is based on dehydration
•Sterile silica gel
•Sterile filter paper
•Sterile dry soil
•Freeze drying, lyophilization
•Liquid drying

Answer 1

Answer:

These methods include refrigeration, paraffin method, cryopreservation, and lyophilization (freeze drying). Strains can be maintained by periodically preparing a fresh culture from the previous stock culture.

Explanation:

Answer 2

The given techniques are used for the long-term preservation of microbial cultures.

Explanation:

Sterile silica gel- A microbial suspension is encapsulated in sterile silica gel and dried for long-term storage.

Sterile filter paper- Filter paper has pores that are used to trap microbial spores. This can be stored at low or room temperatures to be used for experiments.

Sterile dry soil- Soil samples can be directly stored in an appropriate container before being processed.

Freeze drying, lyophilization- It involves the removal of water by sublimation of ice crystals formed thus helping in the storage of samples in powder form.

Liquid drying- It uses vacuum to remove water without freezing. This is used for samples sensitive to low temperatures.