The task of culture collections is to collect and store microorganisms in order to protect the biodiversity of biological resources. Culture collections function as strain repositories for the purpose of scientific research, teaching, industrial applications and patent deposits. Also, in the culture collections of microorganisms, research is conducted to identify, characterise, classify and improve functional properties of the resources stored. During storage it is important to keep the morphology, enzymatic activity and genetic material of those microorganisms unaltered and to ensure their high survival rate. For safety reasons and to minimise the risk of losing strains, it is recommended by the World Federation for Culture Collection (WFFCC) to use at least two various procedures for storing them. In the paper there are presented freezing and freeze-drying as techniques of preserving and storing microorganisms most frequently applied in collections. The article may be useful when selecting a suitable preservation technique, process and storage conditions, and an appropriate technique to revive the preserved microorganisms.
techniques of preserving and storing microorganisms, freezing, freeze-drying, cryoprotectants