EN
As with all products and processes exploiting
biological materials algal biotechnology has an absolute
requirement for stable, function-fulfilling master stockcultures.
Conventionally microalgae and cyanobacteria
are maintained by serial transfer with inocula (2.5-25%
v/v) being transferred to fresh medium and the culture
being held under controlled environmental conditions.
This method is satisfactory for many algal taxa, but by its
nature cannot provide an absolute guarantee of phenotypic
or genotypic stability. Cryopreservation at ultra-low
temperatures (> -130oC) is the only methodology that can
provide this level of security to master stock-cultures;
however, many algae are recalcitrant to cryopreservation
with low or no survival. This review explores the reasons of
this cryo-recalcitrance on the application of conventional
colligative, two-step cryopreservation protocols and
points towards the options available to enhance postcryopreservation
viability.