CRYOPRESERVATION OF TETRASELMIS-SUECICA CULTURED UNDER DIFFERENT NUTRIENTS REGIMES

The commercially important member of the Prasinophyceae Tetraselmis suecica CCAP 66/4, which is widely used in the aquaculture industry, can be cryopreserved with levels of post-thaw viability in excess of 65%. The nutritional mode which the alga uses appears to be of secondary importance to the cryoprotectant and cooling protocol used, to maximise survival. Glycerol was the least cytotoxic and most protective of the cryoprotectants employed and a cooling rate of 5-degrees-C min-1 to -30-degrees-C with a 10-minute equilibration, followed by plunging into liquid nitrogen was found to give the highest levels of post-thaw viability.