PRESERVATION OF THE MARINE MICROALGA, ISOCHRYSIS-GALBANA - INFLUENCE ON THE FATTY-ACID PROFILE

Preservation of marine microalgae is of interest for storage in cultur e collections as well as a method of having living biomass available f or aquaculture feed. The present paper reports the effects of lyophili zation, freezing and maintenance of refrigerated cell concentrates on the viability and fatty acid profile of Isochrysis galbana. Lyophiliza tion led to a viability loss of about 98%, and the initial fatty acid profile remained unchanged throughout the experiment (1 month). Surviv al rate after freezing was enhanced by a 10% v/v glycerol addition and remained around 20% at the end of the experiment. No effect was obser ved on the fatty acid profile. A concentrate of 9 g.l-1 maintained at 4-degrees-C for 30 days retained up to 85% viability. There was a sign ificant decrease in saturated and mono-unsaturated fatty acids, while polyunsaturated content remained constant.