| Abstract |
The Prasinophyceae Tetraselmis suecica Butcher, was cultivated at a density of 2 to 3 million cells per ml and was concentrated with a decanting centrifugal extractor at 1 m3/hr flow. The samples, obtained in the form of a paste, were diluted to 50 x 10(6) cells per ml and mixed with two cryoprotective agents such as glycerol (10, 20, 30%) and dimethyl sulfoxide (DMSO, 5, 10, 15%), then frozen and stored a t -25 C. After a 1 month period, results by decreasing order of viability areas follows : glycerol, l0%, 20%, DMSO 15%, glycerol 10%, a starting culture of 0.69 x 10(6) cells per ml in 500 ml sea water enriched with Conway stock solution reached 5.49 x 10(6) cells per ml culture a t the end of 4 days. The aim of these experiments was to obtain a good conservation of phytoflagellate "master cultures" and to store seed cultures so that they could be distributed to "field hatcheries", eliminating the need for them to produce their own seed cultures which must be voluminous in order to obtain the rapid and efficient growth of the necessary large volume cultures. [NOT CONTROLLED OCR] |
