Preliminary approach to the characterization and seasonal variation of carrageenans from four Rhodophyceae on the Normandy coast (France)

Carrageenans extracted under alkaline conditions were studied in some Rhodophyceae from the Normandy coast. Among these, four species yielding iota-carrageenan were studied throughout a whole year: Calliblepharis ciliata, Calliblepharis jubata, Cystoclonium purpureum and Gymnogongrus crenulatus. Carrageenan content varied with season, being maximal at the end of spring and minimal in autumn, and was positively correlated with the growth of these algae. A culture of Cystoclonium purpureum was initiated and, without trying to optimize growth conditions, yielded a mean production of 50 g fresh wt m^–2 d^–1 in 36 weeks of continuous tank culture.