CARRAGEENANS IN THE STERILE STAGE OF GIGARTINA-SKOTTSBERGII S-ET-G

Carrageenans from the ''sterile'' stage from Gigartina skottsbergii we re studied from the chemical and anatomical point of view. The system of carraggenans biosynthesized by the seaweed is constituted by a gell ing kappa-carrageenan, and a soluble, partially cyclized upsilon-carra geenan. The ''sterile'' stage yields carrageenans from the kappa-famil y, as the corresponding gametophytic stage, with no evidence of carrag eenans from the lambda-family, arising from an immature tetrasporic st age. The carrageenans are located in the cortex and lax medulla of the thallus, with an increase of the polysaccharide content towards the c ortex. Acidic polysaccharides, possibly carrageenans, form, at least, the amorphous phase of the cell wall.