Ricerche Sui Pigmenti Delle Alghe Rosse. I: Analisi Qualitativa e Quantitativa dei Pigmenti diPterocladia Capillacea(Gmel.) Born. et Thur. Coltivata in Presenza di Alcune Fonti Minerali di Azoto

Abstract

Research on the Red Algae pigments. I: Pigments of « Pterocladia capillacea » cultured with some nitrogenous mineral sources. — In the present paper the effects of different nitrogen sources on the growth and pigments content and composition of P. capillacea are reported. Apical segments of the erect frond showed a variation of the pigments content after one month culture in sea water containing NaN0₃, NH₄Cl, NH₄N0₃. When the segments are kept in limited volumes of sea water not supplemented with a nitrogen source, a decrease of the pigment content, especially phycoerythrin, is observed. 10⁻³M NH₄ inhibits growth and regeneration of the segments, while stimulating the pigment synthesis. Maximum growth was observed when the sea water was supplemented with 10⁻⁴ NH₄NO₃ (initial concentration). Under these conditions the proportions among the pigments studied are almost the same as in freshly harvested plants.