On the pigment system of the red alga Porphyra Lacineata

Absorption and fluorescence around 725 mμ of suspensions of the red alga Porphyra lacineata were studied both with and without the phycobilins attached to the pigment system. The in vivo occurrence of 2 chlorophyll a types was confirmed spectroscopically. Their red absorption maxima are located at 678 and 672 mμ respectively. Removal of the phycobilins did not affect the shape of the red absorption band of these types. It is therefore concluded that phycobilins are not responsible, e.g. by complex formation, for the occurrence of one or both of these types. It is possible that withdrawal of the phycobilins causes quenching of chlorophyll fluorescence. The “pigment X” fluorescence around 725 mμ remains unaffected by removal of the phycobilins