No abstract

The influence of culture conditions on the biosynthesis and degradation of polysaccharides (starch and carrageenan) in the red alga Solieria chordalis was investigated. Following 1 week of incubation in the dark, the alga synthesized floridean starch at two irradiances, 50 and 480 µmol photons m −# s −" (400-700 nm), in nutrient-unenriched seawater. Upon transfer of these cultured algae to nutrient-enriched seawater at 50 µmol photons m −# s −" , the stored floridean starch was found to break down. "%C labelling revealed that during floridean starch breakdown the tracer was transferred to carrageenan. These results are interpreted as carbon transfer from stored floridean starch for use in carrageenan biosynthesis.