LIPID-METABOLISM IN THE BROWN MARINE-ALGAE FUCUS-VESICULOSUS AND ASCOPHYLLUM-NODOSUM

Lipid metabolism and environmental effects on this process have been s tudied in the marine brown algae Fucus vesiculosus and Ascophyllum nod osum. These algae showed very similar patterns of lipid metabolism dur ing 24 h incubations. Labelling from [1-C-14]acetate showed the major labelled lipids to be the beta-alanine ether lipid and the neutral lip id fraction in both algae. Of the glycolipids, only sulphoquinovosyldi acylglycerol was well labelled and the phosphoglycerides were all poor ly labelled. The major labelled fatty acids were palmitate and oleate, again in both algae, although Fucus vesiculosus also showed significa nt labelling of stearate and behenate. Although the amount of fatty ac id labelling increased with time, the proportion of label in palmitate and oleate remained approximately constant. Very long chain fatty aci ds (arachidic, behenic) were increasingly labelled with time. Lowered incubation temperatures decreased labelling of the saturated fatty aci ds. Cu2+ increased the proportion of oleate labelled in both algae, an d of linoleate in Fucus vesiculosus. This cation decreased the percent age labelling of stearate and myristate in Ascophyllum nodosum. Lipid metabolism in Ascophyllum nodosum was more sensitive to raised Cu2+ le vels than in Fucus vesiculosus.