Lipid Metabolism in the Brown Marine AlgaeFucus vesiculosusandAscophyllum nodosum

Abstract

Lipid metabolism and environmental effects on this process have been studied in the marine brown algae Fucus vesiculosus and Ascophyllum nodosum. These algae showed very similar patterns of lipid metabolism during 24 h incubations. Labelling from [1-¹⁴C]acetate showed the major labelled lipids to be the β-alanine ether lipid and the neutral lipid fraction in both algae. Of the glycolipids, only sulphoquinovosyldiacylglycerol was well labelled and the phosphoglycerides were all poorly labelled. The major labelled fatty acids were palmitate and oleate, again in both algae, although Fucus vesiculosus also showed significant labelling of stearate and behenate. Although the amount of fatty acid labelling increased with time, the proportion of label in palmitate and oleate remained approximately constant. Very long chain fatty acids (arachidic, behenic) were increasingly labelled with time. Lowered incubation temperatures decreased labelling of the saturated fatty acids. Cu²⁺ increased the proportion of oleate labelled in both algae, and of linoleate in Fucus vesiculosus. This cation decreased the percentage labelling of stearate and myristate in Ascophyllum nodosum. Lipid metabolism in Ascophyllum nodosum was more sensitive to raised Cu²⁺ levels than in Fucus vesiculosus