Seasonal variations of triacylglycerols and fatty acids in Fucus serratus

The triacylglycerols and fatty acids of Fucus serratus were analysed during the course of a year. The amount of triacylglycerols was maximal in July (19.2% total lipids), but minimal in February (6.6%). Triacylglycerols accumulated more in summer (2.8 mg g(-1) dry wt) and autumn (2.6 mg g(-1) dry wt) than spring (0.7 mg g(-1) dry wt) and winter (0.5 mg g(-1) dry wt). In the total lipids, the dominant fatty acids were palmitic (16:0, 24.1%), oleic (18:1, 22.4%) and arachidonic (20:4, 14.4%), but in the triacylglycerols, palmitic 16:0 (22.8%), oleic 18:1 (36.4%) and linoleic acids (18:2, 16.4%) were most abundant. C-16 fatty acids were predominant in winter and C-18 ones in summer and autumn. The ratios 16:0/18:1 and 20:4/20:5 appeared to be important indicators of the status of the seaweed according to variation of environmental conditions. We conclude that, although the emersion of F. serratus in situ is more effective during winter and spring, correlating with good growth and productivity of thalli, synthesis of triacylglycerols is activated during the summer. Copyright (C) 1996 Elsevier Science Ltd