Effects of nutritional deficiency on the seasonal distribution of lipids substances in eutrophic lakes

ABSTRACT

The seasonal distribution of particulate lipids coupled with N-nutrient availability was studied in eutrophic Lake Aydat [Massif Central, France]. The concentrations of lipids ranged between 196.9 and 2971.5 micro g. l [-1] [mean +/- s. d = 1090.1 +/- 705.5 micro g. I [-1]]. Lipids were abundant in summer and fall when nitrates were unsufficient reflecting thus an orientation of cell metabolism towards an accumulation of storage products. In such conditions, the heterocystous Cyanobacteria were found to develop due to their competitive advantage of exploiting atmospheric nitrogen. Their lipid metabolism did not seem to be affected at least partially by NO [3] exhaustion