Fatty acid concentrations in synchronous cultures ofChlorella pyrenoidosa, grown in the presence and absence of glucose.

Total cellular fatty acids, of a high-temperature strain ofChlorella pyrenoidosa, were measured during a synchronous growth cycle in continuous light in the presence and absence of glucose.The fatty acid composition, consisting of saturated monoenoic, dienoic, and trienoic C(16) and C(18) fatty acids, remained essentially the same whether or not the cells were grown on glucose.Nearly all of the fatty acids increased irregularly in concentration during the growth cycle, showing a periodism during the prenuclear and cell-division stages of growth. Cultures exposed to glucose showed a more pronounced drop in the concentration of most of the fatty acids during both stages.None of the fatty acid concentrations, some of which have been implicated in the Hill reaction of a number of photosynthetic organisms, reflected the periodism in photosynthetic activity which was previously observed during the synchronous growth cycle of this organism.The changes in fatty acid concentration are discussed with relation to concurrent metabolic and cytological changes during cell maturation in this organism.