Fatty acids in the thermophilic alga, Cyanidium caldarium

Lipids and fatty acids were compared in 20° and 45° photoautotrophically grown Cyanidium caldarium. Glycolipids were increased by 90% in 45° as compared to 20° grown cells. Linolenic acid was the most abundant fatty acid in the 20° grown cells but was very low in the 45° cultures. The replacement of linolenic acid in glycolipids might likely be met in 45° grown cells by linoleic acid since linoleic acid was increased several fold. If polyunsaturated fatty acids play a special role in photosynthesis, it would appear that linoleic acid has assumed this role in high temperature grown cells. On the other hand, phospholipids were decreased by 40% in 45° as compared with 20° grown cells. Yet, the marked decrease in linolenic acid in phospholipids is not replaced by linoleic acid.