The Effects of Nitrogen Deficiency on Pigments and Lipids of Cyanobacteria

Abstract

In contrast to what happens in higher plants and eukaryotic algae, a nitrogen deficiency during growth causes a change in pigment composition but no significant changes in whole cell lipid and fatty acid composition of the two Cyanobacteria, Pseudanabaena sp. (strain M2) and Oscilla- toria spkndida (strain L3). Nitrogen deficiency does not affect the cellular content in chlorophyll a, but it causes a selective loss in phycobiliproteins; carotenoid content increases with phycocyanin depletion. The major cellular lipids in both Cyanobacteria studied are monogalactosyl diacylglycerol, digalactosyl diacylglycerol, sulfoquinovosyl diacylglycerol, and phosphatidylglycerol. The fatty acid composition is particularly interest- ing as both these filamentous Oscillatoriaceae show important contents in a-and 'y-linolenic (18:3) and parinaric (18:4) acids. This seems to be very unusual in Cyanobacteria.