[24] Membrane lipids

TLDR: This chapter describes procedures in cyanobacterial lipid analysis, including extraction and fractionation of lipids, analysis of their fatty acids, determination of positional distribution of fatty acids within thelipids, and analysis of lipid molecular species.

Abstract: Publisher Summary This chapter describes procedures in cyanobacterial lipid analysis, including extraction and fractionation of lipids, analysis of their fatty acids, determination of positional distribution of fatty acids within the lipids, and analysis of lipid molecular species Cyanobacterial cells contain two types of membrane, the plasma membrane and thylakoid membranes, which are distinct from each other in their composition of proteins, lipids, and pigments The composition of the fatty acids of the lipids in both types of membrane changes with growth temperature so that cyanobacterial cells adapt themselves to the environmental temperature Major lipid classes in cyanobacterial membranes are monogalactosyl diacylglycerol (MGDG), monoglucosyl diacylglycerol (GIcDG), digalactosyl diacylglycerol (DGDG), sulfoquinovosyl diacylglycerol (SQDG), and phosphatidylglycerol (PG) Thin-layer chromatography (TLC) is a convenient method for separating major classes of lipids The content and composition of fatty acids in lipids are determined by gas chromatographic analysis of the methyl esters which are obtained by methanolysis of the lipids Methanolysis is generally performed without isolating lipids from the silica gel