Fine structure of Ectothiorhodospira mobilis strain 8113 thylakoids: Chemical fixation and freeze-etching studies

An electron microscopic examination of thin-sections of chemically fixed cells and of frozen-etched cell preparations of the marine photosynthetic bacterium Ectothiorhodospira mobilis has been carried out. The morphology of cells grown in media with 3,5 or 10% (w/v) NaCl is similar. The photosynthetic apparatus is a lamellar type. The number of thylakoid stacks is a function of light intensity; at low light intensity there is generally only one large thylakoid stack, while at high light intensity 3-4 small, randomly distributed thylakoid stacks occur.