Composition of the Sulfur Particle of Chromatium vinosum Strain D

Sulfur particles were isolated from the purple sulfur photosynthetic bacterium, Chromatium vinosum strain D. The composition of these particles was determined to be 93% sulfur, 5% protein, and 0.6% lipid. Gel electrophoresis indicated the presence of a single protein species with a molecular weight of 13,500 daltons. From these results, the sulfur particle is postulated to be bounded by a membrane consisting entirely of protein.