Chromatiaceae

The Chromatiaceae are the main family of purple sulfur bacteria. Many members conduct an anoxygenic photosynthesis. They are distinguished from the Ectothiorhodospiraceae by producing sulfur globules and storing them inside their cells. Most species of Ectothiorhodospiraceae are also purple sulfur bacteria but they store the globules outside their cells. The sulfur is an intermediate in the oxidization of sulfide, which is ultimately converted into sulfate, and may serve as a reserve.