Chromatium okenii

In addition to the filament-shaped sulphur bacteria, there are coccoid forms, which as a rule form reddish pigments. The most well-known representative of these sulphur bacteria is Chromatium okenii, also known as "red sulphur bacterium", and Lamprocystis roseo-persicina. The latter is often to be found on water plants and forms a pink-coloured covering when it develops en masse. 

The growth of pure cultures of C. warmingii in this medium was slow and the yields at stationary phase were much lower than in the membrane-separated cultures, as seen in Figure 5. Their growth was limited by the availability of sulfide. Triiper and Schlegel (11) reported that the biomass yield of Chromatium could be increased by the addition of sodium sulfide after the initial supply was exhausted. At exhaustion of initial sulfide, their yields were about 150 mg/1 at pH 6.8, while in our case, at that pH our yields were only 60 to 100 mg/1. Their study used C. okenii, a species of larger bacteria than C. warmingii. They increased their yields to 250 mg/1 upon addition of a second supply of sulfide. 

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