Lysine and arginine transport in the photosynthetic bacterium Chromatium vinosum

The photosynthetic purple sulfur bacterium Chromatium vinosum can take up both arginine and lysine in the light and, to a lesser extent, in the dark. Competitive inhibition experiments suggest the likely presence of two transport systems in this bacterium: One capable of transporting either lysine or arginine and a second capable of transporting arginine but not lysine. Uptake of both amino acids is electrogenic and appears to involve the cotransport of neither protons nor sodium ions. It is suggested that the transport occurs via an electrogenic uniport.