Active transport in the photosynthetic bacterium Chromatium vinosum.

Whole cells of Chromatium vinosum show energy-dependent uptake of several amino and organic acids. The energy for metabolite uptake can be provided by light, via cyclic electron flow, or by ATP hydrolysis catalyzed by a N,N′-dicyclohexylcarbodiimide-sensitive ATPase. Metabolite transport is inhibited by uncouplers known to collapse transmembrane electrochemical proton gradients, suggesting that such a gradient may provide the driving force for transport in C. vinosum.