A thermodynamic analysis of the plasma membrane electron transport components in photoheterotrophically grown cells of Chloroflexus aurantiacus

The thermodynamic and spectroscopic properties of the membrane bound iron‐sulphur centers and cytochromes in phototrophically grown cells of the thermophilic facultative photosynthetic green bacterium Chloroftexus aurantiacus have been examined. The present study shows that Chloroflexus contains several cytochromes of b and c type, along with multiple ferredoxin‐like centers with resonances centered at g = 1.93, g = 2.017 (HiPIP‐like center) and g = 1.90 (Rieske‐type protein). The g = 1.90 centre appears to be actively involved in photooxidative reactions. These observations suggest the presence of a previously undetected cytochrome complex in this bacterium.