Quenching of the Spheroiden Triplet State with Oxygen in the Reaction Centers of C. sphaeroides in the Temperature Range 0–45°C

Abstract

The lifetime of the triplet state of the carotenoid, spheroiden (^TCar) in the photosynthetic reaction center of the purple bacteria Cereibacter (Rhodobacter) sphaeroides in the temperature range from 0 to 45°C and the effect of the concentration of molecular oxygen in the medium on this time was studied. O-phenanthroline (10^–2 M), which partially displaces the primary quinone acceptor from the structure of the reaction center, was added to the preparations to form ^TCar upon light excitation of the reaction center. The activation energies of the ^TCar quenching process were determined under normal aerobic conditions and during partial degassing of the studied preparations.