Instability of the tetrathionate respiratory chain of Citrobacter freundii.

The formate--tetrathionate reductase redox pathway of Citrobacter freundii is associated with the cytoplasmic membrane fraction. A high concentration of phosphate in the buffer used for cell disintegration assists in the preparing of membrane particles capable of efficient tetrathionate respiration. A part of this effect at least may be attributed to the high ionic strength of the buffer.