Acetogenesis and ATP synthesis inAcetobacterium itwoodiiare coupled via a transmembrane primary sodium ion gradient

Abstract

In cell suspensions of Acetobacterium woodii the acetyl-CoA pathway is coupled to net ATP formation. Acetate formation as well as ATP synthesis and the generation of a transmembrane sodium ion gradient are not inhibited by protonophores but by sodium ionophores. Acetogenesis from CO or formaldehyde + CO as catalyzed by inverted vesicles is coupled to sodium ion uptake. Both processes are not inhibited by protonophores but by sodium ionophores. These experiments are in accordance with the presence of a primary sodium ion pump connected to the acetyl-CoA pathway which enables the cells to synthesize net ATP by means of a ΔμNa+ in concert with a Na+-translocating ATPase.