A mineral-electron-driven photophosphorylation has potential impacts on photosynthetic bacteria evolution and...

In this study, we reported that the photoelectrons excited from lava can enter the photosynthetic chain of the strain Rhodopseudomonas palustris K7, and participate in a mineral-electron-driven photophosphorylation reaction. We found that mineral photoelectrons could promote the development of the photosynthetic system in the bacterial cells. Further studies confirmed that although less photon energy from light was harvested by the bacterial cells when they were connected to lava, more mineral photoelectrons could transfer along the photosynthetic chain and be coupled with ATP generation. We denoted the new photosynthetic pathway as "mineral-assisted pohotophosphorylation". With the support of this pathway, the carbon assimilation efficiency of photosynthetic bacteria was significantly improved. The additional carbon fixation by photosynthetic bacteria supported by mineral photoelectrons may accelerate the carbon cycle in the environment, which consequently make a impact on the changes in the ecological environment.