Some microorganisms have been reported to be able to use reduced Pcompounds as a sole P source [8–17], strongly suggesting the existence of an ancient P redox cycle in life [18]. Geological evidencesuggests that Phi was an abundant P-species in the ocean priorto the evolution of oxygenic photosynthesis 3.5 Ga ago (ArcheanEon) and that Phi was a possible and an important reagent in theprebiotic synthesis of phosphorylated biomolecules