Is H2 the universal energy source for long-term survival?

This review revisits anabiosis (cryptobiosis or latent life); but more specifically with the discrepancy (time factor) between the finding of viable bacteria in ancient material and the racemization of amino acids and depurination of DNA that would have contributed to their death. The omnipresence of H-2 in the biosphere since life began, its ability to penetrate the microbial cell, its low energy of activation, its ability to form protons and electrons in the presence of Fe(II), and its (including electrons and protons) role in many biochemical reactions make H-2, the best candidate as the energy of survival for microbial cells. Although the concentration of H-2 in most environments is below the threshold level for microbial growth, the surviving cells have a long period of time to carry out the necessary metabolism to offset the racemization and depurination processes. This paper explores a hypothesis that explains this discrepancy.