Sputnik News reports that researchers are finding a "subterranean Galapagos" including "creatures such as microbial life thriving at 121 degrees Celsius or 'zombie bacteria', which can reproduce or live for millions to tens of millions of years."
In a recent 700-page book called "Carbon in Earth", in chapter 17 "Nature and Extent of the Deep Biosphere", Frederick S. Colwell and Steven D'Hondt write:
Given the extraordinarily low rates of microbial respiration in many subsurface environments, subsurface microbes are generally assumed to reproduce very slowly, if at all. D'Honda et al. (2002a) speculated that most subseafloor sedimentary microbes are either inactive (dormant) or adapted for extraordinarily low metabolic activity. Price and Sowers (2004) suggested that subsurface sedimentary microbes exhibit survival metabolism (sufficient to repair macromolecular damage but insufficient to sustain growth or motility). Whether they are actually growing or merely repairing macromolecular damage, amino acid racemization ratios indicate that subseafloor sedimentary biomass turns over very slowly, on timescales of hundreds to thousands of years (Lomstein et al. 2012). We do not yet know whether the microbes of these subsurface environments reproduce at these slow rates of biomass turnover or live without dividing for millions to tens of millions of years.
Is this possible? Could "Zombie" cells have been alive for millions or tens-of-millions of years "without turnover"?