For individual cells, this power minimum hovers around a zeptowatt, or 10−21 watts. That is the power required to lift 0.001% of a grain of salt 1 nanometer once a day. (For reference, a human body uses ~100 watts, the power of a reading light.) The new model suggests that cells living in sub-seafloor sediments are drawing only slightly more power than that.

2022-11-02: Inert spores may be close to that energy limit, and use a passive sensing technique.

The spores might be able to sense small cumulative changes in their environment, until enough signals build up to trigger a sort of wake-up alarm. The mechanism that would induce these changes would be the movement of ions out of the cell—specifically, potassium ions.

These movements can be triggered by positive environmental signals, like the presence of nutrients. When the ions travel out of the cell thanks to passive transport, they generate a difference in potassium concentration inside versus outside the cell. This concentration difference allows the spore to store potential energy. Over time, as the spore continues to sense more positive signals, more ions would move out of the cell. This would also create a corresponding drop in potassium levels, as the ions exit. Eventually, the potassium content in the spore would lower to a certain threshold, signaling that it is safe for the cell to wake up. That would trigger reanimation and germination.

2024-07-23: Most life is dormant

60% of all microbial cells are hibernating at any given time. Even in organisms whose entire bodies do not go dormant, like most mammals, some cellular populations within them rest and wait for the best time to activate. esearchers reported the discovery of a new hibernation factor, which they have named Balon. The protein is shockingly common: A search for its gene sequence uncovered its presence in 20% of all cataloged bacterial genomes. And it works in a way that molecular biologists had never seen before.

Previously, all known ribosome-disrupting hibernation factors worked passively: They waited for a ribosome to finish building a protein and then prevented it from starting a new one. Balon, however, pulls the emergency brake. It stuffs itself into every ribosome in the cell, even interrupting active ribosomes in the middle of their work. Before Balon, hibernation factors had only been seen in empty ribosomes.