biostudies-literatureGault SRCUK | Science and Technology Facilities CouncilRCUK | Science and Technology Facilities Council (STFC)Science and Technology Facilities Council588https://www.ebi.ac.uk/biostudies/studies/S-EPMC11099114biostudies-literatureUnknown7(1)Although a low temperature limit for life has not been established, it is thought that there exists a physical limit imposed by the onset of intracellular vitrification, typically occurring at ~-20 °C for unicellular organisms. Here, we show, through differential scanning calorimetry, that molar concentrations of magnesium perchlorate can depress the intracellular vitrification point of Bacillus subtilis cells to temperatures much lower than those previously reported. At 2.5 M Mg(ClO₄)₂, the peak vitrification temperature was lowered to -83 °C. Our results show that inorganic eutectic salts can in principle maintain liquid water in cells at much lower temperatures than those previously claimed as a lower limit to life, raising the prospects of active biochemical proceCommunications biologyPreservation of Bacillus subtilis' cellular liquid state at deep sub-zero temperatures in perchlorate brines.PMC11099114ST/V000586/1Gault SFonseca FCockell CSfalsePreservation of Bacillus subtilis' cellular liquid state at deep sub-zero temperatures in perchlorate brines.Although a low temperature limit for life has not been established, it is thought that there exists a physical limit imposed by the onset of intracellular vitrification, typically occurring at ~-20 °C for unicellular organisms. Here, we show, through differential scanning calorimetry, that molar concentrations of magnesium perchlorate can depress the intracellular vitrification point of Bacillus subtilis cells to temperatures much lower than those previously reported. At 2.5 M Mg(ClO₄)₂, the peak vitrification temperature was lowered to -83 °C. Our results show that inorganic eutectic salts can in principle maintain liquid water in cells at much lower temperatures than those previously claimed as a lower limit to life, raising the prospects of active biochemical proce2024-01-01T00:00:00Z2024 May2026-04-12T15:29:50.906Z2026-04-07T13:17:55.085ZS-EPMC110991143875526410.1038/s42003-024-06277-4