Bacterial Sentience Is Determined by the Stochastic, Chaotic, and Deterministic Behavior of Cytoplasmic Particles.

Bacteria are constantly exposed to stress, which intensifies as cells age, nutrients are depleted, and metabolite levels change. As metabolic activity increases, the cytoplasm transitions from a glass-like to a more fluid state, supporting the stochastic (spontaneous) and chaotic (nonlinear and unpredictable) movement of particles. The rate at which suspended particles or those in vacuole-like "cages" move depends on the cytoplasm's energized and fluidic state. Cells respond to stochastic and chaotic behavior by regulating gene transcription, translation, and post-translational modifications. These stochastic and chaotic reactions generate a liquid-liquid phase separation (LLPS), causing particles to separate. This produces a dynamic force that drives cytoplasmic "turnover". Internal and external physicochemical changes are monitored by chemoreceptors on the cell surface and embedded in the cell membrane, which activate transcriptional regulators to control gene expression, modulate enzymatic fluctuations, and regulate post-translational modifications. Sentience may also arise from the quantum-like behavior of ions, electrons, neutrons, and protons (tunneling and entanglement) and from hyperstructures that drive complex enzymatic reactions. This is, however, a highly debated topic. We argue that bacteria are conscious and do not rely solely on phosphorylation states, as in two-component systems (TCSs), but also on other cytoplasmic dynamics. We provide several examples to support the argument. It is, however, important to note that bacterial consciousness cannot be compared to that of higher life forms with a central nervous system. We refer to bacteria's awareness of their environment as sentience and define bacterial sentience as the ability to respond to external stimuli and to reactions within a dynamic cytoplasm, thereby transferring signals either directly or via signal transduction pathways to turn gene expression on or off. We also point out that stochastic/chaotic randomness keeps the cytoplasm in a permanently dynamic, flexible, and stochastic state, safeguarding the cell against sudden, unpredictable environmental changes.