Toward Self-Optimizing Bioprocesses: Real-Time Biosensing by Riboswitches Enables Autonomous Cell Factories

Industrial bioprocesses remain constrained by their inability to directly monitor what happens inside cells in real time. Instead, they rely on external measurements such as nutrient or metabolite levels in the culture medium that only provide delayed and indirect clues about the cell's internal state. Riboswitches, RNA elements that respond to specific small molecules, offer a powerful alternative. Acting as intracellular biosensors, they can detect metabolites at nanomolar to micromolar concentrations within milliseconds. When coupled with gene regulatory systems, riboswitches enable dynamic feedback control, allowing cells to sense imbalances and autonomously adjust their metabolism. This transition from external, delayed monitoring to internal, responsive regulation has the potential to transform microbial production systems into self-optimising factories that are more efficient, adaptive, and resilient.