Polyol-Induced 100-Fold Enhancement of Bacterial Ice\nNucleation Efficiency

Ice-nucleating proteins\n(INPs) from bacteria like Pseudomonas syringae are among the most effective\nice nucleators known. However, large INP aggregates with maximum ice\nnucleation activity (at approximately −2 °C) typically\naccount for less than 1% of the overall ice nucleation activity in\nbacterial samples. This study demonstrates that polyols significantly\nenhance the assembly of INPs into large aggregates, dramatically improving\nbacterial ice nucleation efficiency. Simple compounds like polyvinyl\nalcohol increased the abundance of large INP aggregates by a factor\nof 100. This remarkable boost in ice nucleation efficiency is attributed\nto the stabilization of INP aggregates through membrane–polyol\ninteractions that stabilize INP interactions and reduce structural\nfluctuations. The ability to regulate the abundance of large INP aggregates\nin bacterial ice nucleators enables fine-tuning ice nucleation processes\nat much lower concentrations for specific biomedical and technological\npurposes.