Toward Understanding Bacterial Ice Nucleation

Bacterial ice nucleators (INs) are among the most effective ice nucleators known and are relevant for freezing processes in agriculture, the atmosphere, and the biosphere. Their ability to facilitate ice formation is due to specialized ice-nucleating proteins (INPs) anchored to the outer bacterial cell membrane, enabling the crystallization of water at temperatures up to -2 degrees C. In this Perspective, we highlight the importance of functional aggregation of INPs for the exceptionally high ice nucleation activity of bacterial ice nucleators. We emphasize that the bacterial cell membrane, as well as environmental conditions, is crucial for a precise functional INP aggregation. Interdisciplinary approaches combining high-throughput droplet freezing assays with advanced physicochemical tools and protein biochemistry are needed to link changes in protein structure or protein-water interactions with changes on the functional level.

Automated summary

The exceptional ice nucleation activity of bacterial ice nucleators is highlighted in this perspective, emphasizing the importance of functional aggregation of ice-nucleating proteins (INPs) anchored to the outer bacterial cell membrane. It is crucial to consider the role of the bacterial cell membrane and environmental conditions in facilitating precise functional aggregation of INPs, and interdisciplinary approaches combining various tools are needed to study changes at the protein level.