Konrad Meister, an assistant professor in the Department of Chemistry, recently published a paper titled “Hierarchical assembly and environmental enhancement of bacterial ice nucleators” in the Proceedings of the National Academy of Sciences. Meister’s research focuses on ice nucleating bacteria, which facilitate the state transition of water to ice at low temperatures.
In completely sterile conditions, pure water does not turn to ice at about zero degrees Celsius, the freezing point most people are familiar with. Instead, pure water freezes at about -40 degrees Celsius – much colder than we usually experience on Earth.
Yet we encounter ice everywhere, without needing temperatures that cold. How? It’s all thanks to ice nucleators – small impurities in water like bacteria that promote freezing at much warmer temperatures than -40 degrees Celsius.
Scientists have known about the existence of ice nucleators for many years now, with bacteria being the most potent ones. However, their mechanism was poorly understood until now. Meister’s latest research has identified the size of the active bacterial ice nucleating protein assemblies responsible for superior freezing efficiency. Alongside collaborators from the Max Planck Institutes, the University of Utah and the Air Force Research Laboratory, the team further discovered a hierarchical assembly mechanism for why bacteria have distinct ice nucleation temperatures and how they respond to environmental factors.
The researchers were able to enhance the ice nucleation potency of the bacteria by changing its acidity and ionic content. Their work could change how we use ice nucleating bacteria in freezing applications such as artificial snowmaking and paves the way for their potential use as potent cloud seeding agents.
Meister’s work on ice nucleating bacteria is supported by a National Science Foundation CAREER award that he received earlier in 2024.