TY - JOUR
T1 - Specific Ion–Protein Interactions Influence Bacterial Ice Nucleation
AU - Schwidetzky, Ralph
AU - Lukas, Max
AU - YazdanYar, Azade
AU - Kunert, Anna T.
AU - Pöschl, Ulrich
AU - Domke, Katrin F.
AU - Fröhlich-Nowoisky, Janine
AU - Bonn, Mischa
AU - Koop, Thomas
AU - Nagata, Yuki
AU - Meister, Konrad
N1 - Publisher Copyright:
© 2021 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH
PY - 2021/5/6
Y1 - 2021/5/6
N2 - Ice nucleation-active bacteria are the most efficient ice nucleators known, enabling the crystallization of water at temperatures close to 0 °C, thereby overcoming the kinetically hindered phase transition process at these conditions. Using highly specialized ice-nucleating proteins (INPs), they can cause frost damage to plants and influence the formation of clouds and precipitation in the atmosphere. In nature, the bacteria are usually found in aqueous environments containing ions. The impact of ions on bacterial ice nucleation efficiency, however, has remained elusive. Here, we demonstrate that ions can profoundly influence the efficiency of bacterial ice nucleators in a manner that follows the Hofmeister series. Weakly hydrated ions inhibit bacterial ice nucleation whereas strongly hydrated ions apparently facilitate ice nucleation. Surface-specific sum-frequency generation spectroscopy and molecular dynamics simulations reveal that the different effects are due to specific interactions of the ions with the INPs on the surface of the bacteria. Our results demonstrate that heterogeneous ice nucleation facilitated by bacteria strongly depends upon the nature of the ions, and specific ion–protein interactions are essential for the complete description of heterogeneous ice nucleation by bacteria.
AB - Ice nucleation-active bacteria are the most efficient ice nucleators known, enabling the crystallization of water at temperatures close to 0 °C, thereby overcoming the kinetically hindered phase transition process at these conditions. Using highly specialized ice-nucleating proteins (INPs), they can cause frost damage to plants and influence the formation of clouds and precipitation in the atmosphere. In nature, the bacteria are usually found in aqueous environments containing ions. The impact of ions on bacterial ice nucleation efficiency, however, has remained elusive. Here, we demonstrate that ions can profoundly influence the efficiency of bacterial ice nucleators in a manner that follows the Hofmeister series. Weakly hydrated ions inhibit bacterial ice nucleation whereas strongly hydrated ions apparently facilitate ice nucleation. Surface-specific sum-frequency generation spectroscopy and molecular dynamics simulations reveal that the different effects are due to specific interactions of the ions with the INPs on the surface of the bacteria. Our results demonstrate that heterogeneous ice nucleation facilitated by bacteria strongly depends upon the nature of the ions, and specific ion–protein interactions are essential for the complete description of heterogeneous ice nucleation by bacteria.
KW - atmospheric chemistry
KW - bacteria
KW - Hofmeister series
KW - ice nucleation
KW - nonlinear optics
UR - http://www.scopus.com/inward/record.url?scp=85102494047&partnerID=8YFLogxK
U2 - 10.1002/chem.202004630
DO - 10.1002/chem.202004630
M3 - Article
C2 - 33464680
AN - SCOPUS:85102494047
SN - 0947-6539
VL - 27
SP - 7402
EP - 7407
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 26
ER -