Like the Marvel Comics superhero Iceman, some bacteria have harnessed frozen water as a weapon. Species such as Pseudomonas syringae have special proteins embedded in their outer membranes that help ice crystals form, and they use them to trigger frost formation at warmer than normal temperatures on plants, later invading through the damaged tissue. When the bacteria die, many of the proteins are wafted up into the atmosphere, where they can alter the weather by seeding clouds and precipitation.
Now scientists from Germany have observed for the first time the step-by-step, microscopic-level action of P. syringae‘s ice-nucleating proteins locking water molecules in place to form ice. More in the full article:
Archived as pdf here: Uncovering the tricks of nature’s ice-seeding bacteria