This year I have decided to try to do a series of fun little posts entitled Microbial Advent Calendar over the course of December. Until Christmas I will try to come up with random microbial facts cetered around various Christmas, cold and winter themed topics.
Snow and Christmas are two ideas which are often associated, even if I’ve so far only had a handful of white Christmas’in my life. Today our first Microbial Advent Calendar will be about snow making bacteria! Maybe snow making is bit strong, let’s say capable of bioprecipitation.
The most studied case is Pseudomonas syringae, a gram negative plant pathogen which enhances the ice formation of plants and fruits (Early paper here). The bacteria synthesize proteins on its membrane that act has ice nuclei and can allow the formation of ice on surface from -1,8°C, where without it would occur between -4 and -12°C (more info here). Some studies (in short here, in long here) also suggest that these ice nucleation properties could be involved in rain making and snowfall, this being a complex mechanism of bio-dispersion across large distance.
The ice nuclei formation proteins from P. synrigae are commercially available and widely used by ski resort in their snow blowgun to make more snow! (You can find an old review here)