Snapshot Issue 1 April 2004

Ice Nucleation Protein

It cannot snow on cue for the purposes of a winter scene on a film set. The answer, as we all know, is artificial snow. Artificial snow has been on the scene for some years now and is quite extensively used in the States, as in Europe, to satisfy tourists on skis besides the film industry.

A number of methods are used to make snowflakes out of water. One of which uses the abilities of bacteria such as Pseudomonas syringae. This little critter can initiate crystallization at temperatures as high as –3° C. High? Yes, –3° C is warm for ice formation considering that pure water only crystallizes at temperatures as low as –40°C! How does P.syringae do it? Well, in its membrane is lodged a protein – known as the ice nucleation protein (INP) – which is at the heart of ice nucleation. Precisely. The protein’s structure is such that it could well act as a template for the ice nucleation process by mimicking the pattern of an ice crystal lattice.

Why bacteria sport INPs in the first place is a mystery. Would it be for some kind of protection? It is difficult to grasp how the process of freezing could protect an organism in the first place. However, whatever secret purpose may lurk behind ice nucleation promoted by bacteria, INPs are certainly serving the interests of a certain number of humans in their pursuit of pleasure and consumption, be it for the purposes of entertainment, sport or perhaps, with time, even frozen foods.

Ice nucleation protein, Pseudomonas syringae : P06620

L'édition française de cette chronique est disponible dans l'Instantanés du mois de Prolune.

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On ice nucleation protein discussion it is always stated that water only crystallizes at temperatures as low as 40C. However, in all scientific litrature freezing temprature of water is reported 4C. Can someone explain it.

If water start to freeze at 4C then in the presence of INP (freezing point elevation factor)why water need to get to 3 C for freezing.

Posted by Opal on Thursday 25 March 2010 2:16 CET

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