The physics of biofilms and ice cream

Cait Macphee

MSc Science Communication and Public Engagement students Anna Purdue, Hanyue Sun and Jiazhuo Lin  interviewed School of Physics and Astronomy researcher Prof Cait MacPhee.


Tell us about your research. How does it link to ice cream?

We are studying a biofilm formed by a very common microbe called Bacillus subtilis. We’re interested in the fact that it’s basically waterproof. We discovered the protein that makes this biofilm water repellent, and it does this by going to an interface between liquid and air and forming a film. Ice cream contains air bubbles which make it lighter and easier to scoop.  It also contains oil (fat) and ice crystals. The protein we found goes to the surface of the ice crystals, the surface of the air bubbles and the surface of the oil droplets and stabilises all of them. By doing this you can slow the melting down of the ice cream! Continue reading “The physics of biofilms and ice cream”