Edinburgh Workshop Report

Earlier this week I was in Edinburgh for a workshop on microbe modeling. The meeting focused on biofilms and included many presentations of experimental and modeling research. My work is not directly focused on biofilms per se, but there are a lot of the same tools/methods/questions/problems, so I found it very useful. I felt like I got a good overview of where the state-of-the-science is in this area. There is an interesting story about the use of modeling in biofilm science, which I want to briefly outline. It has to do with social conflict in biofilms. Specifically, bacteria in biofilms produce a sort of glue (extracellular polymer substance, EPS), which helps to hold the biofilm together. This is believed to be a public good (i.e. it benefits all cells in the biofilm), but the production is carried out by individual cells. This raises the question why individual cells produce this substance. In other words, why do they not evolve to not produce EPS and grow faster, while taking advantage of the EPS produced by other cells (i.e. why do “cheaters” not evolve). A few years ago, Xavier and Foster (PNAS, 2007) explored this question using a model. They found that, EPS is not a public good, but that it helps the cells that produce it to push up into the high oxygen regions. Subsequently, there have been a number of experimental investigations that have explored this hypothesis, and indeed, confirmed it. For more information see the workshop outline below. I think its an interesting story which illustrates the role of models in moving science forward, at a time scale greater than an individual paper or project. http://www2.ph.ed.ac.uk/~rallen2/epsrcworkshop.html