When tiny microbes jam up like fans exiting a baseball stadium, they can do some real damage. UC Berkeley physicists found this out the hard way when the baker’s yeast cells (Saccharomyces cerevisiae) they were studying multiplied so prolifically that they burst the tiny chamber in which they were being raised. When UC Berkeley postdoctoral fellow Morgan Delarue measured the force the growing mass of cells exerted as they pushed against one another, he calculated that it can be nearly five times higher than the pressure in a car tire — about 150 psi, or 10 times atmospheric pressure. This is more than just a weird observation, said Oskar Hallatschek, a UC Berkeley assistant professor of physics and leader of the team. Budding yeast or other living cells, which split in two and grow exponentially in number, may well generate such mechanical forces to alter their environment, possibly in damaging ways. This may be even more important for cells like yeast that cannot move. For full story, visit: http://news.berkeley.edu/2016/05/13/beware-of-microbial-traffic-jams/ ...