Understanding Microbial Polarity


Microbes are not just “bags of salt water” in which everything floats freely and is evenly distributed inside a spherical cell. Instead, microbes establish and maintain the unequal distribution of their internal components, i.e., they have “polarity.” Polarity enables a microbe to move in the direction of a nutrient or away from a toxin, divide unequally into daughter cells that can display different behaviors (one can swim off looking for a new place to live and eat and the other may stay behind), or from structures that push the cell in one direction or another. A Stanford University research team is studying polarity in a microbe, Caulobacter crescentus, whose DNA was sequenced with Biological and Environmental Research support and that can remediate heavy metals in aquatic environments. A review article in the December 6, 2002, issue of Science, surveys the establishment of polarity in this and other microbes. This is a key step towards understanding the reality of complex microbial biology and the eventual use of microbes to address DOE needs in energy and the environment.