One of the most basic and intensively studied processes in biology—one which has been detailed in biology textbooks for decades—has gained a new level of understanding, thanks to the application of simple math to a problem that scientists never before thought could benefit from mathematics.
The scientists who made the discovery, published in this week’s advance online publication of Nature, found that the process bacteria use to quickly adapt to metabolize preferred energy sources such as glucose—a process called “catabolite repression”—is controlled not just by glucose, as had long been known and taught, but just as much by other essential nutrients, such as nitrogen and sulfur, available to bacteria in their growth medium.
“This is one of the most studied processes in molecular biology; it’s in every textbook,” says Terence Hwa, a professor of physics and biology at UC San Diego, who headed the team of scientists. “We showed that this process doesn’t work the way most people thought it did for the past several decades, and its purpose is different from what had generally been assumed.”
The basic phenomenon, Hwa says, is analogous to a balanced diet: To reduce an individual’s sugar uptake, common wisdom is to reduce the availability of sugar. This strategy backfires on bacteria because they would increase their appetite for sugars—the process of catabolite repression would direct the bacteria to increase the production of their sugar uptake system to counteract the scarcity of sugar in the environment. However, by figuring out that catabolite repression actually works by sensing the difference between the influx of sugar and that of other essential nutrients such as nitrogen, it is possible to drastically lower the bacteria’s appetite for sugar by simply rationing the supply of nitrogen.
Read more at: Phys.org