Bacteria can Anticipate, Prepare for Sporadic Events

by VR Sreeraman on Oct 5 2008 12:37 PM

Microbes, it seems, are much more smarter than perceived. A new research has shown that bacteria don’t just react to changes in their surroundings, they anticipate and prepare for them.

According to the Princeton University study, the humble single-celled creatures are sophisticated enough to anticipate regular events, such as the arrival of day, thanks to their internal circadian clocks.

Also, they can anticipate and prepare for sporadic events, as long as the events are reliably preceded by a signal. And the events include, colonizing the gut of a mammal, Escherichia coli must first enter the warm-blooded diner’s mouth, where the bacteria experience a temperature rise; a short time later, they end up in the intestines, a place with low oxygen levels, as well as fierce competition from other microscopic settlers.

Bacteria would do well to anticipate low-oxygen conditions and begin to adjust metabolically from the moment they enter the mouth.

When Ilias Tagkopoulos, his graduate advisor Saeed Tavazoie, and Yir-Chung Liu cranked up the heat on E. coli in the laboratory from 77 to 98.6 degrees Fahrenheit, the bacteria immediately deactivated genes involved in aerobic respiration (which requires oxygen) and activated genes governing anaerobic respiration (which doesn’t), reports Live Science.

Then the team repeatedly exposed a population of E. coli to a rise in oxygen following a rise in temperature, a sequence unlikely to occur in nature.

The bacteria’s native low-oxygen response all but vanished within a hundred generations, confirming that their foresight is flexible and results from natural selection.