Why do bacteria respond quickly to external changes?

Understanding how bacteria adapt so quickly to changes in their external environment with continued high growth rates is one of the major research challenges in molecular microbiology. This is important for understanding of resistance to antibiotics.

A research study from Uppsala University has presnted a model of how bacteria can rapidly adapt to environmental changes through smart regulation of their gene expression.

The study, published in the journal of the American National Academy of Sciences PNAS (Proceedings of the National Academy of Sciences), presents a theoretical model that determines the ultimate limit for how quickly bacteria can adapt their protein levels to changes in their living environment.

For rapid growth in different environments, bacteria need to adjust their enzyme levels in order to rapidly benefit from the nutrient mix that is currently available in the surrounding. If the living environment undergoes rapid changes, the bacterium's own production of proteins has to conform to these changes in an effective way.

The growth of bacteria is determined not only by the composition of their surroundings but also by sudden changes in the living environment. This has been known since the middle of the 20th century. High levels of bacteria growth in a stable environment requires a certain kind of physiology, but environmental changes also require rapid adjustments of the bacteria's protein production. The newly developed model indicates the 'minimum' time such adjustments require.

For further details, see:

Pavlov, M.Y & Ehrenberg, M. Optimal control of gene expression for fast proteome adaptation to environmental change. PNAS, December 2013

Posted by Tim Sandle