Scientists Study Bacterial Shapes

Bacteria appear in myriad shapes and sizes and now U.S. scientists say they’ve answered the form-function question for one bacterium.

Indiana University scientists studied the aquatic bacterium Caulobacter crescentus, whose cells are anchored to solid objects by conspicuous and distinctive stalks.

We’ve found the bacteria can take up nutrients with their stalks, said microbiologist Yves Brun, who led the study. This is the first example that we know of in which a major feature of a bacterium’s shape can be tied to a specific function.

Brun said C. crescentus’ stalk acts as a sort of antenna that amplifies the uptake of organic phosphate from the surrounding environment. The narrow stalk adds little volume to the cell, and incoming nutrients diffuse toward the cell’s main body, where metabolic processes quickly assimilate nutrients.

The study appears in the Proceedings of the National Academy of Sciences.