Bacterial cells produce polyester granuals in water at ambient temperature and pressure via enzymatic self‑assembly.

Bacteria manufacture polyesters as energy reserves. They do so at ambient temperatures and pressures in water. By contrast, industrial polyester manufacturing processes may require some added heat, pressure changes, and/or organic solvents. Although polyesters are not soluble in water, bacteria are able to store small polyester granules in their watery cellular environment by coating each granule with water-soluble proteins.

Enzymes secreted by microbes facilitate the formation of “ester” bonds between organic molecules at normal temperatures and pressures (the process is called a “dehydration” reaction because water is a by-product of bond formation) (1). More starting material is joined to the compound via ester bonds, hence the term polyester (2). Microbes store their polyester granules in water for later use as an energy and carbon source. Artist: Emily Harrington. Copyright: All rights reserved. See gallery for details.

Image: Emily Harrington /

Created by Emily Harrington of eh illustration, http://www.ehillustration.com. This work shall be and remain at all times the shared property of Emily Harrington and the Biomimicry 3.8 Institute, and Emily Harrington grants to the Biomimicry 3.8 Institute a non‑terminating, nonexclusive, non‑limiting right to use the materials for educational purposes. Any use by outside parties requires permission from Emily Harrington and can be requested from [email protected] or through the Biomimicry 3.8 Institute.

Image: Emily Harrington /

Created by Emily Harrington of eh illustration, http://www.ehillustration.com. This work shall be and remain at all times the shared property of Emily Harrington and the Biomimicry 3.8 Institute, and Emily Harrington grants to the Biomimicry 3.8 Institute a non‑terminating, nonexclusive, non‑limiting right to use the materials for educational purposes. Any use by outside parties requires permission from Emily Harrington and can be requested from [email protected] or through the Biomimicry 3.8 Institute.

Last Updated September 25, 2017