Community Spirit

When scientists study bacteria in the lab, they often grow them as flat colonies on plates of nutrient jelly or as single cells in a liquid broth. Out in the real world, things are very different. Bacteria in natural environments grow in three-dimensional communities known as biofilms, which can be made up of several different types of bugs. To discover more about how bacterial cells interact in biofilms, researchers have been seeing what happens when two types of bacteria are grown together in different conditions. One strain is normal (the middle row, and in red top row), and the other carries an alteration in the alrA gene (bottom row, in green top), which is involved in making the essential nutrient alanine. Cells without alrA die if grown in flat or liquid cultures but they will survive in biofilms by feeding on alanine produced by the normal cells around them, revealing how bacteria can co-operate together.

Written by Kat Arney

Kat Arney

Writer

Dr Kat Arney is an award-winning science writer, broadcaster and public speaker, and is the founder and Creative Director of First Create The Media.

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• Image from work by Heidi A Arjes and colleagues
• Department of Bioengineering, Stanford University School of Medicine, Stanford, CA, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in eLife, February 2021