Cited research: Science 328, 627–629 (2010)

A class of unusual amino acids that disperses films of bacteria might be used to make disease-causing species vulnerable to attack.

Biofilms are communities of bacteria that adhere to each other and are hard to eradicate, causing problems in hospitals and factories. Richard Losick of Harvard University in Cambridge, Massachusetts, and his colleagues found that the bacterium Bacillus subtilis can produce a mixture of D-amino acids that trigger the dispersal of its films. These amino acids are mirror images of the L-amino acids that are more commonly found in proteins.

Adding these D-amino acids to biofilms broke up B. subtilis communities (pictured), as well as films of the pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa. The D-amino acids were incorporated into bacterial cell walls, where they prevented attachment of the protein fibres that hold biofilms together.

Credit: SCIENCE/AAAS