Rival colonies of bacteria—even siblings—produce a lethal protein as they grow that can keep competitors at bay, scientists have found.
Sibling bacterial colonies fight each other with lethal protein
Rival colonies of bacteria—even those that are closely related—produce a lethal protein called “sibling lethal factor” as they grow that can keep competitors at bay, scientists have found.
The protein stops the growth of colonies and kills some of the cells. It is likely used by colonies to preserve scarce resources for themselves.
Alone in a dish, colonies of the bacterium Paenibacillus dendritiformis will send branches of cells in all directions. They secrete a protein called subtilisin that promotes colony growth and expansion. But when subtilisin reaches a certain threshold concentration, as it would on the border between two competing colonies, the colonies secrete “sibling lethal factor” to thwart each other’s growth.
In the video, watch as a single P. dendritiformis colony grows. A droplet of subtilisin was placed on the right side of the growing colony (out of the frame). Each frame of the movie is separate by one hour. Watch as the colony’s branches on the right hand side vanish over time due to the presence of the lethal subsilitin.
Research by: Avraham Be'er, Gil Ariel, Hepeng Zhang, E.L. Florin, Shelley Payne, and Harry Swinney (The University of Texas at Austin), Oren Kalisman, Yael Helman and Alexandra Sirota-Madi (Tel Aviv University), and Eshel Ben-Jacob (University of California San Diego).
Read the original pub: “Lethal protein produced in response to competition between sibling bacterial colonies.” Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1001062107
Comments