Bacteria communicate with other species to recruit them

Long-distance electrical messages attract new bacteria to biofilm communities.

In a 2015 study, researchers discovered that bacteria in a biofilm communicate with each other via electrical signaling. Now, the same group has discovered that this communication extends beyond the community. Bacteria also send long-distance signals to other bacteria—even those of a different species—asking them to join their biofilm. We speak with senior author Gürol Süel, a biologist at UC San Diego, to find out more.

ResearchGate: What is a biofilm?

Gürol Süel: Biofilms are a densely packed community of bacteria that is held together by a sticky matrix produced by the bacteria. Bacteria are unicellular organisms that can exist in solitude, but nearly all bacteria on our planet reside in such biofilm communities.

RG: How do bacteria communicate with each other? And what do they “talk” about?

Süel: In a previous study, my group discovered that bacteria in biofilm communities communicate by means of ion channels, similar to neurons in the brain. They communicate their metabolic state. This means that bacteria use electrical signaling to coordinate their behavior within a large biofilm over long distances.

RG: What have you found in this study?

Süel: That the electrical signaling generated by a biofilm community can extend beyond the biofilm and direct the movement of cells that are swimming at a distance, attracting them to the biofilm. Cells within a biofilm community can thus not only coordinate their own behavior, but also influence the behavior of diverse bacteria at a distance. This communication leads to the recruitment of new members to their community. This process even works between bacteria that belong to different species, allowing the formation of mixed species biofilms. We are all familiar with sending electronic messages to distant friends. Our study shows that bacteria living in communities do something similar.

RG: Would bacteria communicating with other bacteria species be comparable to us speaking with, let’s say, baboons?

Süel: Actually, the two species in the paper are evolutionary speaking very distant, so more like humans talking to mushrooms.

RG: How does understanding this mechanism help humans?

Süel: Our work suggests that the composition of mixed species bacterial communities, such as our gut microbiome, could be regulated through electrical signaling. Perhaps bacteria and human cells can also interact electrically in the human gut. Our work may lead to future electrical-based biomedical approaches to control bacterial behavior and communities.

RG: What advantage does being able to recruit other species give bacteria in a biofilm?

Süel: This is a great question, and we plan to work on that next. It is possible that the different species recruited to the biofilm can provide a benefit by collaborating with cells in the biofilm. It is also possible that the recruited cells are attracted to the biofilm, because they have something to gain. Biofilms in nature can contain several different species, so it will be great to pursue these questions.

Featured image courtesy of SandraG89.