The newly discovered form of communication is a type of electrical signalling, similar to that used by brain cells. Specifically bacteria interact through ion channels. These are proteins that serve as molecular gatekeepers in a cell. The signals produced are channelled by ions. This adds to what is known about bacterial communication through the transmission of chemical molecules.
To arrive at this finding, the researchers looked at microbiological co-operative communities called biofilms (where bacteria are trapped in an extra-cellular matrix.) The basis of the biofilm was a soil bacterium called Bacillus subtilis. Biofilms are important to study because the communities are very resistant to antibiotics and disinfectants. It is thought the communication process is related to the development of resistance.
For example, as the research brief points out, when bacteria at the edge of the community sense a harmful substance like an antibiotic they slowdown activities to prevent the bacteria located in the biofilm core from taking in a chemical like an antimicrobial. In this way the biofilm acts like a ‘super organism’, rather than as individual cells. Because the bacteria are attached to each other, the whole takes on the form of multi-celluarity rather than individual organisms. Bacteria in biofilms are different and more sophisticated that those found in a planktonic state.
The inference is that bacteria should not always be thought of as individual cells, but rather an interactive community and a community that has a primary function of ensuring its own survival. Moreover, new techniques for dealing with disease-causing bacteria may arise from the research. This is particularly so in understanding how bacteria thrive in different environments, especially when biofilms are formed.
The researchers do not think this is the end of the insights into bacterial communication, for there is more to learn. For example, what is the frequency at which bacteria communicate?
The study was conducted by UC San Diego microbiologist, through a team led by Dr. Gürol Süel. The findings are published in the journal Nature, in a study titled “Ion channels enable electrical communication in bacterial communities.”
