Researchers discover ‘switch’ that allows microbes to recognize kin

Published: March 27, 2017

https://phys.org/news/2017-03-microbes-kin.html

In our microbiology class, we learn a lot about how bacteria will interact with each other, but don’t really mention how they might be recognizing their own kind. A plasmid shared among your species is much better than one shared with a competitor in the end. And we also learned how beneficial a biofilm is, but not how a bacteria would know it can be a part of the biofilm. In this article, we learn of TraA receptors —the cause of this recognition. Digesting a study that looked at Mycococcus xanthus, this particular receptor was discovered to help recognition of M. xanthus cells for outer membrane exchange. Additionally, different strains of bacteria have different TraA sequences, further supporting this receptor as a receptor to help with recognition of other bacteria of the same strain. An interesting reason for the recognition receptor had to do with outer membrane exchange (OME). The paper discussed that if different bacteria were to go through OME with each other, there might be toxins exchange that the recipient (being of a different bacterial strain) would then have no antidote to.

The article also discussed that the bacteria in question are phagocytes, and so they are of interest in the agriculture world. So, as these would be great for getting rid of plants’ pathogens, it only makes sense that there would be interest in how they distinguish each other from other microbes.

One confusing part of the study is the way they present the ability to recognize different TraA sequences, saying one amino acid (AA) changed is enough to cause no recognition. The way that the information was presented had me asking myself, “Is it a specific AA that when changed makes it so that the bacteria don’t recognize each other or is it that changing any AA would be enough?’