Researchers at University of California, Berkeley have developed an easy way to put bacteria under, so called, molecular lock and key, which is needed to contain its accidental spread. This is achieved through series of genetic mutations, which render the microbe inactive until another molecule is added. This molecule, the key, enables viability of the bacteria again.
Even though it seems to be a small experiment, this achievement is actually quite important. Biocontainment methods like this are very relevant at the moment as science is quickly advancing techniques for researching bacteria. During this research scientists were working with a strain of E.coli, which is commonly used in research labs. They were targeting five genes that are required for the organism to survive and devising easy ways to modify them.
The researchers have created mutations in the genes, which, after modifications, require the addition of the molecule benzothiazole in order to function. J. Christopher Anderson, senior author of the study, said that “this approach is very robust and simple in that it only requires a few mutations in the genome”. In other words, benzothiazole molecule serves as the key and scientists modify genes of the bacteria to engineer the lock.
To explain this achievement in a simple way, scientists compare the approach to taking out a component in a car. As car can travel without its rear-view mirror, but cannot without the camshaft, fuel tank or other essential components, bacteria can survive without some components, but would die without others. Of the 4,000 genes in E.coli, about 300 are essential to its survival. Gabriel Lopez, one of the co-authors of the study, said that what scientists are doing is “putting an ignition switch onto a handful of the bacteria’s essential genes. Without the right key, the bug won’t live.”
One of the applications for this method could be treating diseases. Organisms are already being engineered to treat diseases, but it would be very beneficial to have mechanisms to ensure that the organism is activated only when needed. Scientists added several such lock-and-key combinations into one organism – activating one of these locks will bring vitality up by a lesser degree than unlocking more of them.
Scientists say that this approach may help to disable other proteins and organisms as well, even though there is no one-size-fits-all solution to biocontainment. There are other methods that achieve similar results. However, they rely upon a “kill switch” that poisons an organism. Even though such methods do work now, in a longer period the organism may evolve a way to survive that signal. In this new approach to control vitality of the organism, the default state of the organism is death and scientists have to actively turn on the genes to enable its survival, which means that evolutionary capabilities to adapt to the situation are impossible. Scientists have demonstrated that this approach is fast, cheap and easy to deploy.
This method was created to prevent the accidental spread of engineered organisms, even though there are other possible applications as well. However, it is not foolproof against intentional attempts to thwart the biosafety net. It is also a good example that scientists have to make scientific discoveries for the sake of science itself – it may not benefit humanity, but will help researchers to create something more useful in the future.