Our laboratory is working on bacteriophages, which are viruses that specifically attack bacteria. They are in fact the biological organisms that are the most abundant on the planet. There is nothing more abundant than viruses.

To illustrate this, if we take water from a lake in our hands, there are more viruses in our hands than there are humans on Earth. So bacteria are surrounded by viruses. There must be mechanisms to defend against these viruses. By studying the relationship between phages and bacteria, we discovered that certain bacteria used a new system called CRISPR-Cas to ward off bacteriophages.

In the first step, a phage or a virus infects a bacterium. So the virus’s genome enters the bacterium, which in turn uses a part of the phage’s genome and incorporates it into its CRISPR.

In the second step, the CRISPR system produces a small molecule — an RNA molecule — and also produces proteins that will become a monitoring system within the cell.

And the third step of the CRISPR-Cas system is called the interference step. So the cell, at that moment, is resistant to the virus, and if a virus infects the cell, the virus’s genetic material will enter the bacterium, but the bacterium will be able to cleave the viral DNA and destroy the virus.

After the CRISPR-Cas system was discovered, European and American researchers used parts of the CRISPR-Cas system to create a powerful genome editing tool. This tool is called CRISPR-Cas9.

People might not know this, but there are many genes inside the genome of which we do not know the function. Now we have a very powerful tool that is highly precise, and we can really explore — or cleave or mutate — a specific region inside the genome and see what impact this mutation will have on the cell.

What I wish to emphasize is that microbiology is an absolutely fascinating field, that there are still many things to discover, and that now we have truly powerful tools that enable us to make significant advances.