The invisible world of microorganisms has fascinated researchers for more than 200 years. How can organisms too small to be seen with the naked eye exist and function, and how can their actions have so important and sometimes dramatic consequences? One would think that 200 years would be enough to know everything about microorganisms. Yet, more than ever we find ourselves in a revolution of new possibilities to study the smallest living beings and try to understand things we have not appreciated so far. Let me give two examples.

First, the development of DNA sequencing technologies over the past twenty years has dramatically accelerated  our knowledge of individual microbial species. It has also offered us insights in the capacities and the diversity of microorganisms living on our planet, the majority of which have never been cultured in the laboratory. The activities of some of those  microbes  have global importance, but we can only study them in their own environment.

As  a  second  example, new  molecular techniques  coupled with advances  in microscopy  now enable the study  of microorganisms as  individuals,  revealing the organization of the protein and DNA machineries inside cells. Microbial cells are not mixed enzyme bags, but instead  highly structured  and organized entities.  At the same time, we find that individual cells in clonal populations can behave very differently. Such different behaviour can have very important consequences, from the action of certain mobile DNA elements to the virulence character of specific individual cells.

We are very fortunate to have a dynamic team of very different scientists in our Department, who each pursue their specific quest as to the wonders of microbial life. Some of us do research on the basic rules that shape cells and make them functional. Others are trying to understand how we can better defend ourselves against the disease-making capacity of certain microorganisms, or are fascinated by the great potential to apply microorganisms for the benefit of mankind and for the restoration of our natural environment.