Brandis lab

Popular science presentation

The answer to the ultimate question of life, the universe, and everything might be simple, but for most questions in real life this is not true. Experiments provide us with objective answers, but do we actually understand which question is being answered? And what good is even the most elegant result, such as ‘42’, if you don’t know the question?

At the beginning of most microbiological projects is a specific “parental strain” that is used as a reference point. This is an important part of the scientific process but it also poses risks that should not be ignored. Most bacterial species have existed and evolved for hundreds of millions of years. For comparison, humans and elephants diverged only 6-7 million years ago and most humans arguably do not look or behave like elephants. This bears the question if the results obtained from a single strain are representative for the entire species or even can be transferred to another species. The answer to this question is both yes and no, but it is not always obvious which of these answers applies to a specific project.

Another level of complexity is the experimental setup that is being used. This includes for example the volumes of bacteria that are being used. Working with smaller volumes is more manageable, but the number of microorganisms within the culture is directly related to its volume. Some experiments are set up with population sizes that correspond to the population of Sweden, other correspond to the entire population of earth. Not surprisingly, this will change the results of the experiment.

Strains and experimental conditions are often chosen arbitrarily based on what is easy to do and what others have done before. These are important considerations for example to be able to compare results between different research groups. Using a single strain with a single experimental condition will provide a result, but will it actually answer the underlying question? In our group we specialize in diversity with regards to experimental conditions and strains (we use hundreds of natural isolates in addition to lab strains). We believe that every experiment is like a stroke on a painting and only by repeating the same experiments with different conditions and strains we are able to add enough strokes to appreciate the complete picture. Using this approach, we try to answer fundamental question related to the evolution of antibiotic resistance and how free-living microorganism react to the ongoing climate crisis.

Research projects

Is collateral sensitivity to antibiotics contingent on population dynamics?
Does size matter? We believe it does with regards to bacterial populations. In this project, we study how experimental conditions, such as population size, affect the outcome of evolutionary experiments using collateral sensitivity as a model system.

How do microorganisms respond to climate change?
The climate is changing and free-living microorganisms have to adapt to survive. In this project, we attempt to understand the evolutionary responses to climate change and try to predict potential dangers to human health care.

Development of a new model system to study translational mutations related to cancer development.
Many human diseases, including various cancers, have been linked to mutations in the translational system. Understanding the molecular mechanism that ultimately leads to the disease development is not always straightforward. In this project, we attempt to develop a novel yeast-based system for the high-throughput analysis of potential detrimental mutations in the human translation system.