How intermolecular interactions determine biological processes?

 

Welcome to the Chai group!

In our laboratory we study the intermolecular interactions that govern extracellular biological processes. Our major research topic is bacterial biofilms. Biofilms are communities of microbial cells that grow on natural and synthetic surfaces. Irrespective of whether biofilms are beneficial or detrimental to the host, their extracellular matrix is critical to their development and survival. The extracellular matrix (ECM) is a mesh of biopolymers, mainly polysaccharides, proteins and nucleic acids that connects the biofilm’s cells together. It is also related with an increased resistance of biofilms to antibiotics relative to single cells.

Our model organism for biofilm and ECM formation is the Gram positive, soil bacterium, Bacillus subtilis.

The main research topics in the group are:

1. Extracellular matrix Biochemistry. What is the composition of the ECM?

We use biochemical separation tools in order to isolate the ECM proteins and polysaccharides. We then use different biochemical and biophysical methods to characterize these biomacromolecules.

     Circular Dichroism

2. Studying intermolecular interactions from a Physical Chemistry and Biophysics perspective. How do the biomacromolecules assemble and what is the interaction between them?

We use an Atomic Force Microscope (AFM) to study the basic interactions between the ECM components.

 Force-Distance Cycle

3. Biomineralization. How do biofilms affect the formation of inorganic minerals?

Here we use methods in Material Science in order to study the effect of biofilms on the formation of minerals, such as calcium carbonate.

    Calcium carbonate

 

The questions that we ask cross the borders of the conventional scientific disciplines (Chemistry, Physics, Biology) and an interdisciplinary approach is taken to answer them. The students in the lab therefore learn and practice a large variety of experimental methods and they acquire broad knowledge in different fields going all the way from Chemistry and Physics to Biology and back.