How does a single Bacillus cereus spore stick to steel ?

Sporeforming spoilage and pathogenic bacteria are a major headache for the food industry, since the spores are notoriously difficult to remove from food-contact surfaces and to inactivate. An example is Bacillus cereus, a pathogen well known to be the cause of food-borne emetic and diarrheal disease associated with rice meals kept at room temperature for too long and a wide range of other foods. In this collaboration between the protein materials group at PCC and prof. Tjakko Abee at Food Microbiology we want to explore whether we can use Atom Force Microscope (AFM) – based measurements to determine the minute forces between individual spores and surface materials relevant to the food industry such as stainless steel. The aim would be to measure what forces are needed to remove them, but also to find out the mechanism of adhesion: which of the surface molecules and/or proteins are responsible for adhesion? This could be addressed for example by studying adhesion efficacy of B. cereus endospores producing different types of surface molecules and/or proteins. At this stage, this project is in an exploratory phase: we want to make the first steps (proof of principle experiments) by a comparative analysis of adhesion capacity of spores derived from different B. cereus strains and with different sporulation histories. You will first grow B. cereus and produce spores at Food Microbiology, and then perform the force measurements at Physical Chemistry and Soft Matter. This is a highly ambitious interdisciplinary project suitable for a Food Technologist or Biotechnologist with an interest in advanced and delicate physical measurements. The AFM-based force measurements produce large amounts of data that need quite extensive processing, so an interest in number crunching with computers is also required. Alternatively, the project could also be interesting for a Molecular Life Scientist with an interest in applications of advanced physical measurements in the food industry.

Techniques: Basic molecular biology (handling B. cereus cells and their endospores), Atomic Force Microscopy imaging in liquid, Atomic Force Microscope-based force spectroscopy,, Bioconjugation chemistry, Working with large datasets (with for example MatLab).