Contact: Laurenz Schröer
Bacteria have the potential to colonize rocks in natural outcrops and building stones. Over the past decades, the negative effect (i.e. biodeterioration) of bacterial colonization have been studied, while more recent studies also focus on the beneficial effect of controlled or induced bacterial growth. The colonization potential (or bioreceptivity) is mainly related to the stone’s chemical composition, texture and structure and to the local environment. As bacteria colonize a stone, they can alter the stone’s properties through their metabolism (e.g. mineral precipitation and gas production) and through the formation of biofilms. While mineral precipitation could increase the bonding strength between mineral grains and therefore improve the stone’s mechanical properties, gas production and the presence and location of the biofilms can alter the fluid transport and therefore the stone’s durability. This project will study the interaction of the location, growth and activity of the biofilms and the petrophysical properties of rocks at the pore scale and vice versa. It will be studied by state of the art high resolution X-ray CT supplemented with some more standard techniques such as Scanning Electron Microscopy. This will allow us to find the precise mechanisms, the role of the organisms as well as the link between microbial colonization and petrophysical properties inside sedimentary rocks.