Kerem Bozkurt, Doktorand am Lehrstuhl für Hydromechanik und Hydrosystemmodellierung (LH2) der Universität Stuttgart, besuchte im Rahmen des Sonderforschungsbereich (SFB) 1313 das Center for Biofilm Engineering der Montana State University für einen dreimonatigen Forschungsaufenthalt. Er ist Mitglied der SFB 1313-Graduiertenschule "Interface-Driven Multi-Field Processes in Porous Media".
Forschungsbericht
The SFB1313 and especially its research project C04 have long-standing collaborations with the Center for Biofilm Engineering (CBE) at Montana State University. The complementary strengths of both groups—CBE’s expertise in biofilm systems and microscopy, and the modeling works in Stuttgart—have enriched each other for many years. The main goal of my three-month research visit was to investigate my biomineralization experiments from the Porous Media Lab (PML) of the University of Stuttgart in greater detail.
In my PhD, I study biomineralization in microfluidics, where bacteria catalyze the hydrolysis of urea, producing ammonia and carbonate that lead to calcium carbonate precipitation. At the PML, I observed strong and homogeneous precipitation in PDMS microchannels but almost none in glass channels. Although I could not directly visualize bacteria, I assumed that this contrast was caused by the different surface properties of PDMS and glass. Since PDMS is more favorable for bacterial attachment, understanding these differences was essential, especially because field-scale systems more closely resemble glass.
The advanced microscopy facilities at the CBE and the availability of the Microfabrication Facility (MMF) provided an ideal environment for this work. At the MMF, we fabricated both glass- and PDMS-based microfluidic devices and developed a plan to systematically modify glass surfaces. We created two types of modified glass devices (one hydrophobic and one positively charged) to assess how surface chemistry affects bacterial behavior.
Bacteria tend to prefer hydrophobic surfaces and are negatively charged, which leads to stronger attachment on positively charged surfaces. Indeed, in our bacterial experiments, we reproduced the earlier results: PDMS showed strong bacterial attachment and calcium carbonate precipitation, while untreated glass did not. However, both hydrophobic and positively charged glass devices exhibited clear bacterial attachment and precipitation, demonstrating that surface properties play a crucial role in biomineralization.
My stay at MSU was a unique and rewarding experience. Bozeman’s beautiful nature and outdoor opportunities made the three months particularly enjoyable. I am deeply grateful to SFB 1313 external partner Prof. Robin Gerlach for his continuous support and hospitality, and I also thank Dr. Andrew Lingley, Dr. Joshua Heinemann, Prof. Recep Avci, Prof. Stephan Warnat, Dr. Michael Neubauer, James Marquis, and the entire Gerlach Lab for their support.
