Das Lehrgebiet BioVT publiziert zusammen mit dem Umweltcampus Birkenfeld (AK Bröckel) in der Zeitschrift "Microorganisms" eine neue Methode zur dreidimensionalen Untersuchung von Biofilmen.

As productive biofilms are increasingly gaining interest in research, the quantitative monitoring of biofilm formation on- or offline to the process remains a challenge. Optical coherence tomography (OCT) is a fast and often used method for this purpose but can measure hardly through solid materials. X-ray microtomography (μCT) can measure biofilms in most geometries but is very time-consuming. By combining both methods for the first time, the weaknesses of both methods could be compensated. The phototrophic cyanobacterium Tolypothrix distorta was cultured in a moving bed photobioreactor inside a biocarrier with a semi-enclosed geometry. An automated workflow was developed to process µCT scans of the biocarriers. This allowed quantification of biomass volume and biofilm-coverage on the biocarrier, both globally and spatially resolved. The spatial resolution made it possible to detect the influence of the flow in the early growth phase of the biofilm. In the later phase, light limitation could be found in-side the biocarrier. µCT data and biofilm thicknesses measured by OCT showed good correlation. The latter could therefore be used to rapidly measure the biofilm formation in a process. The methods presented here can help gaining a deeper understanding of biofilms inside a process and detect any limitations.

S. Schaefer, J. Walther, D. Strieth, R. Ulber, U. Bröckel; Insights into the Development of Phototrophic Biofilms in a Bioreactor by a Combination of X-ray Microtomography and Optical Coherence Tomography; Microorganisms (2021) https://doi.org/10.3390/microorganisms9081743