Regensburg 2022 – scientific programme

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BP: Fachverband Biologische Physik

BP 7: Poster 1

BP 7.39: Poster

Monday, September 5, 2022, 18:00–20:00, P1

Influence of varying pH on individual and collective behavior of filamentous cyanobacteria — •Franziska Papenfuß, Maximilian Kurjahn, Antaran Deka, and Stefan Karpitschka — MPI for Dynamics and Self-Organization, Göttingen, Germany

Photoautotrophic cyanobacteria are responsible for about 10 % of global primary production of reduced carbon and represent a sustainable source of carbon dioxide neutral bio-fuel. Adaptation to environmental changes is a key factor of their evolutionary success, but the emergent phenomena that couple the individual to their collective behavior remain elusive. Here, we investigate three species of filamentous cyanobacteria cultivated in pH-buffered and non-buffered medium over three weeks of cultivation. During cultivation, colony-scale properties like external pH and aggregate morphology were measured as well as properties of individual filaments like gliding velocity and absorption spectra. In the non-buffered cultures, pH varies in dependence on light-driven photosynthesis. Different species seem to adapt colony morphology from compact aggregates to reticulate layers at different pH values in the low alcalic range. Yet, the external pH has no influence on the gliding velocities, but influences the abundance of the dominant photo-pigments Chlorophyll-a, beta-carotene and phycocyanin in some species. Our investigations show that the pH is not only governed by the photosynthetic activity, but also influences the fate of the cyanobacterial colony in a regulating feedback mechanism.