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H. Grothe:
"Macromolecular biomaterials causing heterogeneous ice nucleation";
Hauptvortrag: 2nd International Conference on Biomaterials and Nanomaterials, Vienna (eingeladen); 20.05.2019 - 21.05.2019.

Biological materials from plants, bacteria and fungi are dispersed in the environment. This can be whole organisms or just fragments. When these particles get airborne, they are termed bioaerosols and are in the size range between hundred nanometers and a few micrometers. Here we present the particularity that macromolecules from these bioaerosols can be washed of in aqueous solution and that these macromolecules can exist independently from the mother grain, e.g. in water droplets or on the surface of dust particles.

In general, ice nucleation of bioaerosols is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. We have focused on birch trees, which exhibit an elevated ice nucleation activity and we proof the size of these molecules, their stability against oxidation and their chemical origin. Further we find evidence that these macromolecules can be found on the whole surface of many parts of the tree (pollen, leaves, primary and secondary wood) but with different concentrations.

An interesting point remains the mechanisms of heterogeneous ice nucleation, in which the biomaterials play a crucial role. Spectroscopy and microscopy have been applied to solve these processes and get a fundamental understanding of how ice nucleation in trees is prevented or triggered, respectively. Obviously this is a survival mechanism on molecular level.

http://biomaterials.alliedacademies.com/2019/scientific-program-pdfs