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Bacteria in the atmosphere

In the DRAMA project we will use the plant pathogen Pseudomonas syringae as model organism to study the effect of atmospheric conditions – low water content, high radiation load (UV light) and highly variable temperature conditions – on the survival and activity of bacterial cells. Pseudomonas syringae cells are able to synthesize special proteins that catalyze ice-formation, which ultimately leads to precipitation at higher temperature than the much more common mineral dust aerosols. The presence of bacterial aerosols that are able to produce ice-forming proteins may explain the common observation of ice in “warm-phase clouds", which can’t be explained by the presence of mineral dust.

In the DRAMA-project, we are going to build an experimental system that will allow us to study Pseudomonas syringae aerosols as if they were in the atmosphere. Our results will be used by climate- and weather modelers to improve their models.