On zooplankton and small bacteria…

Hello dear SONNE friends,

Today we are portraying Dr. Heike Freese and Franziska Klann from the Leibniz Institute DSMZ in Braunschweig. The two scientists are part of the collaborative Research Center  (SFB, Sonderforschungsbereich) “Roseobacter” and together they are the team “population genomics” on board.

Their interest focuses on a specific family of bacteria, the rhodobacteraceae. More specifically, the Roseobacter group! This group of marine bacteria is abundant and often dominant in almost all marine ecosystems and plays an important role in the Earth’s biogeochemical cycles. The work of Heike and Franziska revolves around the evolutionary radiation among different species within various genera of the Rroseobacter group. They want to learn how different species may evolve within this group of marine bacteria and why they are so successful adapting to their ecological niches.

In order to collect the small and, as colonies, slightly reddish bacteria, adequate sampling strategy and techniques are crucial.

What does that mean?

This means that Heike and Franziska collect zooplankton with a very fine-meshed net in the upper 150 m of the water column, because the bacteria thrive within and on the zooplankton. As soon as the net is filled with zooplankton, the associated bacteria are isolated in the lab at 15 °C (…Brrr!). In the home lab, they will carry out further work, keyword: genome differentiation.

Besides the net, the two biologists use an in-situ pump. During three hours of operation this pump filters about 250 to 300 liters of seawater in 20 m water depth to collect free-living bacteria on a filter. Meanwhile Heike and Franziska keep their fingers crossed that their pump performs well and resists the water pressure. After a successful operation, the micro-organisms on the filter are deep frozen and kept until further genomic analysis in the lab at home.

Their work keeps them really busy here and we hope you could get an idea of what Heike and Franziska are doing during SO254.

Stay tuned – more to follow soon!

And in the end: Where is the SONNE?

With this in mind,

The science party of SO254

(Translation by Torben Struve)