Lake Microbiology

Group Leader:

Dr. Katrin Wendt-Potthoff

Tel: +49 341 6025 4810

mibi retreat 2024
Mibi retreat at Friedrichshöhenberg (3.24)
mibis at Bautzen
Meeting friends at Bautzen (30.11.23).
last sampling Möhne Reservoir
Sampling bubble traps at Möhne reservoir on 11.10.23.
group photo
Mibi Retreat at Helmstedt 13.4.23
MEDIWA plattform
The GHG measuring plattform was installed at Bautzen Reservoir (13.4.2022).
retreat Gernrode
mibi retreat at Gernrode (11.3.2022)
Bautzen campaign
Mibis at Bautzen Reservoir 10.9.2021.
Hannah doing DryFlux2 measurements at the River Elbe
MEDIWA platform
We installed the MEDIWA platform at Bautzen reservoir (21.5.2021):
Martin and Matthias installed automatic flux chambers at the Elbe River (13.5.2020).
virtual breakfast
The mibi group practices Social Distancing: The first virtual mibi breakfast (20.3.3030).
mibi retreat 2020
The mibis at the retreat at Gernrode 20./21.2.2020
Microplatas Meeting
MikroPlaTas project meeting at Potsdam 18./19.6.2019.
ScaleX Ammer
Matthias measured greenhouse gas emissions at the river Ammer in Bavaria (6.6.2019).
Franzi und Martin
Franzi and Martin during fieldwork on the TregaTa float (8.5.2019).
Peifang sampling

Peifang performed her first sampling at the streams Hassel and 'Rappbode (11.4.19).

The Tregata Platform has been installed at Bautzen Reservoir (3.19)

Mibi Retreat in January in Gernrode

mibi retreat 2019
mibi group at Gernrode

In Ocober 2018 Matthias measured GHG fluxes at Lake Sevan, Armenia.

Sevan Matthias at Lake Sevan.

Recent Research highlight

Fishpond GHG emissions
In the bubble project we investigated greenhouse gas emissions from fishponds.Traditional carp ponds showed very high methane (CH4) emissions by gas bubbles (ebullition). The feeding sites in the ponds had the highest ebullition rates published so far. We found a relation bwetween bubbling quantity, bubble size and bubble composition.

Microbiology of lakes and reservoirs

As a consequence of temporary or permanent stratification and external inputs of nutrients and organic matter, lakes develop redox gradients which are associated with a variety of aerobic and anaerobic microbial metabolic reactions. These gradient-bound reactions are not only of general interest to microbiologists, but provide starting points for management of various water quality problems.

Our current study objects are lakes and reservoirs which are affected by an increasing load of dissolved organic carbon and pit lakes, some of which are meromictic (permanently stratified). Our group studies the microbial reactions of the iron, sulphur, carbon and nitrogen cycles and the organisms involved therein. We also investigate the formation and emission of greenhouse gases (carbon dioxide, methane) from lakes and their temporarily drying shorelines. A recent field of work is microplastics in inland waters, which has received increasing public attention during the last years. redoxcline in Waldsee

We are especially interested in redox boundaries in standing waters, where a transition from oxic to anoxic conditions takes place. These are found in the sediments and at the sediment-water interface, but also within the water column of stratified lakes (chemocline/redoxcline). The water surface as the interface to the atmosphere is of crucial importance for the exchange of gases and is being studied in the field using floating chambers. Plastic particles in lakes also represent surfaces which we study with respect to the influence of different polymers and typical geochemical situations in lakes on microbial colonization and activity. Regarding sediments, the activity of different physiological groups of microbes and their dependence on biotic and abiotic parameters is studied. We adopt high-resolution methods which allow measurements of microbial activity and associated biogeochemical processes in the sub-millimeter range. To supplement the in situ studies, we also study microbial activities with the aid of controlled microcosm experiments in the laboratory.