Microbiological Workbench

Our laboratory is well equipped for culturing anaerobic bacteria. This for example requires that all devices have to be sterilized before use: glass and metal equipment are sterilized in a drying chamber at 180°C; liquids and plastics are sterilized in an autoclave (model VE-40 by Systec), which is capable of several fully automated programs, like solid, waste and liquid matter sterilization and implements all security installations according to the “Technische Regeln zur Druckbehälterverordnung” TRB 402. Our autoclave is additionally equipped with a fast cooling unit which reduces the time to cool the chamber from 100°C to under 80°C – when it is safe to open it – to 5 minutes while preventing the contact of sterilized liquids (e.g. the nutrient solution) with external air, thus preserving the anoxic conditions required for the microbiological experiments.

Microbiological work in our group is done with marine anaerobic microorganisms which have to be handled and incubated in the absence of any oxygen. Anoxic conditions can be realized when working in a glove box. The glove box allows us to carry out standard lab procedures under anoxic conditions. Anoxic conditions are also reinforced by a gassing station at the workbench. In close collaboration with the MPI for Marine Microbiology in Bremen we also always keep track of anaerobic microbiological handling procedures.

In our work with marine anaerobic microorganisms, we are especially interested in electrochemical interactions between bacterial cells and electrodes. Electrochemical measurements at the electrode/bacteria interface can continuously be performed in modified small-scale bench top bioreactors with three-electrode setup under anoxic conditions. A multiplexer (ECM8^TM) that is connected to a Gamry Reference 600^TM potentiostat allows us to perform parallel electrochemical measurements in up to 8 bio-electrochemical cells. Thus several electrochemical measurements in cultures of anaerobic marine microorganisms can be conducted with a single run of experiment.