Overcoming Bottlenecks of Enzymatic Biofuel Cell Cathodes: Crude Fungal Culture Supernatant Can Help to Extend Lifetime and Reduce Cost



Invited for this month′s cover is the Biofuel Cell research group of Sven Kerzenmacher at the University of Freiburg. The image illustrates that the wood-degrading fungus Trametes versicolor can be used to resupply the redox enzyme laccase at an enzymatic biofuel cell cathode. Read the full text of the article on page 1209

What was the inspiration for this cover design?

12The design illustrates the combination of nature and technology by showing both the fungus in its natural environment and the electrochemical reaction at an enzymatic biofuel cell cathode. The arrows represent the exchange and resupply of the deactivated enzyme and illustrate the simplicity and sustainability of the process. The laccase structure was visualized using “Protein Workshop”.

Scheme 1.

Left to right: top: S. Sané, S. Rubenwolf, R. Zengerle, S. Kerzenmacher bottom: C. Jolivalt, G. Mittler, P. J. Nielsen

Scheme 2.

Laboratory for MEMS Applications IMTEK—Department of Microsystems Engineering University of Freiburg, Germany E-mail: kerzenma@imtek.de

How would you describe the most significant result of this study to a layperson?

Enzymatic fuel cell electrodes suffer from limited long-term stability as the enzymes that enable the electrochemical reaction loose activity over time. We show that the culture supernatant of the enzyme-secreting fungus Trametes versicolor can be used to resupply fresh enzymes at the electrode. In this way the functionality of the electrode can be sustained over extended periods of time.

What other topics are you working on at the moment?

Presently, we are investigating the use of different enzymes and enzyme-secreting microorganisms for our concept. In addition, our group is developing microbial fuel cells to simultaneously generate electricity and treat wastewater as well as platinum-based implantable fuel cells as a battery-independent power supply for medical implants.


The authors acknowledge financial support from the German Research Foundation (DFG) through the research training group “Micro Energy Harvesting” (GRK 1322).

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