Experts

To enable an efficient project development, it is essential to regularly talk with experts. These give insights regarding actual requirements on the specific area of expertise. In addition the permanent consolidation of experts during the project development process, it is useful to obtain an assessment at the end of the project, in order to assess aspects such as efficiency, future opportunities and biosecurity. Therefore, we consolidated several experts to evaluate our project. Dr. Falk Harnisch was our permanent expert who helped us especially with the engineering aspects and mediators. For the project assessment we consulted Dr. Arnold Sauter and Aeneas Wanner.

Dr. Falk Harnisch

Introduction

At the congress Biotechnologie2020+ in Berlin, Germany we met [http://www.ufz.de/index.php?de=31006 Dr. Falk Harnisch], an expert in bioelectrocatalysis and bioelectrotechnology, who works at the department of environmental microbiology at the [http://www.ufz.de/index.php?en=11382 Helmholtz-Zentrum for environmental research] in Leipzig, Germany. He is the supervisor of the research group for microbial biocatalysis and bioelectrotechnology.

On October 8th we interviewed him via Skype. After a short discussion about our Microbial Fuel Cell (MFC) at the beginning, where we figured out that the most difficult part of the MFC is the transfer of the electrons through the cell membrane and the oxidation of the mediator at the anode as well and the toxicity of some mediators. After this short introduction we asked him specific questions about our project:

Skype-Interview

CeBiTec-Kolloquium

On September 9_th we invited Dr. Falk Harnisch to our institution for giving him an impression of how our work goes ahead. All in all he was very satisfied with our ideas after we presented him our state of research. Furthermore we engagingly discussed our MFC-design and how we could optimize it. He observed that our carbon electrodes were well chosen and that potassium ferrocyanide (III) in the cathode chamber is a suitable redox system. We discussed that on both sides of the MFC the pH has to be 7. For example 50mM phosphate buffer can be used to avoid liquid diffusion and potential gradients through the membrane. We debatted that glycerin is a more suitable carbon source than glucose and that it is also a great advantage to use as it is a waste material of biodiesel production. In further discussions, it was possible to develop a protocol for the next experiments. With this we were able to measure how well E. coli can metabolize the different carbon sources, like glycerin, acetate, lactate or glucose, under anaerobic conditions. After applying this screening method without using mediators we will screen these carbon sources of choice with added soluble and insoluble electron acceptors like fumerate in order to analyze the growth rate of E. coli with supplemented mediators.

A low growth rate with an insoluble electron acceptor indicates a not usable mediator, whereas high growth rate shows good extracellular electron transfer by the mediator. Dr. Falk Harnisch gave the hint to test these different screenings primarily outside of the MFC. After finding a good combination of carbon source and mediator the optimal system could be transferred to the MFC.

Impacts on our project

The exchange with Dr. Falk Harnisch had a big impact on our project. Together we discussed different problems about the genetical aspects, for example that the orientation of the mtrCAB cluster in the membrane could be problematic or that the nanowires are too complicated to work with in the short time we have. Especially, since the structural proteins have not yet been clearly analyzed which genes are responsible for the pilus and his conductivity. In addition he answered our questions about the MFC design, which aspects were important for measuring or cultivation. All in all he always was available and willing to answer our questions.

Dr. Arnold Sauter

Introduction

To get an expert view on Microbial Fuel Cells concerning technology assessment, biosafety and the embedment in the current discussions about synthetic biology, we asked [http://www.itas.kit.edu/english/tab_staff_sauter_arnold.php Dr. Arnold Sauter] for his opinion. He is from the [http://www.tab-beim-bundestag.de/en/index.html Office of Technology Assessment at the German Bundestag (TAB)] and the deputy head of the TAB which investigates research on synthetic biology. He has got a long-standing experience in technology assessment for methods and applications of genetic engineering.
The TAB is an independent scientific institution created with the objective of advising the German Bundestag and its committees on matters relating to research and technology. Since 1990 the TAB has been operated by the Institute for Technology Assessment and Systems Analysis (ITAS) of the Karlsruhe Institute for Technology (KIT), based on a contract with the German Bundestag. TAB´s steering body is the Committee on Education, Research and Technology Assessment. TAB is a member of the European Parliamentary Technology Assessment (EPTA) Network as well a part of the German language network NTA (Netzwerk TA) (NTA).

Opinion of Dr. Arnold Sauter of our project

Impacts on our project

Dr. Arnold Sauter helped us to estimate our project referring the Biosafety aspect. He confirmed our batch system as a system which has sufficient safeguard against environmental and health risks. For eventual future application, for example in waste water treatment plants, we had to engineer a continuous MFC with advanced plant manufacturing. In addition he feels confident that our human practice motivates people for an active participation in life science. This could be possibly increases interest for biological work and DIY biology, particularly in the non-scientific community.

Dipl. Environmental Scientist Aeneas Wanner

Introduction

The feedback we received following our successful appearance at the European Jamboree made it clear to us that we had to gain more expert opinions regarding the future applicability of our MFC. Searching for companies with a deep knowledge in the field of usage and distribution of renewable energies, we found out about [http://energiezukunftschweiz.ch Energie Zukunft Schweiz] (Energy future Switzerland). The Swiss company is partner of several organizations and energy providers that want to facilitate the production of renewable energies and try to raise their energy efficiency. The EZS also acts as an agent between these institutions and communities that are interested in the usage of renewable energies. All of this is performed under consideration of economic aspects.

Aeneas Wanner is the general manager of Energie Zukunft Schweiz since 2006. Beforehand he was the driving force behind the climate protection organization [http://myclimate.org myclimate]. Besides his appointment at EZS, he also works as an academic at the ETH Zurich and the technical college St. Gallen and is a member of the parliament of Basel for the [http://www.bs.grunliberale.ch/personen_detail.php?id=155 green-liberal party].

Expert classification of our questions

Impacts on our project

For us, it is an encouraging sign that an expert like Mr. Wanner, who has insite in practically every field considering renewable energies, has a positive opinion of our ideas. What becomes obvious, is that we really have to try to develop a system that is free of any inconveniences. The biodegradable MFC is a step towards this goal but consecutive improvements have to be made. What helps our intentions, is the entry of seminal devices like 3D-printers in the everyday life of millions of people. This gives us the opportunity to produce an MFC at very low costs, compared to heavy-metal batteries and especially lithium-ion batteries, which are furthermore dependable on declining resources.
Although the market for MFCs is still minor, this does not mean it cannot grow in the next decades. One might consider the use of MFCs as a bioremediation and energy producing tool in wastewater treatment. A development from this purely industrial usage towards our preferred area of application, as a strong counterpart to normal batteries used in households, could be achieved.
The advantages are clear: No toxic wastes and most important no significant loss of energy due to storage conditions. Lithium-ion batteries and pumped-storage power stations can nowadays only achieve an efficiency of 80%. Great efforts are made to raise these values, but a 100% efficiency can never be reached. For MFC´s alike, we definitely have to take this into account. Until MFC´s reach a higher efficiency than batteries there is still a lot of research to do. Nevertheless, it is clear to us, that the possibilities offered by microbial fuel cells are enormous and should be explored thoroughly.

Contents 1 Dr. Falk Harnisch 1.1 Introduction 1.2 Skype-Interview 1.3 CeBiTec-Kolloquium 1.4 Impacts on our project 2 Dr. Arnold Sauter 2.1 Introduction 2.2 Opinion of Dr. Arnold Sauter of our project 2.3 Impacts on our project 3 Dipl. Environmental Scientist Aeneas Wanner 3.1 Introduction 3.2 Expert classification of our questions 3.3 Impacts on our project