The Senate of the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) set up the Priority Programme “Bioelectrochemical and Engineering Fundamentals to Establish Electro-Biotechnology for Biosynthesis – Power to Value-Added Products (eBiotech)” (SPP 2240). The programme is designed to run for six years. The present call invites proposals for the second three-year funding period.

Electro-biotechnology for biosynthesis is an emerging field at the interface of electrochemistry and biotechnology. Instead of using carbohydrates as an energy source for biosynthesis as in classic biotechnology, electro-biotechnology aims to primarily use regenerative electricity to drive biosynthesis and has the potential to overcome inherent limitations of present bioproduction systems in terms of atom efficiency and product yield. It is especially useful in using low energy-containing wastes or effluents like CO2, providing an ideal solution for power-to-product approaches and the circular economy. It therefore has an immense potential to transform biotechnology for better addressing global challenges, i. e. an increasing world population (food shortage), rise in CO2 emission and depletion of fossil raw materials. Internationally, electro-biotechnology for biosynthesis is in its infancy, and fundamental research in both natural sciences and engineering as well as an interdisciplinary approach are desperately needed to realise its promise.

This Priority Programme focuses on the fundamentals of electro-biotechnology. Specifically, scientific questions from basic electron transfer mechanisms in bio-electrochemical systems (BES) to fundamental reactor and microorganism design should be studied quantitatively and systematically. For these purposes, new and more reliable methods and tools are to be developed for quantitative analysis, basic process characterisation and benchmarking, modeling, and system-level understanding of BES. Based on mechanistic and system-level understanding, design principles should be worked out to develop suitable electrodes and bioreactors and to establish new extracellular electron transfer pathways and electroactive biocatalysts (enzymes and microorganisms) for efficient biosynthesis.

Strategically, the Priority Programme envisages a work programme with the following main topics:

1. Investigation of electro-active microorganisms from fundamental electron-transfer to systems-level (metabolic) engineering
2. Enzyme cascades and electro-enzymatic biosynthesis processes
3. Electrode and reactor engineering for efficient bio-electrochemical processes
4. New methods and tools for quantitative analysis and modeling of BES in combination with 1., 2. or 3

In SPP 2240, already known electro-active microorganisms suitable for biosynthesis should be characterised regarding their physiology, mechanisms of electron transfer, interactions with electrode and bioreactor as well as wiring of the metabolism to extracellular electron transfer (EET). To go beyond the fundamental description of microbial electron transfer pathways and to move towards electro-biotechnological applications, state-of-the-art methods of engineering biological systems on the protein, metabolome, fluxome and regulatome level should be engaged. The key question here is how microorganisms and their reactor environment can be engineered for enhanced bio-electrochemical synthesis of highly value-added products?

Electro-enzymatic biosynthesis comprises different systems that interface enzymes with electrodes. So far, studies mostly cover one enzyme for a redox bio-transformation in combination with a redox mediator. While the combination of enzymes and electrochemistry to build biosensors is an established technique, several fundamental challenges especially for a productive synthesis are still unmet. These comprise instabilities and incompatibilities as well as the complexity of the enzyme systems. SPP 2240 aims to address these questions, but also to establish new enzyme cascades and reaction sequences involving electrochemistry. Model systems in particular should be investigated to broaden the scope and applicability of electro-enzymatic cascades: e. g. for CO2-fixation and electro-enzymatic cascades involving important cofactors.

In order to design and optimise electrodes and corresponding scalable bioreactor systems, SPP 2240 focuses especially on the following aspects:

1. Investigation of electrode-biocatalysts interactions on a quantitative and mechanistic level
2. Improvement of the electron transfer rate by tailor-made electrodes
3. Development and detailed characterisation of novel reactor concepts
4. Design and characterisation of integrated reactors to combine electrochemical and biotechnological steps, ideally in one reactor

The key scientific question is how electrodes with high current density and bioreactors with high energetic efficiency, that are suitable for both fundamental study and potential scale-up, can be developed and quantitatively studied based on modeling and simulation of the electro-biotechnological processes.

Previous studies of electron transfer and its relations with electrodes and/or biocatalysts have been primarily qualitative and focused mainly on characterisation of extracellular events. Projects in the SPP 2240 should move beyond this state of the art to conduct a more quantitative and systematic study on the electron transfer and its interaction with intracellular processes for biosynthesis, both in suspension culture with a single specie – especially engineered strains from Topic 1) – and in more complex systems like biofilms. For these purposes, new quantitative and non-invasive methods and tools are to be developed or adapted. It is emphasised that this topic is cross-sectional and should be studied with a concrete scientific question derived from the other topics. An interdisciplinary collaboration in tandem projects is particularly encouraged.

The Priority Programme focuses on collaborations between groups of natural science and engineering across locations. They are expected to jointly explore the topics and central scientific questions mentioned above.

Topics not considered in the SPP 2240 include:

1. Microbial and enzymatic fuel cells
2. Wastewater treatment, bioremediation or biogeochemical applications
3. Biofilm reactors without fundamental understanding or engineering of the underlying electron transfer processes
4. Biocomputing and biosensors

The Priority Programme comprises two funding phases, each lasting three years. In the first funding period, the SPP focused on quantitative and mechanistic studies of underlying processes in BES for enzymatic and microbial biosynthesis and the corresponding development of the necessary methods, tools, suitable electrodes and reactors. Work has been started to establish synthetic electroactive bioreactions and electron transfer pathways and to explore principles for engineering electroactive biocatalysts. In the second funding period, work will deepen the research topics of the first phase, validate the outcome and integrate it with a systems-level understanding and/or mathematical modelling of the whole biosynthetic processes. This might also open routes for an integrated model-based design and optimisation of both the biological system (e. g. by systems metabolic engineering) and the reactor.

Proposals must be written in English and submitted to the DFG by 18 July 2023. Please note that proposals can only be submitted via elan, the DFG’s electronic proposal processing system.

Applicants must be registered in elan prior to submitting a proposal to the DFG. If you have not yet registered, please note that you must do so by 4 July 2023 to submit a proposal under this call; registration requests received after this time cannot be considered. You will normally receive confirmation of your registration by the next working day. Please note that you will be asked to select the appropriate Priority Programme call during both the registration and the proposal process.

If you wish to submit a proposal for a new project within the existing Priority Programme, please go to Proposal Submission – New Project – Priority Programmes and select “SPP 2240” from the current list of calls. Previous applicants can submit a proposal for the renewal of an existing project under Proposal Submission – Proposal Overview/Renewal Proposal.

When preparing your proposal, please review the programme guidelines (DFG form 50.05, section B) and follow the proposal preparation instructions (DFG form 54.01). These forms can either be downloaded from our website or accessed through the elan portal.

The review colloquium for the Priority Programme will be held on 26/27 October 2023 in Bonn.

Further Information

More information on the Priority Programme is available under:

• www.e-biotech.de/en

The elan system can be accessed at:
https://elan.dfg.de/en

DFG forms 50.05 and 54.01 can be downloaded at:

• www.dfg.de/formulare/50_05
• www.dfg.de/formulare/54_01

For scientific enquiries please contact the Priority Programme coordinator:

• Professor Dr. Miriam Agler-Rosenbaum
  Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie e. V.
  Hans-Knöll-Institut (HKI)
  Beutenbergstraße 11 a
  07745 Jena
  phone +49 3641 5321120
  miriam.rosenbaum@leibniz-hki.de

Questions on the DFG proposal process can be directed to:
Programme contact:

• Dr. Vera Stadelmann
  phone +49 228 885-2834
  vera.stadelmann@dfg.de

Administrative contact:

• Silke Stieber
  phone +49 228 885-2687
  silke.stieber@dfg.de