Electroactive microorganisms possess the unique capability to transfer catabolically
generated electrons via extracellular electron transfer (EET) to solid electron acceptors beyond their cell membranes. Presumably, electroactive microorganisms have a considerable impact on natural redox processes and show potential for being harnessed in microbial electrochemical technologies (METs) providing novel solutions for environmental issues. Although many aspects of electroactive microorganisms and EET have been elucidated, the respective thermodynamics and the energy fluxes during growth are almost untapped. However, understanding thermodynamics is the key for realisticall assessing the influence of electroactive microorganisms on natural ecosystems and the feasibility of METs. Thus, the intention of the present thesis was to establish methods for analyzing the thermodynamics of electroactive microorganisms. This was achieved by
developing the method bioelectrocalorimetry and a model framework for biofilm anodes. A bioelectrocalorimeter was used to measure the heat production of a Geobacter species dominated biofilm performing EET. By creating a heat flux balance, the microbial electrochemical Peltier heat was identified representing an entropic hurdle for EET reactions. The mathematical model for biofilm anodes comprises calculations of microbial growth thermodynamics and kinetics as well as physical, chemical, and electrochemical processes at different spatial and temporal scales. It demonstrates that more detailed experimental assessments of thermodynamic parameters of electroactive microorganisms are urgently required. Furthermore, the thesis at hand provides a comprehensive data set on the energy content of wastewater that can be used to evaluate the feasibility as well as the thermodynamic efficiencies of METs. In conclusion, the thesis provides tools and useful thermodynamic information for the establishment of a complete energy balance of electroactive microorganisms and the elucidation of the driving forces for EET.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:15917 |
| Date | 26 July 2017 |
| Creators | Korth, Benjamin |
| Contributors | Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0016 seconds