On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells
Bio-electrochemical systems such as microbial fuel cells and microbial electrosynthesis cells depend on efficient electron transfer between the microorganisms and the electrodes. Understanding the mechanisms and dynamics of the electron transfer is important in order to design more efficient reactor...
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| Format: | Article |
| Language: | English |
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MDPI AG
2019-02-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/24/3/646 |
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| author | Adolf Krige Magnus Sjöblom Kerstin Ramser Paul Christakopoulos Ulrika Rova |
| author_facet | Adolf Krige Magnus Sjöblom Kerstin Ramser Paul Christakopoulos Ulrika Rova |
| author_sort | Adolf Krige |
| collection | DOAJ |
| description | Bio-electrochemical systems such as microbial fuel cells and microbial electrosynthesis cells depend on efficient electron transfer between the microorganisms and the electrodes. Understanding the mechanisms and dynamics of the electron transfer is important in order to design more efficient reactors, as well as modifying microorganisms for enhanced electricity production. <i>Geobacter</i> are well known for their ability to form thick biofilms and transfer electrons to the surfaces of electrodes. Currently, there are not many “on-line„ systems for monitoring the activity of the biofilm and the electron transfer process without harming the biofilm. Raman microscopy was shown to be capable of providing biochemical information, i.e., the redox state of C-type cytochromes, which is integral to external electron transfer, without harming the biofilm. In the current study, a custom 3D printed flow-through cuvette was used in order to analyze the oxidation state of the C-type cytochromes of suspended cultures of three <i>Geobacter sulfurreducens</i> strains (PCA, KN400 and ΔpilA). It was found that the oxidation state is a good indicator of the metabolic state of the cells. Furthermore, an anaerobic fluidic system enabling in situ Raman measurements was designed and applied successfully to monitor and characterize <i>G. sulfurreducens</i> biofilms during electricity generation, for both a wild strain, PCA, and a mutant, ΔS. The cytochrome redox state, monitored by the Raman peak areas, could be modulated by applying different poise voltages to the electrodes. This also correlated with the modulation of current transferred from the cytochromes to the electrode. The Raman peak area changed in a predictable and reversible manner, indicating that the system could be used for analyzing the oxidation state of the proteins responsible for the electron transfer process and the kinetics thereof in-situ. |
| first_indexed | 2024-12-13T01:15:16Z |
| format | Article |
| id | doaj.art-7822c1477ebe4277b67b42b365f8e5ff |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-13T01:15:16Z |
| publishDate | 2019-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-7822c1477ebe4277b67b42b365f8e5ff2022-12-22T00:04:22ZengMDPI AGMolecules1420-30492019-02-0124364610.3390/molecules24030646molecules24030646On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel CellsAdolf Krige0Magnus Sjöblom1Kerstin Ramser2Paul Christakopoulos3Ulrika Rova4Biochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, SwedenBiochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, SwedenExperimental Mechanics, Division of Fluid and Experimental Mechanics, Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå, SwedenBiochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, SwedenBiochemical Process Engineering, Division of Chemical Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, SwedenBio-electrochemical systems such as microbial fuel cells and microbial electrosynthesis cells depend on efficient electron transfer between the microorganisms and the electrodes. Understanding the mechanisms and dynamics of the electron transfer is important in order to design more efficient reactors, as well as modifying microorganisms for enhanced electricity production. <i>Geobacter</i> are well known for their ability to form thick biofilms and transfer electrons to the surfaces of electrodes. Currently, there are not many “on-line„ systems for monitoring the activity of the biofilm and the electron transfer process without harming the biofilm. Raman microscopy was shown to be capable of providing biochemical information, i.e., the redox state of C-type cytochromes, which is integral to external electron transfer, without harming the biofilm. In the current study, a custom 3D printed flow-through cuvette was used in order to analyze the oxidation state of the C-type cytochromes of suspended cultures of three <i>Geobacter sulfurreducens</i> strains (PCA, KN400 and ΔpilA). It was found that the oxidation state is a good indicator of the metabolic state of the cells. Furthermore, an anaerobic fluidic system enabling in situ Raman measurements was designed and applied successfully to monitor and characterize <i>G. sulfurreducens</i> biofilms during electricity generation, for both a wild strain, PCA, and a mutant, ΔS. The cytochrome redox state, monitored by the Raman peak areas, could be modulated by applying different poise voltages to the electrodes. This also correlated with the modulation of current transferred from the cytochromes to the electrode. The Raman peak area changed in a predictable and reversible manner, indicating that the system could be used for analyzing the oxidation state of the proteins responsible for the electron transfer process and the kinetics thereof in-situ.https://www.mdpi.com/1420-3049/24/3/646microbial fuel cellRaman spectroscopy<i>Geobacter</i> <i>sulfurreducens</i>cytochrome-COmc |
| spellingShingle | Adolf Krige Magnus Sjöblom Kerstin Ramser Paul Christakopoulos Ulrika Rova On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells Molecules microbial fuel cell Raman spectroscopy <i>Geobacter</i> <i>sulfurreducens</i> cytochrome-C Omc |
| title | On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells |
| title_full | On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells |
| title_fullStr | On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells |
| title_full_unstemmed | On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells |
| title_short | On-Line Raman Spectroscopic Study of Cytochromes’ Redox State of Biofilms in Microbial Fuel Cells |
| title_sort | on line raman spectroscopic study of cytochromes redox state of biofilms in microbial fuel cells |
| topic | microbial fuel cell Raman spectroscopy <i>Geobacter</i> <i>sulfurreducens</i> cytochrome-C Omc |
| url | https://www.mdpi.com/1420-3049/24/3/646 |
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