CymA and Exogenous Flavins Improve Extracellular Electron Transfer and Couple It to Cell Growth in Mtr-Expressing Escherichia coli
| Autor: | Jensen, Heather M, TerAvest, Michaela A, Kokish, Mark G, Ajo-Franklin, Caroline M |
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| Jazyk: | angličtina |
| Rok vydání: | 2016 |
| Předmět: |
energy conservation
Shewanella Iron Riboflavin Bacterial multiheme cytochrome c Cytochrome c Group Ferric Compounds Recombinant Proteins Electron Transport Bacterial Proteins Gene Expression Regulation dissimilatory metal-reducing bacteria Flavins Escherichia coli ATP-Binding Cassette Transporters synthetic biology Genetic Engineering Oxidation-Reduction bioelectrochemical systems |
| Zdroj: | Jensen, HM; TerAvest, MA; Kokish, MG; & Ajo-Franklin, CM. (2016). CymA and Exogenous Flavins Improve Extracellular Electron Transfer and Couple It to Cell Growth in Mtr-Expressing Escherichia coli. ACS Synthetic Biology, 5(7), 679-688. doi: 10.1021/acssynbio.5b00279. Lawrence Berkeley National Laboratory: Retrieved from: http://www.escholarship.org/uc/item/2qm6f21z ACS synthetic biology, vol 5, iss 7 |
| DOI: | 10.1021/acssynbio.5b00279. |
| Popis: | © 2016 American Chemical Society. Introducing extracellular electron transfer pathways into heterologous organisms offers the opportunity to explore fundamental biogeochemical processes and to biologically alter redox states of exogenous metals for various applications. While expression of the MtrCAB electron nanoconduit from Shewanella oneidensis MR-1 permits extracellular electron transfer in Escherichia coli, the low electron flux and absence of growth in these cells limits their practicality for such applications. Here we investigate how the rate of electron transfer to extracellular Fe(III) and cell survival in engineered E. coli are affected by mimicking different features of the S. oneidensis pathway: the number of electron nanoconduits, the link between the quinol pool and MtrA, and the presence of flavin-dependent electron transfer. While increasing the number of pathways does not significantly improve the extracellular electron transfer rate or cell survival, using the native inner membrane component, CymA, significantly improves the reduction rate of extracellular acceptors and increases cell viability. Strikingly, introducing both CymA and riboflavin to Mtr-expressing E. coli also allowed these cells to couple metal reduction to growth, which is the first time an increase in biomass of an engineered E. coli has been observed under Fe2O3(s) reducing conditions. Overall, this work provides engineered E. coli strains for modulating extracellular metal reduction and elucidates critical factors for engineering extracellular electron transfer in heterologous organisms. |
| Databáze: | OpenAIRE |
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