Electroactivity across the cell wall of Gram-positive bacteria

Paquete, Catarina M.

doi:10.1016/j.csbj.2020.11.021

Cited by 33 publications

(20 citation statements)

References 94 publications

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“…Most parts of such microorganisms are listed among weakly or not electroactive bacteria. As they mostly use direct electron transfer and/or have defective electron transport chains, they are less effective in producing electric power in MFCs if compared to Gram-negative, nonfermentative bacteria [46]. As an example, Lactobacillaceae are widely colonizing vegetable In [43], the authors report how supernatants of a Pseudomonas chlororaphis PCL1121 producing phenazine-1-carboxamide enhanced the electricity generation in an MFC inoculated with a mixed culture.…”

Section: Acidogenic and Acetogenic Microflora In Organic Wastementioning

confidence: 99%

“…Most parts of such microorganisms are listed among weakly or not electroactive bacteria. As they mostly use direct electron transfer and/or have defective electron transport chains, they are less effective in producing electric power in MFCs if compared to Gram-negative, nonfermentative bacteria [46]. As an example, Lactobacillaceae are widely colonizing vegetable residues and are characterized by an incomplete electron transport chain, involved in nitrate reduction and in the respiration-like behavior under aerobic conditions [47].…”

Section: Acidogenic and Acetogenic Microflora In Organic Wastementioning

confidence: 99%

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Use of Biochar-Based Cathodes and Increase in the Electron Flow by Pseudomonas aeruginosa to Improve Waste Treatment in Microbial Fuel Cells

Nastro¹,

Flagiello

Gambino

et al. 2021

Processes

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In this paper, we tested the combined use of a biochar-based material at the cathode and of Pseudomonas aeruginosa strain in a single chamber, air cathode microbial fuel cells (MFCs) fed with a mix of shredded vegetable and phosphate buffer solution (PBS) in a 30% solid/liquid ratio. As a control system, we set up and tested MFCs provided with a composite cathode made up of a nickel mesh current collector, activated carbon and a single porous poly tetra fluoro ethylene (PTFE) diffusion layer. At the end of the experiments, we compared the performance of the two systems, in the presence and absence of P. aeruginosa, in terms of electric outputs. We also explored the potential reutilization of cathodes. Unlike composite material, biochar showed a life span of up to 3 cycles of 15 days each, with a pH of the feedstock kept in a range of neutrality. In order to relate the electric performance to the amount of solid substrates used as source of carbon and energy, besides of cathode surface, we referred power density (PD) and current density (CD) to kg of biomass used. The maximum outputs obtained when using the sole microflora were, on average, respectively 0.19 Wm−2kg−1 and 2.67 Wm−2kg−1, with peaks of 0.32 Wm−2kg−1 and 4.87 Wm−2kg−1 of cathode surface and mass of treated biomass in MFCs with biochar and PTFE cathodes respectively. As to current outputs, the maximum values were 7.5 Am−2 kg−1 and 35.6 Am−2kg−1 in MFCs with biochar-based material and a composite cathode. If compared to the utilization of the sole acidogenic/acetogenic microflora in vegetable residues, we observed an increment of the power outputs of about 16.5 folds in both systems when we added P. aeruginosa to the shredded vegetables. Even though the MFCs with PTFE-cathode achieved the highest performance in terms of PD and CD, they underwent a fouling episode after about 10 days of operation, with a dramatic decrease in pH and both PD and CD. Our results confirm the potentialities of the utilization of biochar-based materials in waste treatment and bioenergy production.

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Section: Acidogenic and Acetogenic Microflora In Organic Wastementioning

confidence: 99%

“…Most parts of such microorganisms are listed among weakly or not electroactive bacteria. As they mostly use direct electron transfer and/or have defective electron transport chains, they are less effective in producing electric power in MFCs if compared to Gram-negative, nonfermentative bacteria [46]. As an example, Lactobacillaceae are widely colonizing vegetable residues and are characterized by an incomplete electron transport chain, involved in nitrate reduction and in the respiration-like behavior under aerobic conditions [47].…”

Section: Acidogenic and Acetogenic Microflora In Organic Wastementioning

confidence: 99%

Use of Biochar-Based Cathodes and Increase in the Electron Flow by Pseudomonas aeruginosa to Improve Waste Treatment in Microbial Fuel Cells

Nastro¹,

Flagiello

Gambino

et al. 2021

Processes

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“…Microorganisms capable of producing electricity were reported more than one century ago [ 3 ]. The ability of these microorganisms to exchange electrons with electrodes earned the designation of electroactive but only recently their EET mechanisms have been explored in detail [ 1 , 4 , 5 , 6 , 7 ]. There is a great interest in understanding the EET mechanisms of electroactive organisms due to their capacity to produce electricity and added-value products from renewable and carbon-neutral sources (e.g., municipal wastewater), under ambient temperature and pressure and with low greenhouse gas emissions contributing to tackle numerous societal challenges including clean energy and global warming [ 8 , 9 , 10 , 11 , 12 ].…”

Section: Introductionmentioning

confidence: 99%

Crossing the Wall: Characterization of the Multiheme Cytochromes Involved in the Extracellular Electron Transfer Pathway of Thermincola ferriacetica

et al. 2021

Self Cite

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Bioelectrochemical systems (BES) are emerging as a suite of versatile sustainable technologies to produce electricity and added-value compounds from renewable and carbon-neutral sources using electroactive organisms. The incomplete knowledge on the molecular processes that allow electroactive organisms to exchange electrons with electrodes has prevented their real-world implementation. In this manuscript we investigate the extracellular electron transfer processes performed by the thermophilic Gram-positive bacteria belonging to the Thermincola genus, which were found to produce higher levels of current and tolerate higher temperatures in BES than mesophilic Gram-negative bacteria. In our study, three multiheme c-type cytochromes, Tfer_0070, Tfer_0075, and Tfer_1887, proposed to be involved in the extracellular electron transfer pathway of T. ferriacetica, were cloned and over-expressed in E. coli. Tfer_0070 (ImdcA) and Tfer_1887 (PdcA) were purified and biochemically characterized. The electrochemical characterization of these proteins supports a pathway of extracellular electron transfer via these two proteins. By contrast, Tfer_0075 (CwcA) could not be stabilized in solution, in agreement with its proposed insertion in the peptidoglycan wall. However, based on the homology with the outer-membrane cytochrome OmcS, a structural model for CwcA was developed, providing a molecular perspective into the mechanisms of electron transfer across the peptidoglycan layer in Thermincola.

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“…Especially in Grampositive species, these proteins are hard to anchor and align through a thick peptidoglycan. [10] A few c-Cyts were proposed to localize on the surface of some Gram-positive bacteria, [11] while redox shuttles such as flavins can be more essential for electron transfer across the cell wall. [11][12] On the other hand, the behavior of expressing high levels of c-Cyts is not common in microbial cells.…”

Section: Introductionmentioning

confidence: 99%

“…[10] A few c-Cyts were proposed to localize on the surface of some Gram-positive bacteria, [11] while redox shuttles such as flavins can be more essential for electron transfer across the cell wall. [11][12] On the other hand, the behavior of expressing high levels of c-Cyts is not common in microbial cells. These factors limit the accessibility of natural models to inspire bioelectrochemical applications.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Activity Produced from Abundant Expression of C‐Type Cytochromes in a Filamentous Gram‐Positive Bacterium

Zheng

Yang

et al. 2021

ChemElectroChem

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Natural microbes employing c-type cytochromes (c-Cyts) for extracellular electron transport (EET) were greatly valuable to develop redox-based bioelectrochemical applications. However, low levels of c-Cyt expression limited the phylogenetically diverse Gram-positive species to be used in bioelectrochemical devices. This work reported the remarkable finding that a high level of c-Cyts was expressed in the cells of the Gram-positive strain Lysinibacillus varians GY32. c-Cyts in Lysinibacillus varians GY32 cells were expressed at a level close to those in Shewanella oneidensis. These c-Cyts were found to cluster in cytoplasmic membrane and periplasmic space, along the length of Lysinibacillus varians GY32 cell. With voltammetry and spectroelectrochemical titration, phenazine methosulfate-mediated electron transfer between the c-Cyts and an electrode was proved. These results expanded the accessible natural models of EET and suggested a new microbial platform for developing bioelectrochemical applications.

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Electroactivity across the cell wall of Gram-positive bacteria

Abstract: Graphical abstract

Cited by 33 publications

References 94 publications

Use of Biochar-Based Cathodes and Increase in the Electron Flow by Pseudomonas aeruginosa to Improve Waste Treatment in Microbial Fuel Cells

Use of Biochar-Based Cathodes and Increase in the Electron Flow by Pseudomonas aeruginosa to Improve Waste Treatment in Microbial Fuel Cells

Crossing the Wall: Characterization of the Multiheme Cytochromes Involved in the Extracellular Electron Transfer Pathway of Thermincola ferriacetica

Electrochemical Activity Produced from Abundant Expression of C‐Type Cytochromes in a Filamentous Gram‐Positive Bacterium

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