Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate

Handle URI:
http://hdl.handle.net/10754/621478
Title:
Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate
Authors:
Rao, Hari Ananda ( 0000-0002-8916-1809 ) ; Katuri, Krishna; Gorron, Eduardo; Logan, Bruce E.; Saikaly, Pascal ( 0000-0001-7678-3986 )
Abstract:
Microbial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths of electron flow involved in propionate oxidation in the anode of two-chambered MECs were examined at low (4.5 mM) and high (36 mM) propionate concentrations. Electron mass balances and microbial community analysis revealed that multiple paths of electron flow (via acetate/H2 or acetate/formate) to current could occur simultaneously during propionate oxidation regardless of the concentration tested. Current (57–96 %) was the largest electron sink and methane (0–2.3 %) production was relatively unimportant at both concentrations based on electron balances. At a low propionate concentration, reactors supplemented with 2-bromoethanesulfonate had slightly higher coulombic efficiencies than reactors lacking this methanogenesis inhibitor. However, an opposite trend was observed at high propionate concentration, where reactors supplemented with 2-bromoethanesulfonate had a lower coulombic efficiency and there was a greater percentage of electron loss (23.5 %) to undefined sinks compared to reactors without 2-bromoethanesulfonate (11.2 %). Propionate removal efficiencies were 98 % (low propionate concentration) and 78 % (high propionate concentration). Analysis of 16S rRNA gene pyrosequencing revealed the dominance of sequences most similar to Geobacter sulfurreducens PCA and G. sulfurreducens subsp. ethanolicus. Collectively, these results provide new insights on the paths of electron flow during propionate oxidation in the anode of MECs fed with low and high propionate concentrations.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; Water Desalination and Reuse Research Center (WDRC)
Citation:
Hari AR, Katuri KP, Gorron E, Logan BE, Saikaly PE (2016) Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate. Applied Microbiology and Biotechnology 100: 5999–6011. Available: http://dx.doi.org/10.1007/s00253-016-7402-2.
Publisher:
Springer Nature
Journal:
Applied Microbiology and Biotechnology
Issue Date:
3-Mar-2016
DOI:
10.1007/s00253-016-7402-2
Type:
Article
ISSN:
0175-7598; 1432-0614
Sponsors:
This work was sponsored by a Ph.D. fellowship, a Global Research Partnership-Collaborative Fellows Award (GRP-CF-2011-15-S), and Center Competitive Funding (FCC/1/1971-05-01) to P.E.S. from King Abdullah University of Science and Technology (KAUST). Special thanks are extended to Bioscience Core Laboratory at KAUST for 454 pyrosequencing.
Appears in Collections:
Articles; Water Desalination and Reuse Research Center (WDRC); Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorRao, Hari Anandaen
dc.contributor.authorKaturi, Krishnaen
dc.contributor.authorGorron, Eduardoen
dc.contributor.authorLogan, Bruce E.en
dc.contributor.authorSaikaly, Pascalen
dc.date.accessioned2016-11-03T08:30:20Z-
dc.date.available2016-11-03T08:30:20Z-
dc.date.issued2016-03-03en
dc.identifier.citationHari AR, Katuri KP, Gorron E, Logan BE, Saikaly PE (2016) Multiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionate. Applied Microbiology and Biotechnology 100: 5999–6011. Available: http://dx.doi.org/10.1007/s00253-016-7402-2.en
dc.identifier.issn0175-7598en
dc.identifier.issn1432-0614en
dc.identifier.doi10.1007/s00253-016-7402-2en
dc.identifier.urihttp://hdl.handle.net/10754/621478-
dc.description.abstractMicrobial electrolysis cells (MECs) provide a viable approach for bioenergy generation from fermentable substrates such as propionate. However, the paths of electron flow during propionate oxidation in the anode of MECs are unknown. Here, the paths of electron flow involved in propionate oxidation in the anode of two-chambered MECs were examined at low (4.5 mM) and high (36 mM) propionate concentrations. Electron mass balances and microbial community analysis revealed that multiple paths of electron flow (via acetate/H2 or acetate/formate) to current could occur simultaneously during propionate oxidation regardless of the concentration tested. Current (57–96 %) was the largest electron sink and methane (0–2.3 %) production was relatively unimportant at both concentrations based on electron balances. At a low propionate concentration, reactors supplemented with 2-bromoethanesulfonate had slightly higher coulombic efficiencies than reactors lacking this methanogenesis inhibitor. However, an opposite trend was observed at high propionate concentration, where reactors supplemented with 2-bromoethanesulfonate had a lower coulombic efficiency and there was a greater percentage of electron loss (23.5 %) to undefined sinks compared to reactors without 2-bromoethanesulfonate (11.2 %). Propionate removal efficiencies were 98 % (low propionate concentration) and 78 % (high propionate concentration). Analysis of 16S rRNA gene pyrosequencing revealed the dominance of sequences most similar to Geobacter sulfurreducens PCA and G. sulfurreducens subsp. ethanolicus. Collectively, these results provide new insights on the paths of electron flow during propionate oxidation in the anode of MECs fed with low and high propionate concentrations.en
dc.description.sponsorshipThis work was sponsored by a Ph.D. fellowship, a Global Research Partnership-Collaborative Fellows Award (GRP-CF-2011-15-S), and Center Competitive Funding (FCC/1/1971-05-01) to P.E.S. from King Abdullah University of Science and Technology (KAUST). Special thanks are extended to Bioscience Core Laboratory at KAUST for 454 pyrosequencing.en
dc.publisherSpringer Natureen
dc.subjectElectron flowen
dc.subjectMethanogenesisen
dc.subjectMicrobial electrolysis cellen
dc.subjectPropionateen
dc.titleMultiple paths of electron flow to current in microbial electrolysis cells fed with low and high concentrations of propionateen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentWater Desalination and Reuse Research Center (WDRC)en
dc.identifier.journalApplied Microbiology and Biotechnologyen
dc.contributor.institutionDepartment of Civil and Environmental Engineering, The Pennsylvania State University, University Park, PA, United Statesen
kaust.authorRao, Hari Anandaen
kaust.authorKaturi, Krishnaen
kaust.authorGorron, Eduardoen
kaust.authorSaikaly, Pascalen
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