TY - JOUR
T1 - Electrochemical and genomic analysis of novel electroactive isolates obtained via potentiostatic enrichment from tropical sediment
AU - Doyle, Lucinda E.
AU - Yung, Pui Yi
AU - Mitra, Sumitra D.
AU - Wuertz, Stefan
AU - Williams, Rohan B.H.
AU - Lauro, Federico M.
AU - Marsili, Enrico
N1 - Funding Information:
This research was supported by the Singapore National Research Foundation and Ministry of Education under the Research Centre of Excellence Programme. L.E.D. was supported by the Singapore International Graduate Award (SINGA) and the Interdisciplinary Graduate School of Nanyang Technological University. We thank Daniela Moses and her colleagues for library construction and sequencing.
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2017
Y1 - 2017
N2 - Enrichment of electrochemically-active microorganisms (EAM) to date has mostly relied on microbial fuel cells fed with wastewater. This study aims to enrich novel EAM by exposing tropical sediment, not frequently reported in the literature, to sustained anodic potentials. Voltamperometric techniques and electrochemical impedance spectroscopy, performed over a wide range of potentials, characterise extracellular electron transfer (EET) over time. Applied potential is found to affect biofilm electrochemical signature. Geobacter metallireducens is heavily enriched on the electrodes, as determined by metagenomic and metatranscriptomic analysis, in the first report of the species in a lactate-fed system. Two novel isolates are grown in pure culture from the enrichment, identified by 16S rRNA gene sequencing as Aeromonas and Enterobacter, respectively. The names proposed are Aeromonas sp. CL-1 and Enterobacter sp. EA-1. Both isolates are capable of EET on carbon felt and screen-printed carbon electrodes without the addition of exogenous redox mediators. Enterobacter sp. EA-1 can also perform mediated electron transfer using the soluble redox mediator 2-hydroxy-1,4-naphthoquinone (HNQ). Both isolates are able to use acetate and lactate as electron donors. This work outlines a comprehensive methodology for characterising novel EAM from unconventional inocula.
AB - Enrichment of electrochemically-active microorganisms (EAM) to date has mostly relied on microbial fuel cells fed with wastewater. This study aims to enrich novel EAM by exposing tropical sediment, not frequently reported in the literature, to sustained anodic potentials. Voltamperometric techniques and electrochemical impedance spectroscopy, performed over a wide range of potentials, characterise extracellular electron transfer (EET) over time. Applied potential is found to affect biofilm electrochemical signature. Geobacter metallireducens is heavily enriched on the electrodes, as determined by metagenomic and metatranscriptomic analysis, in the first report of the species in a lactate-fed system. Two novel isolates are grown in pure culture from the enrichment, identified by 16S rRNA gene sequencing as Aeromonas and Enterobacter, respectively. The names proposed are Aeromonas sp. CL-1 and Enterobacter sp. EA-1. Both isolates are capable of EET on carbon felt and screen-printed carbon electrodes without the addition of exogenous redox mediators. Enterobacter sp. EA-1 can also perform mediated electron transfer using the soluble redox mediator 2-hydroxy-1,4-naphthoquinone (HNQ). Both isolates are able to use acetate and lactate as electron donors. This work outlines a comprehensive methodology for characterising novel EAM from unconventional inocula.
KW - Aeromonas
KW - Electrochemically-active bacteria
KW - Enterobacter
KW - Extracellular electron transfer
KW - Geobacter
KW - Sediment
UR - http://www.scopus.com/inward/record.url?scp=85017115171&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2017.03.147
DO - 10.1016/j.jpowsour.2017.03.147
M3 - Article
AN - SCOPUS:85017115171
SN - 0378-7753
VL - 356
SP - 539
EP - 548
JO - Journal of Power Sources
JF - Journal of Power Sources
ER -