Skip to main content
bioRxiv
  • Home
  • About
  • Submit
  • ALERTS / RSS
Advanced Search
New Results

Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species

Yamini Jangir, Sarah French, Lily M. Momper, Duane P. Moser, Jan P. Amend, Mohamed Y. El-Naggar
doi: https://doi.org/10.1101/046979
Yamini Jangir
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Sarah French
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Lily M. Momper
2Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Duane P. Moser
3Division of Earth and Ecosystem Sciences, Desert Research Institute, Las Vegas, NV,USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Jan P. Amend
2Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
4Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Mohamed Y. El-Naggar
1Department of Physics and Astronomy, University of Southern California, Los Angeles, CA, USA
2Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
5Department of Earth Sciences, University of Southern California, Los Angeles, CA, USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: mnaggar@usc.edu
  • Abstract
  • Full Text
  • Info/History
  • Metrics
  • Preview PDF
Loading

Abstract

Continental subsurface environments can present significant energetic challenges to the resident microorganisms. While these environments are geologically diverse, potentially allowing energy harvesting by microorganisms that catalyze redox reactions, many of the abundant electron donors and acceptors are insoluble and therefore not directly bioavailable. Extracellular electron transfer (EET) is a metabolic strategy that microorganisms can deploy to meet the challenges of interacting with redox-active surfaces. Though mechanistically characterized in a few metal-reducing bacteria, the role, extent, and diversity of EET in subsurface ecosystems remains unclear. Since this process can be mimicked on electrode surfaces, it opens the door to electrochemical techniques to enrich for and quantify the activities of environmental microorganisms in situ. Here, we report the electrochemical enrichment of microorganisms from a deep fractured-rock aquifer in Death Valley, California, USA. In experiments performed in mesocosms containing a synthetic medium based on aquifer chemistry, four working electrodes were poised at different redox potentials (272, 373, 472, 572 mV vs. SHE) to serve as electron acceptors, resulting in anodic currents coupled to the oxidation of acetate during enrichment. The anodes were dominated by Betaproteobacteria from the families Comamonadaceae and Rhodocyclaceae. A representative of each dominant family was subsequently isolated from electrode-associated biomass. The EET abilities of the isolated Delftia strain (designated WE1–13) and Azonexus strain (designated WE2–4) were confirmed in electrochemical reactors using working electrodes poised at 522 mV vs. SHE. The rise in anodic current upon inoculation was correlated with a modest increase in total protein content. Both genera have been previously observed in mixed communities of microbial fuel cell enrichments, but this is the first direct measurement of their electrochemical activity. While alternate metabolisms (e.g. nitrate reduction) by these organisms were previously known, our observations suggest that additional ‘hidden’ interactions with external electron acceptors are also possible. Electrochemical approaches are well positioned to dissect such extracellular interactions that may be prevalent in the subsurface.

Copyright 
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.
Back to top
PreviousNext
Posted May 21, 2016.
Download PDF
Email

Thank you for your interest in spreading the word about bioRxiv.

NOTE: Your email address is requested solely to identify you as the sender of this article.

Enter multiple addresses on separate lines or separate them with commas.
Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species
(Your Name) has forwarded a page to you from bioRxiv
(Your Name) thought you would like to see this page from the bioRxiv website.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Share
Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species
Yamini Jangir, Sarah French, Lily M. Momper, Duane P. Moser, Jan P. Amend, Mohamed Y. El-Naggar
bioRxiv 046979; doi: https://doi.org/10.1101/046979
Reddit logo Twitter logo Facebook logo LinkedIn logo Mendeley logo
Citation Tools
Isolation and characterization of electrochemically active subsurface Delftia and Azonexus species
Yamini Jangir, Sarah French, Lily M. Momper, Duane P. Moser, Jan P. Amend, Mohamed Y. El-Naggar
bioRxiv 046979; doi: https://doi.org/10.1101/046979

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Subject Area

  • Microbiology
Subject Areas
All Articles
  • Animal Behavior and Cognition (4384)
  • Biochemistry (9602)
  • Bioengineering (7100)
  • Bioinformatics (24885)
  • Biophysics (12625)
  • Cancer Biology (9968)
  • Cell Biology (14364)
  • Clinical Trials (138)
  • Developmental Biology (7966)
  • Ecology (12115)
  • Epidemiology (2067)
  • Evolutionary Biology (15997)
  • Genetics (10932)
  • Genomics (14746)
  • Immunology (9875)
  • Microbiology (23683)
  • Molecular Biology (9486)
  • Neuroscience (50907)
  • Paleontology (370)
  • Pathology (1540)
  • Pharmacology and Toxicology (2684)
  • Physiology (4022)
  • Plant Biology (8669)
  • Scientific Communication and Education (1510)
  • Synthetic Biology (2397)
  • Systems Biology (6442)
  • Zoology (1346)