Skip to main content
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Accessibility Statement
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian
  • Log in
  • My Cart

Main menu

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses
  • Submit
  • About
    • Editorial Board
    • PNAS Staff
    • FAQ
    • Accessibility Statement
    • Rights and Permissions
    • Site Map
  • Contact
  • Journal Club
  • Subscribe
    • Subscription Rates
    • Subscriptions FAQ
    • Open Access
    • Recommend PNAS to Your Librarian

User menu

  • Log in
  • My Cart

Search

  • Advanced search
Home
Home

Advanced Search

  • Home
  • Articles
    • Current
    • Special Feature Articles - Most Recent
    • Special Features
    • Colloquia
    • Collected Articles
    • PNAS Classics
    • List of Issues
  • Front Matter
  • News
    • For the Press
    • This Week In PNAS
    • PNAS in the News
  • Podcasts
  • Authors
    • Information for Authors
    • Editorial and Journal Policies
    • Submission Procedures
    • Fees and Licenses

New Research In

Physical Sciences

Featured Portals

  • Physics
  • Chemistry
  • Sustainability Science

Articles by Topic

  • Applied Mathematics
  • Applied Physical Sciences
  • Astronomy
  • Computer Sciences
  • Earth, Atmospheric, and Planetary Sciences
  • Engineering
  • Environmental Sciences
  • Mathematics
  • Statistics

Social Sciences

Featured Portals

  • Anthropology
  • Sustainability Science

Articles by Topic

  • Economic Sciences
  • Environmental Sciences
  • Political Sciences
  • Psychological and Cognitive Sciences
  • Social Sciences

Biological Sciences

Featured Portals

  • Sustainability Science

Articles by Topic

  • Agricultural Sciences
  • Anthropology
  • Applied Biological Sciences
  • Biochemistry
  • Biophysics and Computational Biology
  • Cell Biology
  • Developmental Biology
  • Ecology
  • Environmental Sciences
  • Evolution
  • Genetics
  • Immunology and Inflammation
  • Medical Sciences
  • Microbiology
  • Neuroscience
  • Pharmacology
  • Physiology
  • Plant Biology
  • Population Biology
  • Psychological and Cognitive Sciences
  • Sustainability Science
  • Systems Biology
Research Article

N2 gas is an effective fertilizer for bioethanol production by Zymomonas mobilis

Timothy A. Kremer, Breah LaSarre, Amanda L. Posto, and James B. McKinlay
PNAS first published February 2, 2015; https://doi.org/10.1073/pnas.1420663112
Timothy A. Kremer
Department of Biology, Indiana University, Bloomington, IN 47405
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Breah LaSarre
Department of Biology, Indiana University, Bloomington, IN 47405
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Amanda L. Posto
Department of Biology, Indiana University, Bloomington, IN 47405
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
James B. McKinlay
Department of Biology, Indiana University, Bloomington, IN 47405
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: jmckinla@indiana.edu
  1. Edited by Lonnie O. Ingram, University of Florida, Gainesville, FL, and approved December 31, 2014 (received for review October 28, 2014)

  • Article
  • Figures & SI
  • Info & Metrics
  • PDF
Loading

Significance

Recently there has been a surge in ethanol biofuel production from cellulosic feedstocks, offering more environmental benefits than conventional ethanol production from food crops. However, cellulosic feedstocks are low in nitrogen, requiring that millions of dollars be spent on nitrogen supplements to grow the ethanol-producing microbes. Zymomonas mobilis is a bacterium that has long been viewed as a potential rival to Baker’s yeast as an ethanol producer. Contrary to published remarks, we discovered that Z. mobilis can use the most abundant gas in the atmosphere, N2, as a nitrogen source and does so without detriment to the high ethanol yield. Using N2-utilizing Z. mobilis could offset much of the monetary and environmental costs of current industrial nitrogen supplements.

Abstract

A nascent cellulosic ethanol industry is struggling to become cost-competitive against corn ethanol and gasoline. Millions of dollars are spent on nitrogen supplements to make up for the low nitrogen content of the cellulosic feedstock. Here we show for the first time to our knowledge that the ethanol-producing bacterium, Zymomonas mobilis, can use N2 gas in lieu of traditional nitrogen supplements. Despite being an electron-intensive process, N2 fixation by Z. mobilis did not divert electrons away from ethanol production, as the ethanol yield was greater than 97% of the theoretical maximum. In a defined medium, Z. mobilis produced ethanol 50% faster per cell and generated half the unwanted biomass when supplied N2 instead of ammonium. In a cellulosic feedstock-derived medium, Z. mobilis achieved a similar cell density and a slightly higher ethanol yield when supplied N2 instead of the industrial nitrogen supplement, corn steep liquor. We estimate that N2-utilizing Z. mobilis could save a cellulosic ethanol production facility more than $1 million/y.

  • Zymomonas mobilis
  • nitrogenase
  • ethanol
  • cellulosic
  • biofuel

Footnotes

  • ↵1T.A.K. and B.L. contributed equally to this work.

  • ↵2To whom correspondence should be addressed. Email: jmckinla{at}indiana.edu.
  • Author contributions: T.A.K., B.L., and J.B.M. designed research; T.A.K., B.L., A.L.P., and J.B.M. performed research; T.A.K., B.L., A.L.P., and J.B.M. analyzed data; and T.A.K., B.L., and J.B.M. wrote the paper.

  • Conflict of interest statement: The authors have a patent pending related to this material.

  • This article is a PNAS Direct Submission.

  • This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1420663112/-/DCSupplemental.

Next
Back to top
Article Alerts
Email Article

Thank you for your interest in spreading the word on PNAS.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
N2 gas is an effective fertilizer for bioethanol production by Zymomonas mobilis
(Your Name) has sent you a message from PNAS
(Your Name) thought you would like to see the PNAS web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Exploiting N2 gas for bioethanol production
Timothy A. Kremer, Breah LaSarre, Amanda L. Posto, James B. McKinlay
Proceedings of the National Academy of Sciences Feb 2015, 201420663; DOI: 10.1073/pnas.1420663112

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
Request Permissions
Share
Exploiting N2 gas for bioethanol production
Timothy A. Kremer, Breah LaSarre, Amanda L. Posto, James B. McKinlay
Proceedings of the National Academy of Sciences Feb 2015, 201420663; DOI: 10.1073/pnas.1420663112
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like
  • Mendeley logo Mendeley
Proceedings of the National Academy of Sciences: 118 (2)
Current Issue

Submit

Sign up for Article Alerts

Jump to section

  • Article
  • Figures & SI
  • Info & Metrics
  • PDF

You May Also be Interested in

Abstract depiction of a guitar and musical note
Science & Culture: At the nexus of music and medicine, some see disease treatments
Although the evidence is still limited, a growing body of research suggests music may have beneficial effects for diseases such as Parkinson’s.
Image credit: Shutterstock/agsandrew.
Scientist looking at an electronic tablet
Opinion: Standardizing gene product nomenclature—a call to action
Biomedical communities and journals need to standardize nomenclature of gene products to enhance accuracy in scientific and public communication.
Image credit: Shutterstock/greenbutterfly.
One red and one yellow modeled protein structures
Journal Club: Study reveals evolutionary origins of fold-switching protein
Shapeshifting designs could have wide-ranging pharmaceutical and biomedical applications in coming years.
Image credit: Acacia Dishman/Medical College of Wisconsin.
White and blue bird
Hazards of ozone pollution to birds
Amanda Rodewald, Ivan Rudik, and Catherine Kling talk about the hazards of ozone pollution to birds.
Listen
Past PodcastsSubscribe
Goats standing in a pin
Transplantation of sperm-producing stem cells
CRISPR-Cas9 gene editing can improve the effectiveness of spermatogonial stem cell transplantation in mice and livestock, a study finds.
Image credit: Jon M. Oatley.

Similar Articles

Site Logo
Powered by HighWire
  • Submit Manuscript
  • Twitter
  • Facebook
  • RSS Feeds
  • Email Alerts

Articles

  • Current Issue
  • Latest Articles
  • Archive

PNAS Portals

  • Anthropology
  • Chemistry
  • Classics
  • Front Matter
  • Physics
  • Sustainability Science
  • Teaching Resources

Information

  • Authors
  • Editorial Board
  • Reviewers
  • Librarians
  • Press
  • Site Map
  • PNAS Updates

Feedback    Privacy/Legal

Copyright © 2021 National Academy of Sciences. Online ISSN 1091-6490