U.S. Department of Energy Office of Biological and Environmental Research

Searchable Research Highlights

How Bacteria Produce Manganese Oxide Nanoparticles
Published: September 29, 2017
Posted: November 21, 2017

Structural characterization of bacterial enzyme complex sheds light on manganese biomineralization and other elemental cycles.

The Science
Bacteria that produce manganese (Mn) oxides are extraordinarily skilled engineers of nanomaterials they contribute significantly to global biogeochemical cycles. However, mineralization mediated by these organisms is poorly understood because enzymes involved in these processes are largely uncharacterized. A recent study revealed for the first time the structure of Mnx—a bacterial enzyme complex responsible for Mn biomineralization—and the Mn oxide nanoparticles it produces.

The Impact
An improved understanding of biomineralization enzymes may allow scientists to engineer proteins for applications such as environmental remediation and bioenergy production. The novel analytical tools used in this study could also be applied to solve the structure of other enzymes that play a critical role in global biogeochemical cycles, especially enzymes intractable by more conventional nuclear magnetic resonance, crystallography, or electron microscopy approaches.

Mn is a very important transition metal for all life. Mn cycling between its reduced primarily soluble form (Mn(II)) and its oxidized insoluble forms (Mn(III,IV) oxides) is coupled in myriad ways to many elemental cycles. Research has established Mn(II) is oxidized to Mn(III,IV) minerals primarily through activities of bacteria and fungi. Yet, the biomineralization enzymes produced by these organisms are very challenging to study because it is difficult to isolate and purify them. To address this challenge, researchers from the Oregon Health & Science University, the Ohio State University, and EMSL, the Environmental Molecular Sciences Laboratory, used state-of-the-art mass spectrometry, ion mobility, and electron microscopy to solve the previously uncharacterized structure of Mnx and the Mn oxide nanoparticles it produces. The researchers used high resolution mass spectrometry and atomic resolution aberration-corrected scanning transmission electron microscopy at EMSL, a DOE Office of Science user facility. These data provide critical structural information for understanding Mn biomineralization, which is potentially well suited for environmental remediation applications. Moreover, the new insights into the structure of Mnx may inform ongoing research into the mechanisms of photosynthesis and catalytic oxygen production.


Paul Bayer, SC-23.1, 301-903-5324

(PI Contacts)
Bradley Tebo
Oregon Health & Science University

Vicki Wysocki
Ohio State University

Ljiljana Paša-Tolić

This work was supported by the U.S. Department of Energy’s Office of Science (Office of Biological and Environmental Research), including support of the Environmental Molecular Sciences Laboratory (EMSL), a DOE Office of Science User Facility. Part of the project was also funded by the National Science Foundation (NSF), the National Institutes of Health, and an NSF Postdoctoral Research Fellowship in Biology Award.

Romano, C.A., M. Zhou, Y. Song, V.H. Wysocki, A.C. Dohnalkova, L. Kovarik, L. Paša-Tolić, and B, M. Tebo. 2017. “Biogenic Manganese Oxide Nanoparticle Formation by a Multimeric Multicopper Oxidase Mnx.” Nature Communications DOI: 10.1038/s41467-017-00896-8.

Related Links
How Bacteria Produce Manganese Oxide Nanoparticles on EMSL’s website

Topic Areas:

  • Research Area: DOE Environmental Molecular Sciences Laboratory (EMSL)
  • Research Area: Microbes and Communities
  • Cross-Cutting: Scientific Literature

Division: SC-23.1 Climate and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Nov 01, 2017
Electrical and Seismic Response of Saline Permafrost Soil During Freeze-Thaw Transition
The Science This study demonstrated the mechanical and electrical resp [more...]

Nov 01, 2017
Rapid Characterization of Northern Cold-Region Soil Organic Matter
Infrared spectroscopy discriminated variations in soil properties and extent of organic matter d [more...]

Oct 13, 2017
Measuring Photosynthesis via the Glow of Plants
Novel observations suggest a great potential of measuring global gross primary production via so [more...]

Oct 05, 2017
Networking Science to Improve Soil Organic Matter Management Opportunities
A perspective from the International Soil Carbon Network. The Science [more...]

Sep 29, 2017
How Bacteria Produce Manganese Oxide Nanoparticles
Structural characterization of bacterial enzyme complex sheds light on manganese biomineralizati [more...]