New data suggest bacteria have a direct effect on rock weathering

Sep 21, 2012
New data suggest bacteria have a direct effect on rock weathering
Mössbauer spectroscopy helped researchers gain new knowledge about how lithotrophic bacteria behave in the environment, for example, in the subsurface and in the rhizosphere where soil, bacteria, and plant roots interact.

New research shows that in a bid to derive energy from iron, bacteria may be directly responsible for kicking off a cascade of reactions that reduce rocks to soil and free biologically important minerals.

These findings from a team of EMSL staff and users are based on a model microbial community called the Straub culture. The Straub culture is lithotrophic, or literally an "eater of rock," meaning that it can turn non-carbon sources, such as iron, into energy. This energy is produced via a driven by a series of electron exchanges, which in the case of the Straub culture is initiated by taking an electron from, or oxidizing, iron.

To gain insight into how lithotrophs behave in the environment, the research team incubated the Straub culture with media containing fine particles of an iron-rich mica called biotite. After two weeks, Mössbauer spectroscopy at EMSL was used to compare a biotite control to biotite incubated with the Straub culture. Mössbauer spectroscopy is used to quantify how much iron exists in what in a sample.

In the biotite, Mössbauer confirmed that the microbes did oxidize iron from Fe(II) to Fe(III). Moreover, revealed that this oxidation affected the biotite structure, leading to changes that resemble those observed in nature. This work offers new insight into the roles of microbes in soil production and in the biogeochemical cycling of minerals and suggests that microbes have a direct effect on rock weathering—that bacteria oxidize iron, leading to mineral transformations then rock decomposition.

Explore further: New lab technique reveals structure and function of proteins critical in DNA repair

More information: Shelobolina ES, H Xu, H Konishi, RK Kukkadapu, T Wu, M Blothe, and EE Roden. 2012. "Microbial Lithotrophic Oxidation of Structural Fe(II) in Biotite." Applied and Environmental Microbiology 78(16):5746–5752. DOI 10.1128/AEM.01034-12.

Related Stories

Long-distance communication, microbial style

Oct 06, 2010

Scientists knew that the microbe Shewanella oneidensis transformed the electronic structure of the iron oxide it touched in the ground as well as without direct contact. Scientists from Pacific Northwest National ...

The earliest blacksmiths may have been bacteria

Oct 16, 2008

(PhysOrg.com) -- Talk about a Cold Case. This mystery goes back to when there was no oxygen on the planet and bacteria were the most sophisticated life form. But Kurt Konhauser holds a clue to answering some ...

Recommended for you

The mechanics of life

Apr 16, 2015

An interdisciplinary research team formed by Otger Campàs, assistant professor in the Department of Mechanical Engineering at the University of California, Santa Barbara (UCSB), and colleague Jérome Gros, ...

New transitional stem cells discovered

Apr 16, 2015

Pre-eclampsia is a disease that affects 5 to 8 percent of pregnancies in America. Complications from this disease can lead to emergency cesarean sections early in pregnancies to save the lives of the infants and mothers. ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.