Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Microbes at work cleaning up the environment

Abstract:
It may sound counterintuitive to use a microbial protein to improve water quality.

Microbes at work cleaning up the environment

LIVERMORE, CA | Posted on June 14th, 2007

But some bacteria are doing just that to protect themselves from potentially toxic nanoparticles in their own environments, and clean up crews of the future could potentially do the same thing on a larger scale.

A team from Lawrence Livermore National Laboratory, UC Berkeley and Lawrence Berkeley National Laboratory found that bacteria from an abandoned mine excrete proteins that cause metal nanoparticles to aggregate. The bacteria are binding and immobilizing the metals in the nanoparticles and the nanoparticles themselves, which are potentially toxic to the bacteria.

Sulfate-reducing bacteria can cause heavy metals such as zinc (Zn) to precipitate and form nanoparticles. However, these particles are able to move freely because they are so small (typically 2-6 nanometers in diameter) and can redissolve if conditions change.

In the case of the mine bacteria, the researchers showed that the bacteria are causing the nanoparticle aggregation, thereby protecting themselves. When the metal nanoparticles aggregate, they don't move as easily and are less soluble.

Using secondary ion mass spectrometry, transmission electron microscopy and infra-red spectroscopy, the scientists were able to study whether protein contributes to the formation of densely aggregated nanoparticulate zinc sulfide spheroids.

They also studied whether various amino acids induce rapid aggregation in metal-sulfide nanoparticles.

The answer was yes in both cases.

"This demonstrates an extracellular biomineralization mechanism that is unexpected because it involves the bacteria excreting proteins for nanoparticle aggregation away from the cells," said Peter Weber, one of the LLNL authors of the paper appearing in the June 15 edition of the journal Science.

Weber and LLNL colleague Ian Hutcheon used LLNL's NanoSIMS (high- resolution secondary ion mass spectrometer) to study the metal-sulfide nanoparticle aggregation in sulfate-reducing bacteria dominated biofilms collected from the Piquette Mine, a flooded system in southwestern Wisconsin.

The team found that organic nitrogen was highly concentrated in all of the zinc-sulfide aggregates, indicating a high protein or polypeptide content relative to inorganic zinc-sulfide minerals. In combination with the other techniques and experiments, the team concluded that the protein caused the zinc-sulfide nanoparticle aggregation.

The researchers conducted experiments guided by known bacterial metal-binding proteins that bind zinc and other potentially toxic metals at cysteine locales. Cysteine is a sulfur-containing amino acid. Amino acids are the building blocks of proteins.

The researchers found that inorganic aggregation of zinc-sulfide initially occurred rapidly to 100-nanometer diameter aggregates but then slowed or ceased after one week. However, zinc-sulfide nanoparticles in the presence of cysteine displayed more extensive and prolonged aggregation, accumulating up to 1-10 micron (1/1000th of a millimeter)-sized structures.

"Potentially we can use cysteine or cysteine-rich polypeptides or proteins for nanoparticle clean up," Weber said. "With the boom in nanoscience, people are naturally asking questions about the potential environmental impacts. Here, we see that naturally produced nanoparticles can be naturally controlled."

####

About DOE/Lawrence Livermore National Laboratory
Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

For more information, please click here

Contacts:
Anne Stark

925-422-9799

Copyright © DOE/Lawrence Livermore National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Discoveries

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Joint Efforts by Iranian, Malaysian Scientists Produce Antibacterial Coatings for Isolated Areas February 4th, 2016

Announcements

Study reveals how herpes virus tricks the immune system February 5th, 2016

Hepatitis virus-like particles as potential cancer treatment February 5th, 2016

Organic crystals allow creating flexible electronic devices: The researchers from the Faculty of Physics of the Moscow State University have grown organic crystals that allow creating flexible electronic devices February 5th, 2016

Researchers discover new phase of boron nitride and a new way to create pure c-BN February 5th, 2016

Environment

Scientists have put a high precision blood assay into a simple test strip: Researchers have developed a new biosensor test system based on magnetic nanoparticles February 3rd, 2016

Herbal Extracts Applied to Synthesize Titanium Dioxide Nanoparticles January 28th, 2016

FLEXcon shares insights on developments and safety guidelines in nanotechnology: FLEXcon hosted New England Nanotechnology Association event, discussing latest industry activities and innovations January 25th, 2016

Highly efficient heavy metal ions filter January 25th, 2016

Human Interest/Art

Rice to enter first international nanocar race: Five teams will participate in October 2016 event in France December 15th, 2015

Bionic liver micro-organs explain off-target toxicity of acetaminophen (Tylenol): Israeli-German partnership aims to replace animal experiments with advanced liver-on-chip devices August 17th, 2015

Omni Nano and Time Warner Cable Partner to Provide Nanotechnology Education to the Boys & Girls Clubs of Los Angeles: A $10,000 Donation to Benefit Youth of Los Angeles County's Boys & Girls Clubs August 4th, 2015

Kalam: versatility personified August 1st, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic