Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


INEEL uses extremophile bacteria to ease bleaching’s environmental cost


In the steamy waters of Yellowstone National Park’s hot springs lives a type of bacterium that could help make industrial bleaching cheaper and more environmentally friendly. Scientists have found Thermus brockianus bacteria produce a hardy enzyme that can be put to work breaking down hydrogen peroxide in industrial wastewater, producing only harmless oxygen and water as byproducts. Most important, the so-called extremozyme endures harsh industrial conditions better than currently available alternatives and lasts thousands of times longer.

R&D Magazine declared the isolation and production of the enzyme -- named the Ultrastable Catalase Enzyme by the Department of Energy’s Idaho National Engineering and Environmental Laboratory researchers who found it -- to be one of the 100 most significant technological achievements of 2004. Chemical engineer Vicki Thompson and biologists William Apel and Kastli Schaller from INEEL will be recognized at the R&D Magazine awards banquet in Chicago on Oct. 14, 2004.

"It’s exciting that the R&D 100 chose a project involving extremophiles," Thompson says. "It will help spread the word about the practical applications and environmental benefits that can come from extremophilic research."

Since the 1980s, cloth and paper manufacturers and other industries have experimented with using hydrogen peroxide instead of toxic chlorine bleach to whiten and disinfect products. Hydrogen peroxide can rid fresh fruits and vegetables of harmful bacteria such as Salmonella and E. coli; pasteurize dairy products; and sterilize paper food packages such as juice boxes, which eliminates the need for refrigeration.

To remove the hydrogen peroxide left over in wastewater after bleaching, some industrial chemists turn to a special type of enzyme called a catalase. Catalase enzymes, found in most living things, break down hydrogen peroxide into water and oxygen. This protects cells from oxidative stress -- the biological equivalent of rust.

But industrial waters can push enzymes to their limit. Most commercial catalase enzymes hail from organisms that prefer moderate temperatures, such as cows and fungi; high temperatures and high pH of industrial processes destroy these enzymes quickly. "Animals and people are designed to operate between 95 and 105 degrees Fahrenheit," Thompson says. "Any catalase derived from a mammal is not going to be stable at extreme conditions."

The INEEL team isolated the catalase enzyme from T. brockianus and found its industrial half-life to be 15 days instead of the 15 seconds of other catalase enzymes -- an 86,000-fold improvement. Scientists use an enzyme’s half-life -- the amount of time it takes to lose half its effectiveness -- as a yardstick for comparing two enzymes.

Large-scale production of the T. brockianus enzyme could end decades of environmental costs from industrial bleaching. Chlorine, used for more than a century, forms toxic and carcinogenic chemicals called dioxins as byproducts. Industries switching to greener hydrogen peroxide have developed wastewater treatment options -- though all have come with extra cost or environmental problems.

One hydrogen peroxide treatment dilutes wastewater with pure water, but this drives up cost and produces even more waste. Another solution treats wastewater chemically with salts, but its harmful residue essentially cancels out the environmental benefits of using hydrogen peroxide in the first place.

The most direct wastewater treatment uses a catalase to break down hydrogen peroxide. But scientists working with commercial catalases have had to make a choice: either spend time and money bringing wastewater temperatures and pH down to tolerable levels, or else continually add more catalase to untreated wastewater to replenish the enzyme.

With the T. brockianus extremozyme, hydrogen peroxide decomposes safely, and wastewater needs no extra pretreatment. What’s more, the enzyme lasts long enough to treat multiple batches of wastewater. Thompson didn’t set out to find an enzyme specifically for bleaching applications, she says. The INEEL team stumbled on T. brockianus in 160-degree Yellowstone pools as part of its extremophile research, studying organisms named for their love of extreme living conditions that would snuff out most living creatures.

But when she examined the bacteria, Thompson quickly recognized its potential. "We purified the enzyme, and it was robust, hardy, and stable," she says. In fact, the T. brockianus enzyme has been the only catalase to boast such industrial-strength properties. Potential applications came next, Thompson recalls. "It was so stable that we said, ’There’s got to be a place this can be used,’ and we started looking around. We found the answer in industrial bleaching."

Still puzzling to Thompson, however, is why the extremozyme survives alkaline waters better than its mammalian counterparts do. Its long life in high-temperature wastewater can be traced back to T. brockianus’ fondness for hot springs. But it turns out the bacterium doesn’t fare as well as its enzyme in high pH conditions. "Along the way, we may figure out why the enzyme is stable in alkaline environments," Thompson says. "But if it works in industry, that’s the most important thing right now."

The INEEL team is discussing collaborations for industrial development with major enzyme manufacturers. After isolating and producing large quantities of the enzyme in the lab, scientists can use existing technology to chemically bind them to tiny plastic beads the size of sand grains. Columns packed with the plastic-and-enzyme beads can filter wastewater and break down hydrogen peroxide, Thompson says. And since the enzyme retains its stability, the beads can be reused to treat additional batches of wastewater.

The INEEL is a science-based, multiprogram national laboratory dedicated to advancing the U.S. Department of Energy’s strategic goals in the areas of environment, energy, science and national security. It is the home of science and engineering solutions and is operated for the DOE by Bechtel BWXT Idaho, LLC.

Regina Nuzzo | EurekAlert!
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

Im Focus: New Products - Highlights of COMPAMED 2016

COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.

In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...

Im Focus: Ultra-thin ferroelectric material for next-generation electronics

'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.

Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Resolving the mystery of preeclampsia

21.10.2016 | Health and Medicine

Stanford researchers create new special-purpose computer that may someday save us billions

21.10.2016 | Information Technology

From ancient fossils to future cars

21.10.2016 | Materials Sciences

More VideoLinks >>>