. Energy News .

NREL researchers use imaging technologies to solve puzzle of plant architecture
by Staff Writers
Washington DC (SPX) Nov 30, 2012

File image.

Scientists at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) and the BioEnergy Science Center (BESC) combined different microscopic imaging methods to gain a greater understanding of the relationships between biomass cell wall structure and enzyme digestibility, a breakthrough that could lead to optimizing sugar yields and lowering the costs of making biofuels.

A paper on the breakthrough, "How Does Plant Cell Wall Nanoscale Architecture Correlate with Enzymatic Digestibility?" appears in the current issue of Science Magazine.

Principal Investigator Dr. Shi-You Ding of NREL said the imaging technologies allowed the interdisciplinary team of scientists to view the plants' architecture at scales ranging from millimeter to nanometer, a range of 1 million to one.

That allowed them to learn not just the plant cell wall architecture, but also the localization of the enzymes responsible for deconstruction of the cell wall polymers and the effects of enzyme action on the cell wall.

They didn't have to resort to wet chemistry, which ascertains the molecular makeup of a substance at the cost of destroying the spatial relationships. "The typical way to understand the structure of biomass is to break down all the individual components so they can be analyzed," Ding, a biologist, said. "The problem with that method is that then you don't know where all the components came from. You lose the structural integrity."

That's a crucial loss, because an understanding of how enzymes digest plants requires an understanding of where everything is inside the cell walls.

"Our imaging techniques gave us a deeper understanding of the cell wall structure and the process of enzyme hydrolysis of cell-wall carbohydrate polymers to release simple sugars," Ding said. "That allows us to optimize the process and reduce costs."

Dr. Paul Gilna, the director of the BESC, in which the project was conducted, added: "This work greatly improves our ability to closely examine the mechanisms behind the scientific improvements we have developed, all of which are targeted at enabling the emergence of a sustainable cellulosic biofuels industry." BESC is a multi-institutional Bioenergy Research Center supported by the Office of Biological and Environmental Research in the Department of Energy Office of Science.

The correlative imaging in real time allowed the team to assess the impact of lignin removal on biomass hydrolysis and to see the nanometer-scale changes in cell wall structure. And, that allowed them to see how those changes affected the rate at which enzymes from two different organisms digested the plant cell walls.

The aim in the biofuel industry is to access the plants' polymeric carbohydrate structures without damaging the basic molecules of which the polymers are constructed.

"It's more like dis-assembling a building with wrenches, hammers and crowbars to recover re-useable bricks, wiring, pipes and structural steel than it is like using a wrecking ball or explosives," Gilna said. Enzymes, unlike typical harsh chemical catalysts, excel at this relatively gentle disassembly.

The NREL team examined two enzyme systems - one from a fungus, the other from a bacterium - both holding promise as biocatalysts for producing sugar intermediates for the biofuels industry.

The particular bacterial enzymes studied are organized through a large scaffolding protein into a multi-enzyme complex from which they make a coordinated attack on the cell walls. The separate fungal enzymes act more individualistically, although the ultimate result is cooperative in that case, as well.

The NREL team found that the easier the access to the cell walls, the better and faster the enzymes will digest the material.

In biofuels production, enzymes are needed to greatly speed up the chemical reactions that break down the biomass during fermentation.

The NREL scientists found that the gummy, poly-aromatic non-sugar lignin in plants interferes with enzymes' ability to access the polysaccharides in the cell wall - the stuff that both the enzymes and the industry want.

So, they concluded, ideal pre-treatment should focus on getting rid of the lignin while leaving the structural polysaccharides within the cell walls intact, thus leaving a relatively loose, porous native-like structure that allows easy access by the enzymes and rapid digestion, as opposed to pretreatments that remove some of the spongier carbohydrate polymers and allow the remainder to collapse into tighter and less-accessible structures.

To continue the building dis-assembly and salvage analogy, removal of the lignin is like unlocking all of the doors in the building so that the workers can get in to pull out re-useable materials, but without collapsing the overall structure so that access is blocked.

By understanding the changing structure of the plant material, scientists can learn more about how enzymes work.

"The enzyme has evolved to deal with the real structure, not the pretreated, artificially decomposed one," Ding said. "So to understand how the enzyme goes about its business, it is really important to know where cell wall components are located, as well as the various modes of enzyme action."

"Then we can optimize the whole process," Ding said. "By observing where cellulase enzymes are localized and the nanostructural changes in the plant cell wall architecture that their actions produce, we hope to suggest rational strategies for more cost effective pretreatments and better enzymes."


Related Links
DOE/National Renewable Energy Laboratory
Farming Today - Suppliers and Technology

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Get Our Free Newsletters
Space - Defense - Environment - Energy - Solar - Nuclear


Major breakthrough in deciphering bread wheat's genetic code
Swindon UK (SPX) Nov 30, 2012
Scientists have unlocked key components of the genetic code of one of the world's most important crops. The first analysis of the complex and exceptionally large bread wheat genome, published in Nature, is a major breakthrough in breeding wheat varieties that are more productive and better able to cope with disease, drought and other stresses that cause crop losses. The identification of a ... read more

NASA's TRMM Satellite Confirms 2010 Landslides

NASA's Tropical Rainfall Measuring Mission Turns 15

GOES-R Satellite Program Undergoes Successful Review

Tracking Pollution from Outer Space

GTX Gets Approval For Custom Two-Way GPS Tracking Devices On Planes

East Riding Of Yorkshire Council Selects Ctrack For Specialist Vehicle Tracking Solution

Researchers Use GPS Tracking to Monitor Crab Behavior

US Navy, Raytheon receive Pentagon engineering award for GPS-guided precision landing program

Ash dieback poses threat

China demand fuels illegal logging: report

New study shows how climate change could affect entire forest ecosystems

Brazil says Amazon deforestation at record low

Garbage bug may help lower the cost of biofuel

Tiny algae shed light on photosynthesis as a dynamic property

Algae held captive and genes stolen in crime of evolution

Marine algae seen as biofuel resource

The Future Looks Bright: ONR, Marines Eye Solar Energy

The Installed Price of PV Systems in the U.S. Continues to Decline at a Rapid Pace

Upsolar Modules Earn High Marks for Long-Term Performance

Aerospace Museum of California solar installation

US Navy, DoD, Developer Announce Wind Farm Agreement

Britain: Higher energy bills 'reasonable'

Areva commits to Scotland turbine plant

AREVA deploys its industrial plan to produce a 100 percent French wind power technology

China mine blast toll rises to 23

China mine blast kills 18: state media

US shale gas drives up coal exports

Coal investment in Queensland unlikely

British ministers 'banned from meeting Dalai Lama'

China dissident brands nephew's conviction 'revenge'

Blind Chinese lawyer's nephew jailed for 3 years

China jails local government 'interceptors': report

The content herein, unless otherwise known to be public domain, are Copyright 1995-2012 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement