Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

McBride shows DNA detective work with paper-eating bacteria that ‘glide’

05.01.2007
The eco-friendly fuel ethanol is usually made from grain, but the U.S. Department of Energy (DOE) would like to find other renewable materials that will be cost-effective alternatives, such as paper pulp, sawdust, straw and grain hulls.

A UWM professor recently helped DOE do just that by analyzing the DNA of a bacterium that can break down cellulose, the major structural component of plants that is also found in forestry by-products (including paper) and waste feedstocks.

Mark McBride, a professor of biological sciences, worked with DOE’s Joint Genome Institute and scientists at Los Alamos National Laboratory to examine the genes of Cytophaga hutchinsonii that are responsible for the organism’s ability to digest cellulose – the first step in the carbohydrate’s conversion into ethanol.

Sequencing the genome of C. hutchinsonii provides what McBride calls a “parts list” for the microbe, allowing scientists to explore how bacteria use these parts to build and run their key functions – some of which have potential uses in bioenergy.

The genome has revealed surprises, he says.

“Microorganisms typically require two kinds of enzymes to efficiently break down cellulose,” he says. “One type cuts the long carbohydrate molecule through the middle, while another chews small pieces from the ends.”

Not so with C. hutchinsonii. Although it efficiently digests cellulose, in DNA analysis it appears to be lacking one of the usual enzymes, suggesting that it may use either a novel strategy or novel enzymes.

The information McBride reports could help DOE devise mixtures of microorganisms or enzymes that will more efficiently convert cellulose into glucose, and finally into ethanol.

McBride’s interest in C. hutchinsonii goes beyond its possible value in bioenergy.

What really intrigues him is that it’s a “gliding bacterium,” able to crawl rapidly over surfaces by an unknown mechanism, which is the main subject of McBride’s research with another glider called Flavobacterium johnsoniae. The two microbes are not closely related.

“You are more closely related to a fruit fly than these two organisms are to each other,” he says.

However, from analysis of genes from the two bacteria, McBride suspects that they use the same basic machinery to move.

And there may be another connection. F. johnsoniae doesn’t eat cellulose, but it is able to digest a similar carbohydrate polymer, chitin. Like cellulose, chitin, which is found in the hard shells of lobsters and insects, is also difficult to break down.

McBride hypothesizes that digestion of cellulose and chitin may also be linked to cell movement, or motility.

“Loss of motility results in loss of ability to digest chitin,” he says. “This suggests that motility and digestion of some carbohydrate polymers may be connected in both gliding microbes.”

McBride and his students have used F. johnsoniae to study the motility of gliding bacteria for more than a decade. They cloned “mutants” of F. johnsoniae that are unable to move, and then attempted to “repair” them by inserting certain pieces of DNA.

In this way, they have uncovered nearly all the genetic components that propel the cells. It has been a long process. A decade ago, his lab had found one protein involved. He now knows of 24, and he doesn’t expect to find many more.

Until recently, McBride was not able to image the bacteria closely enough to see the structures involved in movement. Instead, he bonded latex spheres to the surface of F. johnsoniae cells and observed that they moved in all directions around the cell’s perimeter.

“The cell wall appears to have a series of moving conveyer belts,” he says.

He also has learned that some of the motility proteins (“parts”) act at the surface of the cell, and he thinks some are involved in forming nearly invisible filaments around the perimeter of the cell.

These filaments were recently imaged in collaboration with Sriram Subramaniam and Jun Liu at the National Institutes of Health by cryo-electron tomography.

“The filaments may be the cell’s ‘tires,’ and there are different kinds,” McBride says. “They are designed to help the organism move over a variety of surfaces, like an all-terrain vehicle.”

Besides providing movement, McBride says the filaments also may be needed to move the cellulose and chitin molecules to certain sites where they can be digested or taken into the cell.

McBride hopes the complete genome for C. hutchinsonii will yield other clues to the interconnections among gliding bacteria. He is now collaborating with DOE to sequence the entire genome of F. johnsoniae, which will allow a full comparison of the genes of the two microorganisms.

Mark McBride | EurekAlert!
Further information:
http://www.uwm.edu
http://www.uwm.edu/Dept/Biology/Docs/Faculty/mcbride.html

Further reports about: Cellulose DNA DOE McBride filaments hutchinsonii johnsoniae motility

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

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

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>