Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Enzyme Trio for Biosynthesis of Hydrocarbon Fuels

22.06.2010
If concerns for global climate change and ever-increasing costs weren’t enough, the disastrous Gulf oil spill makes an even more compelling case for the development of transportation fuels that are renewable, can be produced in a sustainable fashion, and do not put the environment at risk. Liquid fuels derived from plant biomass have the potential to be used as direct replacements for gasoline, diesel and jet fuels if cost-effective means of commercial production can be found.

Researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have identified a trio of bacterial enzymes that can catalyze key steps in the conversion of plant sugars into hydrocarbon compounds for the production of green transportation fuels.

Harry Beller, an environmental microbiologist who directs the Biofuels Pathways department for JBEI’s Fuels Synthesis Division, led a study in which a three-gene cluster from the bacterium Micrococcus luteus was introduced into the bacterium Escherichia coli. The enzymes produced by this trio of genes enabled the E. coli to synthesize from glucose long-chain alkene hydrocarbons. These long-chain alkenes can then be reduced in size – a process called “cracking” – to obtain shorter hydrocarbons that are compatible with today’s engines and favored for the production of advanced lignocellulosic biofuels.

“In order to engineer microorganisms to make biofuels efficiently, we need to know the applicable gene sequences and specific metabolic steps involved in the biosynthesis pathway,” Beller says. “We have now identified three genes encoding enzymes that are essential for the bacterial synthesis of alkenes. With this information we were able to convert an E. coli strain that normally cannot make long-chain alkenes into an alkene producer.”

Working with Beller on this study were Ee-Been Goh and Jay Keasling. The three were the co-authors of a paper that appeared earlier this year in the journal Applied and Environmental Microbiology, titled “Genes Involved in Long-Chain Alkene Biosynthesis in Micrococcus luteus.”

It has long been known that certain types of bacteria are able to synthesize aliphatic hydrocarbons, which makes them promising sources of the enzymes needed to convert lignocellulose into advanced biofuels. However, until recently, little was known about the bacterial biosynthesis of non-isoprenoid hydrocarbons beyond a hypothesis that fatty acids are precursors. JBEI researchers in the Fuels Synthesis Division, which is headed by co-author Keasling, are using the tools of synthetic biology, and mathematical models of metabolism and gene regulation to engineer new microbes that can quickly and efficiently produce advanced biofuel molecules. E.coli is one of the model organisms being used in this effort because it is a well-studied microbe that is exceptionally amenable to genetic manipulation.

“We chose to work with M. luteus because a close bacterial relative was well-documented to synthesize alkenes and because a draft genome sequence of M. luteus was available,” Beller says. “The first thing we did was to confirm that M. luteus also produces alkenes.”

Beller and his colleagues worked from a hypothesis that known enzymes capable of catalyzing both decarboxylation and condensation should be good models for the kind of enzymes that might catalyze alkene synthesis from fatty acids. Using condensing enzymes as models, the scientists identified several candidate genes in M. luteus, including Mlut_13230. When expressed in E. coli together with the two adjacent genes – Mlut_13240 and 13250 – this trio of enzymes catalyzed the synthesis of alkenes from glucose. Observations were made both in vivo and in vitro.

“This group of enzymes can be used to make aliphatic hydrocarbons in an appropriate microbial host but the resulting alkenes are too long to be used directly as liquid fuels,” Beller says. “However, these long-chain alkenes can be cracked – a technique routinely used in oil refineries – to create hydrocarbons of an appropriate length for diesel fuel.”

The next step Beller says is to learn more about how these three enzymes work, particularly Mlut_13230 (also called OleA), which catalyzes the key step in the alkene biosynthesis pathway – the condensation of fatty acids.

“We’re also studying other pathways that can produce aliphatic hydrocarbons of an appropriate length for diesel fuels without the need for cracking,” Beller says. “Nature has devised a number of biocatalysts to produce hydrocarbons, and our goal is to learn more about them for the production of green transportation fuels.”

JBEI is one of three Bioenergy Research Centers funded by the U.S. Department of Energy to advance the development of the next generation of biofuels. Headquartered in Emeryville, California, JBEI is a scientific partnership led by Lawrence Berkeley National Laboratory (Berkeley Lab) and including the Sandia National Laboratories, the University of California (UC) campuses of Berkeley and Davis, the Carnegie Institution for Science (located on the campus of Stanford University), and the Lawrence Livermore National Laboratory.

Berkeley Lab is a U.S. Department of Energy national laboratory located in Berkeley, California. It conducts unclassified scientific research for DOE’s Office of Science and is managed by the University of California. Visit our Website at www.lbl.gov/

Additional Information

For more information about JBEI, visit the Website at www.jbei.org

For more information about Harry Beller and his research visit http://esd.lbl.gov/about/staff/harrybeller/

Lynn Yarris | EurekAlert!
Further information:
http://www.lbl.gov

More articles from Life Sciences:

nachricht Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology

nachricht Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>