Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

DOE JGI plumbs termite guts to yield novel enzymes for better biofuel production

23.11.2007
Termites -- notorious for their voracious appetite for wood, rendering houses to dust and causing billions of dollars in damage per year -- may provide the biochemical means to a greener biofuel future. The bellies of these tiny beasts actually harbor a gold mine of microbes that have now been tapped as a rich source of enzymes for improving the conversion of wood or waste biomass to valuable biofuels.

The genomic sequencing and analysis of the termite gut microbes by the U.S. Department of Energy Joint Genome Institute (DOE JGI), the California Institute of Technology, Verenium Corporation (formerly Diversa), a biofuels company, INBio, the National Biodiversity Institute of Costa Rica, and the IBM Thomas J. Watson Research Center, are highlighted in the November 22 edition of the journal Nature.

"The termite is a remarkable machine," said Dr. Raymond L. Orbach, Under Secretary for Science, U.S. Department of Energy, whose program supports DOE JGI. "Termites can digest a frightening amount of wood in a very short time, as anyone who has had termites in their house is painfully aware. Instead of using harsh chemicals or excess heat to do so, termites employ an array of specialized microbes in their hindguts to break down the cell walls of plant material and catalyze the digestion process. Industrial-scale DNA sequencing by DOE JGI was key to identifying the genetic structures that comprise the tools that termites use. Our task now is to discover the metabolic pathways generated by these structures to figure out how nature digests plant materials. We can then synthesize the novel enzymes discovered through this project to accelerate the delivery of the next generation of cellulosic biofuels."

While termites have been the subject of keen scientific study for more than a century, the precise identity and role of the microbes from their digestive tract remained a mystery. With this new work, the symbiotic orchestration of these compartmentalized, complex microbial communities required for wood digestion is now coming to light.

Like cows, termites have a series of stomachs, each harboring a distinct community of microbes under precisely defined conditions. These bugs within bugs are tasked with particular steps along the conversion pathway of woody polymers to sugars that can then be fermented into fuels such as ethanol. The mandibles of the insect chomp the wood into bits, but the real work is conducted in the dark recesses of the belly, where the enzymatic juices exuded by microbes attack and deconstruct the cellulose and hemicellulose, which, along with lignin, are the basic building blocks of wood.

The tiny insects that gave up their stomach contents to advance the frontiers of science were isolated on a safari into the rainforest of Costa Rica, the world's geographic hotbed of biodiversity for termites, by co-author Jared Leadbetter of Cal Tech, first author Falk Warnecke of DOE JGI's Microbial Ecology Program, and members of Verenium and INBio. Traipsing through the jungle, the team came upon a massive, tumor-like nest of termites clinging to an otherwise nondescript tree. With a flick of a machete, the contents of this dense network of tunnels forged from wood waste were revealed, along with a frenzy of higher termites from the genus Nasutitermes, which are only about the size of the date imprinted on a penny.

Foregoing the funnel-headed "soldiers," the project focused on the larger "workers," with bulbous heads and inflated bellies. In the laboratory of INBio, researchers armed with fine forceps and needles painstakingly extracted the contents of the workers' third paunch or hindgut, referred to as P3, a distended kink in the convoluted plumbing system of the termite. Each sample was barely visible to the naked eye, and care was taken not to contaminate it with material from neighboring stomachs. Contents from 165 specimens were purified, yielding only a few valuable drops -- a veritable microbial mosh pit -- that was sent on ice to Verenium for DNA extraction and preparation, then on to DOE JGI's Walnut Creek (CA) Production Genomics Facility for sequencing.

From the sample, about 71 million letters of fragmented genetic code were elaborated and computationally reassembled, like putting Humpty Dumpty back together again, to tease out the identities of the microbial players in the mixture and the metabolic profile of the enzymes that they produce. From this reconstructed liquid puzzle emerged the identities of a dozen different phyla -- broad groupings of microbial life forms.

"Our analysis revealed that the hindgut is dominated by two major bacterial lineages, treponemes and fibrobacters," said co-author Phil Hugenholtz, DOE JGI's Microbial Ecology Program head. "Treponemes have long been recognized in the termite gut due to their distinctive cork-screw shape, but fibrobacters were an exciting new find, because they have relatives in the cow rumen known to degrade cellulose. We could directly link the termite fibrobacters and treponemes to enzymes capable of breaking down wood. However, fibrobacters are specialists in this regard and don't appear to participate in sugar fermentation, leaving that to the treponemes. This project has really given me a new appreciation for the lowly termite, a mobile miniature bioreactor."

In the termite P3 compartment alone, more than 500 genes related to the enzymatic deconstruction of cellulose and hemicellulose were identified by Hugenholtz and colleagues. This dataset has since been uploaded by DOE JGI onto its metagenome data management and analysis system, IMG/M (http://img.jgi.doe.gov/) for public access and further analysis.

"Adapting these findings for an industrial-scale system is far from easy," said Eddy Rubin, JGI Director. "Termites can efficiently convert milligrams of lignocellulose into fermentable sugars in their tiny bioreactor hindguts. Scaling up this process so that biomass factories can produce biofuels more efficiently and economically is another story. To get there, we must define the set of genes with key functional attributes for the breakdown of cellulose, and this study represents an essential step along that path."

Nature paper first author Falk Warnecke is a postdoctoral fellow in the Hugenholtz lab. Other DOE JGI authors include Natalia Ivanova, Rotem Sorek, Susannah Tringe, Hector Garcia Martin, Victor Kunin, Daniel Dalevi, Julita Madejska, Edward Kirton, Darren Platt, Ernest Szeto, Asaf Salamov, Kerrie Barry, Natalia Mikhailova, Nikos Kyrpides, and Director Rubin.

These findings follow on the heels of the announcement by DOE Secretary Samuel Bodman in June that DOE will invest up to $375 million in three new Bioenergy Research Centers (http://genomicsgtl.energy.gov/centers/) to accelerate basic research in the development of cellulosic ethanol and other biofuels. DOE JGI will conduct genome sequencing in support of these centers.

The termite hindgut whodunit builds upon DOE JGI's pioneering "metagenomic" research, where genetic material is isolated, identified, and characterized directly from environmental samples, providing a profile of a particular (often extreme) ecological niche. Published investigations by DOE JGI include glimpses into such diverse slices of the biosphere as acid mine drainage, a gutless worm, farm soil, submerged whalebones, and sewage sludge.

Currently among the scores of projects in the sequencing queue at DOE JGI are metagenomes from contents of the Tammar wallaby forestomach, the Asian longhorned beetle gut, and other exotic species that promise to be treasure troves of enzymes involved in cellulose deconstruction. These targets were submitted through DOE JGI's Community Sequencing Program (CSP), which provides the scientific community with access to high-throughput sequencing for projects of relevance to DOE missions.

David Gilbert | EurekAlert!
Further information:
http://www.jgi.doe.gov/

Further reports about: Biofuel Cellulose DOE JGI JGI' Sequencing contents enzymes fibrobacters hindgut

More articles from Life Sciences:

nachricht Bare bones: Making bones transparent
27.04.2017 | California Institute of Technology

nachricht Link Discovered between Immune System, Brain Structure and Memory
26.04.2017 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Bare bones: Making bones transparent

27.04.2017 | Life Sciences

Study offers new theoretical approach to describing non-equilibrium phase transitions

27.04.2017 | Physics and Astronomy

From volcano's slope, NASA instrument looks sky high and to the future

27.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>