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 What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | 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: 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...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

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

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>