New DOE Genome Sequencing Project Could Fuel the Future
PostTime : Thursday, 03 July 2008
| Posted by : DigitalWeekly
| Author : Jason Mick
How do we make
ethanol from cellulose found in yard waste? What's an efficient
process to produce long-chain
hydrocarbons for synthetic oil? These are among the most pressing
questions in the alternative energy industry as gas prices soar.
The U.S. Department of Energy (DOE), which is tasked – among other things --
with promoting energy independence, is turning the search for answer to a time
immemorial source of inspiration: nature.
The DOE is launching
a major project to sequence the genomes of many species with promising
biologic processes. The hope is that the results will yield enzymes which
can be synthetically manufactured and used in the next generation of biofuels.
The DOE Joint Genome Institute (DOE JGI) received 150 proposals from the
Community Sequencing Program (CSP), and selected the best 44 for
sequencing. The work will begin next year.
Eddy Rubin, DOE JGI Director stated:
The scientific and
technological advances enabled by the information that we generate from these
selections promise to take us faster and further down the path toward clean,
renewable transportation fuels while affording us a more comprehensive
understanding of the global carbon cycle. The range of projects spans
important terrestrial contributors to biomass production in the Loblolly
pine—the cornerstone of the U.S. forest products industry—to phytoplankton,
barely visible to the naked eye, but no less important to the massive
generation of fixed carbon in our marine ecosystems.
The work is possible thanks to new sequencing strategies coming online this
year. The Loblolly pine (Pinus taeda); with a massive genome of over 21
billion bases, is finally within sequencing reach thanks to these
developments. This type of pine accounts for 75 percent of the seedlings
planted each year in the U.S.
The research aims to find genes that can be manipulated to increase growth,
carbon sequestration, and the quality of raw materials for lumber and pulp
fiber. Another common plant being tested is Greater Duckweed, Spirodela
polyrhiza. Duckweed is a waste water remediator, biotech protein factory
(yielding high protein animal feed), toxicity testing organism, and a key
player in the carbon cycle. By understanding the genes for these valuable
characteristics, they can be improved or transferred to other plants.
"These plants produce biomass faster than any other flowering plant, and
their carbohydrate content is readily converted to fermentable sugars by using
commercially available enzymes developed for corn-based ethanol
production. Moreover, duckweed relates to all three of DOE JGI's mission
areas: bioenergy, bioremediation, and global carbon cycling," added Rubin.
Duckweed reduces algal growth (by shading), coliform bacteria counts, suspended
solids, evaporation, biological oxygen demand, and mosquito larvae. It
also balances the pH and sequesters or breaks down heavy metal residues, halogenated
organic, and phenolic organic compounds.
The study also focuses on so called "meta-genomes" genese from
several species living together symbiotically; for example, and invertebrate
and organism in its gut. The perfect example is the Bankia setacea, the
giant Pacific shipworm. It is a superior wood eater to termites in that
it can completely digest lignocellulose with the help of only a handful of
microbial partners. The end product is ethanol; so scientists hope to
discover the cellulases and other hydrolases that it employs, which could be
used in commercial cellulosic ethanol production.
Yet another promising organism is Botryococcus braunii, which is a
colony-forming green microalga. The algae sequesters carbons and makes
them into long chains which provide the organism with buoyancy. The
chemical chains are called botryococcenes and make up part of current petroleum
deposits. If they could be synthetically produced, they could be made
into synthetic gasoline.
Other organisms to be sequenced include the Opisthocomus hoazin -- a
leaf-eating Amazonian pheasant-like stinkbird, or hoatzin. It features
ruminative digestion via fermentation, similar to a cow and Nanoflagellates, a
group of marine microbes which prey on phytoplankton and play a critical role
in the ocean ecosystem and the carbon cycle.
Another target is white rot fungi, which depolymerize lignin, the toughest
component of plant cell walls. Desulfurococcus fermentans, an
archaebacteria which produces hydrogen from cellulose (the only known
archaebacteria to digest cellulose) will also be sequenced.
Rhodopseudomonas palustris strain DX-1, which generates electricity directly
from biomass generation, will likewise be analyzed.
A complete list of the projects can be found here
-- in short they encompass how nature makes a variety of fuels, and how such
enzymes might be reproduced or harvested cost effectively.
The research will be carried out at five national labs -- Lawrence Berkeley,
Lawrence Livermore, Los Alamos, Oak Ridge, and Pacific Northwest -- along with
the Stanford Human Genome Center. It is funded by the DOE Office of
Science, which receives funding in the Congressional budget.