http://www.utexas.edu/news/2008/04/23/biofuel_microbe/[*QUOTE*]
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UT Home -> Public Affairs -> News -> New Source for Biofuels Discovered...
New Source for Biofuels Discovered by Researchers At The University of Texas at Austin
April 23, 2008
AUSTIN, Texas - A newly created microbe produces cellulose that can
be turned into ethanol and other biofuels, report scientists from The
University of Texas at Austin who say the microbe could provide a
significant portion of the nation's transportation fuel if production can
be scaled up.
Along with cellulose, the cyanobacteria developed by Professor R.
Malcolm Brown Jr. and Dr. David Nobles Jr. secrete glucose and
sucrose. These simple sugars are the major sources used to produce
ethanol.
"The cyanobacterium is potentially a very inexpensive source for sugars
to use for ethanol and designer fuels," says Nobles, a research associate
in the Section of Molecular Genetics and Microbiology.
Dr. R. Malcolm Brown (left) and Dr. David Nobles with one of the
cyanobacterial strains that produces cellulose and glucose.
Brown and Nobles say their cyanobacteria can be grown in production
facilities on non-agricultural lands using salty water unsuitable for
human consumption or crops.
Other key findings include:
The new cyanobacteria use sunlight as an energy source to produce
and excrete sugars and cellulose
Glucose, cellulose and sucrose can be continually harvested
without harming or destroying the cyanobacteria (harvesting
cellulose and sugars from true algae or crops, like corn and
sugarcane, requires killing the organisms and using enzymes and
mechanical methods to extract the sugars)
Cyanobacteria that can fix atmospheric nitrogen can be grown
without petroleum-based fertilizer input
They recently published their research in the journal Cellulose.
Nobles made the new cyanobacteria (also known as blue-green algae) by
giving them a set of cellulose-making genes from a non-photosynthetic
"vinegar" bacterium, Acetobacter xylinum, well known as a prolific
cellulose producer.
The new cyanobacteria produce a relatively pure, gel-like form of
cellulose that can be broken down easily into glucose.
"The problem with cellulose harvested from plants is that it's difficult
to break down because it's highly crystalline and mixed with lignins [for
structure] and other compounds," Nobles says.
He was surprised to discover that the cyanobacteria also secrete large
amounts of glucose or sucrose, sugars that can be directly harvested from
the organisms.
Fluorescence microscopy of the cyanobacterium (chlorophyll in red) and
blue cellulose material stained with a fluorescent brightener.
"The huge expense in making cellulosic ethanol and biofuels is in using
enzymes and mechanical methods to break cellulose down," says Nobles.
"Using the cyanobacteria escapes these expensive processes."
Sources being used or considered for ethanol production in the United
States include switchgrass and wood (cellulose), corn (glucose) and
sugarcane (sucrose). True algae are also being developed for biodiesel
production.
Brown sees a major benefit in using cyanobacteria to produce ethanol is
a reduction in the amount of arable land turned over to fuel production
and decreased pressure on forests.
"The pressure is on all these corn farmers to produce corn for non-food
sources," says Brown, the Johnson & Johnson Centennial Chair in Plant
Cell Biology. "That same demand, for sucrose, is now being put on
Brazil to open up more of the Amazon rainforest to produce more sugarcane
for our growing energy needs. We don't want to do that. You'll never get
the forests back."
Brown and Nobles calculate that the approximate area needed to produce
ethanol with corn to fuel all U.S. transportation needs is around 820,000
square miles, an area almost the size of the entire Midwest.
They hypothesize they could produce an equal amount of ethanol using an
area half that size with the cyanobacteria based on current levels of
productivity in the lab, but they caution that there is a lot of work
ahead before cyanobacteria can provide such fuel in the field. Work with
laboratory scale photobioreactors has shown the potential for a 17-fold
increase in productivity. If this can be achieved in the field and on a
large scale, only 3.5 percent of the area growing corn could be used for
cyanobacterial biofuels.
Cyanobacteria are just one of many potential solutions for renewable
energy, says Brown.
"There will be many avenues to become completely energy independent,
and we want to be part of the overall effort," Brown says. "Petroleum is
a precious commodity. We should be using it to make useful products,
not just burning it and turning it into carbon dioxide."
Brown and Nobles are now researching the best methods to scale up
efficient and cost-effective production of cyanobacteria. Two patent
applications, 20080085520 and 20080085536, were recently published
in the United States Patent and Trade Office.
For more information, contact: Lee Clippard, College of Natural
Sciences, 512-232-0675; Dr. R. Malcolm Brown Jr., 512-471-3364; Dr.
David Nobles, 512-471-3364.
Office of Public Affairs
P.O. Box Z
Austin, TX 78713
512-471-3151
Fax 512-471-5812
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Nicht in geschlossenen Systemen, sondern frei in der Umgebung sollen die Bakterien losgelassen werden...
Die Erde hat kein Rettungsboot!
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