Uses of Thermophilic Cellulase
Structure and Function (CHEM 645)
University of Delaware
Thermophiles come from what was thought to be
places of the earth, such as steam vents, volcanic areas and
places. These small bacteria like organisms can withstand extreme
The images below show a few places where thermophiles can be
The image on the left shows a hot steam vent under the ocean and the
to the right shows a picture of vents at Sylvan Springs.
these thermophiles live in extremely hot temperatures, their enzymes
can still be active at these high temperatures with out
denaturing. There have been numerous enzymes that have been
extracted from thermophiles that
are now being put to use in industry1-4.
Cellulose is one of the most abundant organic molecules on the earth
that is why cellulases
are so important1-3. Thermophilic
ideal for using because they can withstand high temperatures without
denatured like most other proteins would be1-3.
For industrial purposes, this means that the enzymes can still be
and keep the product sterilized because its being prepared at higher
Also, its better for the environment to use thermophilic cellulases
to chemicals1-3.The following is a list of
that are used with thermophilic cellulase:
One of the primary uses of
cellulases that I found in the food industry was for the use of
juices. The example that I will use will be based on apple
The juice used to be prepared by crushing the apples and then filtering
juice1. However, this wasn't good
yield. Now, the cellulases are added, after crushing, to the
pulp1. By adding the cellulases,
are increasing the yield of the juice and preventing further
because they can perform the juicing process at higher temperatures1.
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The textile industry uses
cellulases for of reasons including uses in detergeants for keeping
brightness for longer and creating the stone washed look in jeans1-3,11.
It can be seen that after numerous washings, clothes tend to have a
and fuzzy look to them. Detergent companies have started adding
cellulases to their products to decrease the discoloration and fuzzing
caused by numerous washes2-3,11.
The following picture shows what happens to fibers after numerous
with and without the use of the cellulases:
As you can see from the pictures above, there is a lot more
occuring to the fibers after washing without the use of the cellulases.
One of the other textile processes that commonly
thermophilic cellulases is the stone washing of jeans to make them
faded and afterwards the jeans tend to be softer. At first, to
get the stoned washed
look, the new jeans would be washed with pumice stones that would break
the dye from the surface of the jeans and cause the threads to degrade1. After washing with the stones,
would have to manually be removed from the jeans, as well as, the
creating a powder that would be harmful to the people that had to
them1. Now they add
thermophilic cellulases in the wash with the jeans and the cellulases
only eataway at the dye that is used to color the jeans and it
maintains the durability1-3,11.
They create different affects depending on the amount of the cellulases
they added to the wash. Besides limiting the pollution that is
created, the jeans can be stoned washed in less time than washing with
You might be thinking how can the cellulases brighten and keep color
then they are able to make it fade? Well, if you looked at the
overview of cellulases, I mentioned the three different
Well, if you change the ratio of these types of cellulases, you can get
types of reactions.
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To create and recycle paper strong chemicals are
that are both unsafe to us and the environment9-10.
Because paper is mad out of wood, it obvious that it's more difficult
break it down in to small pieces that can made into paper because of
cellulose cell walls in the wood. Well cellulases would be good
doing this without using harsh chemicals that can harm the environment1. One of the big processes that they
used for is the bleaching process. They use to use chlorine based
chemicals that would be harmful not only to the environment but
health as well2,9-10.
Now, by adding the thermophilic cellulases, they bleach the wood pulp
make it white. And it is also used to take the ink out of
paper. Both of these ways do not degrade the strength of the
The picture below shows the effects of using chemicals that have been
and the fibers after cellulase application:
that the chemically treated fiber (left picture) is much thinner and
more frayed ends coming off of it than the fibers that were treated
the thermophilic cellulases10.
you can see, thermophilic cellulases tend to be a better alternative to
is done with chemicals when doing paper processing. Not only do
keep fiber strength but they are more environmentally friendly than the
that were used.
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One of the most recent developments
the use of thermophilic cellulases has been the production of ethanol
fuel. Iogen Corporation is the
for this type of production with a process they call EcoEthanol. The
thing about this process is that uses the non-edible portions of corn
wheat8. Currently ethanol fuel is
made from corn, however, this limits the animal feed that is
By using EcoEthanol, production of CO2 will be decreased by
with comparison to gasoline, which is a lot better than ethanol fuel
is produced from corn8. Iogen is
working on a plant for mass production.
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A Brief Overview of
Cellulase is the enzyme that is used
break up cellulose into glucose or other oligosacharide
Cellulose is composed of glucose units linked together by a ß-1.4
bond. The picture below shows the basic structure of a cellulose
The actual number of units of glucoses can be numerous and is not
to a specific number (it can be up in the thousands).
Cellulases are defined by their ability to cut the ß-1.4
glycosidic bond. There are three different types of cellulases,
are explained below5:
By varying how much of each type goes into a mixture, different types
reactions can occur. Below is a picture of an endoglucanase
from Rhodothermus marinus
with a cellulose in the binding domain of the Cellulose6:
tend to have three main components to them. The cellulose binding
or CBD is responsible for bringing the molecule into position with
to the the cellulose molecule7. The
core is where the cellulose is broken down and the flexible and heavily
linker region guides the CBD and the core over the substrate7.
For more information on Cellulases, I such you visit this
Utilization: Fundamentals and Biotechnology
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This webpage was created by Katie
If you have any questions or comments please email
1. M.K. Bhat. Cellulases
and related enzymes in biotechnology. Biotechnology
Advances. 2000, 18, 355-383.
2. Haki, G.D.; Rakshit, S.K. Developments
in industrially important thermostable
enzymes: a review. Bioresource
3. Vielle, C.; Zeikus, G.J. Hyperthermophilic
Enzymes: Sources, Uses, and Molecular
Mechanisms for Thermostability. Microbiology
and Molecular Biology
4. Schiraldi, C.; De Rosa,M. The
production of biocatalysts and biomolecules from
in Biotechnology. 2002,
5. Hreggvidsson, G.O.; Kaiste, E.; Holst, O.;
G.; Palsdottier, A.; Kristjansson,
J.K. An Extremely Thermostable Cellulase
Eubacterium Rhodothermus marinus. Applied
6. Crennell, S.J.; Hreggvidsson, G.O.; Karisson,
E.N. The Structure of Rhodothermus
marinus Cel12A, A Highly Thermostable Family 12 Endoglucanase,
at 1.8Å Resolution. J.
Mol. Biol. 2002,
7. Hirvonen, M.; Papageorgiou, A.C.
Structure of a Family 45 Endoglucanases from Melanocarpus albomyces:
Implications Based on the Free and Cellobiose-bound Forms. J. Mol. Biol. 2003, 329, 403-410.
8. Iogen doubles EcoEthanol Capacity. April
2003. http://www.iogen.ca/news/28_03_2003.html (accessed May 17, 2003).
9. Pelach, M.A.; Pastor, F.J.; Puig, J.;
F.; Mutje, P. Enzymic deinking of
newspapers with cellulase. Process
10. Dienes, D.; Egyhazi, A.; Reczey, K. Treatment of recycled fiber with Trichoderma
Crops and Products. 2004,
11. Csiszar, E.; Losonczi, A. Szakacs, G.
I.; Bezur, L.; Reicher, J. Enzymes
and chelating agent in cotton pretreatment. Journal
of Biotechnology. 2001,