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Bio Assign 3
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Transcript of Bio Assign 3
![Page 1: Bio Assign 3](https://reader036.fdocuments.in/reader036/viewer/2022072008/55cf8fed550346703ba1621d/html5/thumbnails/1.jpg)
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Some of the most important processes based on
immobilized enzymes and used commercially are as
follows:
1. High Fructose Corn Syrup
2. Immobilized Raffinase
3. Immobilized Invertase
4. Immobilized Lactase
5. Antibiotic Production
6. Preparation of Acrylamide.
The advantages offered by immobilized enzyme
systems include the following:
(i) use of continuous processes, which reduces the plant size
to nearly one-half,
(ii) easy, cheap, off-site fabrication of plants,
(iii) greatly increased productivity/unit of enzyme used, and
(iv) often process advantages.
The various important processes based on immobilized
enzymes and used commercially are briefly described below
and listed in Table 15.5.
1. High Fructose Corn Syrup:
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D-glucose is only 70% as sweet as sucrose and is
comparatively less soluble in water. Fructose, on the other
hand, is 30% more soluble than sucrose and is twice as
soluble as glucose at lower temperatures. Therefore, glucose
syrup is treated with glucose isomerase to produce high
fructose syrup: 42% fructose syrup is good enough for many
uses, but for soft drinks a 55% fructose syrup is required.
Glucose isomerase is obtained from Actinoplanes
missouriensis, Bacillus coagulans and Streptomyces spp. It is
remarkably thermostable and acts at very high substrate
concentrations. It is used in immobilized state obtained by
cross-linking with glutaraldehyde; in some cases, a protein
diluent may be added. The process is continuous using a
packed bed reactor.
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The glucose syrup is purified to remove impurities,
concentrated to 35-45% dry solids and heated to 55-60°C
(pH 7.5-8). Mg2+ and Co2+ are needed by the enzyme as
cofactors; Co2+ is usually immobilized with the enzyme, while
Mg2+ is added into the syrup.
Syrup flow is adjusted to obtain about 42-46% (w/w
fructose). The half-life of most enzymes (at 60°C) is between
50 and 100 days; the enzyme is discarded after 3 half-lives
during which 1 kg enzyme will produce 10-11 tons of 42%
fructose syrup.
The pH of syrup is lowered to 4.5, and the syrup purified and
evaporated to about 70% solids. The 55% fructose syrup is
prepared as follows: fructose is separated from the syrup by
using vast chromatographic columns of zeolite or a suitable
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resin, and mixed with 42% fructose syrup. The present
market of high fructose syrup is over 5 million tons, and still
expanding; it is the major application of immobilised enzyme
technology.
https://books.google.ca/books?id=jIwHmPS1AYQC&pg=PA261&lpg=PA261&dq=covalent+immobilization+glucose+fructose&source=bl&ots=Ug35EpPhS-&sig=7uIpuKoN_pZxoMx5NpBpPWwa144&hl=en&sa=X&ei=0AAJVeG8BMqdygTK7YG4Aw&ved=0CDwQ6AEwBQ#v=onepage&q=covalent%20immobilization%20glucose%20fructose&f=false
https://books.google.ca/books?id=zfZGAAAAQBAJ&pg=PA220&lpg=PA220&dq=covalent+immobilization+glucose+fructose&source=bl&ots=GmSSbYvOcs&sig=amaiKQkTlHYHknsXVaRufFXwb5s&hl=en&sa=X&ei=0AAJVeG8BMqdygTK7YG4Aw&ved=0CDQQ6AEwAw#v=onepage&q=covalent%20immobilization%20glucose%20fructose&f=false
http://www1.lsbu.ac.uk/water/enztech/hfcs.html
https://www.google.ca/search?q=immobilized+enzymes+reactor+high+fructose+corn+syrup&espv=2&biw=1366&bih=624&source=lnms&tbm=isch&sa=X&ei=avoIVaOBBoSayAS6tYGQAg&ved=0CAYQ_AUoATgU
http://aklyosov.home.comcast.net/~aklyosov/Volume4.htm
http://www1.lsbu.ac.uk/water/enztech/reactors.html
http://www.eng.umd.edu/~nsw/ench485/lab13.htm
http://textbookofbacteriology.net/growth.html