22- cloning and biotech Flashcards
(60 cards)
1
Q
Why are isolated enzymes used instead of whole organism?
A
- Less wasteful; whole microorganisms use up substrate growing and reproducing, producing biomass rather than product. Isolated enzymes do not.
- More efficient; isolated enzymes work at much higher concs. than is possible when they are part of the whole microorganism.
- More specific; no unwanted enzymes present, so no wasteful side reactions take place.
- Maximise efficiency; isolated enzymes can be given ideal conditions for maximum product formation, which may differ from those needed for the growth of the whole microorganism.
- Less downstream processing; pure product is produced by isolated enzymes. Whole microorganisms give a variety of products in the final broth, making isolation of the desired product more difficult and more expensive.
2
Q
Why are extracellular enzymes used in industrial processes rather than intracellular?
A
- They are secreted, making them easy to isolate and use.
- Each microorganism produces relatively few extracellular enzymes, making it easy to identify and isolate the required enzyme. In comparison, each microorganism produces hundreds of intracellular enzymes which would need extracting from the cell and separating.
- They tend to be much more robust than intracellular enzymes as the conditions outside the cell are less tightly controlled than conditions in the cytoplasm. So extracellular enzymes are adapted to cope with greater variations in temperature and pH than intracellular enzymes.
3
Q
Give examples of where intracellular enzymes are used as isolated enzymes.
A
- Glucose oxidase for food preservation
- asparaginase for cancer treatment
- penicillin acylase for converting natural penicillin into semi-synthetic drugs which are more effective.
4
Q
What are the advantages of using immobilised enzymes?
A
- They can be reused
- Easily separated from the reactants and products of the reaction they are catalysing so reduced downstream processing- which is cheaper.
- More reliable; there is a high degree of control over the process as the insoluble support provides a stable microenvironment for the immobilised enzymes.
- Greater temperature tolerance- immobilised enzymes are less easily denatured by heat and work at optimum levels over a much wider range of temps, making the bioreactor less expensive to run.
- Ease of manipulation; the catalytic properties of immobilised enzymes can be altered to fit a particular process more easily than those of free enzymes.
5
Q
What are the disadvantages of using immobilised enzymes?
A
- Reduced efficiency- the process of immobilising an enzyme may reduce it’s activity rate.
- Higher initial costs of materials- immobilised enzymes are more expensive than free enzymes or microorganisms. However, the immobilised enzymes don’t need to be replaced frequently.
- Higher initial costs of bioreactor - the system needed to use immobilised enzymes is different from traditional fermenter so there is an initial investment cost.
- More technical issues - reactors which use immobilised enzymes are more complex than simple fermenters- they have more things which can go wrong.
6
Q
Explain how enzymes can be immobilised by surface immobilisation and the advantages and disadvantages.
A
- Adsorption to inorganic carriers e.g. cellulose, silica, carbon nanotubes and polyacrylamide gel.
- Advantages; Simple and cheap to do, can be used with many different processes, enzymes very accessible to substrate and their activity is virtually unchanged.
- Disadvantages; enzymes can be lost from matrix relatively easily.
7
Q
Explain how enzymes can be immobilised by different types of bonding, and the advantages and disadvantages.
A
- Surface immobilisation - Covalent or ionic bonding to inorganic carriers. Covalent bonding e.g. carriers with amino, hydroxyl and carboxyl groups.
- Advantages; cost varies, enzymes bound strongly and therefore unlikely to be lost, enzymes very accessible to substrate, pH and substrate conc. often have little effect on enzyme activity.
- Disadvantages; cost varies, active site of the enzyme may be modified in process, making it less effective.
8
Q
Explain how entrapment in the matrix can be used to immobilise enzymes and the advantages and disadvantages.
A
- Enzymes are entrapped in the matrix e.g. polysaccharides
- Advantages; it is widely applicable to different processes.
- Disadvantages; may be expensive, can be difficult to entrap, diffusion of the substrate to and from the active site can be slow and hold up the reaction, effect of entrapment on enzyme activity is very variable depending on matrix.
9
Q
Explain how membrane entrapment can be used to immobilise enzymes. Advantages and disadvantages.
A
- entrapment; membrane entrapment in microcapsules or behind a semi-permeable membrane, e.g. polymer based semi-permeable membrane,
- Disadvantages; relatively expensive, diffusion of the substance to and product from the active site can be slow and hold up the reaction.
10
Q
How can immobilised enzymes be used in penicillin production?
A
- Immobilised penicillin acylase used to make semi-synthetic penicillins from naturally produced penicillins. Many types of bacteria have developed resistance to naturally occurring penicillins so they are no longer very effective drugs
- Fortunately, many bacterial are still vulnerable to the semi-synthetic penicillins produced by penicillin acylase so they are very important in treating infections caused by bacterial resistant to the original penicillin. Hundreds of tonnes of these medicines are made every year by immobilised penicillin acylase.
11
Q
How are bulbs an example of natural cloning in plants?
A
The leaf bases swell with stored food from photosynthesis. Buds form internally which develop into new shoots, and new plants in the next growing season e.g. daffodils.
12
Q
How are runners an example of natural cloning in plants?
A
e.g. strawberry plants. A lateral stem grows away from the parent plant and roots develop where the runner touches the ground. A new plant develops- the runner eventually withers away leaving the new individual independents.
13
Q
How are rhizomes an example of natural cloning in plants?
A
- E.g. marram grass. A rhizome is a specialised horizontal stem running underground, often swollen with stored food. Buds develop and form new vertical shoots which become independent plants.
13
Q
How are stem tubers an example of natural cloning in plants?
A
- e.g. potato.
- The tip of an underground stem becomes swollen with stored food to form a tuber or storage organ. Buds on the storage organ develop to produce new shoots.
14
Q
Give 4 examples of vegetative propagation.
A
Bulbs
Runners
Rhizomes
Stem tubers
15
Q
What are the advantages of propagating from cuttings?
A
- It is much faster- the time from planting to cropping is much reduced.
- It also guarantees the quality of the plants.
- By taking cuttings from good stock the offspring will be genetically identical and will therefore crop well.
16
Q
When is micropropagation used to produce plants?
A
When the desirable plant;
- doesn’t readily produce seeds
- doesn’t respond well to natural cloning
- is very rare
- has been genetically modified or selectively bred with difficulty
- is required to be ‘pathogen free’ by growers e.g. bananas.
17
Q
What are the basic principles of micropropagation?
A
- Take a small sample of tissue from the plant you want to clone- the meristem tissue from the shoot tips and axial buds is often dissected out in sterile conditions to avoid contamination by fungi and bacteria. This tissue is usually virus free.
- The sample is sterilised, usually by immersing it in sterilising agents such as bleach or ethanol. The material removed from the plant is called the explant.
- The explant is placed in a sterile culture medium containing a balance of plant hormones which stimulate mitosis. The cells proliferate, forming a mass of identical cells known as a callus.
- The callus is the divided up and individual cells or clumps from the callus are transferred to a new culture medium containing a different mixture of hormones and nutrients which stimulates the development of tiny, genetically identical plantlets.
- The plantlets are potted into compost where they grow into small plants
- The young plants are potted out to grow and produce a crop.
18
Q
What are the advantages of micropropagation?
A
- Allows for the rapid production of large numbers of plats with known genetic make-up which will yield good crops.
- Culturing meristem tissue produces disease free plants
- It makes it possible to produce viable numbers of plants after genetic modification of plants.
- It provides a way of producing very large numbers of new plants which are seedless and therefore sterile to meet consumer tastes.
- It provides a way of growing plants which are naturally relatively infertile or difficult to grow from seed.
- It provides a way of reliably increasing the numbers of rare or endangered plants.
19
Q
What are the disadvantages of micropropagation?
A
- It produces a monoculture- many plants which are genetically identical- they are all susceptible to the same diseases or changes in growing conditions.
- It is a relatively expensive process and requires skilled workers.
- The explants and plantlets are vulnerable to infection by moulds and other diseases during the production process.
- If the source material is infected with a virus, all of the clones will also be infected.
- In some cases, large numbers of new plants are lost during the process.
20
Q
What is artificial twinning?
A
- The early embryo is split into two (or more) and two foetuses go on to develop from the two halves of the divided embryo.
- It is used by the farming community to produce the maximum offspring from particularly good dairy or beef cattle or sheep.
21
Q
Explain the process of artificial twinning in cattle.
A
- A cow with desirable traits is treated with hormones so she super-ovulates, releasing more mature ova than normal.
- They may be fertilised naturally or by artificial insemination, by a bull with particularly good traits. The early embryos are flushed out of the uterus.
- Alternatively, the mature eggs are removed and fertilised in the lab.
- Usually before or around day six, when the cells are still totipotent, the cells of early embryo are split to produce several smaller embryos, each capable of growing on to form a healthy full-term calf.
- Each of the split embryos is grown in the lab for a few days to ensure all is well before it is implanted into a surrogate mother. Each embryo is implanted into a different mother as single pregnancies carry fewer risks than twin pregnancies.
- The embryos develop into foetuses and are born normally, so a number of identical cloned animals are produced by different mothers.
22
Q
How is somatic cell nuclear transfer carried out?
A
- The nucleus is removed from a somatic cell of an adult animal.
- the nucleus is removed from a mature ovum harvested from a different female animal of the same species (it is enucleated).
- The nucleus from the adult somatic cell is placed into the enucleated ovum and is given a mild electric shock so it fuses and begins to divide. In some cases, the nucleus from the adult cell is not removed - it is simply placed next to the enucleated ovum and the two cells fuse (electrofusion) and begin to divide under the influence of the electric current.
- The embryo that develops is transferred into the uterus of a third animal where it develops to term.
- The new animal is a clone of the animal from which the original somatic cell is derived, although the mitochondrial DNA will come from the egg cell.
23
Q
How is SCNT used?
A
- It is used in pharming- the production of animals that have been genetically engineered to produce therapeutic human proteins in their milk.
- It can be used to produce GM animals which grow organs that have the potential to be used in human implants.
24
What are the pros of animal cloning?
- Enables high yielding farming animals to produce many more offspring than normal reproduction.
- Artificial twinning enables the success of a male animal at passing on desirable genes to be determined. If the first cloned embryo results in a successful breeding animal, more identical animals can be reared from the remaining frozen clones.
- SCNT enables GM embryos to be replicated and to develop, giving many embryos from one engineering procedure. It is an important process in pharming- the production of therapeutic human proteins in the milk of genetically engineered farm animals, such as sheep and goats.
- SCNT enables scientists to clone specific animals e.g. top class race horses.
- SCNT has the potential to enable rare, endangered or even extinct animals to be reproduced. In theory, the nucleus from dried or frozen animal tissue could be transferred to the eggs of a similar living species and used to produce clones of species that have been dead for a long time.
25
What are the arguments against animal cloning?
- SCNT is a very inefficient process- in most animals it takes many eggs to produce a single cloned offspring.
- Many cloned animal embryos fail to develop and miscarry or produce malformed offspring.
- Many animals produced by cloning have shortened lifespans, although cloned mice have now been developed which live a normal 2 years.
26
Why is the use of microorganisms in manufacturing processes ideal?
- There are no welfare issues to consider- all that is needed is the optimum conditions for growth.
- There is an enormous range of microorganisms capable of carrying out many different chemical synthases or degradations that can be used.
- Genetic engineering allows us to artificially manipulate microorganisms to carry out synthesis reactions that they would not do naturally e.g. to produce human insulin.
- Microorganisms have a very short life cycle and rapid growth rate. As a result, given the right conditions of food, oxygen and temp, huge quantities of microorganisms can be produced in short periods of time.
- The nutrient requirements of microorganisms are often very simple and relatively cheap. Genetic manipulation means we can modify them so that the microorganisms can utilise materials which would otherwise be wasted, making the raw materials for microorganism-controlled syntheses much cheaper than the raw materials needed for most other industrial processes.
- The conditions which most microorganisms need to grow include a relatively low temperature, a supply of oxygen and food, and the removal of waste gases. They provide their own catalysts in the form of enzymes. This make bioprocesses relatively cheap compared to the high temps and pressures and expensive catalysts often needed in non-biological industrial processes.
27
What are the downsides of using microorganisms in indirect food production?
- If the conditions are not ideal, the microorganisms do not grow properly and so they don't work efficiently.
- Conditions that are ideal for the microorganisms can also be ideal for microorganisms that cause the food to go off or cause disease, so the processes have to be sterile.
28
What microorganism is used in baking, what are the steps in the commercial process?
- Yeast; mixed with sugar and water to respire aerobically. CO2 produced makes bread rise.
- Active yeast mixture is added to other ingredients. Mixed and left in warm environment to rise.
- knocked back, kneaded and left to rise again.
- Cooked in hot oven. CO2 bubbles expand, so the bread rises more. Yeast cells are killed during cooking.
29
What microorganism is used in brewing and what are the steps in the commercial process?
- Yeast; respires anaerobically to produce ethanol. Tradition yeasts ferment at 20-28 degrees. GM yeasts ferment at lower temps and clump together and sink at the end of the process.
- Malting- barley germinates producing enzymes that break starch molecules down to sugars which yeast can use. Seeds then killed by slow heating but enzyme activity retained to produce malt.
- Mashing- malt mixed with hot water (60 degrees) and enzymes break down starches to produce wort. Hoops are added for flavour and antiseptic qualities. Wort is sterilised and cooled.
- Fermentation- wort is inoculate with yeast. Temp is maintained for optimum anaerobic respiration. Yeast inhibited by falling pH due to build up of ethanol and lack of oxygen.
- Maturation- beer is conditioned at temps of 2-6 degrees in tanks
- Finishing- beer is filtered, pasteurised and then canned.
30
What are the advantages of using microorganisms to produce human food?
- They reproduce fast and produce protein faster than animals and pants
- microorganisms have a high protein content with little fat
- microorganisms can use a wide variety of waste materials including human and animal waste, reducing costs
- microorganisms can be genetically modified to produce the protein required
- production of microorganisms is not dependent on weather, breeding cycles ect. it takes place constantly and can be increased or decreased to match demand.
- no welfare issues when growing microorganisms
- can be made to taste like anything
31
What are the disadvantages of using microorganisms to produce human food?
- Some microorganisms can also produce toxins if the conditions are not maintained at the optimum
- the microorganisms have to be separated from the nutrient broth and processed to make the food
- need sterile conditions that are carefully controlled adding to costs
- often involve GM organisms and many people have concerns about eating GM food
- the protein has to be purified to ensure it contains no toxins or contaminants
- many people dislike ethe thought of eating microorganisms grown on waste
- has little natural flavour, needs additives
32
Explain some features of the process of making penicillin
- The process uses relatively small fermenters because it is very difficult to maintain high levels of oxygenation in very large bioreactors
- there is a rich nutrient medium
- the growth medium contains a buffer to maintain pH at around 6.5
- The bioreactors are maintained at about 25-27 degrees
33
What is bioremediation?
microorganisms are used to break down pollutants and contaminants in soil or water.
34
Explain how natural organisms can be used for bioremediation.
- Many microorganisms naturally break down organic material producing CO2 and water. Soil and water pollutants are often biological e.g. sewage and crude oil. If these naturally occurring microorganisms are supported, they will break down and neutralise many contaminants.
35
How can GM organisms be used for bioremediation?
Scientists are trying to develop GM bacterial which can break down or accumulate contaminants which they would not naturally encounter e.g. bacterial have been engineered so they can remove mercury contamination from water.
36
Why must safety precautions always be followed when culturing microorganisms even when they are considered harmless?
- there is always the risk of a mutation taking place making the strain pathogenic
- there may be contamination with pathogenic microorganisms from the environment
37
How are microorganisms cultured?
- They need food as well as the right conditions of temp O2 and pH.
- The food provided for microorganisms is known as the nutrient medium. It can be either in liquid form, broth, or solid form, agar.
- Nutrients are often added to the agar or the broth to provide a better medium for microbial growht
- some microorganisms need a precise balance of nutrients but often the medium is simply enriched with good protein sources such as blood, yeast extract or meat. Enriched nutrient media allow samples containing a very small number of organisms to multiply rapidly.
- the nutrient medium must be kept sterile until it is ready to use. Aseptic techniques are important
38
How do you inoculate broth?
- make a suspension of the bacteria to be grown
- mix a known volume with the sterile nutrient broth in the flask
- stopper the flask with cotton wool to prevent contamination from the air
- incubate at a suitable temp, shaking regularly to aerate the broth providing oxygen for the growing bacteria
39
How do you inoculate agar?
- The wire inoculation loop must be sterilised by holding it in a bunsen flame until it glows red hot. It must not be allowed to touch any surfaces as it cools to avoid contamination.
- Dip the sterilised loop in the bacterial suspension. Remove the lid of the perti dish and make a zigzag streak across the surface of the agar. Avoid the loop digging in the agar by holding it almost horizontal. However many streaks are applied, the surface of the agar must be kept intact.
- Replace the lid of the Petri dish. It should be held down with tape but not sealed completely so oxygen can get in, preventing the growth of anaerobic bacteria. Incubate at a suitable temp.
40
What are the 4 stages of growth in bacterial colonies?
- The lag phase; when bacteria are adapting to their new environment. They are growing and synthesising the enzymes they need, and are not yet reproducing at their maximum rate.
- The log or exponential phase; when the rate of bacterial reproduction is close to or at it's theoretical max.
- The stationary phase; the total growth rate is 0- the number of new cells formed by binary fission is cancelled out by the number of cells dying.
- The decline or death stage; when reproduction has almost ceased and the death rate of cells is increasing.
41
What are some factors which limit the exponential growth in a culture of bacteria?
- Nutrients available- initially, there is plent of food, but as numbers of microorganisms mulitply exponentially it is used up. The nutrient level will become insufficient to support further growth and reproduction unless more nutrients are added.
- O2 levels- as the pop increases, so does demand for respiratory oxygen so O2 levels can become limiting
- Temp; the enzyme controlled reactions within microorganisms are affected by the temp of the culture medium. For most bacteria, a low temp slows down growth and reproduction, and a higher temp speeds it up. If temp is too high, it will denature the enzymes, killing the microorganisms even thermophiles have a max temp they can withstand.
- Build up of waste; as bacterial numbers rise, the buildup of toxic material may inhibit further growth and can even poison and kill the culture.
- Change in pH; as CO2 produced by respiration increases, the pH of the culture falls until a point where the low pH affects enzyme activity and inhibits population growth.
42
What are primary metabolites?
- Substances wanted which are formed as an essential part of the normal functioning of a microorganism e.g. ethanol and a range of amino acids and enzymes.
43
What are secondary metabolites?
- Organisms produce substances which are not essential for normal growth, but are still used by the cells. E.g. pigments and the toxic chemicals plants use to protect themselves against attack from herbivores.
- Organisms wouldn't suffer (in the ST) without them.
- Often required products in a bioprocess e.g. penicillin.
44
What is batch fermentation?
- The microorganisms are inoculated into a fixed volume of medium.
- As growth takes place, nutrients are used up and both new biomass and waste products build up.
- As the culture reaches the stationary phase, overall growth ceases, but microorganisms often carry out biochemical changes to form the desired end products such as enzymes.
- The process is stopped before the death phase and the products harvested. The whole system is then cleaned and sterilised and a new batch culture started up.
45
What is a continuous culture?
- Microorganisms are inoculated into sterile nutrient medium and start to grow.
- Sterile nutrient medium is added continually to the culture once it reaches the exponential point of growth.
- Culture broth is continually removed- the medium, waste products, microorganisms and products, keeping the culture volume in the bioreactor constant.
46
How does the temp in a bioreactor affect it?
- If the temp is too low, the microorganisms will not grow quickly enough
- if the temp gets too high, enzymes start to denature and the microorganisms are inhibited or destroyed. Bioreactors often have a heating and or cooling system linked to temp sensors and a negative feedback system to maintain optimum conditions.
47
Why are bioreactors mixed?
- there are large volumes of liquid which may be quite viscous and thick due to the growth of microorganisms inside the bioreactor.
- Simple diffusion is not enough to ensure that all the microorganisms receive enough food and oxygen or that the whole mixture is kept at the right temp, so most bioreactors have a mixing mechanism and many are stirred continuously.
48
Why is asepsis maintained for bioprocesses?
- If a bioprocess is contaminated by microorganisms from the air, or from workers, it can seriously affect the yield.
- To solve this problem, most bioreactors are sealed, aseptic units. If the process involves genetically engineered organisms, it is a legal requirement that they should be contained within the bioreactor and not be released into the environment.
49
Why are isolated enzymes used instead of whole organisms?
- Less wasteful; whole microorganism use up substrate growing and reproducing, producing biomass rather than product. Isolated enzymes do not.
- More efficient; isolated enzymes work at much higher concs than is possible when they are part of the whole microorganism.
- More specific; no unwanted enzymes present, so no wasteful side reactions take place.
- Maximise efficiency; isolated enzymes can be given ideal conditions for max product formation, which may differ from those needed for the growth of the whole organism.
- Less downstream processing; pure product is produced by isolated enzymes. Whole organisms give a variety of products in the final broth, making isolation of the desired product more difficult and therefore expensive.
50
Why are extracellular enzymes cheaper to use than intracellular enzymes?
- Extracellular enzymes are secreted, making them easy to isolate and use.
- Each microorganism produced relatively few extracellular enzymes, making it easy to identify and isolate the required enzyme. In comparison, each microorganism produces hundreds of intracellular enzymes which would need extracting from the cell and separating.
- Extracellular enzymes tend to be much more robust than intracellular enzymes. Conditions outside a cell are less tightly controlled than conditions in the cytoplasm, so extracellular enzymes are adapted to cope with greater variations in temp and pH than intracellular enzymes.
51
Why are intracellular enzymes sometimes used and not extracellular enzymes?
- There is a bigger range of them, so in some cases, they provide the ideal enzyme for a process.
- In this case, the benefits of using a very specific intracellular enzyme outweighs the disadvantages of the more expensive extraction and isolation process and the need for more tightly controlled conditions. e.g. glucose oxidase, used in food preservation and penicillin acylase for converting natural penicillin into semi-synthetic drugs which are more effective.
52
What are the advantages of using immobilised enzymes?
- Can be reused- cheaper
- Easily separated from the reactants and products of the reaction they are catalysing so reduced downstream processing- cheaper.
- More reliable- there is a high degree of control over the process as insoluble support provides a stable microenvironment for the immobilised enzymes.
- Greater temp tolerance- less easily denatured by heat and works at optimum levels over a much wider range of temps making the bioreactor less expensive to run.
- Ease of manipulation- the catalytic properties of immobilised enzymes can be altered to fit a particular process more easily than those of free enzymes
53
What are the disadvantages of using immobilised enzymes?
- Reduced efficiency- the process of immobilising and enzyme may reduce its activity rate
- Higher initial costs of materials- immobilised enzymes are more expensive than free enzymes or microorganisms. However, the immobilised enzymes, unlike free enzymes, do not need to be replaced frequently.
- Higher initial costs of bioreactor- the system needed to use immobilised enzymes is different from traditional fermenters so there is an initial investment cost.
- More technical issues- reactors which use immobilised enzymes are more complex than simple fermenters- they have more things which can go wrong.
54
What are the 4 ways of immobilising enzymes?
- Surface immobilisation - adsorption to inorganic carriers e.g. cellulose and silica
- Surface immobilisation- covalent or ionic bonding to inorganic carriers.
- Entrapment- in matrix e.g. polysaccharides
- entrapment- membrane entrapment in microcapsules (encapsulation) or behind a semipermeable membrane.
55
What are the advantages and disadvantages of immobilising enzymes via surface immobilisation- adsorption?
ADV;
- Cheap and simple to do
- can be used with many different processes
- enzymes very accessible to substrate and their activity is virtually unchanged.
DIS;
- enzymes can be lost from matrix relatively easily
56
What are the advantages and disadvantages of immobilising enzymes via surface immobilisation- covalent or ionic bonding to inorganic carriers?
cost varies
ADV;
- enzymes strongly bound and therefore unlikely to be lost
- enzymes very accessible to substrate
- pH and substrate conc. often have little effect on enzyme activity.
DIS;
- active site of the enzyme may be modified in process, making it less effective.
57
What are the advantages and disadvantages of immobilising enzymes via entrapment in matrix?
ADV;
- widely applicable to different processes
DIS;
- may be expensive
- can be difficult to entrap
- diffusion of the substrate to and products from the active site can be slow and hold up the reaction
- effect of entrapment on enzyme activity very variable, depending on matrix.
58
What are the advantages and disadvantages of immobilising enzymes via entrapment in microcapsules or behind a semi-permeable membrane?
ADV;
- relatively simple to do
- relatively small effect on enzyme activity
- widely applicable to different processes
DIS;
- relatively expensive
- diffusion of the substrate to and product from the active site can be slow and hold up the reaction.
59
What can immobilised enzymes be used for?
- making semi synthetic penicillins from naturally produced penicillins by using penicillin acylase.
- Immobilised glucose isomerase used to produce fructose from glucose. Fructose is sweeter than sucrose or glucose, so used as a sweetener.
- Immobilised lactase is used to produce lactose free milk
- Immobilised aminoacylase used to produce pure samples of L-amino acids.
- Immobilised glucoamylase, which can be used to complete the breakdown of starch to glucose syrup.
- Immobilised nitrile hydratase, an enzyme used in the plastic industry. For converting acrylonitrile to acrylamide.
