Recent discoveries have formulated mass industrial enzyme immobilisation. To immobilise a substance, it involves it being changed from a water-soluble state, which is mobile to an immobile water-insoluble condition. This immobilisation is conducted in four ways.
Immobilisation Techniques;
Sodium alginate serves to encapsulate a yeast molecule(s). It forms a membrane upon contact with the yeast. As a result of this it is possible to vary bead size purely by varying the size of the syringe, which place the droplets in the solution, this allows a simple method of varying bead surface area, and producing more beads as a consequence.
From here I was able to conduct a preliminary investigation as to the strength of the sodium alginate solution required. using previously collected data from the other immobilised enzyme investigations and studying a 0.5%, 2% and 10% solution I found that the most acceptable concentration was 2%.
Yeast itself is a Fungus, and its most common form is in brewer’s yeast, used in the formation of alcoholic beverages. It is unicellular, as it carries out the characteristics of life within itself.
Yeast is capable of selectively taking in and ejesting substances through a selectively permeable membrane. The cell is seen as simple internally, a nucleus, cytoplasm surrounded by a non-living cell wall, and selectively permeable membrane allowing substances to be engulfed or ejested depending on it’s necessity in the cytoplasm is where the Sucrose is passed, and is hydrolysed, alongside many other reactions taking place. New material can be added for growth, and budding carries out production.
The Hypothesis;
Yeast can be used to break down sucrose to its constituent monosaccharides, if yeast were to be immobilised it would become more stable, hence it would be easier to separate from the hydrolysed sucrose. The smaller the surface area of the beads, the larger the resultant surface area, and consequently the larger the yield. This is possible to test by varying the bead surface area, and straining Sucrose through them in order to observe whether this hypothesis is provable.
The plan continued;
The apparatus chosen is best suited to the needs of the experiment. The syringes allow a simple method of varying bead size. The calcium chloride solution allows beads to be formed quickly. Distilled water prevents any extra-chemicular interference. The Glucose test strips provide swift and accurate readings: muslin is used to prevent clogging in the straining process, no beads can block or travel through the bottom of the test syringe. The beakers used are neither unnecessarily small nor excessively large, and are suited to their intended use.
Meticulous attention to safety should be observed at all times. Each chemical is to be kept separately at all times and also clearly labelled. The sodium alginate can be irritant to the skin and appropriate warnings should be included. Non of the chemicals should be handled directly and all glassware should be kept in a sensible location. Unused solution should be kept away from the test area and eventually disposed of with all the equipment cleaned with extra care. The beads should also not be handled directly when they are not in use.
Safety equipment should be worn constantly such as goggles and any appropriate equipment including spatulas for handling are also important. Care should also be taken in solution preparation to keep all chemicals labelled and separate, as well as being made in controllable environments.
The changing variable is bead size to try and prove the hypothesis however, at a constant will be the temperature of the room for the duration of straining or draining. 5 minutes before testing as used and as the amounts of solution used in each case alongside the amount of time each bead set is used.
In order to asses the amount of sodium alginate required to provide adequate beads for my test, a preliminary investigation as to which concentration was sufficient. As a result I concluded from these results that a 2% solution was viable.
From here I concluded that 2% solution would be suitable, as the beads produced were of a better durability and quality than of a 5% solution, and were quicker to form than a 0.5% solution.
The Experiment;
In order to observe whether bead size effects the Glucose produced, the following equipment is required;
- 2% Sodium alginate solution
- 5% Yeast solution
- 3% Sucrose Solution
- Glucose test strips
- Muslin
- 20ml Syringe and varied needles for bead sizing
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100cm3 beaker
-
100cm3 Conical Flask
- Glass Rod
- Filter Paper
- Funnel
- Distilled Water
- 1.4% Calcium Chloride Solution
From here, the Sodium alginate solution should be mixed separately then the yeast solution also mixed separately. Each in 100ml batches. Then mix these in 10:1 ratios, then using the syringe, make droplets of this solution into calcium chloride until all is used (20ml). Filter excess from beads, and then place in a muslin bedded syringe, then strain 20ml of Sucrose solution through the beads. The liquid, which then appears in the conical flask, should be tested for Glucose using the test strips relates the colours to the table to ascertain the percentage of the Glucose present in the sample.
This experiment plan serves to maximise efficiency, as all results are easy to collect. Great care should be taken in bead preparation to avoid chemicular interference, and to ensure all beads are used. Each experiment should be conducted at room temperature using the same type of apparatus including the size of the apparatus. Furthermore it would be ideal to perform each experiment, as close together as possible, as simultaneous is impossible to achieve. Each set of solutions from each experiment should be from the ‘mother’ solution, which increases reliability and reduces the possibility of error. Another point is that the apparatus should also be cleaned, so that none of it directly used and comes in contact with the second test. Once the yeast has been immobilised, there are different ways of conducting the experiment in order to achieve the desired results. The other possibility, which I explored was to place the beads in a petris dish and add the sucrose then however this would have been less efficient, as each would have to be tested simultaneously, so no extra hydrolysis time could have been given. In addition the solutions would have been reacting during testing, reducing result accuracy and configuration.
Diagram of Setup;
From the evidence collated the results should incline towards the greater Glucose yield being towards the smaller beads owing to the superior surface area exposing larger surface of the selectively permeable membrane to be able to obtain the Sucrose.
Throughout the experiment safety guidelines should be followed at all times. Goggles should be worn at all times and chemicals mixed individually. Although the reactions are not volatile by nature, all chemicals should be handled cautiously using a spatula however if any skin contact is made it should be washed off immediately using water.
