6.2.1 - (e) Flashcards
Define biotechnology
The use of biological organisms or enzymes to carry out industrial processes (e.g. producing food, medicinal drugs etc)
Why are microorganisms used in biotehnology?
- There are no ethical issues surrounding microorganism welfare
- Genetic engineering allows microorganisms to be modified to carry out reactions they wouldn’t normally do – e.g. human insulin production
- Have a short lifecycle and reproduce quickly – given the correct conditions (oxygen, temp., nutrients etc.) many can be produced in a short space of time for use
- Reproduce asexually so all individuals are genetically identical
- Make bioprocesses cheap as nutrient requirements are simple and cheap, low temperatures required, they provide their own catalysts in the form of enzymes
What are the uses of microorganisms in food production?
- Baking
- Brewing
- Cheese production
- Yoghurt production
How are microorganisms used in:
Baking
Microorganisms involved: Yeast – a single-celled fungus
- Mix active yeast with flour, water and sugar and leave the dough to prove (rise in a warm place)
- Knead the dough to remove excess air (the carbon dioxide produced by the yeast anaerobically respiring)
- Bake the dough in an oven
How are microorganisms used in:
Brewing
Microorganisms involved: Uses yeast which anaerobically respires to produce ethanol
- During wine production, grapes with naturally occurring yeast on their skin is used, the grapes are crushes and the yeast uses the sugars fructose and glucose in the grapes to produce carbon dioxide and ethanol
- During beer production, barley grains are used.
- The barley grains germinate, converting stored starch to maltose, which the yeast then respires
- The anaerobic respiration of the yeast then produces carbon dioxide and alcohol
How are microorganisms used in:
Cheese production
- Milk is fermented by the action of Lactobacillus (bacteria) producing lactic acid acidifying the milk
- The enzyme rennin (chymosin) is added to coagulate casein (milk protein) in the presence of calcium ions
- The resulting solid curd is separated from the whey (liquid)
- The curd is pressed into moulds and left to dry and mature as bacteria continue to act to characterise the cheese and its flavours
How are microorganisms used in:
Yoghurt making
- Milk is fermented by Lactobacillus bulgaricus and Streptococcus thermophilus bacteria to form ethanal and lactic acid
- This lowers the pH and denatures milk proteins causing coagulation (it thickens)
- The yoghurt is placed into cartons to ferment in the pot
How are microorganisms used to directly produce food?
- Protein shortage has led to the use of microorganisms to directly produce edible protein, best known as single cell protein (SCP)
- Fungi (Fusarium venenatum) are fermented with glucose syrup to manufacture a protein called mycoprotein
- It is commonly known as Quorn
- It is healthy as it is high in protein and low in fat
How are microorganisms used in medicinal drug production?
Penicillin Production
- Produced through the fermentation of the fungus Penicillium chrysogenum in small fermenters with rich nutrients and stirring to keep oxygenated
- There is pH buffer of 6.5 and temperature between 25 and 27 degrees C
- The fungus is left to culture with nutrients as the population increases
- Once the population reaches a certain size, penicillin is then produced
Insulin Production
- Synthetic human insulin was developed by genetically modifying the bacteria Escherichia coli
- The GM bacteria are grown in fermenters
- Better than the use of pig insulin in the past as pig insulin supply was dependant on the demand for meat, as the insulin can be taken if the animals are killed
What is bioremediation?
Use of microorganisms to break down pollutants and contaminants in soil and water
- Use of natural organisms – microorganisms naturally break down organic material to produce carbon dioxide and water
- Use of GM organisms – scientists developing GM bacteria to break down contaminants, such as mercury in water
What are the advantages of using bioremediation to clean pollution over conventional techniques?
- Uses natural systems
- Less labour/equipment
- Treatment carried out at site
- Fewer waste products
- Less risk of harmful exposure to toxic substances for personnel involved
