Biotechnology Flashcards
(36 cards)
What are the four main areas microorganisms are used in biotechnology?
Food
Pharmaceutical drugs
Enzymes
Other products such as biogas, citric acid and bioremediation
Examples of microorganisms being used in the food industry
- Ethanol in beer and wine (yeast)
- Carbon dioxide to make bread rise (yeast)
- Lactic acid to make cheese and yoghurt (Lactobacillus bacteria)
- Mycoprotein to make veggie food (fungus)
- Soya - soya beans fermented to make soy sauce (yeast)
Examples of microorganisms being used to make pharmaceutical drugs
- Penicillin (penicillium fungus)
- Other antibiotics
- Insulin (genetically modified bacteria)
Advantages of using microorganisms in biotechnology
- cheap and easy to grow
- in most cases, process takes place at lower temperatures saving energy and reducing costs
- process can take place at normal atmospheric pressure which is safer
- not dependent on climate
- microorganisms have a short life cycle and reproduce quickly
- microorganisms can be genetically modified relatively easily
- Fewer ethical considerations
- product is often more pure and easier to isolate
How are other organisms used in biotechnology?
Genetically modified mammals can be used to produce useful proteins. Some have the protein incorporated into milk which can be easily harvested. Others have it incorporated into their blood.
How to make yoghurt
Yoghurt is milk that has undergone fermentation by Lactobacillus bacteria which converts lactose to lactic acid. The acidity denatures the milk protein causing it to coagulate and thicken. Flavours and colours are then added.
How to make cheese
- Milk is treated with Lactobacillus to produce lactic acid from lactose
- Once acidified it it mixed with rennetwhich contains the enzyme rennin
- rennin coagulates the milk protein caesin in the presence of calcium ions to produce curd
- curd is separated from the liquid component and pressed into moulds
- production of blue cheese involves the addition of fungi
How to bake bread
Yeast makes bread rise.CO2 produced by fermentation of sugars in the dough ensures it doesn’t stay flat. Any alcohol evaporates during the cooking process.
Brewing
Yeast is added to a type of grain (e.g barley) which respires anaerobically using glucose from the grain o produce ethanol and CO2. This is called fermentation.
Penicillin production
Penicillium fungus grown under stress in industrial fermenters and penicillin is produced and collected. When under stress, penicillin is produced to stop bacteria from growing and competing for resources.
Insulin production
Made by genetically modified bacteria which have had the gene for human insulin production inserted into their DNA. Grown in an industrial fermenter and the insulin is collected and purified.
Bioremediation
The process of using microorganisms to remove pollutants. Pollutant removing bacteria that occur naturally at a site are provided with extra nutrients and enhanced growing conditions so they can multiply. The bacteria break down the pollutants into less harmful products.
Advantages of using microorganisms in food production
- production of protein can be much faster
- very high protein content
- production can be increased/decreased according to demand
- no animal welfare issues
- protein contains no animal fat/cholesterol
- microorganism can be easily modified to adjust the amino acid content
- can go all year round
- not much land required
Disadvantages of using microorganisms in food production
- some people may not want to eat fungal protein
- protein needs to be purified to ensure it isn’t contaminated
- microbial biomass can have a lot of nucleic acids which must be removed
- amino acid profile may be different from animal protein
- care must be taken to ensure the culture is not infected with the wing organisms
What conditions must be controlled in fermenters?
Temperature - too hot will denature enzymes, too cold and growth will be limited
Nutrients available - sources of carbon, nitrogen, vitamins and minerals are needed
Oxygen availability - for aerobic respiration
pH - will affect enzymes
concentration of product - if product is allowed to build up it may affect the synthesis.
What is the water jacket for on a fermenter?
Allows circulation of water around a fermenter to regulate temperature
What is batch fermentation?
Where microorganisms are grown in individual batches in a fermentation vessel. Products made only when cells are placed under stress such as high population density or limited nutrients availability. These are secondary metabolites and are produced in the stationary phase of growth.
What is continuous fermentation?
Microorganisms are continually grown in a fermentation vessel without stopping. Nutrients are put in and products taken out at a constant rate. These are primary metabolites.
Why is asepsis important?
Unwanted miroorganisms will:
- compete with the cultured microorganisms for nutrients and space
- reduce the yield of useful products
- spoil the product
- may produce toxic chemicals
Advantages of bioremediation
- uses natural systems
- less labour/equipment required
- treatment in situ
- few waste products
Aseptic techniques
- wash hands
- disinfect working area
- have bunsen burner operating nearby to prevent microorganisms settling
- when opening a vessel, pass neck of bottle over flame to prevent bacteria entering
- do not lift lid off completely
- equipment should be passed through flame before and after contact with microorganism
Sterilisation
Medium sterilised by heating in an autoclave which kills all living organisms. Then poured into sterile petri dishes.
Inoculation
The introduction of microorganisms to a sterile medium by:
- streaking, wire loop used to transfer liquid medium by dragging it across the surface
- seeding, sterile pipette used to transfer small drop of liquid medium to the surface
- spreading, glass spreader may spread inoculated drop across surface
Incubation
Petri dish taped up and placed in a warm environment such as an incubator.
