22.4 Microorganisms and Biotechnology Flashcards
What is biotechnology?
The large scale, industrial use of living organisms and enzymes to produce food, drugs and other products
What are examples of food made through biotechnology?
Cheese, yoghurt, beer, mycoprotein
What are microorganisms?
Bacteria and fungi
Why are microorganisms used for biotechnology?
-No welfare or ethical issues to consider
-Their ideal growth conditions can be easily created
-Grow rapidly under the right conditions due to their short lifespan
-Can be genetically engineered, artificially manipulate microorganisms to produce things they do not synthesise naturally eg. insulin
-Nutrient requirements are often very simple and cheap
-Can be grown on unwanted materials which would be wasted (unwanted food, nutrients)
-Products easy to separate
-Conditions needed have a relatively low temperature, pressure which makes it cheaper and safer to maintain
-Low oxygen supply and food needed = cheaper
Definition of bioremediation
The use of microorganisms to break down pollutants and contaminants in the soil or water
What is the fungus used to make quorn?
Fusarium venatatum
What is the food source of Fusarium venatatum?
Glucose
What is albumen?
Egg white
Why is albumen added to Fusarium venatatum when making quorn?
To increase protein levels, while fat content is still low
What are the advantages of using microorganisms in food production?
-Reproduce fast and produce protein faster than animals and plants
-High protein content with little fat
-Can use a wide variety of waste materials including human and animal waste reducing costs
-Can be genetically modified to produce the protein required
-Not dependant on the weather and breeding cycles, can take place constantly and can be increased or decreased to match demand
-No welfare issues when growing
-Can be made to taste like anything
-Production costs are low because they have simple growth requirements (low temperature, pressure, oxygen and nutrients)
-Makes single-cell protein which is considered healthier than animal protein
What are the disadvantages of using microorganisms in food production?
-Some microorganisms can produce toxins if the conditions are not maintained at optimum
-Have to be separated from the nutrient broth and processed to make the food
-Need sterile conditions that are carefully controlled, adding cost
-Can involved GM organisms, many people have concerns about eating them
-The protein has to be purified
-Many dislike the though of easting microorganisms grown on waste
-Has little natural flavour, needs additives, and has a different texture
-Food can become contaminated with other unwanted bacteria which can be dangerous and spoil the good
-If single-cell protein consumed in high quantities, health problems could rise like high loves of uric acid
How are microorganisms used in baking?
-Yeast is added and mixed with sugar and water to respire anaerobically
-CO2 is produced by fermentation
-CO2 makes the bread rise as bubbles expand when cooked
-Yeast cells are killed during cooking
What is fermentation?
When anaerobic respiration produces ethanol and CO2
How are microorganisms used in brewing (making beer)?
-Yeast is added to a type of grain and other ingredients.
-It respires anaerobically using the glucose from the grain and produces ethanol and CO2
Why is GM yeast used in brewing?
They ferment at lower temperatures and therefore cheaper. They clump together and sink at the end of the process leaving the beer very clear
How are microorganisms used in cheese-making?
-Bacterial feed on lactose in milk, changing the texture and taste, inhibiting the growth of bacteria will make make milk go off
-Milk is pasteurised to kill off microbes so no competition or unwanted reactions occur and homogenised, to ensure fat droplets are evenly distributed throughout milk
-Rennet used which contains enzyme chymosin which clots the milk, yeast cells can be genetically modified to make this enzyme
-Lactobicillius and Streptococcus used to convert the lactose in milk into lactic acid which makes it sour, contributing to it solidifying
How are microorganisms used in yogurt production?
-Use Lactobacillus bulgaicus (forms ethanal) and streptococcus (forms lactic acid) to clot milk to give it its smooth and thick texture
What bacteria is used in cheese-making?
Lactobacillus and streptococcus
What bacteria is used in yoghurt production?
Lactobacillus bulgaricus
Streptococcus
Why is milk pasteurised in yoghurt and cheese making?
To kill off microbes so no competition or unwanted reactions occur
Why is milk homogenised in cheese and yoghurt production?
To ensure fat droplets are evenly distributed throughout milk
