Biotechnology- Module 6 Flashcards
Biotechnology =
The industrial use of living organisms (or parts of living organisms) to produce food, drugs and other products.
Uses of Biotechnology
Food production
Medicine
Bioremediation
Culturing
Medicine - biotechnology
-Insulin production- (GM bacteria)
-Penicillin production- (from fungi, secondary metabolite)
Bioremediation-
using microorganisms to remove pollutants e.g oil & pesticides from environment
Cheese production-
uses rennet (containing chymosin to clot milk) from GM yeast cells & lactic acid bacteria to convert lactose into lactic acid
Brewing-
yeast is added to barley and produces CO2 and ethanol under anaerobic conditions
Yoghurt production-
involves lactic acid bacteria to clot milk and cause it to thicken.
Why are microorganisms usually used in biotechnology?
-Can be genetically engineered.
-Normally grow well in relatively low temperatures.
-Generate products in a very pure form.
-Grow rapidly in favourable conditions (generation time of 30 minutes).
-Often release the products into the medium, which makes them easy to harvest.
-Can be grown anywhere in the world, growth is not dependent on climate.
How is Quorn produced
Made of Fusarium Venetatum, a single celled fungus grown in large fermenters using glucose syrup as a food source
-Microorganisms combined with albumen (egg white) and then compressed and formed into meat substitutes
Indirect vs Direct food production
e.g
Indirect. Microorganisms convert food A into food B
e.g: cheese, bread
Direct, Microorganisms directly make food C e.g: Quorn
Advantages of Using microorganisms to produce Quorn
(+)high protein content, little fat
(+) Microorganisms reproduce fast + produce protein faster than animals and plants
(+)Use wide variety of waste materials
(+)Can be genetically modified to produce protein required
(+)Production of microorganisms not dependant of weather, breeding cycles etc, Constant , can in or de crease to match demand
(+)No welfare issues when growing
(+)Can be made to taste like anything
Disadvantages of Using microorganisms to produce Quorn
(-) Can produce toxins if conditions are not optimum
(-) Microorganisms have to be separated from nutrient broth + processed to make food
(-)Need sterile conditions that are carefully controlled adding to costs
(-)Often involve GM microorganisms, people have concerns about this
(-) Protein has to be purified to ensure it contains no toxin or contaminants
(-)Many people dislike the thought of eating microorganisms grown on waste
(-)Has little natural flavour - needs additions
Sigmoidal growth curve of microorganisms in a closed culture
Stages in order
Lag phase
Log/Exponential stage
Stationary phase
Death/Decline phase
What happens in the Lag phase of a Sigmoidal growth curve of microorganisms in a closed culture
Bacteria are adjusting to the conditions
The bacteria need to synthesise enzymes to absorb the nutrients available.
What happens in the Log/Expo phase of a Sigmoidal growth curve of microorganisms in a closed culture
Birth rate is higher than death rate
Bacteria multiply very rapidly by binary fission.
There are very few limiting factors.
The bacteria are only limited by the rate of cell division.
What happens in the Stationary phase of a Sigmoidal growth curve of microorganisms in a closed culture
The population of the bacteria is constant.
The “birth rate” equals the death rate of the bacteria.
Excretory products start to build up within the petri-dish.
There is increased competition for nutrients.
What happens in the Decline phase of a Sigmoidal growth curve of microorganisms in a closed culture
Nutrients have run out.
There is a high concentration of excretory products.
There is no reproduction of bacteria, so the ones that die are not replaced.
Eventually the population equals zero.
What are microorganisms cultured in in a lab setting?
Broth
Agar plate
What are microorganisms cultured in in an industry setting?
Bioreactor / fermenter
All components of a fermenter
Pressure vent
Probes
Tap
Water jacket inlet
Water jacket outlet
Air inlet
Air outlet
Inlet
Mixing blades
Motor
What are the functions of the Pressure vent on a fermenter
Prevents any gas build up
What are the functions of the Air inlet on a fermenter
Sterile air provides oxygen in aerobic fermenters
Other name for mixing blades in fermenter
impellers
What are the functions of the water jacket inlet on a fermenter
allows circulation of water around the fermenter to regulate temp
What are the functions of the motor on a fermenter
rotates the blades (impellers) to mix the culture evenly
What are the functions of the outlet tap on a fermenter
To drain fermenter
What are the functions of the Inlet on a fermenter
for addition of nutrients
What are the functions of the air outlet on a fermenter
Often in a ring-
air bubbles out from outlets, mixing with culture (known as sparging)
What are the inlets and outlets fitted with on a fermenter and why
Filters to prevent contamination
What are the functions of the probes on a fermenter
Electronic probe for measuring oxygen, pH and temperature levels
Limiting factors in a fermenter / factors to control
why
-Temperature- too low & MOs don’t grow quickly enough, too high and enzymes denature
-pH- as carbon dioxide builds up it lowers the pH of the culture so may not be optimum for enzymes
-Nutrients available
-Oxygen
-Build up of waste- can inhibit further growth
To maximise growth in a fermenter, Do
niche
-Stirring- diffusion is not enough to ensure MOs receive enough food and oxygen
-Asepsis- ensure no contamination which can affect yield
Primary metabolites are made during ____ _____ e.g proteins, enzymes, nucleic acids, ethanol etc.
They are essential to the ______ of the organism.
normal growth
functioning
Production of primary metabolites _____the growth curve
follows
Secondary metabolites are substances that ____ essential for normal growth e.g pigments, toxins from plants and antibiotics.
are not
Secondary metabolites ________ produced during exponential growth. They are usually produced in the _______ _______.
are not
stationary phase
Batch fermentation process
MOs are inoculated into a fixed volume of medium
Nutrients are used up and waste products build up
As it reaches stationary phase, overall growth ceases
The process is stopped before the death phase and the products are harvested
The system is cleaned and sterilised and a new culture started up.
(products must be separated which is expensive )*
Continuous fermentation Process + use
Sterile nutrient medium is added continually once it reaches exponential growth point.
Culture broth ( medium, waste products, MOs and products) are continually removed.
Continuous balanced growth is enabled- levels of pH, nutrients and metabolic products are kept constant.
Used for production of single-celled protein and waste water treatment.
Asepsis:
The absence of microorganisms.
Aseptic technique:
A technique used to culture microorganisms in sterile conditions that prevents the transfer or growth of unwanted microorganisms.
Culturing microorganisms using the aseptic technique
INOCULATING BROTH
-Sterile nutrient medium is mixed with a suspension of bacteria
-Flask is stoppered with cotton wool (to allow the passage of air, but prevent the passage of micro-organisms)
-Incubate at a suitable temp and shake regularly
Culturing microorganisms using the aseptic technique
INOCULATING AGAR
-Use inoculating loop to spread bacterial suspension in zig zag streaks ( making sure not to damage agar)
-Replace lid and seal with two pieces of tape ( not all the way around)
-Incubate at around 25°C
culture microorganisms using aseptic techniques Before Inoculation
-Sterilise all glassware in an autoclave ( a machine which steams equipment at high pressure)
-Disinfect work surfaces
culture microorganisms using aseptic techniques During Inoculation
-Work near a Bunsen flame- hot air rises so MOs in the air should be drawn away from the culture.
-Sterilise equipment ( inoculating loop etc) by passing through a Bunsen
-Pass the neck of the broth bottle through Bunsen flame just before and after using it- causes air to move out of container preventing MOs getting in.
-Minimise the time agar plate is opened ( or use inoculation cabinet which has a flow of sterile air)
culture microorganisms using aseptic techniques After Inoculation
Seal plate but not all the way around- so oxygen can get in (dangerous pathogens respire anaerobically)
After the bacteria have been cultured in the desired conditions, there may be too many to count colonies overlap, forming a_____
A solution to this problem is to use a_______ _______method to _____the bacteria in the broth before plating them onto the agar
lawn
serial dilution
dilute
Number of microorganisms in original culture= Number of colonies x _________ _________
dilution factor
How to create solutions at different pH easily
Use pH buffers
why are immobilised enzymes used?
using free enzymes is wasteful as they can not usually be recovered and are lost at the end of the process.
Immobilised enzymes are held stationary, they can be recovered from reaction mixture and reused.
These enzymes do not contaminate end product, less downstream processing needed
Different methods of immobilising enzymes
Surface immobilisation
-aDsorption
-Covalent or ionic Bonding
Entrapment
-In a matrix
-In a capsule
Immobilising enzymes - advantage, disadvantage
adsorption to inorganic carriers
vs
Covalent or ionic bonding
adsorption to inorganic carriers
weaker bonds, so:
(+)Flexible
(-) easily lost
Stronger ionic + covalent bonding
(+) Harder to be lost
(-) Less flexibility (less efficient
Immobilising enzymes -
Entrapment vs Surface immobilisation
Entrapment
(+) more stable - no enzymes lost
(-) material more expensive
(-) Diffusion of substrate to, and product from active site can be slow efficiency not as high
(+) Widely applicable to different processes
Surface immobilisation
(+) Cheaper
(-) Enzymes easier to be lost
(+) Enzyme accessible to substrate
Immobilising enzymes -
Encapsulation vs Matrix
Encapsulation
(+) simple
(+) small effect on enzyme activity
Matrix
(-) Difficult to entrap
3 factors to consider when stating pros and cons of immobilised enzymes
1) Purity
2)Cost
3) Efficiency
Artificial plant clones using cuttings process
- Cut the stem of the plant at a slant
- Dip into rooting powder
- Plant into a pot containing soil in a warm, moist environment to reduce transpiration e.g in a propagator/ cover in plastic bag
- Re-plant when roots are grown.
Advantages of taking cuttings
+ Cheap and does not require specific skills
+ Much faster than growing from seed
+ Gives clones of plants with desirable characteristics
Disadvantages of taking cuttings
-Lack of genetic variation in offspring
-Doesn’t make as many plants as tissue culture
name of sterilising tablets used in Micropropagation and sterilising water
dichloroisocyanurate
Process of micropropagation
1)take small sample of plant tissue (usually from shoot tips and axial bulbs as they are usually virus-free)
2)sterilise sample by immersing in sterilising agent
3)the Explant (material removed from plant) placed in sterile culture medium containing balance of plant hormones which stimulate mitosis (Auxins + Cytokines). The cells proliferate, forming mass of identical cells known as callus
4)the callus are divided up and transferred to new culture medium containing different hormones and nutrients which stimulate development of tiny, genetically identical plantlets
5)plantlets then potted into sterile soil where they grow into small plants
6)Young plants are planted out to grow and produce crop
Advantages of micropropagation
+ Large numbers of identical crops always good yield
+ Can make crops disease- free/ seedless
+ Provides a way of growing lots of plants which are difficult to grow from seeds e.g orchids
+ Can produce lots of rare/endangered plants
+ Can happen at any time of year
Disadvantages of micropropagation
No genetic variation in offspring-> susceptible to disease/ climate change
Expensive
Requires skilled workers
Contamination can lead to getting rid of whole culture
Non-desirable traits also passed on e.g fruit with lots of seeds
when is micropropagation used
when desireable plant:
* deosn’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: strawberry, banana, potatoes
Artificuall twinning process
Eggs from cow with desireable traits and sperm from bull are collected .
Eggs are firtilised in Vitro to form an early embryo
embryo split into totipotent cells
each totipote cell develops into an embryo
embryos transfered to surrogate mothers
identical cloned offspring
Somatic cell nuclear transfer (SCNT) process
- Nucleus removed from a somatic cell of the animal to be cloned
- Nucleus removed ftom an oocyte (immature egg cell) forming an enucleated oocyte
- Nucleus inseted into enucleated oocyte
- Mild electric shock is give nso the enucleated oocyte and nucleus fuse and begin to divide into an embryo
- Embryo is implanted into the Uterus of a surrogate mother
- Offspring genetically identical to sheep A
Grafting
what is it
why
- A slit is cut in a wooden stem and another woody stem is placed into it.
- You must ensure that the xylem and phloem of the two plants are lined up and the wound is covered until it’s healed.
- This is often done with trees and shrubs to combine the best characteristics of the two plants. E.g making shorter fruit trees for gardens
Totipotent
- a stem cell that can differentiate into any type of cell and form a whole new organism.
Uses of cloning animals
-Testing new drugs on cloned animals animals are all genetically identical so the variables that come from genetic differences( e.g the likelihood of getting cancer) are removed.
-Used in agriculture to increase the numbers of animals with desirable features to breed from.
-Can clone animals that have been genetically modified to produce a specific substance e.g goats producing beneficial proteins in milk.
-To save endangered animals from extinction.
Reasons for Animal cloning
-Desirable genetic characteristics are always passed on to clones
-Infertile animals can be reproduced
-Animals can be cloned at any time- not just breeding season
-Increasing population of endangered species gets to preserve biodiversity
-Can help develop new treatments for disease
Reasons against animal cloning
Undesirable characteristics( e.g weak immune system) are also passed on to clones
-Population all susceptible to same diseases
-SCNT is inefficient-takes many eggs to produce one clone
-Animals may have shortened lifespan
-Animals may fail to develop/miscarry
after insertion of nucleus into enucleated oocyte, what happends to allow fusion, what is thic called
electric shock - electrofusion
