Biotechnology

Front 1

What is biotechnology

Back 1

Biotechnology is the use of living organisms to produce foods, drugs and other similar products.

Front 2

Why do you use microorganisms in biotechnology

Back 2

1) They grow rapidly in favourable conditions with low generation times
2) Often produce proteins or other chemicals that are given out into surrounding tissue medium that can be harvested
3) Can be genetically engineered to produce a particular product
4) Can be grown anywhere in the world and are not dependent on climate
5) Tend to generate products that are in a more pure form that those generated via chemical processes
6) Can often be grown using nutrient materials that would be otherwise useless or even toxic to humans

Front 3

Describe and explain, with the aid of a diagram, the standard growth curve of a population of microorganisms

Back 3

- Lag phase - organisms are adjusting to the surroundings meaning that they may be taking in water, expanding in size, activating genes and synthesising specific enzymes- cells are active but are not reproducing so population remains relatively stable
- Log phase - population size increases exponentially as they are rapidly reproducing
- Stationary Phase - nutrient levels decrease and waste products like carbon dioxide and other metabolites build up - individual organisms die at the same rate at which new individuals are produced
- Decline phase - nutrient levels exhaust and increased levels of toxic/waste products leading to the death rate increaseing above the reproduction rate - eventually all organisms die in a closed system

Front 4

What are primary metabolites

Back 4

Substances produced by an organism as part of its normal growth including amino acids, proteins, enzymes, nucleic acids, ethanol and lactate.

Front 5

What are secondary metabolites

Back 5

Substances produced by an organism that is not part of its normal growth - the antibiotic chemicals produced by a number of microorganisms are almost all secondary metabolites and the production of secondary metabolites usually begins after the main growth period of the organism and so does not match the growth in population of the organism.

Front 6

Compare and contrast the processes of continuous and batch culture

Back 6

1) Batch rate is slower because nutrient levels decline, whereas in continuous the growth rate is higher as nutrients are continuously added to the fermentation tank
2) Batch is easier to set up and maintain, in continuous it is more difficult to set up and maintenance can be quite difficult
3) In batch, if it is contaminated, only one batch is lost whereas in continuous if it is contaminated - huge volumes of products could be lost
4) Batch culture is less efficient and fermenter is not in operation all the time whereas continuous is more efficient and the fermenter operates continuously
5) Batch is more useful for production of secondary metabolites whereas in continuous culture - it's very useful for processes involving the production of primary metabolites

Front 7

What is a batch culture

Back 7

A batch culture is where the microorganism starter population is mixed with a quantity of nutrient solution and allowed to growth for a fixed period with no further nutrients being added and at the end it is removed

Front 8

What is continuous culture

Back 8

A continuous culture is where nutrients are added to the fermentation tank and products are removed from the fermentation tank at regular intervals or continuously as they form

Front 9

Explain the importance of asepsis in biotechnological processes involving microorganisms

Back 9

Nutrient medium in which the microorganisms growth could also support unwanted microorganisms
These:
- Compete with the culture microorganisms for nutrients and space
- Reduce the yield of useful products from the culture microorganisms
- Cause spoilage of the products
- Produce toxic chemicals
- May destroy the culture microorganisms and their products.

Front 10

Give examples of aseptic techniques used in laboratory and starter culture level

Back 10

1) All apparatus for carrying / moving microorganisms are sterilised before and after use, for example by heating in a flame until glowing or using UV light and steam sterilisation at 121 degrees for 15 minutes in an autoclave
2) Work can be carried out in fume cupboard where the air circulation carries away airborne contaminants from the bench space
3) Cultures of microorganisms are kept closed where possible and away from the bench surface when open and in use

Front 11

Give examples of aspetic techniques and measures at large scale culture level

Back 11

1) Washing, disinfecting and steam cleaning the fermenter and associated pipes when not in use.
2) Fermenter surfaces made of polished stainless steel prevents microbes and medium sticking to surface
3) Sterilising all nutrient medium before adding them to the fermenter prevents the introduction of contaminants
4) Fine filters on inlet and outlet pipes to avoid microorganisms entering or leaving the fermentation vessel.

Front 12

What are the methods of immobilising enzymes

Back 12

- Adsorption
- Covalent bonding
- Entrapment
- Membrane separation