Cloning 2

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what is biotechnology

it is the industrial use of living organisms to produce food,drugs or other products

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Why are microorganisms used in biotecnology

  • ideal growth conditions can be easily created
  • they grow rapidly under the right conditions so products can be made quickly
  • they can grow on a range of inexpensive materials
  • they can be grown at any time of year
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How can enzymes be immobilised

An immobilised enzyme is an ansyme that is attachd to an insoluble material so it can't become mixed with the products of the reaction

Enzymes can be emobilised in three ways

  • encapsulated in jelly like alginate beads
  • trapped in a silica gel matrix
  • covalently bonded to cellulose or collagen
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How can enzymes be immobilised

An immobilised enzyme is an ansyme that is attachd to an insoluble material so it can't become mixed with the products of the reaction

Enzymes can be emobilised in three ways

  • encapsulated in jelly like alginate beads
  • trapped in a silica gel matrix
  • covalently bonded to cellulose or collagen
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Advantages of using immobillied enzymes in industr

  • columns of immoblised enzymes can be washed and reused - this reduces the cost of running a reaction on a industrial scale because you don't have to keep buying new enzymes.
  • The product isn't mixed with the enzymes- no money or time is spent seperating them
  • immobilised enzymes are more stable than free enzymes - they are less likely to denature in high temperatures or extremes of pH.
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Advantages of using immobillied enzymes in industr

  • columns of immoblised enzymes can be washed and reused - this reduces the cost of running a reaction on a industrial scale because you don't have to keep buying new enzymes.
  • The product isn't mixed with the enzymes- no money or time is spent seperating them
  • immobilised enzymes are more stable than free enzymes - they are less likely to denature in high temperatures or extremes of pH.
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what is a culture

a population of one type of microorganism thats been grown under controlled conditions

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what is a closed culture

This is when growth takes place in a vessel that's isolated from the external environment - extra nutrients are not added and waste products are not removed from the vessel during growth.

in a closed culture a population of microorganisms follow a standrad growth curve of 4 stages.

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describe the four stages of a closed culture growt

1- Lag phase

The population size increases very slowly because the microorganisms have to make enzymes and other molecules before they can reproduce. This means the reproduction rate is lower

2- Exopential value

The population size increases quickly because the culture conditionsare at their most favourable for reproduction (lots of food and little competition). The number of microorganisms doubles at regular intervals.

3- Stationary Phase

The population size stays level because the death rate of the microorganisms equals their reproductive rate. Microorganisms die because there is not enough food and poisonous waste poducts build up.

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four stages of closed culture

4-Decline Phase

The population size falls because the death rate is greater than the reproductive rate. This is because food is very scarce and waste products are at toxic levels.

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define the following

 A metabolite- a substance that is formed during a metabolic reacton

Primary Metabolite- produced in favourable conditions

Secondary Metabolite- produced in less favourable conditions- they help microorganisms survive

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define the following

 A metabolite- a substance that is formed during a metabolic reacton

Primary Metabolite- produced in favourable conditions

Secondary Metabolite- produced in less favourable conditions- they help microorganisms survive

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fermentation state in vessels

pH

- monitored by probes/ increases product yield because enzymes can work effectively/ rate of reaction is kept as high as possible

Temperature

-Kept optimum by water jacket/ increases yield because enzymes can work effienctly

Oxygen Supply

- kept optimum by pumping sterile air in

Nutrient content

-kept in contact with fresh medium by paddls that circulate the medium around the vessel. This increases the product yield because the microorganisms can always access the nutrients needed for growth

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fermentation state in vessels

Contamination

- vessels are sterilised with super heated steam

- this means microorganis's are not competing with other organisms

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Describe a batch culture

This is where microorganisms are grown in individual batches in a fermentation vessel- when one culture ends it's removed and then a different batch of microorganisms is growin in the vessel

  • A fixed volume of growth medium (nutrients) is added to the fermentation vessel at the start of the culture and no more is added. The culture is a closed system.
  • Each culture goes through the lad, exponential and stationary growth phases.
  • The product is harvested once, during the stationary phase.
  • The product yield is relatively low- stopping the reaction and sterilising the vessel between fermentations means there's a period when no product is being harvested
  • If contamination  occcurs it only affects one batch. It's not very expensive to discard the contaminated batch and start a new one
  • It's used when you want to produce secondary metabolities
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describe a continuous culture

This is where microorganisms are continually grown in a fermentation vessel without stopping.

  • Growth mediuim flows through the vessel at a steady rate so there's a constant supply of fresh nutrients. The culture is an open system.
  • The culture goes through the lag phase but is then kept at the exponential growth phase.
  • The product is continuously taken out of the fermentation vessel at a steady rate.
  • The product yield is relatively high - microorganisms are constantly growing at a exponential rate
  • If the culture is contaminated the whole lot has to be discarded- this is very expensive when the cultures are done on an industrial scale.
  • It isusually  when you want primary metabolite or the microorganisms themselves as the desired product.
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what is asepsis

This is the practice of preventing contamination of cultures by unwanted microorganisms.e.g.

- disinfecting work surfaces

- tieing hair back

- lids held over open containers.

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