1. Genetic control of metabolism
Key Area 2.7
Genetic control of metabolism
Growth media and environmental factors
Phases of growth
Control of metabolism

2. Word Splat! Secondary metabolite aseptic Growth medium Growth Log
Inducer
Fermenter
Lag
death
Semi-logarithmic
stationary

3. Improving Micro-Organisms
Learning Intentions
Describe the methods by which wild strains of microbes can be improved for human use.

4. Wild strains
Wild strains of micro-organisms that occur naturally can be selected and cultured
We look for desired traits, we can then improve the strain for our own benefit 4

5. Strain improvement
Wild strains may have some desirable characteristics but may lack other important features:
Genetic stability
Ability to mass produce desired compounds
Strains of micro-organism can be improved by:
Mutagenesis
Selective breeding
Recombinant DNA technology. 5

6. What things do you know of that increase the risk of cancer in humans?
1. Mutagenesis
Mutagenesis is the creation of mutations
The rate of mutagenesis can be increased by exposing an organism to mutagenic agents
What things do you know of that increase the risk of cancer in humans? 6

7. Mutagenic agents Mutagenic agents alter DNA and induce mutations
UV light
X-rays
Nuclear radiation 7

8. Mutagenesis in microbes
Mutagenic agents are used by us to induce the production of mutant alleles in microbes
Most commonly UV light is used to mutate microorganisms which MAY produce an improved strain
Mutated strains are usually very unstable and will revert back to their original ‘wild-type’ 8

9. 2.Selective breeding
In organisms that reproduce sexually (fungi) new genotypes are likely to be expressed in offspring.
This can be used by scientists who will select parents with different desirable characteristics in the hope that both characteristics will be expressed in the offspring
It doesn’t always work! 9

10. Super bacteria
Scientists try to create new bacteria by culturing strains of bacteria next to each other and allowing horizontal gene transfer to occur.
Can you remember the three different ways that bacteria can uptake new genetic information via horizontal transfer? 10

11. Transformation
Bacterial cell takes up foreign DNA from a cell that had been destroyed 11

12. Transduction
Bacterial DNA is packaged in a bacteriophage virus instead of viral DNA
Phage infects new bacteria, which incorporates the DNA as its own 12

13. Conjugation
A conjugation tube (pilus) can form between 2 bacterial cells with different genetic information
They can pass and recombine their genetic information 13

14. Using the information in the diagrams, summarise Transformation, transduction and conjugation.

15. Starter
Unscramble the keywords to todays lesson and match them to their definitions
dmispal
Transports genetic information from one cell to another
sagile
An enzyme used to ‘glue’ the sticky ends of DNA together
nodencluseae
A small loop of DNA found in bacterial cells
rovect
An enzyme that can be used to cut up DNA.

16. Starter Plasmid A small loop of DNA found in bacterial cells Ligase
Unscramble the keywords to todays lesson and match them to their definitions
Plasmid
A small loop of DNA found in bacterial cells
Ligase
An enzyme used to ‘glue’ the sticky ends of DNA together
Endonuclease
Transports genetic information from one cell to another.
Vector
An enzyme that can be used to cut up DNA.

17. Recombinant DNA technology
Learning Intentions
What is the effect of recombinant DNA technology on growth of microorganisms and their products?
How is gene expression controlled in recombinant plasmids and artificial chromosomes?

18. Strain improvement RDT can be used to give microorganisms genes that:
Amplify metabolic steps or remove inhibitory controls –increasing yield
Cause cells to secrete their products into surrounding medium for easier extraction
Prevents the organism surviving in an external environment - safety 18

19. Artificial transformation
Artificial transformation using RDT is more commonly known as genetic engineering!
Write down what you remember about genetic engineering from N5 Biology or what you know from the news/media. 19

20. Artificial transformation
Artificial transformation is is the transfer of genes from one species of organism to another enabling the second organism to produce a specific protein
E.g. an enzyme or hormone 20

21. What does that even mean?!!!!!
Simple steps
Gene for a desirable characteristic is identified
DNA is spliced into the DNA of a vector
Vector inserted into a host cell
What does that even mean?!!!!! 21

22. Vectors
Plasmids and artificial chromosomes are used as ‘vectors’ to carry information from the genome of one organism to another
Vectors transform the organism they are transferred to 22

23. Restriction endonuclease
Restriction endonuclease is an enzyme that can cut up DNA and open bacterial plasmids at a restriction site.
Endonuclease cuts plasmid open
Endonuclease cuts out required gene
DNA fragment with required genes. ‘sticky end’ at each side of gene.
Plasmid (vector) with ‘sticky ends’ 23

25. DNA fragment sealed into plasmid using ligase.
Ligase seals the sticky ends of the required DNA fragment to the sticky ends in the vector (plasmid)
DNA fragment sealed into plasmid using ligase. 25

26. Transformation
Plasmids are then inserted into bacterial cells lacking plasmids 26

28. Marker Genes
Marker genes are needed to see which cells have been successfully transformed.
These are usually antibiotic resistance genes

29. In the example above, a gene that gives the cell resistance to tetracycline is the selective marker.
Screenable markers such as the GFP gene can also be used to detect transformed cells.

30. Health and safety
As a safety mechanism, genes are often introduced that prevent the survival of the microorganism in an external environment. 30

31. Origin of replication
Genes that control self-replication of plasmid DNA and regulatory sequences
Allow control of existing gene and expression of inserted genes
Many copies of gene are expressed and more product is made by fewer cells 31

32. Artificial chromosomes
Have been created by scientists to carry longer sequences of DNA into bacteria
Suggest a benefit of these chromosomes?
More genes can be transferred to the bacteria for production 32

33. Limitations
Prokaryotic cells don’t carry out post or pre translational modification. No splicing occurs (Prokaryotic DNA does not contain introns)
Proteins made may be inactive because the bacteria cannot carry out the modifications
Yeast is often used instead of bacteria to overcome this issue. 33

34. Ethics, risks, hazards
Pharmaceutical companies need to turn profit, less likely to research diseases that are rare or common in poor countries.

35. New strains of micro-organism produced as a ‘result of human research’ can be patented.
Gives the scientist the sole right to make and sell product.
Hinders research and scientific progress

36. Research
Research the development of a microbiological product from discovery to market. 36

37. Tasks
Complete the questions on BST

38. STARTER – Find someone who can answer 1 question only.
The particles cannot move from place to place
Name: 
Explain why gases can be compressed or squashed.
The particles are far apart and have space to move into
Name:
Name a property of a liquid.
It can flow.
Explain why liquids cannot be compressed or squashed.
The particles are close together and have no space to move into
Explain why gases can flow and completely fill their container.
 The particles can move quickly in all directions
Explain why liquids can flow and take the shape of their container.
The particles can move around each other
Explain why solids cannot be compressed or squashed.
 The particles are close together and have no space to move into
Give a definition of diffusion.
Random spreading out of particles in a fluid.
Rules – You can only ask a person to answer one question. Then you must ask another person to answer another question. Teacher can be involved too – if they are struggling. Reward for first people to finish.
Miss M Burns

39. pGlo Transformation Learning Intentions
Carry out a practical to transform E-coli bacteria with the pGlo plasmid.
Assess and minimise risk
Interpret the findings of the investigation.

40. Aequorea victoria

41. Central Framework of Molecular Biology
DNA
RNA
Protein
Trait

42. Transformation Procedures
Lesson 1
Next
week

43. What is transformation?
Uptake of foreign DNA, often a circular plasmid
GFP
Amp Resistance

44. What is a plasmid? A circular piece of autonomously replicating DNA
ori
bla
Originally evolved by bacteria
May express antibiotic resistance gene or
be modified to express proteins of interest

45. The many faces of plasmids
pGLO
ori
bla
GFP
araC
Transmission electron micrograph
Agarose Gel
Graphic

46. pGLO Plasmid Beta Lactamase Green Fluorescent Protein
Ampicillin resistance
Green Fluorescent Protein
Aequorea victoria jellyfish gene
araC regulator protein
Regulates GFP transcription
pGLO
ori
bla
GFP
araC

47. Bacterial Transformation
GFP
Beta lactamase
(ampicillin resistance)
pGLO plasmids
Bacterial
chromosomal DNA
Cell wall

48. Transformation Procedure
Suspend bacterial colonies in Transformation Solution
Add pGLO plasmid DNA
Place tubes on ice
Heat shock at 42oC and place on ice
Incubate with nutrient broth
Streak plates

49. Predictions
The bacteria will not grow as it does not contain the plasmid with the ampicillin resistance gene so it will be killed of by the antibiotic.
The bacteria will grow as it contains the plasmid with ampicillin resistance. The bacteria will not glow as the inducer (arabinose) is not present
LB/AMP +pGlo
LB/AMP -pGlo
The bacteria will grow as it contains the plasmid with ampicillin resistance. The bacteria will glow as the inducer (arabinose) is present
Bacteria growing as no antibiotic to kill them off
LB/AMP/ARA +pGlo
LB -pGlo

50. Volume Measurement

51. Outcome