22.5 Microorganisms, Medicines and Bioremedicine

Question 1

What is penicillin produced by?

Answer 1

Penicillium notatum, penicillium chrysogenum

Question 2

Who discovered penicillium chrysogenum?

Answer 2

Mary hunt, on a melon covered in gold mould on a marker stall

Question 3

What is the difference between penicillium notatum, and penicillium chrysogenum?

Answer 3

-penicillium notatum produced very small yield of penicillin

Question 4

What is the problem with penicillium chrysogenum?

Answer 4

Needs relatively high oxygen levels, and a nutrient rich medium to grow well, it is sensitive to pH and temperature

Question 5

What are the conditions for growing penicillin on a mass scale in a fermenter?

Answer 5

-Small fermenter as it if difficult to maintain high level of O2 in very large bioreactors
-Bioreactors maintained at about 25-27
-Growth medium contains a buffer to keep optimum pH at 6.5
-Nutrient rich medium

Question 6

How is insulin made through microorganisms?

Answer 6

-Genetically modified bacteria which have the gene for human insulin production is inserted into their DNA
-These bacteria are grown in an industrial fermenter on a massive scale, the insulin is then collected and purified

Question 7

What were problems with using insulin from microorganisms (before use of fermenters)?

Answer 7

-Supply of insulin from animals was dependent on the demand for meat, when fewer animals were killed less insulin was made
-Used to cause problems as soem were allergic impure insulin but now very pure forms are developed
-Peak activity of animal insulin is several hours after injection, which made calculating meal times difficult
-Some faith groups do not permit using pig products
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Question 8

What are the two approaches for bioremediation?

Answer 8

Using natural organisms, Genetically modified organisms

Question 9

How are naturally occurring organisms used for bioremediation?

Answer 9

-Many microorganisms naturally break down organic material producing CO2 and water
-If microorganisms are supported they will break down and neutralise many contaminants
eg. nutrients added to water to encourage microbial growth and oil dispersed into smaller particles to give the maximum surface area for microbial action

Question 10

How are genetically modified organisms used for bioremediation?

Answer 10

-Scientists finding ways to develop GM bacteria which can break down organic material producing accumulate contaminant as which would not naturally occur
eg. bacteria engineered to remove mercury contamination from water as it is toxic and accumulates in food chains
-Aim to develop filters containing bacteria to remove mercury from contaminated sites

Question 11

What type o bioremediation is more effective?

Answer 11

In most cases natural microorganism outperform genetically modified bacteria, but as ability to change genetic material of microorganisms increases, it may be possible to use bioremediation even more effectively