Lecture 2

Question 1

What are the 5 major groups of microbes exploited in industrial microbiology, and if specified what are they used to produce?

Answer 1

Actinomycetes - antibiotics and amino acids
Cyanobacteria - potential renewable food stuffs in future
Proteobacteria

Fungal yeasts
Filamentous fungi

Question 2

What 4 possible products from microbes do we use?

Answer 2

MIcrobial cells (broken up or whole)
Products from cells:
Enzymes 
Primary metabolic products
2ndry metabolic products

Question 3

Examples of specific products from cells because I know how much you love your examples

Answer 3

enzymes  - glucose isomerase 
Antibiotics  - penicillen 
food additives - amino acids
alcohol - ethanol
chemicals - citric acid

Question 4

Name 4 uses of microbial cells as a whole, give details where poss

Answer 4

food stuffs (Quorn)
Whole cell biotransformation - ‘cell factories’ (often living but not growing cells)
Why good: work at low temps, few side products, normally specific, grown in aqueous rather than organic solvents. If whole metabolic pathways are undisturbed.
Removing nuclear waste - resting cells of Desulfovibrio desulfricans precipitate 99Tc (waste product of nuclear fuel cycle with long half life) and immobilise it
Steriod production and purification - Rhizopus Arrhizus and Curvularia Lunata covert basic (cheap steroid) to cortisol

Question 5

What are the 2 ways to get enzymes from microbes?

Answer 5

Direct extraction

expressed as recombinant protein

Question 6

Main benefits of enzymes

Answer 6

specificity
efficiency under optimum conditions
producing them, is very rapid
growth conditions and materials inexpensive

Question 7

Define bulk enzyme

Answer 7

partially purified

Question 8

Give 2 examples of them and their uses

Answer 8

Detergenets - proteases and lipases
clothe colour improvement - cellulases (strips off outer layer)
Sweet making - Intvertases

Question 9

What’s the other type of enzyme used, other than bulk

Answer 9

purified recombinant enzyme

Question 10

Examples of recombination purified enzymes and uses

Answer 10

Restriction endonucleases - used to make other enzymes and proteins
Glucose oxidase - test blood sugar - diagnostics
cholesterol esterase - monitoring cholesterol levels - diagnostics

Question 11

When are primary metabolites made?

Answer 11

majority of the time in the cell’s life cycle

Question 12

4 most important primary metabolites

Answer 12

purine nucleotides
vitamins
organic acids
amino acids

Question 13

Main use of amino acids and the 3 main required

Answer 13

food additives

Glutamate, lysine, tryptophan

Question 14

What is primarily used for making aa’s

Answer 14

gram +ve bacterium Corynebacterium glutamicum

Question 15

Why must 2ndry metabs be grown in particular ways or genetically engineered?

Answer 15

only produced at particular time in cell life, often in periods of stress

Question 16

What is the main example of a biopolymer and it’s use in the EU

Answer 16

bacterial exopollysaccharide xanthan gum - a thickner

Question 17

What’s exg made by?

Answer 17

Xanthomonas sp. and X. campestris (in lab) as a defense mechanism

Question 18

properties of exg

Answer 18

soluble in hot or cold water, high viscosity at low concs, secreted (-therefore extraction theoretically easy but actually very viscous so tricky)

Question 19

What did Fleming originally observe to discover penecillin

Answer 19

Penecillium notatum killed Staph. a.

Question 20

How did scientists get around the problem of low yield produced by P. notatum

Answer 20

Discovered P. chrysogenum

Question 21

Where were more antibiotics discovered and of those that they make what’s the most well known AB called?

Answer 21

soil bacteria collectively called Actinomycetes.

Streptomycin

Question 22

How are new antibiotics being discovered and made?

Answer 22

• metagenomics used to find novel clusters of genes for antibiotic synthesis. These are then expressed in a heterologous host and screen for new antibiotics.
• use gene shuffling to biologically modify ab

Question 23

How are antibiotics made currently?

Answer 23

fermentation for natural and semi synthetic abs.