chapter 20

Question 1

industrial microbiology

Answer 1

• Indutrial use of microorganisms to produce useful compunds
  
  • Primary metabolites are produced during exponential phase: ALCOHOL
    Secondary metabolites at the end of growth, near or at the stationnary phase: ANTIBIOTICS

Question 2

fermentors

Answer 2

• Vessels used for industrial growth of microorganisms (chemostat)
  
  • In industrial micribiology, fermentation refer to any large-scal microbial process (aerobic or anaerobic)
  • Control of:
    1. TEMPERATURE
    2. NUTRIENTS
    3. PH
    DISSOLVED OXYGEN

Question 3

microorganisms in industry

Answer 3

• Wild-type strains are usually not suitable
  
  1. Use mutant strains that overproduce the desired metabolites; desregulated mutant with respect to desired metabolic pathway. Leds to large scale production of the compund
     - Versu useful to produce AA (corynebacterium sp.)
     Genetically modified organisms, genes are cloned into and expressed in bacteria and yeasts. Can control expression to synthesize as much (or as little) products as required. Human insulin and a variety of enzymes (rennet) are produces this way

Question 4

somatotropin

Answer 4

Somatropin:
1. Human growth hormone
2. Deficiency causes hereditary dwarfism
- In some cases, administration of human somatropin drugs can correct stunted growth in children
Recombinant human somatotropin gene cloned and expressed in bacteria (ex: e. coli, convert BST by reverse transcriptase, injected it in the E. coli., do commercial production and inject it in the cow)

Question 5

insulin production

Answer 5

• Hormone produced by beta cells of pancreas
  
  • Regulates metabolism of CHO, fats, proteins
  • Type 1 diabetes mellitus = pancreas no longer makes insulin: leads to very high blood sugar levels
  • Insulin injections are necessary to preserve glucose homeostasis and FOR SURVIVAL (lower blood sugar levels)
    INSULIN WAS THE FIRST HUMAN PROTEIN TO BE PRODUCED BY BACTERIA

Question 6

herbicide resistant plants

Answer 6

• Can genetically engineer herbicide or insect resistance into a crop plant
  
  • Herbicide example: GLYPHOSATE (roundup) kills pants by inhibiting AA synthesis:
    1. Take gene from glyphosate resistant bacteria
    2. Modifiy expression in plants
    3. Clone (transfer) into crop plant
    End result: crop plant is resistant, can use glyphosate to kill weeds (ex: most soybean crops)

Question 7

insect resistance

Answer 7

Resistance to insects:
1. Introduces genes encoding bacterial toxin that is toxic to insect into the plant
2. Plants produce the toxin
3. Insects that come into contact with plant ingest toxin and die
Ex: BT toxin very toxic to moths and butterflies (but not mammals)