Week 8: Microbes and industry

Question 1

1917

Answer 1

scientists at Pfizer discovered that Aspergillus niger produces citric acid under
specific environmental conditions

Question 2

1929

Answer 2

Commercial production began; cheaper and faster product

Question 3

1940

Answer 3

Pfizer used similar processing technology for large-scale production of
penicillin (Penicillium notatum)

Question 4

Once identified, most strains used for commercial production require

Answer 4

strain improvement

Question 5

subjecting stgrain to UV radiation

Answer 5

• Induces random mutations
• Some harmless, some harmful and occasionally one that results in a strain that
overproduces the useful metabolite
• Artificially select and isolate the overproducer and grow this strain

Question 6

optimizing environmental conditions can also enhance metabolite production:

Answer 6

pH, temp, O2 levels, nutritional factors

Question 7

primary metabolite production

Answer 7

mirrors cell growth, throughout long phase of growth

Question 8

secondary metabolite production

Answer 8

occurs after microbial population enters the stationary phase of growth

Question 9

other important factors of strain selection

Answer 9

• Ability to grow in large-scale cultures
• Rapid growth rate, ideally in inexpensive liquid media
• Safety for humans, animals and the environment (accidental release)

Question 10

commercial production of antibiotics occurs after

Answer 10

• Shown to be effective against microorganisms in vitro (cells, lab setting) and in vivo
(living animals, lab setting)
• Shown to be safe in animal trials followed by human clinical trials
• Able to be produced large-scale

Question 11

steroids produced through

Answer 11

bioconversion

Question 12

bioconversion

Answer 12

microbe converts a common sterol compound into steroid of interest, this is faster adn less expensive than chemical synthesis

Question 13

proteases

Answer 13

Used to tenderize meat, clean out clogged drains (hair), laundry detergents (blood stain)

Question 14

cellulases

Answer 14

laundry detergents

Question 15

extremozymes

Answer 15

derived from microbes living in extreme environments

Question 16

biopesticides

Answer 16

Proteins produced by microbes that are harmful to insects

Question 17

bacillus thurigiensis

Answer 17

produce toxins harmful to moth and mosquito larvae

Question 18

bioremediation

Answer 18

use of microbes to break down pollutants in the environment

Question 19

biofilm

Answer 19

microbes held together by carbohydrates secreted by the microbe

Question 20

example organism in bioremediation

Answer 20

pseuodomonas sp.

• readily forms biofilms
• used in oil spills since it contains enzymes that can digest hydrocarbons

Question 21

bioremediation is being investiagted as a solution to reduce the enviro. contamination of several compounds:

Answer 21

• PCBs (carcinogens)
• Radioactive waste (uranium, plutonium)
• Heavy metals (mercury)
• Explosives (TNT)
• Plastics

Question 22

composting

Answer 22

Degradation of solid organic wastes by bacteria

Question 23

biofuels

Answer 23

ethanol, methane, algal biofuel, microbial fuel cells

Question 24

ethanol

Answer 24

• Produced through fermentation using
various carbohydrate sources
• Corn
• Cellulose (agricultural wastes)

Question 25

methane

Answer 25

capture from sealed landfills to generate electricity

Question 26

algal biofuel

Answer 26

Different components of algae cells used in

production of ethanol or biodiesel

Question 27

microbial fuel cells

Answer 27

Passing final electrons to electrodes, rather

than a final electron acceptor