Lecture 12: Industrial Microbiology

Question 1

What did Sir Alexander Fleming (1881-1955) do for industrial microbiology?

Answer 1

1) Discovered the enzyme lysozyme in 1922.
2) Discovered the antibiotic penicillin from the fungus Penicillium notatum in 1928.
3) Shared Nobel Prize in Physiology or Medicine in 1945 with Florey and Chain.

Question 2

1) Who helped Fleming produce penicillin?
2) What did Fleming warn people about penicillin?

Answer 2

1) Fleming didn’t have the equipment to produce much penicillin, so the US govt and beer brewers aided its production.
2) Cautioned people to be responsible with penicillin because he observed antibiotic resistance development pretty quickly.

Question 3

Define industrial fermentation

Answer 3

Any large-scale microbial process occurring with or without air.

Question 4

What are the 5 general steps of fermentation?

Answer 4

1) Start with a stock culture in a bioreactor (O2 and pH control)
2) Recovery (filtration)
3) Recovery extraction (solvents)
4) Purification
5) Product.

Question 5

1) Name 2 factors in the general fermentation scheme
2) During filtration in general fermentation, what can be done with the unneeded stuff?

Answer 5

1) Stock culture to inoculum (microbial cells) and medium preparation are also factors.
2) During filtration, stuff can be recycled through sterilization, thrown away as waste, or used as biofuel.

Question 6

Give 2 other names for an industrial fermenter

Answer 6

Bioreactor and chemostat

Question 7

Describe industrial fermenters (chemostats)

Answer 7

1) Has paddles on the inside to accelerate microbial growth
2) Has pH and oxygen probes
3) Has an air in line with a filter and a tube to add culture or nutrients

Question 8

1) What are the primary metabolites of fermentation?
2) What are the secondary metabolites of fermentation?

Answer 8

1) Primary: amino acids, nucleotides, fermentation end products
2) Secondary: antibiotics

Question 9

1) When are the primary metabolites of fermentation made?
2) When are the secondary metabolites of fermentation made?

Answer 9

1) Primary: Exponential (log) phase
2) Secondary: Stationary phase

Question 10

Describe anaerobic digesters

Answer 10

Used in farms, built into the ground and allows manure to enter a chamber where biogas (methane) is produced by bacterial fermentation.

Question 11

Describe microbial fuel cells, what do they try to do?

Answer 11

Trying to utilize bacteria to generate electricity; would bypass the need for biofuel because the bacteria would pass the electrons directly to an anode.
Movement of electrons from anode to cathode would generate electricity.

Question 12

Name 5 ways to increase the yields of microbial products and define each

Answer 12

1) Mutagenesis: inducing mutagenesis by stressing the bacteria out; doesn’t allow for targeting specific mutations
2) Protoplast fusion: 2 organisms fuse together, allows for recombination
3) Genetic transfer between organisms: horizontal gene transfer (transformation, conjugation, transduction)
4) Modification of gene expression: modify transcription binding sites, modification of proteins, etc.
5) Directed evolution: direct approach by mutating specific targets, allows for specific inactivation or complementation of a gene.