VJ - Fungi II

Question 1

Why do fungi prefer fermentation over respiration despite the energy trade-off?

Answer 1

Due to high competition

Question 2

What are the important products of sugar fermentation? (4)

Answer 2

• Ethanol (brewing)
• CO2 (baking)
• flavor compounds (brewing)
• biomass

Question 3

How is Aspergillus oryzae used in food processing?

Answer 3

It is used in the fermentation of soybean paste, roasted wheat, water, and salt to produce soy sauce

Question 4

How are Penicillium camemberti and P. roqueforti utilized in cheese-making? (3)

Answer 4

• Added to substrate in cheese-making process
• Either grows on the surface or penetrates into the cheese
• Gives unique flavour and texture to the finish product

Question 5

What is Botrytis cinerea (‘A’) used for? (4)

Answer 5

• Spores may be sprayed on grapes to encourage development
• Mould penetrates grapes, dehydrates, converts some sugars to glycerol
• Individual berries hand-picked from bunches – may take 6+ passes
• Juice (syrup) undergoes partial fermentation by yeast to produce sweet dessert wines

Question 6

What is the recreational use of magic mushrooms attributed to?

Answer 6

Psilocybin, which is similar to serotonin and interferes with serotonin receptors in the brain

Question 7

What are 2 types of biopesticides?

Answer 7

Biopesticides – entomopathogenic fungi

• Common soil fungi (so not obligate parasitic)
• Control of locusts, aphids, bedbugs, thrips, whiteflies, termites

Biopesticides – nematophagous fungi

• Nematodes (worms) attack roots of crop plants
• Attempts to use fungi to control nematodes
• Nematode-trapping, endoparasitic, attack eggs/cysts

Question 8

How can crop yield be increased?

Answer 8

Inoculating soil with spores of mycorrhizal fungi increases yield

Question 9

What is Mycoremediation?

Answer 9

Use of fungi in decontamination of the environment

• Absorb (thus discard the fungus) or break down pollutants

Question 10

What are 5 features of fungi as medicines?

Answer 10

1) Statins (cholesterol control): Penicillium spp (‘A’), Aspergillus terreus (‘A’), Monascus purpureus (‘A’), etc

• Actually inhibit other fungi by interfering in sterol synthesis
• Same effect in humans

2) Anti-cancer drugs: Penicillium spp (‘A’)

3) Immuno-suppressants: Penicillium spp (‘A’), Tolypocladium inflatum (‘A’), etc.

4) Drugs against malaria, diabetes

5) Production of D vitamins

Question 11

Why is Saccharomyces cerevisiae significant in research? (2)

Answer 11

• It is a model organism in cell biology, genetics, DNA repair, aging, and other fields
• Saccharomyces Genome Database (SGS) serves as a curated repository of gene function, linkages, pathways, and publications