Fungal food

Question 1

What are the types of fungal hyphae?

Answer 1

C106
A3/5 wild type
MC1-1
CC1-1

Question 2

What are the most cultivated mushrooms?

Answer 2

Basidiomycota

Question 3

How popular is the global mushroom market?

Answer 3

Global demand for mushrooms has rapidly increased and thus large scale growers have been established, with year round marketing dominating commercial mushroom production

Question 4

Where are most cultivated mushrooms from?

Answer 4

Natural varieties of wood-decay Basidiomycota species

Question 5

What are Saprophytes?

Answer 5

Saprophytes: a plant, fungus or microorganism that lives on dead or decaying organic matter

Question 6

What are some examples of mushrooms?

Answer 6

Shiitake- is a white rot fungus raised on logs for more than 1000 years. More than 1 million tonnes of shiitake are produced every year and China dominates the market

Oyster- 19% of global mushroom production. Mainly grown in China (87% of global production)

White button mushroom (Agaricus bisporus)- Most popular cultivated mushroom, with a global crop exceeding 2 million tonnes

Question 7

When was the first cultivar of Agaricus bisporus?

Answer 7

Found in 1926 by Lewis Downing, an American farmer, who passed it on to a spawn company
The cultivation method for A. bisporus was established and developed by Sinden and Hauser in 1950
A. bisporus can be grown on standard compost based on wheat straw and horse manure and other agricultural waste

Question 8

How can gene editing be used on mushrooms?

Answer 8

Crispr-Cas9 technology to create small deletions in a specific gene encoding a polyphenol oxidase (PPO) enzyme polyphenol oxidase which causes browning to occur
A bacterial plasmid construct to deliver the guide RNA and Cas9 enzyme into mushroom cells to achieve the necessary deletions

Question 9

What is involved in the mushroom cultivation process?

Answer 9

Mushroom spawn
Preparation of compost
Spawning of mulch
Casing
Croping and harvesting

Question 10

What are the layers in cultivation of mushrooms?

Answer 10

Casing layer
Spawn
Compost

Question 11

What are the total GHG emissions by sources?

Answer 11

> 30% of the total greenhouse gases (GHG) emitted by humans are a side product of the agricultural sector, with more than half of it (approx 18%) being connected with the production of meat

Question 12

What are the 9 essential amino acids?

Answer 12

Phenylalanine
Valine
Threonine
Trypotphan
Methionine
Leucine
Isoleucine
Lysine
Histidine

Question 13

During the 1960’s what were some of the 3000 fungal isolates investigated as potential foods?

Answer 13

1967- Fusarium venenatum was discovered in soil from a garden in Marlow, Buckinghamshire

1984- The ministry of Agriculture, Fisheries and Food in the United Kingdom certified Fusarium venenatum A3/5 for trade as food

Question 14

What is Fusarium venenatum?

Answer 14

Fusarium venenatum is a filamentous ascomycete fungus

Question 15

When were the first mycotoxin products?

Answer 15

1985

Question 16

What is Fusarium venenatum used to produce?

Answer 16

Mycoprotein

Question 17

What do the hyphae of the Fusarium venenatum contain?

Answer 17

48% protein

Question 18

How is Fusarium venenatum grown?

Answer 18

Grown under controlled temperature, pH, nutrient concentration, dissolved oxygen and growth rate maintained constant
Fungal growth is controlled by supply of glucose

Question 19

What is the fermentation process of mycoprotein?

Answer 19

Air introduced at the base of the fermenter column creating millions of microbubbles that the rise up to the top of the fermenter column at which point the gas disengages, causing a density difference
Liquid falls to the base of the fermentation column. Leads to mixing and preserves hyphal structure (critical to achieving texture)
Mycoprotein fermentations- 6 weeks

Question 20

How much mycoprotein can be produced from Fusarium venenatum?

Answer 20

From milligrams of Fusarium venenatum culture over 1500 tonnes of mycoprotein are produced

Question 21

What results in the fermentation process of mycoprotein having to be stopped prematurely?

Answer 21

Branched c-variants (B) result in the fermentation process having to be stopped prematurely during production

Question 22

How would the fermentation process look without branched c-variants?

Answer 22

Without c-variants then each fermentation process could be extended. This would make Quorn production far more efficient

Question 23

How are things that grow fast bad for human metabolism?

Answer 23

They produce proteins quickly containing a lot of RNA for translation
Humans metabolize RNA into uric acid and orotic acid and the overaccumulation these can lead to gout and liver damage, respectively

Question 24

How is mycoprotein produced without c-variants?

Answer 24

Mycoprotein is produced by fermenting Fusarium venenatum in large bioreactors with glucose as the carbon source. The fungus grows rapidly, producing a high protein biomass. The biomass is then heat treated to stop fungal growth, harvested, and processed into a fibrous texture for food products

Heat-shocked to induce the natural RNAase enzymes in the mycelium
The action of these enzymes reduces the RNA content content of the mycelium from approx 10% to below 2%