Fungal food Flashcards
What are the types of fungal hyphae?
C106
A3/5 wild type
MC1-1
CC1-1
What are the most cultivated mushrooms?
Basidiomycota
How popular is the global mushroom market?
Global demand for mushrooms has rapidly increased and thus large scale growers have been established, with year round marketing dominating commercial mushroom production
Where are most cultivated mushrooms from?
Natural varieties of wood-decay Basidiomycota species
What are Saprophytes?
Saprophytes: a plant, fungus or microorganism that lives on dead or decaying organic matter
What are some examples of mushrooms?
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
When was the first cultivar of Agaricus bisporus?
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
How can gene editing be used on mushrooms?
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
What is involved in the mushroom cultivation process?
Mushroom spawn
Preparation of compost
Spawning of mulch
Casing
Croping and harvesting
What are the layers in cultivation of mushrooms?
Casing layer
Spawn
Compost
What are the total GHG emissions by sources?
> 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
What are the 9 essential amino acids?
Phenylalanine
Valine
Threonine
Trypotphan
Methionine
Leucine
Isoleucine
Lysine
Histidine
During the 1960’s what were some of the 3000 fungal isolates investigated as potential foods?
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
What is Fusarium venenatum?
Fusarium venenatum is a filamentous ascomycete fungus
When were the first mycotoxin products?
1985
What is Fusarium venenatum used to produce?
Mycoprotein
What do the hyphae of the Fusarium venenatum contain?
48% protein
How is Fusarium venenatum grown?
Grown under controlled temperature, pH, nutrient concentration, dissolved oxygen and growth rate maintained constant
Fungal growth is controlled by supply of glucose
What is the fermentation process of mycoprotein?
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
How much mycoprotein can be produced from Fusarium venenatum?
From milligrams of Fusarium venenatum culture over 1500 tonnes of mycoprotein are produced
What results in the fermentation process of mycoprotein having to be stopped prematurely?
Branched c-variants (B) result in the fermentation process having to be stopped prematurely during production
How would the fermentation process look without branched c-variants?
Without c-variants then each fermentation process could be extended. This would make Quorn production far more efficient
How are things that grow fast bad for human metabolism?
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
How is mycoprotein produced without c-variants?
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%
