''Fusarium venenatum'' is a microfungus of the genus ''

Fusarium ''Fusarium'' (; ) is a large genus of filamentous fungi, part of a group often referred to as hyphomycetes, widely distributed in soil and associated with plants. Most species are harmless saprobes, and are relatively abundant members of the s ...

'' that has a high

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

content. One of its strains is used commercially for the production of the single cell protein mycoprotein Quorn. ''Fusarium venenatum'' was discovered growing in soil in

Buckinghamshire Buckinghamshire (, abbreviated ''Bucks'') is a Ceremonial counties of England, ceremonial county in South East England and one of the home counties. It is bordered by Northamptonshire to the north, Bedfordshire to the north-east, Hertfordshir ...

in the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

, in 1967 by ICI as part of the effort during the 1960s to find alternative sources of food to fill the protein gap caused by the growing

world population In demographics of the world, world demographics, the world population is the total number of humans currently alive. It was estimated by the United Nations to have exceeded eight billion in mid-November 2022. It took around 300,000 years of h ...

.From petri dish to plate: The £172m fungi

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published 2005-06-07, accessed 2011-06-27 It was originally misidentified as ''

Fusarium graminearum ''Gibberella zeae'', also known by the name of its anamorph ''Fusarium graminearum'', is a fungal plant pathogen which causes fusarium head blight (FHB), a devastating disease on wheat and barley. The pathogen is responsible for billions of doll ...

''. The strain ''Fusarium venenatum'' A3/5 (IMI 145425, ATCC PTA-2684) was developed commercially by an ICI and Rank Hovis McDougall joint venture to derive a mycoprotein used as a food. Because the

hypha A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one o ...

e of the fungus are similar in length and width to animal muscle fibres the mycoprotein is used as an alternative to

meat Meat is animal Tissue (biology), tissue, often muscle, that is eaten as food. Humans have hunted and farmed other animals for meat since prehistory. The Neolithic Revolution allowed the domestication of vertebrates, including chickens, sheep, ...

and is marketed as Quorn. It is also suitable as a substitute for fat in dairy products and a substitute for cereal in breakfast cereals and snacks.

Commercial production

''Fusarium venenatum'' intended for use in Quorn products is grown under aerobic conditions in culture vessels by what is known as the 'Quorn Process'. The vessels are composed of two vertical cylinders around high, connected to one another at their top and bottom so as to form a continuous loop with a volume of about . Ports on the vessel allow the various ingredients involved to be added and removed. The culture broth is composed of 95%

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

, derived by the predigestion of maize starch.

Potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

and

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

sources are added as a necessary mineral trace. Both these and the glucose are sterilized prior to use. Additional make up broth can be injected at the base of the vessel as material is removed. The broth is maintained at a pH of 6 and a temperature of , with a

biomass Biomass is a term used in several contexts: in the context of ecology it means living organisms, and in the context of bioenergy it means matter from recently living (but now dead) organisms. In the latter context, there are variations in how ...

density Density (volumetric mass density or specific mass) is the ratio of a substance's mass to its volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' (or ''d'') can also be u ...

of equating to a total vessel biomass of . As culture growth occurs,

carbon dioxide Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...

is produced and released through a vent at the top of the loop. A

heat exchanger A heat exchanger is a system used to transfer heat between a source and a working fluid. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing or they may be in direct contac ...

, located in the union between the towers at their base, allows excess heat generated by the culture to be removed. One tower contains a sparge bar near the tower's base, through which air and

ammonia Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...

are injected to provide the

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

and

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

required for respiration and

production. This sparging action causes the pair of towers to function as an air lift culture vessel. The broth continually circulates between the two towers; as it is driven upwards by the sparge bar in one tower, it falls in the opposing tower. Such a stirring (or circulating) method can be preferable for biological cultures as it is less likely to cause damage to

cell membrane The cell membrane (also known as the plasma membrane or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of a cell from the outside environment (the extr ...

s by mechanical compression or abrasion. The denser ''Fusarium venenatum'' culture falls to the base of the loop, where it is removed and pasteurized. Filtration is used to harvest the ''Fusarium venenatum'', with this then being dried prior to blending with a binder. The majority of Quorn products are bound by rehydrated

egg white Egg white is the clear liquid (also called the albumen or the glair/glaire) contained within an egg. In chickens, it is formed from the layers of secretions of the anterior section of the hen's oviduct during the passage of the egg. It forms a ...

, which makes them unsuitable for a vegan diet. The complete vessels contain 230 tonnes of broth, as glucose is denser than water. 30 tonnes of the cultured broth are removed per hour. The culture density within the broth at filtration varies from 1.5% (the vessel's standard culture density) to 25–30% w/v, equating to a standard production rate of 292 hydrated kilograms per hour, or 7 hydrated metric tons per 24-hour cycle. This gives a vessel dilution rate of about 13% w/w per hour; the amount of broth and culture mass being removed and then made back up per hour, with respect to the total mass in the vessel. The dry mass contains 25% cell wall, 48% protein, 12% soluble carbohydrate and 12%

fat In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food. The term often refers specif ...

. The total protein content varies from 43-85%. Allergic reactions to Quorn products are usually caused by an allergy to its mycoprotein content – a fungal protein derived from the fungus ''Fusarium venenatum''.

Regulation

In the

the Ministry of Agriculture, Fisheries and Food approved mycoprotein for sale as a food in 1984.

References

{{Taxonbar, from=Q2401756 venenatum Edible fungi Fungi in cultivation Fungi of Europe

Commercial production

Regulation

See also

References