Fusarium venenatum

Fusarium venenatum is a microfungus of the genus Fusarium that has a high protein 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 in the United Kingdom, 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. It was originally misidentified as Fusarium graminearum. 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 hyphae of the fungus are similar in length and width to animal muscle fibres the mycoprotein is used as an alternative to meat and is marketed to vegetarians as Quorn. It is also suitable as a substitute for fat in dairy products and a substitute for cereal in breakfast cereals and snacks. 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, derived by the predigestion of maize starch. Potassium, magnesium and phosphate 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 28–30 °C, with a biomass density of 15 grams per litre; equating to a total vessel biomass of 2,250 kg. As culture growth occurs, carbon dioxide is produced and released through a vent at the top of the loop. A heat exchanger, located in the union between the towers at their base, allows excess heat generated by the culture to be removed.