Economic importance

Fungi cut both ways economically. Their beneficial roles span several areas. As food, mushrooms such as Lentinus edodes, Agaricus bisporus and Volvariella volvacea are eaten for their high nutritive value, and yeasts supply vitamin B (Eremothecium ashbyii being a particularly rich source of vitamin B12). As medicine, fungi are the source of antibiotics that arrest or kill bacteria - Penicillin (from Penicillium notatum), Cephalosporins (from Acremonium chrysogenum) and Griseofulvin (from Penicillium griseofulvum) - and of ergot alkaloids such as ergotamine (from Claviceps purpurea), used as vasoconstrictors. In industry, fungi produce organic acids commercially - citric acid and gluconic acid (Aspergillus niger), itaconic acid (Aspergillus terreus), kojic acid (Aspergillus oryzae) - and yeast (Saccharomyces cerevisiae) is the workhorse of bakeries and breweries, fermenting sugars into alcohol and leavening bread, buns and rolls, while Penicillium roquefortii and Penicillium camemberti are used in cheese production; Aspergillus oryzae and Aspergillus niger are also used to manufacture enzymes such as amylase, protease and lactase, and 'rennet', which coagulates milk during cheese-making, is derived from Mucor. In agriculture, mycorrhiza-forming fungi (e.g. Rhizoctonia, Phallus, Scleroderma) help plants absorb water and minerals; Beauveria bassiana and Metarhizium anisopliae are used as biopesticides against crop pests; and gibberellin (from the fungus Gibberella fujikuroi) is used commercially as a plant growth promoter. On the harmful side, fungi such as Amanita phalloides, Amanita verna and Boletus satanus are dangerously poisonous (commonly called 'toad stools'); Aspergillus, Rhizopus, Mucor and Penicillium spoil stored food, and Aspergillus flavus specifica …