Mushrooms are fruiting bodies of macro fungi.They are heterotrophic organisms which must obtain all their nutritive requirements from the substrate.Mushroom substrates are lignocellulosic material that are by-products of either agro-industrial plants or the forest.When these lignocellulosic materials combine with other fungi,something special is created in the living world.Because mushroom cell walls contain chitin rather than cellulose,they are neither plants nor animals.A recent report on mushroom fossils indicates that a 440-million-year-old fossilized mushroom may be the oldest organism to have lived on dry land.Mushroom biology is a relatively new discipline in science as it concerns all aspects of the scientific studies of mushrooms.Applied mushroom biology is the study of two main disciplines:mushroom science which is about mushroom production and mushroom biotechnology that is about mushroom products.As such,mushroom science and mushroom biotechnology can be characterized as the two legs of the mushroom industry.The aim of applied mushroom biology is to tackle the two basic problems that the world faces today and will continue to face as the world population continues to grow.Two issues are studied closely and attempt to provide a solution to them:food and health.