Lentinula edodes and Pleurotus ostreatus; their interactions with other microorganisms

Abstract

Both Lentinula edodes (black oak mushroom or Shiitake in Japanese) and Pleurotus ostyeatus (oyster mushroom or Hiratake) belong to the class Hymenomycetes (Basidiomycotina), and are important commercial mushrooms in Japan. In nature, these fungi inhabit dead broad-leaved trees, and they interact with various kinds of microorganisms in wood. However, little is known about the precise nature of the majority of such interactions. These fungi cause white rot of wood by first removing lignin and other amorphous wood components, followed by the degradation of exposed cellulose microfibrils. Wood is a unique substrate for microorganisms because it contains exceptionally large amounts of cellulose, hemicellulose and lignin, while water-soluble and solvent-soluble (e.g. fats, oils, waxes) and proteins occur relatively in small quantities. Therefore, wood in general is strongly deficient in nitrogen, containing less than 0.3% (w/w). Mechanisms by which wood-decay fungi manage to decay nitrogen-deficient wood are not well known.