Saprophytic higher fungi are a great source of secondary metabolites, which they produce for protection and to get an advantage against other organisms. Otherwise they are not necessary for normal development and growth of the fungi. Many secondary metabolites are bioactive therefore they are especially interesting in the fields of medicine and pharmaceutical industry as potential novel drugs against various diseases. Secondary metabolites can potentially also be exploited in food and textile industries where they could be used as coloring agents. Secondary metabolites can be produced in various ways, namely with solid state fermentation or submerged fermentation. In solid state fermentation the used substrate does not have any free water in it. On the other hand, in submerged fermentation the fungal culture is submerged in liquid medium. Higher fungi that are most commonly used in production of secondary metabolites are known, especially in Asian cultures, as medicinal mushrooms. These are Ganoderma lucidum, Hericium erinaceus, Cordiceps militaris, Pleurotus ostreatus, Grifola frondosa and many others.
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