Aspergillus oryzae

Aspergillus oryzae, also known as koji (Japanese: ニホンコウジカビ, Hepburn: nihon koji kabi), is a filamentous fungus (a mold) used in Japan to ferment soybeans for making soy sauce and fermented bean paste (including miso), and also to saccharify rice, other grains, and potatoes in the making of alcoholic beverages such as sake and shōchū. The domestication of Aspergillus, a supercategory of A. oryzae occurred at least 2000 years ago. A. oryzae is also used for the production of rice vinegars. Barley koji (麦麹) or rice koji (米麹) are made by fermenting the grains with aspergillus oeryzae mold. Eiji Ichishima of Tohoku University called the kōji fungus a 'national fungus' (kokkin) in the journal of the Brewing Society of Japan, because of its importance not only for making the koji for sake brewing, but also for making the koji for miso, soy sauce, and a range of other traditional Japanese foods. His proposal was approved at the society's annual meeting in 2006. It is different from Rhizopus used in Huangjiu. 'Red kōji-kin' is a separate species, Monascus purpureus. Aspergillus, a supercategory of A. oryzae was first mentioned in the Zhouli (Rites of the Zhou dynasty) in China in 300 BCE. Its development is a milestone in Chinese food technology, for it provides the conceptual framework for three major fermented soy foods: soy sauce, jiang / miso, and douchi, not to mention grain-based wines (including Japanese sake) and li (the Chinese forerunner of Japanese amazake). The following properties of A. oryzae strains are important in rice saccharification for sake brewing: Three varieties of kōji mold are used for making shōchū, each with distinct characteristics. Initially kept secret, the A. oryzae genome was released by a consortium of Japanese biotechnology companies in late 2005. The eight chromosomes together comprise 37 million base pairs and 12 thousand predicted genes. The genome of A. oryzae is thus one-third larger than that of two related Aspergillus species, the genetics model organism A. nidulans and the potentially dangerous A. fumigatus. Many of the extra genes present in A. oryzae are predicted to be involved in secondary metabolism. The sequenced strain isolated in 1950 is called RIB40 or ATCC 42149; its morphology, growth, and enzyme production are typical of strains used for sake brewing. Resveratrol can be produced from its glucoside piceid through the process of fermentation by A. oryzae.