Aspergillus oryzae
Aspergillus oryzae, also known as , is a filamentous fungus (a mold) used in East Asia to saccharify rice, sweet potato, and barley in the making of alcoholic beverages such as "sake" and "shōchū", and also to ferment soybeans for making soy sauce and "miso". However, in the production of fermented foods of soybeans such as soy sauce and "miso", "Aspergillus sojae" is mainly used instead of "A. oryzae". "A. oryzae" is also used for the production of rice vinegars. Barley "kōji" (麦麹) or rice "kōji" (米麹) are made by fermenting the grains with "A. oryzae" hyphae. 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 "kōji" for "sake" brewing, but also for making the "kōji" for "miso", soy sauce, and a range of other traditional Japanese foods. His proposal was approved at the society's annual meeting in 2006. The Japanese word "kōji" (麹) is used in several meanings, and in some cases it specifically refers to "A. oryzae", while in other cases it refers to all molds used in fermented foods, including "Monascus purpureus" and  other molds, so care should be taken to avoid confusion. Properties desirable in "sake" brewing and testing. The following properties of "A. oryzae" strains are important in rice saccharification for sake brewing: Varieties used for "shōchū" making. Three varieties of kōji mold are used for making "shōchū", each with distinct characteristics. Genome. 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. Use in biotechnology. Trans-resveratrol can be efficiently cleaved from its glucoside piceid through the process of fermentation by "A. oryzae". Secondary metabolites. "A. oryzae" is a good choice as a secondary metabolite factory because of its relatively few endogenous SMs. Transformed types  can produce: polyketide synthase-derived 1,3,6,8-tetrahydroxynaphthalene, alternapyrone, and 3-methylorcinaldehyde; citrinin; terrequinone A; tennelin, pyripyropene, aphidicolin, terretonin, and andrastin A by plasmid insertion; paxilline and aflatrem by co-transformation; and aspyridone originally from "A. nidulans" by Gateway cloning. History of "kōji" in a broad sense. "麹" (Chinese "qū", Japanese "kōji") which means mold used in fermented foods, 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 Chinese "huangjiu") and "li" (the Chinese forerunner of Japanese "amazake").