Aspergillus oryzae

Aspergillus flavus var. oryzae (Japanese scientific: 日本麹黴 Nihon Kōjikabi, trivial name: 麹菌 kōjikin, Eng. "yeast fungus"; Chinese 麴霉菌 / 曲霉菌, [麴菌/曲菌], pinyin qūmeíjūn [qūjūn]; Korean: 누룩곰팡이, nurukgompangi) is a mold (watering can mold) that plays a major role in Japanese cuisine. It is the most important of the Kōji mushrooms.

It is used to ferment soybeans in solid-state bioreactors to produce miso and soy sauce. The delicacy Daitokuji-Nattō, which originated in Kyōto, is also made with Aspergillus flavus var. oryzae inoculated soybeans. Another use is in the fermentation of rice, for which the fungus is named, for sake, amazake, and for mirin. A. flavus var. oryzae is also used in Chinese and Korean cuisine.

A. flavus var. oryzae is one of the main industrial sources for the production of α-amylases. It is one of the organisms that are fully gene sequenced.