also: しゅきん
noun
starter culture; mother; seed fungus
Refers to a fungal colony or microbial culture used to initiate fermentation in food production (e.g., for making koji, natto, or yogurt).
味噌を作るには、まず種菌を米に植え付けます。
To make miso, you first inoculate the rice with the starter culture.
この納豆の種菌は、昔ながらの製法で培養されています。
This natto starter culture is cultivated using traditional methods.
麹菌 specifically refers to the koji mold (Aspergillus oryzae), while 種菌 is a broader term for any starter culture, including bacteria and yeasts.
スターター is a loanword often used for sourdough or yogurt starters, while 種菌 is more technical and typically used in industrial or traditional fermentation contexts.
Compound of 種 (seed) and 菌 (fungus/bacterium). The reading たねきん uses the kun'yomi for 種 and the on'yomi for 菌, while しゅきん uses on'yomi for both.