Fuzo nyusankin (spoilage lactic acid bacteria)

Fuzo nyusankin (spoilage lactic acid bacteria) refers to a specific group of lactic acid bacteria that are active in the moromi (fermentation mash) and produce lactic acid. These bacteria play an important role mainly in the sake brewing process. There are two types of fuzo nyusankin: homofermentative rods (bacilli) and heterofermentative cocci. Homofermentative rods are characterized by higher tolerance to alcohol and acid. Heterofermentative cocci, on the other hand, have different metabolic pathways and produce a variety of fermentation products. Fuzo nyusankin grow better than ordinary lactic acid bacteria in low-temperature environments and can remain active even in the range of 5°C to 8°C, for example. This characteristic makes them less susceptible to the influence of other microorganisms during fermentation and helps ensure the stability of sake quality. Because they have a favorable effect on the flavor and aroma of sake, they are regarded as a very important element in brewing.