Solid state fermentation refers to a biological reaction process with one or more microorganisms in a water-soluble solid substrate with a certain humidity in the absence or almost no free water. Considering the essence of the biological reaction process, solid-state fermentation is a biological reaction process in which the gas phase is the continuous phase. Solid fermentation has the advantages of simple operation, low energy consumption, easy control of the fermentation process, relatively low requirements for sterility, and no large-scale pollution. Solid fermentation tanks are widely used in various fermentation fields such as medicine, food, brewing, biological fertilizers, and biological feeds.
