The Critical Challenge: Why Can’t Liquid Spawn Fermentation Tanks “Breathe” Contaminated Air?

The Critical Challenge: Why Can’t Liquid Spawn Fermentation Tanks “Breathe” Contaminated Air?

In the industrial production of liquid spawn for edible fungi, compressed air serves multiple vital functions: it provides the oxygen necessary for mycelial growth, facilitates agitation and mixing, and maintains positive pressure within the tank to prevent contamination by unwanted microorganisms. However, improper handling of the air system can lead to catastrophic consequences:

**Water and Oil:**

Compressed air from standard compressors often contains significant amounts of moisture and lubricating oil. Mineral oil can coat spores and inhibit mycelial respiration, resulting in sparse mycelial growth and a failure to form healthy pellets. Meanwhile, accumulated water in the piping creates a breeding ground for microorganisms—such as *Rhizopus*, *Aspergillus*, and bacteria—while also altering the concentration of the fermentation broth.

**Contaminants and Dust:**

Ambient air teems with countless microorganisms; if these enter the fermentation tank, they can cause fermentation failure, resulting in the loss of an entire batch of spawn worth tens of thousands of yuan. Additionally, pipe rust and airborne impurities can clog the tank's aeration screen, leading to insufficient aeration and inadequate dissolved oxygen levels.

**Odors:**

Volatile odor molecules—such as those from oils and plasticizers—can adhere to mycelial cell membranes and block oxygen absorption. Furthermore, specific odor compounds like aldehydes and sulfides possess biocidal properties that can diminish the viability of the fungal culture.

Therefore, the purification of compressed air is a "make-or-break" factor in the liquid fermentation of edible fungi spawn.