Key points of aseptic technique for inoculating edible mushroom stock cultures

Inoculating edible mushroom stock cultures refers to the process of transferring grown mother-culture mycelium onto stock-culture medium. The stock culture occupies the intermediate stage in the successive expansion of mushroom spawn, taking over from the mother culture and leading on to the planting spawn; the quality of inoculation directly affects the purity and vigor of the spawn at every stage, making it an important link in spawn production.

Inoculation is generally carried out in an inoculation box, inoculation room or clean bench, and the space and utensils must be strictly disinfected and sterilized beforehand. After the medium has been sterilized, inoculation should begin only once the substrate temperature has dropped to a suitable range; inoculation hooks, tweezers, alcohol lamps and other tools should be prepared in advance to avoid introducing contaminant organisms by reaching for them midway.

Aseptic technique is the key to successful inoculation. The operator's hands should be wiped with disinfectant, inoculation movements should be quick and steady, the spawn blocks cut should be of moderate size, and the transfer should be completed over the flame of an alcohol lamp as far as possible to shorten the time the spawn is exposed to the air. After inoculation, plug the cotton stopper or seal the bag opening properly and move it into the culture room promptly.

During culturing, maintain a suitable temperature, keep the area away from light and ensure ventilation, and regularly observe the germination and spread of the mycelium. If green mold, Neurospora or bacterial contamination is found, it should be removed as early as possible to prevent it from spreading. The success of stock-culture inoculation is closely related to the quality of sterilization, the cleanliness of the environment and the operator's skill, so every step must be strictly controlled in production.