A Detailed Guide to Termite Mushroom Cultivation Techniques: Growing Methods and Key Management Points

The termite mushroom is delicious in flavor, the finest among seedlings and the best of mountain delicacies, and is one of the famous wild edible mushrooms in our country. It is highly favored in the market, so what are the cultivation techniques for the termite mushroom?

1. Culture techniques

The termite mushroom is cultured through liquid submerged culture of mycelium, serving as a raw material for developing nutritional foods and beverages. Its protein content is higher than that of other mushrooms, and in particular its lysine and leucine contents are very high, so the production of termite mushroom mycelium through liquid submerged culture has attracted attention.

Suitable liquid medium formulas for the culture medium:

Formula 1: peptone 2%, sucrose 2%, magnesium sulfate 1.5%, potassium dihydrogen phosphate 0.3%, vitamin B1 1 mg/100 ml, pH adjusted to 6.

Formula 2: yeast extract 0.1%, sucrose 3%, magnesium sulfate 0.05%, potassium dihydrogen phosphate 1%, sodium nitrate 0.3%, potassium chloride 0.05%, pH adjusted to 6.

Formula 3: yeast extract 0.1%, sucrose 3%, potassium dihydrogen phosphate 0.1%, magnesium sulfate 0.5%, sodium nitrate 0.3%, potassium chloride 0.05%, pH around 6 (Hong Zhen, China Medical University, 1992).

2. Nutrition

Nutrition. The main nutrient sources for the growth and development of the wild termite mushroom are obtained from the ant nest, the fungus garden and the surrounding environment. The ant nest is mainly formed from the semi-digested matter of worker ants, which becomes the fungus garden, also called the fungus bed. The fungus garden is rich in co-nutrients, including lignin, cellulose, fats, various amino acids and ash elements. Together with the minerals and moisture around the fungus garden, this constitutes the natural culture medium for the growth and development of the termite mushroom. The excrement of termites contains amino acids and soluble nitrogen-containing compounds, which also provide a good nitrogen source for the termite mushroom and are beneficial to the growth of its mycelium. According to observations by He Xinsheng (1995): ant nests are mostly built 20-100 cm underground, with volumes ranging from 0.1-10 m; there are a central large nest and scattered satellite nests, connected to each other by ant trails, and the ant colony will reproduce in the nest for as long as several years to several decades.

3. Temperature

In the termite nests where the termite mushroom grows, the temperature is stable at 22 °C ± 3 °C, with a minimum of 15 °C and a maximum not exceeding 28 °C, almost constant. The stable temperature is favorable for the growth of the mycelium and the hatching and reproduction of the termites. From observations in artificial domestication trials: the temperature range for spore germination of the termite mushroom is 12 °C-24 °C; the optimum temperature for mycelial growth is 16 °C-20 °C; at 18 °C only 10 days are needed from inoculation to full colonization of the tube, and the mycelium grows up to 0.73 cm per day; fruiting body formation can occur at 25 °C-35 °C, with the optimum temperature being 25 °C-30 °C, and a daily temperature difference of 5 °C being optimal; above 35 °C, the fruiting body can still develop normally.

4. Humidity

The stable environmental conditions inside the ant nest are suitable for the growth of the termite mushroom mycelium, but are not favorable for the formation of fruiting bodies. Therefore, under normal circumstances, the mycelium grows in large amounts inside the ant nest without forming fruiting bodies. Only after the rainy season arrives and rainwater seeps into the soil around the ant nest does the mycelium grow outward from the nest and produce fruiting bodies on the surface layer, which shows the importance of water and humidity to the termite mushroom. During artificial cultivation, the moisture content of the substrate can be 60%-75%, with 65% being the best; when the moisture content of the substrate is 70%-75%, fruiting body formation is most suitable. For the growth environment of the termite mushroom mycelium, an air relative humidity of around 80% is good; during the primordium formation stage, the air relative humidity must not be lower than 80; during the fruiting body growth stage, an ambient air relative humidity of 85% is ideal, and the opening of the fruiting body cap requires an air relative humidity of above 95%.

5. pH

The pH of the ant nest fungus garden is relatively stable, often at 4.0-4.5. Chemical analysis shows that the main reason for the pH of the ant nest is the presence of organic acids, such as volatile formic acid, and non-volatile aconitic acid, fumaric acid, succinic acid, etc. The main factor for the relatively stable pH is the buffering effect of the minerals in the nest-building soil and the newly brought-in plant residues. According to research by He Xinsheng (1995), the mycelial growth of the termite mushroom is most suitable at pH 4.0-4.5, and this is unfavorable to the growth of bacteria and other microorganisms, especially the growth of Xylaria, thereby ensuring the absolutely dominant position of the termite mushroom.

6. Light

Spore germination, mycelial growth, primordium differentiation, and the growth and development of fruiting bodies do not necessarily require light. When the fruiting body opens its cap, a certain amount of scattered light is needed so that it differentiates and develops well.