What are the growth conditions that need to be paid attention to in the artificial cultivation of Lion's Mane ?

What are the growth conditions that need to be paid attention to in the artificial cultivation of Lion's Mane ?

1. Temperature
Lion's mane  is a mesophilic edible fungus. The temperature required for the growth of its mycelium is different from that for the formation of its fruiting body. The mycelium growth stage requires a higher temperature, and the fruiting body formation stage requires a lower temperature. The mycelium of Hericium erinaceus can grow at 6~33°C, and the optimum growth temperature is about 25°C. When the temperature is high, the mycelium is thin and sparse, grows slowly at 33°C, and stops growing completely when it exceeds 35°C. When the temperature is lower, the mycelium is thick, dense, white, grows vigorously, and has strong vitality. When the temperature is below 6°C, the mycelium almost stops growing.

Fruiting bodies can be differentiated and formed at 6~24°C, but 16~20°C is the most suitable. For strains that have not been bred in a directional manner, fruiting bodies cannot be formed when the temperature exceeds 25°C. When the temperature is too low, the differentiation and growth of fruiting bodies are slow, and when it is below 6°C, the fruiting bodies stop growing completely. The temperature also affects the morphology of fruiting bodies. When the temperature is high, the fruiting body has long spines, small balls, and is soft, and often forms branches; when the temperature is low, the spines are short, the balls are large and compact; when the temperature is below 12℃, the fruiting body is often orange-red.

The adaptability of Hericium erinaceus to temperature is easy to change. When it grows on sugarcane bagasse and wheat bran culture medium, the mycelium is easy to differentiate into fruiting bodies because the culture medium material is loose and has good ventilation. If it is separated and cultured on this culture medium many times, the formation of fruiting bodies will become faster and faster, and the temperature adaptation range will become wider and wider. The parent that can only form fruiting bodies at the highest temperature of 22℃ can form fruiting bodies in the range of 6~28℃.

2. Humidity
Water is an important component of Hericium erinaceus mycelium and fruiting body cells. Generally, the water content of fresh Hericium erinaceus is about 85%. Water is an indispensable basic substance for the metabolism and absorption of nutrients of Hericium erinaceus. All physiological activities of Hericium erinaceus, including the absorption and transportation of nutrients, the secretion of enzymes, and the decomposition and utilization of complex substances such as cellulose and lignin, must be carried out under certain moisture conditions; however, the moisture content should not be too much, as too much moisture will affect the ventilation in the culture medium. It will affect the respiration of mycelium and cause excessive dilution of the cell protoplasm, thereby reducing stress resistance and accelerating its aging. The so-called humidity in production refers to the moisture content of the culture medium and the relative humidity of the air in the cultivation environment.

(1) Moisture content of culture medium
The water contained in the culture medium is the most important source of moisture required by Hericium erinaceus. Only when the culture medium contains sufficient moisture can the fruiting body form normally. The appropriate moisture content for the growth of Hericium erinaceus is closely related to the physical properties of the culture medium. If the texture of the culture medium is solid, the moisture content is low; otherwise, the moisture content is high. Culture medium with a dense texture such as sawdust requires a lower moisture content, preferably about 55%; culture medium with a loose texture such as cottonseed hulls and sugarcane bagasse requires a higher moisture content, preferably about 65%.

(2) Relative humidity of air
During the growth and development of Hericium erinaceus, the growth environment requires a certain relative humidity of air. Generally, during the mycelium growth stage, the relative humidity of air is required to be lower, preferably about 70%. If the humidity is too high, the contamination rate of the fungus bag will increase exponentially; if the humidity is too low, the water in the culture medium will evaporate too quickly, affecting the mycelium growth.

(3) Air
In the air, oxygen and carbon dioxide are important factors affecting the growth and development of Hericium erinaceus. Generally, in normal air, the oxygen content is about 21% and the carbon dioxide content is about 0.03%. Hericium erinaceus is an aerobic fungus. It respires during its growth and development, and needs to continuously absorb oxygen, release carbon dioxide and generate energy for the growth of Hericium erinaceus. Therefore, the growth and development of Hericium erinaceus requires sufficient oxygen. If the air is not circulated and the oxygen is insufficient, the growth of Hericium erinaceus mycelium and the development of fruiting bodies will be inhibited. The growth of Hericium erinaceus mycelium and fruiting bodies have different requirements for air. The mycelium can grow normally in an environment with a carbon dioxide concentration of 0.3%~1%.

During the fruiting body development stage, Hericium erinaceus is very sensitive to carbon dioxide. When ventilation is poor or the carbon dioxide content in the air is high, it has a great impact on the differentiation of primordium and the growth of fruiting bodies. During the growth of fruiting bodies, the carbon dioxide concentration in the air should be 0.03%~0.1%. When it exceeds 0.1%, the fruiting body is not easy to differentiate, the ball core is poorly developed, the stipe is elongated, the stipe continues to branch, the thorns are twisted, the fruiting body is deformed, and the spore formation is slow. When the ventilation conditions are good, the carbon dioxide concentration is low, the fruiting body grows rapidly, and the ball is large. Therefore, the Hericium erinaceus culture room should be ventilated regularly every day to eliminate excessive carbon dioxide and other metabolic waste gases.

(4) Lighting
The mycelium of Hericium erinaceus can grow in the presence or absence of light, and grows faster in the dark, so the cultivation of Hericium erinaceus mycelium does not require light. However, in actual production, since light and ventilation are closely related, there should be a little light in the culture room, but the light should not be too strong.

The formation and growth of Hericium erinaceus fruiting bodies require a certain amount of scattered light. Light stimulation is one of the necessary conditions for the differentiation of the primordium of the fruiting body of Hericium erinaceus. Generally, 50 lux can stimulate the formation of the primordium of the fruiting body.

It is worth noting that blue light, which has an inhibitory effect on the growth of mycelium, promotes the differentiation of the primordium of the fruiting body. Under blue light, not only the primordium differentiation speed is fast, but also the number of primordium is large. In actual production, the illumination is preferably 200~400 lux. Under this illumination condition, the fruiting body grows normally, white and strong. If the light is too strong, exceeding 1000 lux, the fruiting body often turns red, grows slowly, and the quality deteriorates.

The fruiting body of Hericium erinaceus has no phototropism, but the growth of the thorns has obvious geotropism. During the cultivation process, if the mushroom bag is cultivated in an inverted mode, the thorns grow very neatly. If the direction of the container is changed too much, a deformed mushroom with curled thorns will be formed. This deformed mushroom, because the basidiospores cannot be ejected naturally, makes its taste bitter or secondary hyphae appear on the fruiting body, reducing the commodity value.

(5) pH value

pH value is an important environmental factor that affects the growth of Hericium erinaceus. Hericium erinaceus is an edible fungus that prefers an acidic environment. Only under acidic conditions can Hericium erinaceus decompose organic matter in the culture medium well.

The mycelium of Hericium erinaceus can grow in the range of pH 4 to 7, and the optimum pH is about 5. Above pH 7 and below pH 4, the mycelium is thin and grows slowly. When the pH is greater than 7.5, the mycelium is difficult to grow.

The mycelium of Hericium erinaceus will continuously secrete organic acids during its growth, so in the later stage of cultivation, the culture medium will often be over-acidified, thereby inhibiting the growth of the mycelium itself. Therefore, in production, in order to make the mycelium of Hericium erinaceus grow stably at the optimum pH value, 1% to 1.5% of gypsum (calcium sulfate) or calcium carbonate is often added when preparing the culture medium for large-scale cultivation. This can not only provide the calcium and sulfur nutrients needed for the growth of Hericium erinaceus, but also buffer the changes in the pH value of the culture medium.

In production, in addition to considering that the mycelium itself produces organic acids that cause the pH of the culture medium to drop, it is also necessary to consider that the culture medium will also cause the pH to drop during the sterilization process. Therefore, when preparing the original species, cultivated species and culture medium for cultivation, the pH should be appropriately adjusted to 5.5~6.5. In this way, after high-pressure sterilization or normal-pressure sterilization and some organic acids produced during the mycelium metabolism process, the pH of the culture medium can reach the optimal range for Hericium erinaceus.