What are the growing conditions for black fungus? A detailed explanation of the latest requirements

During the growth and development of black fungus, the main external conditions required are nutrients, temperature, moisture, light, air and pH. The factors with the greatest influence here are moisture and light.

1. Nutrients: The nutrient requirements for black fungus growth are mainly carbohydrates and nitrogen-containing substances, and a small amount of inorganic salts is also needed. During the growth and development of the mycelium of black fungus, it continuously secretes a variety of enzymes (enzymes), and therefore has a strong ability to decompose firewood or culture material. Wherever the mycelium spreads, it decomposes there, taking in the needed nutrients through decomposition and supplying the needs of the fruiting body. When we choose firewood to cultivate black fungus, especially when choosing Qinggang oak from sunny hillsides to cultivate black fungus, nutrient issues can be ignored, because the nutrients in the wood are generally relatively sufficient and can fully meet the needs of black fungus growth. If sawdust or other substitute materials are used for cultivation, a small amount of gypsum, sucrose and potassium dihydrogen phosphate, etc. should be added to meet the nutritional needs of black fungus growth and development. Nutrients are added once and supplemented a second time, referred to as “add first, supplement later.”

2. Temperature: Black fungus is a medium-temperature type fungus. Its mycelium can grow and develop between 15℃ and 36℃, but 22℃ to 32℃ is the most suitable. Below 14℃ and above 38℃ it is inhibited, but the black fungus mycelium in firewood has considerable resistance to short-term high and low temperatures. The fruiting body of black fungus can form and grow between 15℃ and 32℃, but between 22℃ and 28℃ the fungus sheets grown are large, thick-fleshed and of good quality. Fungus grown above 28℃ has slightly thinner flesh, is pale yellow in color and of poor quality. Although fungus grown between 15℃ and 22℃ has thick flesh, is black in color and of good quality, its growth period is slow, affecting yield. Cultivating mycelium requires higher temperatures, while fruiting body growth requires slightly lower temperatures, referred to as “high first, low later.”

3. Moisture: Moisture is one of the important factors in the growth and development of black fungus. Both the mycelium and fruiting body of black fungus need large amounts of moisture during growth and development, but their requirements differ. Under the same suitable temperature, the mycelium develops and colonizes relatively quickly under low-humidity conditions, while the fruiting body develops rapidly under high-humidity conditions. Therefore, at the time of inoculation, the moisture content of the fungus logs is required to be 60% to 70%, and the moisture content of the substitute material culture medium is 65%, which is beneficial for mycelial development and colonization. Although the growth and development of the fruiting body requires relatively high moisture, dry and wet conditions should be combined, and according to the temperature, spraying should be given appropriately. When the temperature is suitable, the relative air humidity of the cultivation site can reach 85% to 95%, so that the growth and development of the fruiting body is relatively rapid. When the temperature is relatively low, too much moisture should not be given, otherwise it will cause rotting of the fungus. The mycelium cultivation stage requires dryness; fruiting body growth requires moisture. That is, "dry first, wet later."

4. Light: Black fungus lives saprophytically. Light originally has little relation to the mycelium, and both the mycelium and fruiting body can grow in a dim, dark environment. However, light promotes the formation of the primordia of the black fungus fruiting body, and the fungus buds can only unfold robust fungus sheets under a certain amount of direct sunlight. According to experience, when the fungus yard has a certain amount of direct light, the fungus grown is both thick and large and dark black, while in a fungus yard with alternating light and shade but no direct light, the fungus grown has thin flesh, pale color, lacks elasticity, and appears unhealthy. Although black fungus has a relatively strong tolerance for direct light, appropriate humidity must be provided, otherwise the fungus sheets will shrink, dry out, stop producing, and affect yield. Therefore, in production management, it is best to create a kind of "dappled sunlight" for the fungus yard to promote the rapid development and growth of the fruiting body. In darkness, the mycelium can form fruiting body primordia, but they do not open. Only when there is a certain amount of scattered light do they open and form fruiting bodies. That is, "dark first, bright later."

5. Oxygen: Black fungus is an aerobic fungus. During the formation, growth and development of the mycelium and fruiting body, it continuously carries out oxygen inhalation and carbon dioxide exhalation (carbon dioxide) activities. Therefore, the air circulation of the fungus yard (indoor) should always be maintained to ensure the oxygen needs of black fungus growth and development. Prevent a stuffy environment and avoid the spread of rotting fungus and contaminating microorganisms. Mycelial growth requires little oxygen, while fruiting body growth requires large amounts of oxygen, that is, “weak first, strong later.”

6. pH (pH value): Black fungus is suitable for living in a slightly acidic environment, with a pH value of 5.5-6.5 being best. When cultivating black fungus with fungus logs, this factor is generally rarely considered, because after the fungus logs are stacked, sun-dried and fermented, they have already formed a slightly acidic environment themselves. However, in strain isolation and strain cultivation and substitute material cultivation, this is a problem that cannot be ignored, and the initial value of the culture medium (material) must be adjusted to a suitable level. During substitute material cultivation, first adjust it to the alkaline side of the suitable range, and through natural fermentation, it will reach the most suitable level. In short, the requirement is “alkaline first, acidic later.”