Can yew bark be used to cultivate lingzhi (Ganoderma lucidum)?

Lingzhi is a traditional fungal medicine of ancient China, with good health-care and medicinal effects.

Paclitaxel is considered a natural anticancer drug discovered through research over the past 30 years. It is now used in more than 40 countries for the treatment of various cancer diseases. Yew has become the main tree species for paclitaxel drug production. The bark of yew is the organ with the highest paclitaxel content. Cultivating lingzhi mycelium and fruiting bodies using the sterilized-substrate production method with yew bark as the culture material can achieve relatively good results.

1. Process flow

Collection and sorting of yew bark --- cutting into sections and bundling --- soaking in water and bagging --- sterilization --- inoculation --- mycelium culture --- ventilation and cooling management --- removing the cap and producing lingzhi --- harvesting and drying --- grading and packaging.

2. Cutting, sorting and bundling

Yew bark is generally cut into 20 cm lengths, and after each bundle is tied, the round diameter is based on 15 cm, and the top, bottom, inside and outside of each bundle are tightly stuffed with leftover bark fragments, leaving no gaps. When bundling, the cut surface should be dry, then soak in 1% brown sugar water for more than 6-8 hours, then pour off the water, drain dry, and put into 17 x 35 cm mushroom bags for sterilization.

3. Sterilization, inoculation and culture must strictly follow aseptic operating procedures

Sterilize at 100 degrees C under normal pressure for 14-16 hours; if using high-pressure steam sterilization, maintain at 1.5 kg/cm2 pressure for more than 2 hours.

Before inoculation, the inoculation room should be cleaned in advance and sterilized and disinfected. The inoculation tools and supplies, together with the culture bags whose temperature has dropped below 30 degrees C after sterilization, are all disinfected in the inoculation room, and the operators must carry out inoculation carefully and meticulously in accordance with aseptic requirements.

Culture room management mainly involves three aspects: ventilation, cooling and prevention of contaminating fungi. Correctly handling ventilation and cooling can achieve the effect of reducing contamination. The inspection and management work of the culture room is related to whether the mycelium can colonize the bark or its growth after colonization, and is also an important factor affecting the yield and quality of lingzhi.

4. Management during lingzhi production

For mature mushroom bags, with the air temperature maintained at around 25 degrees C, lingzhi usually emerges in 7-15 days. The growing tip of the mushroom bud is white, and the base is brown. After the stipe reaches a certain length, when ventilation, temperature and light conditions are suitable, the cap can differentiate, and the cap develops horizontally. Management during lingzhi production revolves around three aspects: moisture, ventilation and light, among which moisture and ventilation are particularly important.

5. Harvesting of lingzhi fruiting bodies

(1) Signs that the lingzhi fruiting body is mature. When the cap no longer expands, the cap surface color is consistent with the stipe, the rolled edge ring at the cap margin is consistent with the cap color, the cap is thick, and a large number of brown spores are dispersing, it can be harvested.

(2) When harvesting, use fruit-tree scissors or hands to cut or pick from the base of the stipe. The harvested fresh fruiting bodies must not be pressed by hand on the underside of the cap, must not be allowed to collide with each other, and must not be washed with water. Cut off excessively long stipes, remove impurities at the base of the stipe, and sun-dry or oven-dry them.

After picking off the fruiting body, the stipe should also be removed, otherwise small or deformed fruiting bodies will soon grow from above the old stipe.