Main reasons on bacterial infection of King oyster mushroom are:
1. Infected raw materials are mixed.
2. Lack of sterilization time.
3. Overmuch or over tight fungi sacks in sterilizing stove.
4. Insufficient water absorption on bits of wood or corncob.
5. Inadequate cool air exhaust in pressure-cooker.
Solutions:
1. Choose raw materials which are fresh and free from mould.
2. After boiling, you could continue to let sterilize for 10-12 hours on high fire.
3. Leave 1 cm of gap between each row and wall.
4. When choosing corncob or bits of wood as compost, soak them till white heart disappears.
5. When using pressure-cooker, open exhaust valves when the pressure reaches 0.05MPA, exhaust cool air sufficiently and then close exhaust valves.