News

1. Lime

(1) Quicklime: In the cultivation of edible and medicinal fungi, lime is often used only as a disinfectant in outdoor cultivation sites. In the cultivation of Agaricus bisporus, 1% lime (by dry weight of straw) is often added during the soaking process of rice straw to remove the wax layer on the surface of the rice straw and facilitate the degradation of the straw. Most wood-decomposing fungi prefer to grow on acidic culture media (6.2~6.8 after sterilization).

(2) Quicklime: Calcium hydroxide [Ca(OH2)] is the main component, also known as slaked lime. It is quicklime added with water, releasing a large amount of heat and carbon dioxide. Quicklime is often used for whitewashing walls.

2. Gypsum

Gypsum is calcium sulfate with a molecular formula of CaSO4.7H2O. It is used as a pH regulator in the cultivation of edible and medicinal fungi. It is often used as a leavening agent in the cultivation fermentation material for Agaricus bisporus cultivation. To improve the physical structure of the fermentation material, 3% gypsum powder can be added.

3. Light calcium carbonate

Light calcium carbonate, referred to as light calcium, has a molecular formula of CaCO3. It is obtained by adding lime and water to generate lime milk, and then introducing CO to carbonize it. The particles are fine. It is often added in the production of wood decay fungi, with a usage of 0.3%~2.0%. It can neutralize the organic acid produced by mycelium and act as a buffer to adjust the pH value.

4. Oyster shell

The components of oyster shells and other shellfish shells are calcium carbonate, with a content of 80%~95%. Calcining oyster shells will produce oyster ash. Its main component is calcium oxide, that is, quicklime, and it releases a lot of white smoke (CO2).

The chemical reaction equation is: CaCO3 calcination = CaO + CO2

5. Superphosphate

Superphosphate is an acidic fertilizer. The main components of superphosphate include calcium dihydrogen phosphate Ca(H2PO4), and gypsum, sometimes also expressed as water-soluble calcium phosphate and water-insoluble calcium sulfate. In the formula of edible and medicinal fungi, it mainly adjusts the pH value of the culture medium. If the pH value of the culture medium needs to be lowered (such as cultivating Hericium erinaceus), add 0.5%~1% superphosphate to the water, precipitate, and take the supernatant.

6. Others

There are many examples of fake bran, gypsum or heavy calcium carbonate being used as light calcium carbonate in society. They should be strictly identified according to the standards of each material. We should not lose the big picture for the small and cause losses to the company.