Preparation of wheat grain medium

Formula and treatment: 100 kg of wheat grain, 10 kg of dry dung grass or bran shell after fermentation. Calcium carbonate or stone powder 1kg to 2kg.

The wheat grain is rich in nutrition and the mycelium grows vigorously. In order to prevent the premature senescence of mycelium vitality, 50 grams of magnesium sulfate and 100 grams of potassium dihydrogen phosphate are added in every 100 kilograms of wheat grain. The grain of wheat is full and thick, and there is no worm-eaten grain. Generally, the soaking effect of aged wheat in the next year after dormancy stage is good, and the water absorption and softening is fast.

Soak the wheat grain in 1%-2% lime water, the water surface should be 10-15 cm higher than the wheat grain, and often stir, remove the floating grains and control the soaking time flexibly according to the water temperature. When the inner part of the wheat grain is soaked until there is no white heart, it will take about 12 to 14 hours when the water temperature is about 26 degrees Celsius. The soaked wheat grains are drained and blown on a clean cement floor. after the surface moisture of the wheat grains is properly dried, you can mix in pre-wet dung grass filling grains, stone high powder and so on. According to the standard of controlling the water absorption of wheat grain in a strain bottle, the wet weight reaches 136 to 140 kg per 100 kg wheat grain after water absorption and air drying.

The wheat grains can also be soaked in clear water for about 8 hours, and then boiled in boiling water for 15 to 20 minutes. When the wheat grain is fully cooked (without white heart), remove and drain the water and spread it out. When the moisture on the surface of the wheat grain is properly dried, then mix the ingredients according to the above-mentioned method. In this method, even treatment of wheat grains with water is beneficial to the development of bacteria.

The moisture content of wheat grain must be moderate after absorbing water and adjusting moisture. Too low water content, hard texture, difficult to penetrate sparse bacteria, small number of reproduction, easy to infect bacteria after sowing; too high water content, soft bubbles in texture, easy to break during sterilization, starch exudation paste, easy to make wheat grains agglomerate, fungus cover phenomenon will be produced after mycelium spread. In addition, the water content of pre-wetted fillers should be close to that of wheat grains.

Filling material or called sealing material, guide material, bridge material, etc. It can fix grain culture medium and reduce the gap between grains, which is beneficial to seed block colonization and food cover, beneficial mycelium spread and growth evenly, and avoid mycelium fracture or fungus quilt caused by grain loosening. The commonly used fillers are dung grass, soil, grain chaff, husk and so on. The amount of fillers accounts for about 10% to 20% of the grain medium. The general requirements are relatively short, it is best to go through the development of fermentation, the preparation of mixing, the moisture content after wetting requires the relative consistency of grain water content. The filling grains of fermented dry storage are not moldy. The material that is too long and too thick should be crushed, and the dung grass should be pre-wet with lime water and PH8 about 4 hours before the wheat grain is blown. The dung grass with a moisture content of 55% is used as a filling material to mix well with wheat grains, gypsum powder, etc., and then bottled, and then half of the dung grass is used as the surface sealing material of the matrix.

The wheat grain medium should vibrate up and down when it is sub-packed, so that the matrix can be combined relatively tightly, after the end of the sub-package, there is no need to drill holes and can be sterilized according to the routine, and after cooling, it can be put into the provenance. This method is labor-saving and convenient, and is commonly used in the large-scale production of wheat grain medium.

Sterilization time: the structure of wheat grain is compact, the heat penetration is slow, the sterilization time is long, and the effect of high pressure sterilization is better. Usually 1.5 kg pressure to maintain more than 3 hours, atmospheric pressure sterilization 100 degrees Celsius to maintain more than 10-12 hours.