How many kinds of sterilization methods are there for edible fungi?

There are physical methods and chemical methods for sterilization, among which the thermal sterilization method of physical method is the most widely used one with good and stable effect. Now introduce several commonly used methods.

1. High-pressure steam sterilization: a high-pressure steam boiler is required, and the maximum temperature of the technical index is 140℃ or 2 kg/cm2. When the articles are in a closed container, high-pressure steam is generated by heating water to raise the temperature to achieve the purpose of sterilization. Generally, the culture medium can be sterilized at 12 1℃ for 20 minutes, and the mycelium vegetative body, spores and spores have been killed. However, if the substrate contains substances such as glucose, Marit, bean sprout juice, vitamins, etc., it should be kept at 1 15 degrees Celsius for 20 minutes, otherwise excessive temperature will destroy nutrients and produce toxic substances that are not conducive to the growth of edible fungi. Wood chips, bagasse, cottonseed hulls, wheat grains, forage grass, feces and other substances already contain a lot of bacteria, so it is appropriate to keep 129 degrees Celsius for sterilization 12.5 hours.

Second, atmospheric steam sterilization: articles are sterilized in the pot with atmospheric steam. Usually, the steam temperature is 95 105 degrees Celsius, so the sterilization time takes 68 hours to achieve the effect. This method is suitable for places where manpower and fuel are sufficient and they are unable to buy high-pressure steam boilers. This method is beneficial to maintain the nutrients in the culture medium.

III. fractional sterilization: Articles with high temperature not exceeding 100 degrees Celsius are preferred. Put the culture medium into a pot, steam it at a high temperature of 100℃ 1 hour, kill the vegetative body of miscellaneous bacteria, and keep the temperature at 2530℃ for 24 hours, and the remaining spores germinate into vegetative bodies. The second cooking was carried out for 65438 0 hours to kill the germinated spores. Similarly, the third cooking 1 hour and heat preservation can achieve the effect of complete sterilization.

Fourthly, filtration sterilization: removing some articles that are not resistant to high temperature by mechanical retention technology. Such as serum, vitamins and amino acids. This method is usually used for disinfection. A suction filter bottle and an air compressor are required.

Chemical disinfection: Commonly used chemicals include mercuric chloride, potassium permanganate, bleaching powder, formalin, alcohol, etc. In the cultivation of edible fungi, the sterilization effect of these chemicals is unstable, and some of them affect the safety of products. For example, mercury chloride is not suitable for food, and is mostly used for surface disinfection or environmental disinfection.