Pollution of inoculation box of edible mushroom and its prevention and control, matters needing attention in replenishing water of edible fungus

All kinds of miscellaneous bacteria (such as molds and bacteria) are almost competitive, they live on the same culture medium with edible fungi, compete for the nutrition and living space of edible fungi, and affect the growth of edible fungi; many miscellaneous fungi also inhibit the growth of edible fungi hyphae by producing some toxic substances.

In a sense, the central task of seed production and cultivation of edible fungi is how to prevent and control the pollution of various miscellaneous bacteria in order to obtain the pure culture of mycelium or culture. Vaccination is an important link in the prevention and control of miscellaneous bacteria pollution in production. The pollution caused by vaccination and preventive measures are analyzed as follows for your reference.

1. Pollution caused by mold in inoculation box

The direct cause of pollution caused by the vaccination box is when the vaccination box is used in the production season. When using the inoculation box, the producer's non-standard operation or improper use will make the inoculation box too wet, such as letting the culture medium or bacterial materials be scattered in the box without timely cleaning, or due to the large temperature difference inside and outside the inoculation box, it is not cleaned in time, or due to the large temperature difference between inside and outside the inoculation box, the hot air in the box does not condense into water droplets as expected. After the inoculation box is damp, if it is not ventilated and drained in time, it is easy to breed mold when the inoculation box is not in use.

In view of the above causes of pollution in the inoculation box, in order to prevent pollution, in practical work, one is to reduce the humidity in the inoculation box as far as possible when the inoculation box is used. To avoid the culture medium, bacterial material or alcohol cotton balls falling directly into the box, if not falling into the box, it should be cleaned as soon as possible; to avoid dampness caused by the temperature difference inside and outside the inoculation box, the specific measures should be done:

(1) after sterilization, the material bag or bottle should be fully cooled before entering the inoculation box for disinfection treatment, so as not to cause excessive temperature in the inoculation box.

(2) the dosage of disinfectants should be used in strict accordance with the regulations. At present, common disinfectants, such as aerosol disinfectant and formalin, are used to oxidize these substances to produce smoke or steam, so as to achieve the purpose of air disinfection. We know that oxidation often produces a lot of heat, so under the premise of ensuring the disinfection effect, the use of disinfectants should not be excessive.

(3) improve the inoculation speed and control the inoculation time. The inoculation speed is slow, the time is long, not only the work efficiency is low, the production cycle is long, but also the alcohol lamp burning for a long time will produce a lot of heat, which makes the temperature in the box too high. In addition, a long time of inoculation will also prolong the exposure time of culture medium, bacteria and so on in the air, which will increase the chance of miscellaneous bacteria pollution. Second, when the inoculation box is not used for a long time, the lid and cuff of the inoculation box should be opened in time to facilitate ventilation and dehumidification. In fact, it is often difficult to completely avoid dampness in the inoculation box in production, but the crux of the problem is that when the production season is over, the inoculation box should be ventilated and humidified in time, and the inoculation box should be placed in a ventilated and dry place.

If the inoculation box has been contaminated by mold, how to deal with it? In practical work, some producers often do not pay enough attention to this problem, or are not aware of it at all. when using the inoculation box, it is still disinfected according to the conventional method (but do not realize that the disinfection effect of disinfectant is closely related to the number of miscellaneous bacteria in the air when the concentration of disinfectant and disinfection time are not prolonged.), the result is often "unknown" large-scale pollution. After mold contamination occurs in the inoculation box, wipe the molds visible to the naked eye with alcohol cotton balls or cotton balls dipped in formalin, and then fumigate with formalin or disinfect with aerosol disinfectant, so that it can be used only after 2-3 consecutive treatments.

2. Pollution caused by inoculation operation

Inoculation is a very important link in the seed production and cultivation of edible fungi, and it is very important to control the pollution of miscellaneous bacteria. When inoculating, producers are required to strictly master the operating procedures for microbial asepsis. To sum up, there are mainly the following points:

(1) all kinds of inoculation tools and supplies should be disinfected together with material bags, bottles, bacteria, etc., and the transfer of articles to the box should be avoided as far as possible.

(2) before entering the box, wash your hands with clean water outside the box, wipe your hands and inoculation tools with alcohol cotton balls after entering the box, burn and sterilize the inoculation tools with flame, and use flame sterilization regularly in the process of inoculation.

(3) for the expanded culture of test tube species, the test tube should be held flat, the mouth of the test tube should not be upward, and the mouth of the test tube should not leave the alcohol lamp flame, so as to achieve the purpose of flame "sealing".

(4) the inoculation operation should be "light, fast and accurate". "light" means that the range of action during vaccination should not be too large, in order to reduce air fluctuations; "fast" means to operate quickly to avoid the exposure of bacteria and culture medium in the air for too long; and "accurate" means that the vaccination action should be accurate and accurate. Inoculation tools, bacteria blocks, etc., do not hit or misplace everywhere.

(5) after the vaccination operation, remove the articles in time and clean up the box.

3. Air pollution caused by inoculation box

The number of miscellaneous spores or microorganisms in the air of the inoculation box directly affects the pure bacteria rate of the culture after inoculation. The causes of air pollution in the box are various, such as incomplete disinfection, poor sealing performance of the inoculation box and so on. Among them, incomplete disinfection is the most common cause of air pollution in the box. The incomplete disinfection may be caused by the disinfectant itself, for example, the disinfectant is ineffective and the dosage is not enough, or it may be due to the poor disinfection effect caused by the long-term use of the same disinfectant. If the quality of the disinfectant itself can be ruled out, from a biological point of view, it is often due to the selective effect of disinfectants on the variation of drug resistance of miscellaneous bacteria. As a result, the drug-resistant population of miscellaneous bacteria is increasing. In view of this, attention should be paid to the alternate use of different disinfectants in production. In addition, the poor sealing performance of the inoculation box is also one of the reasons for the incomplete air disinfection.