Causes and Countermeasures of strain degradation of Edible Fungi

First, what is the "degradation of edible fungi"

"strain degradation" is the biggest concern of edible fungus producers.

In microbiology, the definition of "strain degradation" (strain decline): in the process of culture or preservation, due to the existence of spontaneous mutation, there are some phenomena such as the deterioration of some good production characters and the loss of genetic markers, which is called the decline of bacteria. "Edible fungus strain degeneration" is a very abstract phenomenon, which is difficult to define in words. We can think like this: in the production of edible fungus, the genetic character of the strain (mother species) changes, which leads to the decline of yield and quality. This phenomenon is called "edible fungus strain degradation". The decline in yield and quality is the final result of the degradation of edible fungi. In order to avoid the degradation of edible fungi, it is necessary to find out the causes of the degradation of edible fungi, and what is the performance of the degradation of edible fungi?

Second, the reasons for the degradation of edible fungi.

1. Training environment

The growth environment of edible fungi includes temperature, humidity, light and oxygen, in which temperature is the main environmental factor that can cause "degradation of edible fungi". This is because temperature has the greatest impact on biological metabolism. when in an extremely uncomfortable temperature environment, the genetic characteristics of the strain changed and lost the excellent production characters that the mother seed should have, when the mother seed was cultured, preserved and transported. Suffering from high and low temperatures (such as sub-zero) can easily lead to "degradation of edible fungi".

2. Culture medium

The medium is not suitable for strain growth, which will cause "edible fungus strain degeneration", including: the nutritional composition of the medium, pH value, the medium is too rich, the medium is too barren, or it is understood that the medium is not suitable for its growth. With regard to the mother culture medium of edible fungi, the existing theories and textbooks lag far behind the actual production, and the so-called theories such as the alternation of barren and rich media are all applied to the theories and concepts of microbiology. there is no practical guiding significance in the factory production of edible fungi.

3. Times of transfer

There are too many times of subgeneration. Based on the analysis of microbiological theory, too many times of subgeneration is easy to produce "edible fungus strain degeneration", but in the actual edible fungus production, it should be: the use of incorrect strain production and culture of subgeneration, easy to cause "edible fungus strain degradation", the more times of subgeneration, the greater the possibility of "edible fungus strain degradation".

4. Pollen spores, arthrospores and conidia

For the varieties that can produce pollen spores, arthrospores and conidia in the mother mycelium stage, they are prone to "edible fungus species degeneration". When the conditions are right, the mycelium will sprout. These hyphae do not have fruiting ability, or the fruiting ability is very poor. After continued subculture, mixed with the normal hyphae, the overall appearance of the hyphae may not have any performance, but will eventually affect the final yield and quality.

5. Strain preservation

The production of edible fungi is inseparable from the preservation of edible fungi, improper preservation methods, too long preservation time, too high and low storage temperature, all of which may cause "degradation of edible fungi", especially during the preservation period. Although the fruiting body does not grow very large, as long as the cap is formed, the spore bullet may shoot into the slope, and the hyphae will sprout under the right conditions. The formation of asexual reproduction and sexual reproduction mixed together, resulting in "edible fungus strain degradation".

3. What is the manifestation of "the degeneration of edible fungi"?

The degradation of edible fungi is the most serious in a variety or a strain, and there are many varieties of edible fungi, and the specific performance is also different. if the mycelium grows slowly, the tip grows irregularly, grows sparsely, and secretes more pigments, in short, in the maternal stage, there is a continuous and heritable abnormal performance, it is very likely that the strain has degraded.

The performance of several kinds of "edible fungus strain degradation" described above is not obvious most of the time, but the continuous decline of final yield and quality, and can rule out the influence of mushroom environment, it should be considered as "edible mushroom strain degradation". It is shown in the formation of primordium and the differentiation of fruiting body, and the increase of deformed mushroom is also one of the bases to judge the degradation of edible fungus.

"Edible fungus strain degradation" does not occur in a short time, nor does it occur suddenly in a certain subgeneration. therefore, the performance of strain degradation comes quietly, which is more likely to be ignored.

Fourth, how to avoid the degradation of edible fungi

In view of the above reasons for the degradation of edible fungi, we should provide a suitable growth environment and culture medium for the growth of edible fungi, reduce the number of subgeneration as far as possible, reduce the number of pollen spores, reduce arthrospores, reduce conidia, and do a good job in the preservation of strains, so as to avoid the "degradation of edible fungi" to the greatest extent.

In a word, the production of strains in accordance with formal and stringent technical requirements is the fundamental way to avoid "degradation of edible fungi". Once the degradation of strains occurs, the strains should be replaced in time.