1.1. Strain degradation
Strain degradation refers to the phenomenon that the genetic variation of the strain occurs in the process of reproduction, which leads to the change of its character and the decline of the quality and yield of the strain. Strain degradation is a very common problem, which not only affects the development of industry, but also brings challenges to microbiology research.
a. Causes of strain degradation:
b. Impact:
c. Solution:
1.2. Strain aging
Strain aging refers to the phenomenon that the growth rate and reproduction ability of the strain decrease gradually in the process of long-term culture or preservation. Strain aging is also a serious problem, which not only affects the quality and yield of the strain, but also brings difficulties to microbiology research.
a. Causes of strains aging:
b. Impact:
c. Solution:
In order to effectively cope with strain degradation, we need to analyze the causes of degradation in the deep perspective.They include genetic instability of strains, unsuitable culture conditions, changeable culture environment and so on. By analyzing the causes of degradation, countermeasures can be taken to prevent further degradation of the strains.
2.1. Strain selection and improvement: In order to improve the stability and performance of the strain, we need to carry out strain selection and improvement. It includes the selection of strains with good genetic stability, the screening of mutants, and the use of genetic engineering technology for genetic modification. Through breeding and improvement, the adaptability and yield of the strain can be improved, and the risk of strain degradation can be reduced.
2.2. Optimization of culture conditions: Culture conditions have an important impact on the growth and metabolism of strains. To prevent strain degradation, we need to optimize the culture conditions. They include adjusting the composition of the medium, controlling the culture temperature, adjusting the pH value and so on. By optimizing the culture conditions, the growth and metabolism of the strains could be improved, and the risk of strain degradation could be reduced.
2.3. Establishment of scientific strain management system: The scientific strain management system can effectively prevent strain degradation. It includes the establishment of strain storage bank, the regulation of strain use and transmission process, and the regular identification and performance testing of strains. By establishing the scientific culture management system, the stability and reliability of culture can be guaranteed and the risk of culture degradation can be reduced.
2.4. Use of molecular biology technology to assist identification: Molecular biology technology can help us more accurately identify strains and judge their genetic stability and performance. It Includes DNA fingerprinting technology, PCR technology, gene sequencing and so on. With the aid of molecular biology technology, the phenomenon of strain degradation can be more accurately identified, the causes of degradation can be deeply analyzed, and the corresponding countermeasures can be taken.
2.5. Strengthen strain safety assessment: In the process of strain use and transmission, we need to strengthen safety assessment to prevent strain from leakage and pollution of the environment. This includes testing the safety of the strains and assessing the impact of the strains on the environment. By strengthening the culture safety assessment of strain, the potential risks to the environment and human health can be reduced, and the safety and reliability of microbial fermentation process can be ensured.
In the process of microbial fermentation, the aging of strains may lead to the decline of production capacity and the instability of product quality. In order to solve this problem, we need to carry out strain aging and rejuvenation operations. The following content will introduce the aging and rejuvenation operation of the strain from seven aspects to help you restore the production capacity and stability of the strain.
3.1. Screening of dominant strains that produce active substances: In the aging and rejuvenation operation of strains, screening of dominant strains that produce active substances is the first step. We can screen out the dominant strains with higher production capacity by means of plate streak method and liquid culture method. Through the screening of dominant strains, the adaptability and yield of strains could be improved, which provided a good basis for the subsequent rejuvenation of strains.
3.2. Reasonable seed aging: Seed aging is an important step in the aging and rejuvenation operation of strains. Reasonable seed aging can promote the growth and metabolism of the strains and improve the ability of the strains to produce active substances. According to the characteristics of the strains and culture conditions, we can determine the appropriate aging time, temperature and types of aging agents. Reasonable seed aging can promote the recovery and optimization of strains.
3.3. Use of appropriate culture conditions to promote the growth of strains: Culture conditions have an important impact on the growth and metabolism of strains. In the operation of aging and rejuvenation of strains, we can promote the growth of strains by optimizing the culture conditions. For example, controlling the culture temperature, adjusting the pH value, adding the appropriate nutrients and so on. Through suitable culture conditions, the growth and metabolism of the strains can be improved, and the ability of producing active substances can be increased.
3.4. Timely separation and purification to obtain high-purity strains: In the aging and rejuvenation operation of strains, timely separation and purification is the necessary step. Through separation and purification, high purity strains can be obtained to ensure the purity and performance of strains. We can use appropriate separation methods and purification agents to separate and purify strains. By means of separation and purification, the quality and production capacity of the strains can be further improved.
3.5. Reasonable strain preservation to ensure the survival and stability of the strain: Reasonable strain preservation can ensure the survival and stability of the strain, and avoid the mutation and pollution of the strain during the process of use. We can use storage methods which is suitable for strain characteristics, such as low temperature storage, vacuum drying storage, etc. The reliability and stability of the strains can be ensured through reasonable strain preservation, which provides the strong guarantee for the subsequent production.
3.6. Modification and optimization through genetic breeding technology to improve the ability of strains to produce active substances: In the aging and rejuvenation operation of strains, modification and optimization through genetic breeding technology is an effective means to improve the performance of strains. For example, gene recombination and transfer technology can be used to change the genetic characteristics of strains and improve the ability of strains to produce active substances. Through the modification and optimization of genetic breeding technology, the adaptability and yield of strains can be further improved, which provides the good basis for the optimization of fermentation conditions.
3.7. Optimization of fermentation conditions is used to improve production efficiency: We can optimize fermentation conditions according to the characteristics of strains and production requirements, such as controlling temperature, adjusting pH value, adding appropriate nutrients, etc. Through the optimization of fermentation conditions, the growth and metabolism of the strains can be improved, and the production efficiency and product quality can be improved.
Taking beer yeast as an example, whether beer yeast is pure or not has the great influence on beer fermentation and beer quality. The yeast used in beer factory production is cultivated by the preserved pure yeast, and after reaching the certain amount, it is used on the production site. Every brewery should save the pure yeast suitable for the use of the factory to ensure that the beer produced has the stable style and characteristics.
4.1. Process of culture expansion
4.2. Principles of expanded cultivation