BIOTECHNOLOGY OF PROBIOTIC ANTIBIOTIC-RESISTANT STRAINS OF BACILLUS SUBTILIS

Bacillus subtilis is one of the most studied bacteria at present and one of the most significant in biotechnology. Its synthetic capabilities and genetic engineering allow it to be used in the agro-industry, ecology and medicine, with its help they synthesize amino acids and vitamins, and also use it as a model organism for studying gram-positive bacteria. Bacillus subtilis is capable of producing a wide range of enzymes, including those involved in the breakdown of complex organic compounds, such as fiber. Due to these properties, this microorganism is actively used in biotechnology. In addition, it has a strong antagonistic effect on other microorganisms, such as yeast, salmonella, streptococci and staphylococci, which can be pathogenic for higher organisms. Modification of the bacterium allows you to enhance its antagonistic and weaken the properties that are dangerous for the body, obtaining probiotic strains. The expansion of the range of application of probiotics from B. subtilis strains allows them to be classified as heterobiotic drugs that are used for various living organisms [1, 87 p.].

Currently, probiotics are defined as immunobiological drugs that contain live or inactivated apathogenic microorganisms that have antagonistic activity against pathogenic and opportunistic bacteria, as well as their metabolic products or growth factors for normal microflora microbes. These microorganisms are able to maintain microbial balance in the human and animal body, helping to strengthen the immune system, improve digestion and prevent diseases. Probiotics exhibit antagonistic activity against pathogens, which makes them promising in the treatment of acute intestinal infections [2, 37-42 p.]. For example, studies show that probiotic strains of B. subtilis can reduce the population of Clostridium difficile, which, when the microfloral balance is disturbed, can cause intestinal infections. In this regard, B. subtilis is one of the existing bases for probiotic drugs along with Lactobacillus and Bifidobacterium.

The ability of probiotics to restore the body's microflora is also important in recovery after a course of antibiotics. These drugs can also be one of the solutions to the problem of antibiotic resistance, the main cause of which is the excessive and improper use of antibiotics, both in medicine and in agriculture. Antibiotic resistance has become one of the most serious threats to global health, and it requires an integrated approach. The use of probiotics such as Bacillus subtilis is considered a promising way to reduce the spread of resistant bacteria due to their ability to inhibit the growth of pathogens. This is achieved due to the production of antimicrobial substances by the Bacillus, such as subtilosin and bacteriocins. In addition, it is a spore-forming microorganism, which means it has a high resistance to adverse environmental conditions, including the acidic environment of the stomach. The conditions for culturing bacteria in bioreactors contribute to the formation of these spores, and for stabilization, the biomass is lyophilized or freeze-dried. Probiotics also help prevent the development of secondary infections due to their ability to restore the body's microbiota after taking antibiotics. The use of various strains of the genus Bacillus in feed ensures effective competition for epithelial attachment sites, which in turn prevents intestinal colonization by pathogenic microorganisms.

Microorganisms can be considered probiotics if they meet the following WHO requirements:

1.      strains must be obtained from natural substrates;

2.      identified to species level;

3.      have a genetic passport;

4.      have a broad spectrum of antagonistic activity against pathogenic and opportunistic microorganisms;

5.      do not suppress normal microflora;

6.      have a positive effect on the human body;

7.      consist of viable cells or products of their metabolism;

8.      able to survive in extreme conditions of the stomach and intestines;

9.      must rapidly multiply and colonize on intestinal epithelial cells;

10.    must be non-pathogenic and non-toxic to humans;

11.    must be biologically stable, viable over a long period of time [3, 1-5 p.].

Bacillus subtilis meets these criteria. Research also confirms that this bacterium stimulates the body's immune response, increasing its resistance to infectious diseases. In this regard and the above, B. subtilis is a very promising object for the production of probiotics and its inclusion in complex food additives and preparations.

In the United States, Bacillus subtilis probiotics have found wide application, especially in food additives and animal feed. Studies conducted by the Food and Drug Administration (FDA) have confirmed the efficacy and safety of Bacillus subtilis in these products. Probiotics based on their strains help to improve the condition of intestinal microflora, which is especially important for maintaining the health of both humans and animals. European countries, such as Germany, actively use Bacillus subtilis in medicine, especially for the treatment of gastrointestinal diseases. Clinical trials conducted in Germany have confirmed the effectiveness of Bacillus subtilis in improving the condition of patients with such diseases. This demonstrates the high level of trust in their probiotic properties among European medical professionals. The use of these products in Europe illustrates the importance of integrating probiotics into clinical practice to address current health issues. In Asian countries, especially in Japan, products fermented with Bacillus subtilis, such as natto, are traditionally used. These products are not only part of the national cuisine, but also play a significant role in maintaining the health of the population.

Russian probiotic biotechnology has demonstrated positive trends in recent years, as evidenced by the increasing number of scientific publications and developments in this area. Scientists are actively researching the properties of Bacillus subtilis, studying the possibilities of its use for the prevention and treatment of various diseases. In 2019, several new probiotic-based drugs were registered in Russia, indicating a growing interest in this topic.

Despite the successes achieved, Russian scientists face a number of challenges. One of the key problems is insufficient funding for research, which limits the possibility of conducting large-scale experiments and clinical trials. At the same time, there is a need to improve the infrastructure for the development and production of probiotic drugs. These challenges require active support from the state and the private sector to overcome existing barriers.

International cooperation plays an important role in the development of Russian probiotic biotechnology. Exchange of experience with foreign colleagues allows us to introduce advanced technologies and methods into domestic research. For example, joint projects with European laboratories contribute to the development of new drugs and improve the quality of research. The development of such partnerships can significantly accelerate progress in the field of probiotics, but in the current years this is becoming especially difficult.

Prospects for further research and development in the field of Bacillus subtilis probiotics include the study of new strains and their properties, as well as the creation of innovative drugs. Successful resolution of existing problems and active use of international experience can lead to significant progress in this area. An important area is the study of the effect of probiotics on immunity and their use in the complex therapy of various diseases, for example, in the treatment of respiratory infections and allergic diseases [4, 151-152 p.].