Background:Bacteriophages act only host bacterial pathogen selectively not affecting the normal microflora of the human digestive tract, not causing allergies. Also found that the bacteriophage preparations don’t have taste, smell and preparation technology doesn’t affect the structure of bacteriophage. Using of bacteriophages for treatment is safe and has established that they are very effective against multi-drug resistant bacteria according to conducted clinical studies. In our country is using the Bacteriophage preparate which is based on local strain of Salmonella Typhi. Nowadays there is no research data whether environmental physical and chemical factors can affect the Bacteriophage activity.Aim:To study whether the environment physical and chemical factors might influence on Bacteriophage of Salmonella Typhi.Materials and Methods:In this study, were used the test strains of the Salmonellatyphimurium, Salmonella typhi and Bacteriophage of Salmonella Typhi. All procedures are performed according to Mongolian National Standard MNS ISO 2416-94, 3317-94 and Bacteriophage of Salmonella Typhi.Our study was established that physical and chemical factors: temperature of water bath, chloroform action time interval, procedure to kept biopreparates all can affect bacteriophage lysis activity.Conclusions:Any use of bacteriophages did not reveal any adverse effects. From the Bacteriophage of Salmonella Typhi preparations kept up to 3 years can be isolated bacteriophage strains by our improved method.

Background: Soil pollution in Ulaanbaatar has increased in recent years, causing infectious and non-communicable diseases, both benign and malignant.
Therefore, in order to reduce soil pollution, it is necessary to isolate strains resistant to heavy metals and use these microorganisms capable to degrade or accumulate heavy metals for bioremediation purposes. Methods: Bacterial pure cultures were isolated from soil and water samples and incubated in a Nutrient Broth medium with a lead concentration of 1000 mg/L in a thermostat with a shaker at 37°C. The growth rate was determined at a wavelength of 600 nm using a Spectrophotometer. Results: In total 69 pure cultures were isolated from the soil samples and 65 pure cultures from them were able to grow at the concentration of lead of 1 mmol/L. 4 pure cultures (UBLF1, UBLF3, UBMF2, and SUBZ4) were able tolerate lead concentrations up to 8 mM. These cultures were determined by semi-automatic VITEK®2 analyzers and identified as Bacillus sp. (83%) and UBMF2 identified as Bacillus thuringiensis (93%) respectively. Conclusion The lead content in water samples were found to be acceptable, and isolated pure cultures were not able to withstand the lead concentrations.
Pure culture UBLF3 isolated from the soil capable to reduce lead concentration (500 mg/L) up to 302 mg/L and 230 mg/L in the medium, and pure culture UBMF2 up to 340 mg/L and 279 mg/L respectively