NGHIÊN CỨU HOẠT TÍNH KHÁNG VI KHUẨN GÂY BỆNH CHO NGƯỜI CỦA XẠ KHUẨN Streptomyces padanus MIP_L27 PHÂN LẬP TỪ ĐẤT VÙNG RỄ CÂY MÀNG TANG (Litsea cubeba)

Abstract

Objectives: This study investigates the antagonistic ability of Streptomyces MIP_L27 against human pathogenic bacteria Escherichia coli YH15, Bacillus cereus YH34; Biological characteristics of Streptomyces MIP_L27; Sequencing 16s RNA and using phylogenetic trees to identify strains. Methods: Streptomyces MIP_L27 was activated from the Microbial Type Collection of the Department of Microbiology - Military Institute of Preventive Medicine. Morphological characteristics, colony color and spore-forming structure were described according to the method of Tresner (1963); Antagonistic activity of MIP_L27 against E. coli and B. cereus bacteria was performed according to the method of Kirby-Bauer (2009). Using molecular biology methods combined with morphological characteristics, the Streptomyces MIP_L27 was identified to species and phylogenetic tree based on MEGA X. Results: Streptomyces MIP_L27 belongs to the brown group, temperature of 30^oC; pH 7; After 5 days of growing, the colonies were brown. MIP_L27 has the ability to assimilate carbon sources such as starch, sucrose, glucose, and nitrogen sources such as yeast extract and peptone. Antagonistic activity against E. coli YH15, B.cereus YH34 with ring diameter of 22 mm; 11.5 ± 1.5 mm respectively. Phylogenetic analysis based on 16S rDNA gene sequences indicated that MIP_L27 was most closely related to Streptomyces padanus (100% sequence similarity). Therefore, the S. MIP_L27 was named S. padanus MIP_L27. This is a novel study on S. padanus MIP_L27 isolated from soil in the root zone of Litsea cubeba in Ha Giang, Viet Nam. Conclusion: These results of research indicate that S. padanus MIP_L27 apply to developing products in the fields of medicine.