Effects of abiotic and biotic stresses on antagonistic activities of symbiotic bacterial strains isolated from Adenosma bracteosum

Adenosma bracteosum Bonati has been widely used in traditional and modern Vietnamese medicine for treating hepatitis and lung diseases. Endophytic bacteria, which reside within the cells of medicinal plants, play a vital role in enhancing host plant growth and survival through the production of unique secondary metabolites. These metabolites are significant for both fundamental and applied research, particularly in sustainable agriculture. This study identified the Bacillus velezensis strain SB1R13.2, isolated from A. bracteosum, as a producer of extracellular antibacterial compounds when exposed to pathogenic bacteria. However, abiotic factors such as culture medium composition, pH, and temperature did not induce similar production in this strain.

Gas chromatography-mass spectrometry analysis of the cell-free extract identified at least eight compounds, including putative antibacterial agents. These findings highlight the potential of strain SB1R13.2 as a promising antibacterial agent, offering resistance against diverse pathogens. These results highlight the potential of B. velezensis SB1R13.2 as a valuable source of antibacterial compounds, with potential applications in combating a broad range of pathogenic bacteria and advancing both medical therapies and sustainable agricultural practices.