Biological synthesis procedures are gaining importance in these days because they are single step, fast, low cost and environment friendly alternative of well-known chemical and physical synthesis procedures for preparing metallic nanoparticles. The aim of this work is to synthesize silver nanoparticles from aqueous stem bark extract of Boswellia papyrifera , Characterize  and test  its antimicrobial properties against two bacterial strains ( Streptococcus pneumoniea and Shigella dysentriea ).

The AgNPs were synthesized biologically, and they were characterized using visual color development, UV-VIS spectroscopy, Fourier transform infrared ray (FTIR), and scanning electron microscopy (SEM). The antimicrobial activities of the synthesized Boswellia papyrifera silver nanoparticles (BP- AgNPs) were evaluated using the agar well diffusion method, the MIC method, and the MBC method.

The results showed that silver nanoparticels were synthesized, as indicated by the color change from yellow to dark brown. The presence of AgNPs is indicated by UV peaks of 436.90, 458.20, and 459.40 for 1mM, 2mM, and 3mM, respectively. The aqueous stem bark extract of Boswellia papyrifera synthesized AgNPs show the presence of different functional groups such as C=C stretch, C stretch, and Alcohol OH stretch, which represent bioactive compounds such as phenol, amine, and so on. The BP-AgNPs were examined using a scanning electron microscope (SEM), which revealed that the nanoparticles had spherical, cuboidal, and triangular shapes.. The antimicrobial activities such as MIC and MBC showed the efficacy of the synthesized AgNPs against the test organisms Streptococcus pneumoniea and Shigella dysentriea which are gram-ve and gram+ve respectively.

The biologically synthesized silver nanoparticles of Boswellia papyrifera aqueous stem bark extract were found to have effective antimicrobial properties against Streptococcus pneumoniae and Shigella dysenteriae and they can be incorporated into a variety of materials, including bandages, antimicrobial paint, cutting boards, and surgical dressings materials, to control bacterial colonization on a variety of surfaces and prevent infections.

Key words: Boswellia Papyrifera , stem bark,  silver, nanoparticle , antimicrobial , UV-VIS spectroscopy; FTIR.