Synthesis of silver nanoparticles from pure and combined extracts of Satureja bachtiarica Bung. and Satureja hortensis L. effective on some microbial strains causing digestive diseases.

The biological method, which is also called green synthesis, is a safe, cheap and environmentally friendly method. The present study was designed for the first time with the aim of synthesizing silver nanoparticles from pure and mixed extracts of Satureja bachtiarica Bung. and Satureja hortensis L. The extraction of plants was done by boiling water and the synthesis of silver nanoparticles was investigated by UV-VIS, XRD, FTIR and FESEM tests. Antibacterial effect of synthesized silver nanoparticles and extracts was evaluated by diffusion method in agar and determination of the minimum inhibitory concentration and bactericidal concentrations (MIC and MBC). The examination of the UV test confirmed the spectrum of 393-422 nm related to surface plasmon resonance absorption. XRD test determined the silver particle size of S. bachtiarica + S. hortensis more than two species S. bachtiarica and S. hortensis and 14.4 nm. FTIR spectroscopy identified OH, CH, C =C, CH3, CH, C-O groups. The results of FESEM showed that the shape of the particles is mostly quasi-cubic or prism-like.. Energy dispersive X-ray spectroscopy (EDX) also showed an absorption peak of silver at 3 keV. The strongest inhibitory activities related to synthetic silver nanoparticles from S. bachtiarica extract against Gram-negative bacteria Escherichia coli (~ 10 mm) and silver nanoparticles synthesized from combined extract of S. bachtiarica + S. hortensis against Gram-negative bacteria Shigella dysenteriae (~ 9 mm), which matched the control antibiotics rifampin. Therefore, it seems that the pure extract of S. bachtiarica or the combination with the extract of S. hortensis is a natural potential for the synthesis of silver nanoparticles with significant antibacterial activity, which can be a possible substitute for antibiotics against some strains. However, much research needs to be done in the future to confirm this for clinical applications.