Biological, Physical and Chemical Properties of Nanosilver Particles Collected from Soil in Asir, Saudi Arabia.

A study was carried out on soil samples collected from coastal area of Red Sea and from El-Souda Mountains, KSA. Biological, physical and chemical properties of each soil type had been investigated using X-ray fluorescence spectrometer, X-ray diffraction, scanning electron microscopy, UV–Vis-spectrophotometer, conductivity bridge, AgNO3 titration, electronic pH meter, well diffusion and hydrometer methods. It was found that the Red Sea coastal soils contain major components of Ca (39.74%) in (site 1) at 3 meters height, whereas the sandy soil (site 2) has Si (47.61%) at 4 m height. Site 3 at 2640 m height has Si (29.62%), whereas site 4 at 2928 m height has high amount of Fe (62.25%). Except soils of site 2, all other sites are fall into the grains category of a micrometer scale. The pH value of the soil extract was decreased gradually from (7.75 ± 0.08) in site 1 to (6.52 ± 0.09) in site 4. Electrical conductivity was found to be very high in site 1 (9.84 ± 0.03 mS) and less in site 2 (2.35 ± 0.01 mS) and in sites 3 and 4 were very low. Chloride amount was very high in site 1 (2929 ± 1.52 ppm) and in site 2 (692 ± 1.54 ppm) and no traces found in sites 3 and 4. Site 4 had the highest amount of clay 80%. XRD pattern showed there was a remarkable difference in crystalline nature, phase identification and in grain size. Synthesized nanoparticles from all soils showed promising antimicrobial activities against all tested pathogenic microbial strains. [ABSTRACT FROM AUTHOR]