Preparation characterization and therapeutic applications of silver nanoparticles using actinomycetes

Abstract

This work was conducted to explore the in vitro inhibition of selected human pathogens by using silver nanoparticles produced by actinomycetes (Streptomyces atacamensis AK3) and contributes to enhancing knowledge about the effectiveness of silver nanoparticles for the treatment of human diseases. Twenty bacterial strains were isolated from the soils of Gujarat. Streptomyces atacamensis AK3, which was found in soil near the bank of the Tapi river in Surat, Gujarat, showed promising results for synthesizing silver nanoparticles. The Tapi River, located in Surat, has been found to be contaminated with heavy metals, which has resulted in the emergence of bacteria that are resistant to heavy metals. The promising strain of actinomycetes has been examined and sequenced (GenBank MT626067). Streptomyces atacamensis AK3 strain was isolated with the actinomycetes isolation media and then subcultured in starch-casein broth. Following the filtration process, the filtrate was subjected to the addition of silver nitrate and subsequently placed in a shaking incubator. The intensity of the color change from yellow to brown was measured with a Shimadzu spectrophotometer-1700. The peak observed at 420 nm and, furthermore, the turning of the broth culture color to brown signified the synthesis of AgNPs. The size distribution and zeta potential of silver nanoparticles were determined with Malvern, and TEM analysis was done to have a detailed account of the prepared silver nanoparticles characteristics. TEM analysis revealed that AgNPs of size ~20 nm were most abundant in the sample. A Zeta potential of -28 mV revealed a low degree of aggregation of AgNPs. The diffusion method was used for the analysis of the efficiencies shown by the synthesized silver nanoparticles and the antibiotics against various human pathogens. We demonstrated the zones of newlineix newlineinhibition with strain-synthesized silver nanoparticles as 22 mm, 25 mm, 25 mm, 24 mm, 26 mm, 21.6 mm, 23 mm, 20 mm, 21 mm, 24 mm, and 24 mm for Salmonella enterica, co-agulase negative