Abstract:
This research examined the antimicrobial activities of silver nanoparticles synthesized
(AgNPs) from soil bacteria and fungi isolated from Federal University of Technology, Akure
(FUTA). the microorganismswere isolated from the rhizosphere of the some selected soil
samples of food using standard technique. The antimicrobial activity of the synthesized
AgNPs was determined using agar well diffusion method. The bacteria isolated from the soil
rhizosphere were Staphylococcus aureus, S. epidermidis, Proteus vulgaris, Escherichia coli,
Micrococcus leteus, Pseudomonas aeruginosa, Bacillus subtilis, B. cereus, and Serratia
marcescens, while Aspergillus flavus, A. niger, Rhizopus solonifer, Trichoderma viride, Mucor
mucedo, Emericella rugulosa, Fusarium merismoides, Geotrichum albidum were the fungal
isolates. The colour transformation from yellow to brownish indicates the formation of silver
nanoparticles. The UV-Vis analysis revealed that all samples shown an intense peak in the
wavelength range of 410-440nm, bacteria is around 416-428nm, while fungi showed a broad
and strong UV-Visible spectrum within 417-437.5nm. The Fourier Transform Infrared
spectroscopy (FTIR) analysis revealed the existence of a band at 3395cm-1 in the FTIR
spectrograms and a strong peak at 3300-3500cm-1. The peak at 2185cm-1 was also significant
to most of the isolates. The antimicrobial activities of the synthesized AgNps by S. aureus, M.
luteus, and B. subtilis possessed the highest antibacterial activity against E. faecalis with a
zone of 12.17mm, 11.33mm and 14.33mm respectively. Micrococcus luteus and B. subtilis
synthesized-AgNps showed no inhibition on P. aeruginosa. Fusarium
oxysporium-synthesized AgNps showed inhibition on all the test isolates except R. stolonifer.
Microbial synthesized silver nanoparticles obtained from this study showed significant
inhibition on most of the selected isolates. Thus, can be used in the development of novel
antimicrobial agents due to its antimicrobial potentials.
