ANTIMICROBIAL ACTIVITIES OF SILVER NANOPARTICLESSYNTHESIZED FROM SOME SOIL ORGANISMS ISOLATED FROM FEDERAL UNIVERSITY OF TECHNOLOGY, AKURE, NIGERIA

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.