Abstract

Two microbial isolates selected from Egyptian soil were used for ‎biological synthesis of silver nanoparticles using silver nitrate solution. ‎The selection of these two microorganisms was depending on the ‎ability of actinomycetes and fungi to AgNPs synthesis and production ‎of antimicrobial compounds. Results recorded that the dry weight of ‎AgNPs produced from selected Streptomyces clavuligerus and ‎Trichoderma harzianum AUMC 5408 were 66.5 and 11.0 mg/l ‎respectively. Description of AgNPs from Streptomyces clavuligerus ‎supernatant and Trichoderma harzianum AUMC 5408 mycelia were ‎carried out. Results of UV-analysis showed spectrum located between ‎‎420-440 nm for both culture filtrate and mycelium respectively ‎characteristics of AgNPs. Also, the Fourier Transform Infrared ‎Spectroscopy (FTIR) analysis was studied. The average size of AgNPs ‎were between rang from 2.0 to 4.5 nm in case of Streptomyces ‎clavuligerus, but 5.33-29.46 nm in case of Trichoderma harzianum ‎AUMC 5408. Enhancement of the antimicrobial activity of crude ‎antimicrobial compounds with Silver Nanoparticles was assayed. The ‎results revealed that addition of AgNPs to the culture filtrate of ‎Streptomyces clavuligerus and Trichoderma harzianum AUMC 5408 ‎that have antimicrobial activity increased the diameter of inhibition ‎zone between 3-5 mm in both cases.‎

Key words: Silver Nanoparticles, UV-visible, FTIR analysis, TEM and Antimicrobial ‎activity.‎