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Green synthesis of nanosilver particles by Aspergillus terreus HA 1N and Penicillium expansum HA 2N and its antifungal activity against mycotoxigenic fungi
Author(s) -
Ammar H.A.M.,
ElDesouky T.A.
Publication year - 2016
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/jam.13140
Subject(s) - aspergillus terreus , penicillium expansum , aspergillus ochraceus , aspergillus niger , chemistry , penicillium , nuclear chemistry , silver nanoparticle , food science , mycotoxin , ochratoxin a , botany , biology , materials science , nanoparticle , nanotechnology , postharvest
Aims The aim of this study was to synthesize silver nanoparticles (Ag NP s) by an eco‐friendly and low‐cost method using the fungi Aspergillus terreus HA 1N and Penicillium expansum HA 2N as an alternative to chemical procedures mostly requiring drastic experimental conditions emitting toxic chemical byproducts. Also, this study has been extended to evaluate the effect of Ag NP s on the growth of some mycotoxigenic fungi and ochratoxin A ( OTA ) produced by Aspergillus ochraceus . Methods and Results The Ag NP s have been characterized by UV –Visible Spectrophotometer, Dynamic Light Scattering ( DLS ), Fourier Transform Infrared Spectroscopy ( FTIR ) and Transmission Electron Microscope ( TEM ). The TEM analysis has revealed that the size of Ag NP s ranged between 14 and 25 nm in the case of P. expansum and 10–18 nm in the case of A. terreus . The antifungal activity of Ag NP colloids has indicated that the highest inhibition zone was detected with Ag NP s synthesized by A. terreus HA 1N against all tested fungi. The highest inhibition zone was detected with Aspergillus niger at concentrations 3 and 6 μ g of Ag NP solution (7·56 ± 0·38 and 11·3 ± 1·8 mm, respectively) while, A. ochraceus showed the maximum inhibition zone (16·33 ± 0·96 mm) at the concentration 9 μ g of Ag NP s synthesized by A. terreus . The results have also indicated that the Ag NP s synthesized by A. terreus and P. expansum at the concentration 220 μ g/100 ml media gave the highest reduction of OTA , where the percentages of reduction were 58·87 and 52·18% respectively. Conclusions The smallest size Ag NP s synthesized by A . terreus HA 1N are better in their antifungal activity against all tested mycotoxigenic fungi than the largest one synthesized by P. expansum HA 2N. Significance and Impact of the Study This is the first study focused on using Ag NP s in control of OTA production.