Ag nanoparticles generated using bioreduction and

Authors: Aniket Gade Joshua Adams David W Britt FenAnn Shen Joan E McLean Astrid Jacobson YoungCheol Kim Anne J Anderson

Publish Date: 2016/01/25

Volume: 29, Issue: 2, Pages: 211-223

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Abstract

Costeffective “green” methods of producing Ag nanoparticles NPs are being examined because of the potential of these NPs as antimicrobials Ag NPs were generated from Ag ions using extracellular metabolites from a soilborne Pythium species The NPs were variable in size but had one dimension less than 50 nm and were biocoated aggregation and coating changed with acetone precipitation They had dosedependent lethal effects on a soil pseudomonad Pseudomonas chlororaphis O6 and were about 30fold more effective than Ag+ ions A role of reactive oxygen species in cell death was demonstrated by use of fluorescent dyes responsive to superoxide anion and peroxide accumulation Also mutants of the pseudomonad defective in enzymes that protect against oxidative stress were more sensitive than the wild type strain mutant sensitivity differed between exposure to Ag NPs and Ag+ ions demonstrating a nanoeffect Imaging of bacterial cells treated with the biocoated Ag NPs revealed no cell lysis but there were changes in surface properties and cell height These findings support that biocoating the NPs results in limited Ag release and yet they retained potent antimicrobial activityThis work was supported by Grant from the USDA 10867118 the Utah Agricultural Experiment Station to AJA and the Water Research Laboratory to JM The catalase and SOD mutants were generated under support from the Basic Science Research Program through the National Research Foundation of Korea NRF funded by the Ministry of Education Science and Technology 20110011555This is Utah Agricultural Research Paper number 8740

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