Antibacterial Properties Of Silver Nitrate Essay

978 Words Mar 2nd, 2016 4 Pages
Antibacterial properties of silver nitrate in different assay conditions In the presence of intracellular Ag+, the bacterial cytoplasm dissociates from the cell wall, thus disrupting cell wall integrity (Feng et al. 2000). Intracellular Ag+ interacts with thiol (R-SH)- or sulphur- containing compounds to form Ag-RSH/ sulphur complexes that reside in the cytoplasm (Feng et al. 2000; Saulou-Bérion et al. 2015). These interactions may interfere with thiol regulation in the normal enzymatic activity of intracellular proteins. Saulou-Bérion et al., have shown exposure to Ag+ correlates with the down-regulation of gene expression for growth including transcription regulation, transportation of metals ions and ribosomal protein synthesis in E. coli. An increase in Ag+ concentration up-regulates gene expression of stress responses associated with intracellular metal ion accumulation, methionine synthesis and copper ion (Cu2+) transporters (Saulou-Bérion et al. 2015). Methionine is a sulphur-containing amino acid involved in detoxifying cells by chelating to heavy metal ions leading to their eventual exit from the cell (Anon 2016). An increase in methionine production would suggest this is a protective act in response to oxidative stress when exposed to intracellular Ag+. The up-regulation of copA gene expression is associated with intracellular Ag+ and Cu2+, which encodes for an array of efflux pumps in an attempt to resist Ag+ and Cu2+ buildup in the cell. Saulou-Bérion et al.,…

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