Brilliant Steve! dee On 26 Mar 2010, at 17:05, Norton, Steve wrote:
> I think this excerpt from > http://www.fpl.fs.fed.us/documnts/pdf2004/fpl_2004_dorau001.pdf > pretty much answers the question of ionic silver vs silver particles: > > "The mechanisms of the antimicrobial action of silver can be described as > follows (17): > > 1. Silver ions form insoluble compounds in the cell wall with (and thereby > inactivate) sulfhydryl groups, which are essential components of enzymes > responsible for transmembranous energy metabolism and electrolyte transport. > The result is a loss of fluids and electrolytes from the organisms, which dry > out and die. > > 2. Silver ions block the respiratory chain of bacteria in the cytochrome > oxidase and NADH-succinate- dehydroginase region. > > 3. Silver ions enter the cell and bind to bacterial DNA and bacterial spores. > Silver can complex with electron donor groups that contain oxygen or > nitrogen. Reversible binding of bases occurs without aggregation or > disruption of the double helix structure of the cell nucleus. Intercalation > of silver can lead to increased stability of the double helix. > > 4. Silver ions in low concentrations may penetrate a bacterial cell and cause > structural damage to the cell envelope. Upon entering the cell, the molecule > may dissociate, after which the silver binds to the DNA. > > 5. Metal ions, particularly silver, can also bond to phosphate groups, > forming a positive dipole on the phosphate, followed by formation of a cyclic > phosphate and cleavage of these molecules at the phosphodiester bond. > > 6. Silver DNA complexes occur at bases, which cause denaturation by > displacing hydrogen bonds between adjacent nitrogens of purines and > pyrimidines, thereby preventing replication. > > Note that all these mechanisms relate to solvated silver ions, Ag+. The > antibacterial properties of any metal come from its ions, which are generated > from the neutral metal (1 5). In the presence of oxygen, metallic silver can > be bactericidal because silver (I) oxide is soluble enough to release free > silver ions (18). When dealing with metallic silver, though, it is important > to note that antimicrobial activity depends on the extent of the active > silver surface." > > > -- The Silver List is a moderated forum for discussing Colloidal Silver. Rules and Instructions: http://www.silverlist.org Unsubscribe: <mailto:[email protected]?subject=unsubscribe> Archives: http://www.mail-archive.com/[email protected]/maillist.html Off-Topic discussions: <mailto:[email protected]> List Owner: Mike Devour <mailto:[email protected]>
