Biogenic silver for disinfection of water contaminated with viruses.
The presence of enteric viruses in drinking water is a potential health risk. Growing interest has arisen in nanometals for water disinfection, in particular the use of silver-based nanotechnology. In this study, Lactobacillus fermentum served as a reducing agent and bacterial carrier matrix for zerovalent silver nanoparticles, referred to as biogenic Ag(0). The antiviral action of biogenic Ag(0) was examined in water spiked with an Enterobacter aerogenes-infecting bacteriophage (UZ1). Addition of 5.4 mg liter(-1) biogenic Ag(0) caused a 4.0-log decrease of the phage after 1 h, whereas the use of chemically produced silver nanoparticles (nAg(0)) showed no inactivation within the same time frame. A control experiment with 5.4 mg liter(-1) ionic Ag+ resulted in a similar inactivation after 5 h only. The antiviral properties of biogenic Ag(0) were also demonstrated on the murine norovirus 1 (MNV-1), a model organism for human noroviruses. Biogenic Ag(0) was applied to an electropositive cartridge filter (NanoCeram) to evaluate its capacity for continuous disinfection. Addition of 31.25 mg biogenic Ag(0) m(-2) on the filter (135 mg biogenic Ag(0) kg(-1) filter medium) caused a 3.8-log decline of the virus. In contrast, only a 1.5-log decrease could be obtained with the original filter. This is the first report to demonstrate the antiviral efficacy of extracellular biogenic Ag(0) and its promising opportunities for continuous water disinfection.
De Gusseme
Bart
B
Department of Biochemical and Microbiological Technology, Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, B-9000 Ghent, Belgium.
Sintubin
Liesje
L
Baert
Leen
L
Thibo
Ellen
E
Hennebel
Tom
T
Vermeulen
Griet
G
Uyttendaele
Mieke
M
Verstraete
Willy
W
Boon
Nico
N
D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D001435:Bacteriophages / Q000187:drug effects; D004202:Disinfectants / Q000494:pharmacology; D004203:Disinfection / Q000295:instrumentation / Q000379:methods*; D021902:Enterobacter aerogenes / Q000821:virology; D005618:Fresh Water / Q000821:virology*; D006801:Humans; D052197:Limosilactobacillus fermentum / Q000378:metabolism; D053768:Metal Nanoparticles; D051379:Mice; D036103:Nanotechnology; D029322:Norovirus / Q000187:drug effects; D012834:Silver; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*; D014881:Water Supply
D000998:Antiviral Agents; D004202:Disinfectants; D012834:Silver