In the work dependence of interaction of Ag nanoparticles with bacteria Bacillus clausii on the nanoparticles stabilizer and on temperature has been studied. Three different stabilizers were used: sodium dodecyl sulfate, sodium citrate and tryptophan. It has been observed that non-functionalized Ag nanoparticles suppress bacterial growing in the dose-depended manner, and the dependence of antibacterial effect on the concentration of the nanoparticle is nonmonotonic. It has been also shown that nanoparticles stored in glassware under low temperature loss their antibacterial activity. Theoretical model for the observed phenomena has been proposes.