Silver nanoparticles show anti-microbial and antibacterial effect as well as used for milk-spoiling microbes. In this work, cultures of milk spoilage microbes were isolated and the silver nanoparticles were synthesized using sodium borohydride. The milk-spoiling microbes, Trichosporon asahii and Lactobacillus casei were isolated from the spoiled milk. The antibacterial effect of the silver nanoparticles was investigated for both of these microorganisms. The kinetic growth studies as well as the test of zone of inhibition and colony counting showed the successful synthesis of the nanoparticles and their influence on the microbial activity i.e. their inhibitory effects. Moreover, tests were performed for the impregnation of nanoparticles on an aluminum surface. The microbial studies were carried out with silver nanoparticles impregnated on the surface of the aluminum foil. This will provide a stable packaging system for milk storage.