Nanoparticles biosynthesis and its applications is a rapidly developing field. The biological silver
nanoparticles (AgNPs) are being used as inhibitory and antimicrobial agents. In the current
investigation, synthesis of silver nanoparticles by bacterial strain isolated from soil sample contaminated
with crude petroleum oil was studied. Molecular identification of the bacterial isolate showed it as a
strain of Sphingobacterium mizutaii. The biosynthesized nanoparticles characterized by the UV-Vis
spectroscopy which exhibited a broad absorption spectrum band around 420 nm. Transmission electron
microscopy (TEM) and energy dispersive X-ray (EDX) analysis confirmed the formation of varying size
silver particles in the range from 4.5-31.6 nm. The Interaction between silver nanoparticles and proteins
were characterized by Fourier transform infrared (FTIR) spectroscopy. The combination effects of
AgNPs with the antiseptic agent (Dettol) was then studied. The antimicrobial effect of AgNPs- Dettol
combination increased significantely in case of E. coli, K. pneumoniae, B. subtilis and Candida krusei.