Biosynthesis and characterization of silver nanoparticles by a marine strain escherichia coli sj101

ayalakshmi, S and Dinakaran, S

The present study is on characterization of silver nanoparticles synthesized by an E.coli SJ101 strain isolated from Uppanar estuary of Cuddalore coastal waters. The study proved that the above bacterial strain was capable of producing nanoparticles of <10µm size in abundance. Both free proteins capped and aggregated nanoparticles which were spherical in shape and varied in size were observed. Nanoparticles synthesize started by 4-10hrs in various strains tested and in the present strain used, it was continued for 10days at which the experiment was terminated due to want of time. UV spectral study indicated this. The nanoparticles produced were inhibitory to 8 pathogens among 10 tested. They were most inhibitory to Salmonella typhi followed by Salmonella paratyphi and Staphylococcus aureus which are proven pathogens and prevalent in Indian community. FTIR spectral analysis showed bands at at 3410 and 2940 Cm-1 indicating the roles of proteins (primary and secondary amines and other functional groups) in synthesis and stabilization of nanoparticles. Thus the present study revealed many facts about silver nanoparticles synthesized by E.coli SJ101 strain.