Bacteria is used for the synthesis of silver nanoparticles. In this method the reactive response of bacteria to silver results in the synthesis of AgNPs. This method uses Ag resistant strains for the synthesis of AgNPs . A study reported the synthesis of highly stable AgNPs of size 40 nm by reduction of silver ions (Ag + ) to metallic silver (Ag) by using a culture supernatant of Bacillus licheniformis which is an antibacterial strain . Another study suggested the synthesis of silver nanocrystals of size 50 nm by using Bacillus Licheniformis . The antibacterial strains accumulate silver atoms on the cell wall . The AgNPs synthesized by bacteria-mediated synthesis is either by extracellular process (using cell culture supernatant) or intracellular process (biomass) . Generally, the AgNPs obtained by bacteriogenic synthesis are spherical of size ranging from 5nm to 200nm. In a study, synthesized AgNPs of size 5nm to 50nm with the help of culture supernatant of B. subtilis combines with microwave radiation. The microwave radiation increased the rate of reaction and reduced aggregation.